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The control system of a drilling rig is the core command unit of the entire drilling equipment. It is responsible for integrating, transmitting commands, and regulating the coordinated operation of various components. Without it, the power, transmission, and execution systems of the drilling rig cannot work in an orderly manner, making it an indispensable part. Classified by control methods, it mainly includes mechanical control, pneumatic control, hydraulic control, electric control, and integrated control. Among these, pneumatic control has become the most widely used type due to its advantages of high reliability and adaptability to harsh environments, and its core consists of four major mechanisms: "air supply-command issuance-command transmission-execution". Ⅰ. Core Classifications of Control Systems 1. Mechanical Control Mechanical control is the most traditional control method. It directly transmits operating commands through mechanical components such as levers, gears, and wire ropes, featuring the simplest structure and the lowest cost. Core Principle: Operators manually operate mechanical handles to directly drive transmission components, thereby changing the actions of the execution mechanism (e.g., drawworks braking, rotary table start/stop). Applicable Scenarios: Simple control of small workover rigs and old drilling rigs, only suitable for operations with low load and low precision requirements. Limitations: Low control precision (e.g., large drilling pressure adjustment error), labor-intensive operation, inability to achieve remote or automated control, and it has gradually been replaced by other methods. 2. Pneumatic Control Pneumatic control uses compressed air as the power transmission medium. With the characteristics of "anti-pollution, resistance to high and low temperatures, and fast response", it has become the mainstream control method for onshore and offshore drilling rigs, especially suitable for control needs in harsh environments such as wellheads and mud pumps. Four Core Mechanisms and Their Functions Air Supply Mechanism: The power source of the control system, including air compressors, air reservoirs, and dryers, ensuring clean air supply and stable pressure. Command Issuance Mechanism: The command initiation end of the control system, directly operated by operators (e.g., pneumatic control handles for drawworks hoisting/lowering, buttons). When pressed or toggled, it issues control commands by changing the on/off state of the air circuit or the air pressure. Command Transmission Mechanism: The command transmission channel of the control system, including air pipelines, solenoid valves (controlling the on/off or commutation of the air circuit to realize electrical signal conversion), and pressure reducing valves (adjusting air pressure to meet the needs of different execution mechanisms). It accurately transmits commands from the command issuance mechanism to the execution mechanism. Execution Mechanism: The action execution end of the control system, which receives compressed air power and converts it into mechanical actions (e.g., cylinders, air motors, pneumatic control valves for adjusting mud pump displacement), ultimately realizing the start/stop, speed regulation, or commutation of equipment. Core Advantages Adaptability to Harsh Environments: Compressed air is non-conductive and non-flammable, immune to dust and oil/gas, less likely to freeze at low temperatures, and has a low failure rate. Fast Response Speed: The transmission delay of air pressure signals is less than 0.3 seconds, enabling rapid action in emergency working conditions (e.g., shutting down the mud pump in case of well kick) to ensure safety. Simple Structure and Easy Maintenance: No complex circuits or hydraulic oil pipelines; air pipelines and solenoid valves are easy to replace, resulting in low on-site maintenance costs. 3. Hydraulic Control Hydraulic control uses hydraulic oil as the transmission medium and drives the execution mechanism through hydraulic pressure, making it suitable for control scenarios with high load and large torque. Core Applications: Control of heavy-duty components of drilling rigs, such as blowout preventer (BOP) switching, top drive speed regulation, and braking and speed regulation of large drawworks. Advantages: Large torque transmission and high control precision. Disadvantages: Hydraulic oil is prone to contamination and requires regular filtration; its viscosity increases at low temperatures, which affects response speed; maintenance costs are higher than those of pneumatic control. 4. Electric Control Electric control uses electrical signals as the transmission medium and realizes control through motors, frequency converters, and PLC (Programmable Logic Controller). It is the core control method for intelligent drilling rigs. Core Applications: Precise parameter control (e.g., constant drilling pressure, constant speed), remote monitoring (e.g., onshore remote operation of offshore drilling rigs), and automated processes (e.g., automatic pipe connection). Advantages: High control precision, enabling data management and automation. Disadvantages: Relies on stable power supply; anti-short-circuit and anti-interference measures must be taken in humid and dusty environments; initial investment is relatively high. 5. Integrated Control Integrated control combines the advantages of two or more single control methods and is the mainstream choice for modern medium and large-sized drilling rigs (e.g., "pneumatic + hydraulic + electric control" combination). Typical Application: Pneumatic control is used for wellhead control (to adapt to oil and gas environments), hydraulic control for heavy-duty components (e.g., BOPs, to provide large thrust), and electric control for overall parameter regulation (to achieve precision and automation). The three are linked through PLC, ensuring safety and reliability while improving control precision and efficiency. Ⅱ. Core Value of the Control System Safety Guarantee: Whether it is the emergency shutdown of pneumatic control, the rapid shutdown of BOPs in hydraulic control, or the overload protection of electric control, the control system can quickly cut off risk sources in case of sudden failures (e.g., pipe sticking, well kick) to avoid equipment damage or safety accidents. Efficiency Improvement: Through precise control (e.g., constant speed regulation in electric control, top drive torque control in hydraulic control), manual operation errors are reduced, and bit wear and wellbore enlargement caused by parameter fluctuations are avoided, thereby improving drilling speed. The automated linkage of integrated control (e.g., coordination between pneumatic wellhead equipment and electric drawworks) can also shorten the time for tripping and pipe connection. Strong Adaptability: Different control methods can be adapted to different scenarios—pneumatic control for onshore remote oilfields (easy maintenance), integrated control for offshore drilling rigs (balancing safety and precision), and electric control for intelligent drilling rigs (automation needs), ensuring stable operation under various drilling conditions.  

Ⅰ. Core Components and Functions 1. Engine Core Role: As the initial power source of the transmission system, it outputs mechanical energy through fuel combustion or electric drive, and directly connects to the drive shaft via the output shaft, initiating the entire transmission chain. Applicable Scenarios: In mechanically driven or hybrid drilling rigs, it is mostly a diesel engine (e.g., V-type 12-cylinder four-stroke diesel engine); in electrically driven drilling rigs, it can be replaced by an electric motor to directly output power to the drive shaft. 2. Drive Shaft Core Role: A rigid/flexible shaft (mostly hollow steel pipe structure, with length designed according to equipment layout) connecting the engine and gearbox. It transmits the mechanical energy output by the engine to the gearbox without interruption, while adapting to slight vibrations and displacements during equipment operation (compensating for angular deviations via universal joints). Technical Features: It must have high torque-bearing capacity (usually ≥5000N・m) and fatigue resistance. Its surface is heat-treated to enhance wear resistance, preventing fracture due to long-term high-speed rotation. 3. Gearbox Core Role: Through internal gear meshing, it converts the high-speed, low-torque power input by the drive shaft into low-speed, high-torque power (e.g., when driving the drill bit) or medium-speed, medium-torque power (e.g., when driving the drawworks), meeting the working condition requirements of different equipment. Key Functions Shift Regulation: Realizes multi-stage switching of speed/torque through hydraulic or mechanical shifting (e.g., using low gear during drilling to enhance bit rock-breaking force, and high gear during tripping to improve efficiency); Reverse Transmission: Some gearboxes support reverse power output (e.g., when the drawworks lowers the drill string, reverse gears are used to achieve braking and deceleration). 4. Chain Core Role: Connects the output end of the gearbox to the bit drive mechanism (e.g., rotary table, top drive). Through the meshing of the chain and sprocket, it transmits the regulated power from the gearbox to the drill bit, driving it to rotate and break rock. Technical Advantages High torque transmission (a single chain can bear 1000-3000N・m torque), suitable for high-load operations of the drill bit, such as breaking hard rock formations; High transmission efficiency with minimal energy loss, simple structure, and low maintenance costs. Applicable Scenarios: Rotary table transmission of onshore drilling rigs and power transmission of top drive systems. 5. Belt Core Role: Through the friction between pulleys and belts, it diverts and transmits power from the gearbox to the drawworks (for tripping drill string) and mud pump for drilling rig (for circulating drilling fluid). Technical Features Flexible transmission: Can buffer power impacts, reducing wear on the gearbox; Low cost and easy replacement: Compared with chains, belts are lighter and quieter, suitable for medium and low-load scenarios. Limitations: Limited torque transmission (usually ≤1000N・m), prone to slipping under long-term high loads, requiring regular tension adjustment. 6. Hydraulic Motor Core Role: Converts the pressure energy of the hydraulic system into mechanical energy to independently drive the drill bit, drawworks, or mud pump. Technical Advantages Wide speed regulation range: Stepless speed regulation of 0-3000r/min can be achieved by adjusting hydraulic oil flow (e.g., real-time adjustment of bit speed according to formation hardness); Strong overload protection: The hydraulic system is equipped with an overflow valve, which automatically relieves pressure during overload to avoid equipment damage (e.g., protecting the bit and motor during pipe sticking); Flexible layout: No rigid connection required, enabling long-distance driving via hydraulic pipelines (e.g., mud pumps far from the power cabin in offshore drilling rigs). Typical Applications: Fine adjustment of top drives in automated drilling rigs, stable tripping of drawworks, and mud pump driving in small workover rigs. Ⅱ. Working Process of the Transmission System Power Output Stage: The engine or motor starts, outputs mechanical energy to the drive shaft, and the drive shaft stably transmits power to the gearbox by compensating for angular deviations through universal joints. Parameter Regulation Stage: The gearbox shifts according to operational requirements (e.g., drilling/tripping) to adjust speed and torque. Power Diversion Stage: High-torque power output by the gearbox is transmitted to the bit drive mechanism (rotary table or top drive) through the chain, driving the bit to rotate and break rock; Medium-torque power is transmitted to the drawworks and mud pump through the belt; The hydraulic motor independently receives power from the hydraulic system to auxiliary drive the bit, drawworks, or mud pump. Ⅲ. Key Technical Requirements and Maintenance Points 1. Technical Requirements Matching: Components must be adapted according to the "power parameter chain" (e.g., engine output torque ≥ drive shaft bearing capacity, gearbox adjustment range covers equipment requirements) to avoid overload; Reliability: In high-temperature and high-humidity environments, chains/belts must be rust-resistant, hydraulic motors must be leak-proof, and gearboxes must use temperature-resistant gear oil. 2. Maintenance Points Chains/Belts: Check tension weekly; lubricate chains and clean pulleys monthly; Gearbox: Replace gear oil every 500 hours; regularly check gear meshing clearance; Hydraulic Motor: Test hydraulic oil contamination level monthly; replace hydraulic oil filters every 1000 hours to prevent impurities from wearing internal components of the motor. The transmission system realizes full-link control of power from "output-regulation-distribution" through the collaboration of multiple components, and its performance directly determines the operational efficiency and equipment service life of the drilling rig. In modern drilling rigs, the combination of mechanical transmission and hydraulic transmission not only ensures reliability in high-load scenarios but also improves adaptability to complex working conditions, serving as the backbone for efficient operation of the drilling system.

The power equipment of a drilling rig is the core device that supplies energy to the entire drilling system. Currently, the mainstream power types are divided into two major categories: diesel engine power and electric power, while hybrid power mode is adopted in some complex scenarios. Ⅰ. Diesel Engine Power Diesel engines are the traditional mainstream power source for onshore drilling rigs. They output mechanical energy through diesel combustion, which is then distributed to various working units via the transmission system. Core Advantages Strong independence: It does not rely on an external power grid and can operate independently in off-grid scenarios such as wilderness and deserts, with wide adaptability. High power density: The single-unit power can reach 1000-3000 kW, which can meet the high-load requirements of deep wells and ultra-deep wells. Fast start-up speed: It can start and stop quickly under emergency conditions (such as well kick and pipe sticking), with a response time of less than 30 seconds, ensuring operation safety. Key Equipment Main diesel engine: Mostly V-type 12-cylinder / 16-cylinder four-stroke diesel engines, equipped with a turbocharging system to adapt to harsh environments such as high altitude and high temperature. Diesel generator set: Provides low-voltage power (e.g., for control systems, lighting, and mud treatment equipment) to the auxiliary systems of the drilling rig, and usually operates in linkage with the main diesel engine. Applicable Scenarios Onshore remote oilfields, desert / plateau drilling, workover operations, and other scenarios without stable power grid coverage. Ⅱ. Electric Power Electric power is the mainstream development direction of modern drilling rigs, replacing traditional diesel engines through the "power grid supply + motor drive" mode. Core Advantages Low energy consumption and low pollution: Compared with diesel engines, energy consumption is reduced by 15%-25%, and there is no exhaust emission, which complies with environmental regulations. It is suitable for environmentally sensitive areas such as offshore and urban suburbs. High control precision: Variable-frequency speed-regulating motors (e.g., permanent magnet synchronous motors, asynchronous motors) are adopted, which can realize precise adjustment of drilling parameters (such as weight on bit and rotational speed), improving wellbore quality. Low maintenance cost: The motor has a simple structure, without vulnerable parts such as pistons and valves of diesel engines. The annual maintenance cost is reduced by 30%-40%, and the service life is extended to 15-20 years. Key Equipment High-voltage frequency converter: Converts high-voltage electricity from the power grid into variable-frequency power supply to control motor speed, serving as the "control core" of the electric power system. Drive motor: Divided into rotary table motors (driving drill string rotation), mud pump motors (driving mud circulation), and hoisting motors (driving traveling block for tripping operations). The single-unit power ranges from 500-2000 kW, configured according to load requirements. Emergency generator set: A backup power source when the grid power is interrupted, mostly a combination of a small diesel engine and a generator, ensuring uninterrupted operation of key equipment such as blowout preventers and mud pumps. Applicable Scenarios Offshore drilling platforms, large drilling rigs in onshore areas covered by power grids, and drilling in environmentally sensitive areas (e.g., coastal areas, suburban areas). Ⅲ. Hybrid Power Hybrid power combines the advantages of diesel engine power and electric power. The common mode is "diesel engine + battery energy storage system", which is mainly used in scenarios with large load fluctuations (e.g., alternating operations of tripping and drilling). Working Principle During low-load drilling operations (e.g., tripping), the diesel engine drives the generator to charge the battery; during high-load operations (e.g., high-pressure circulation of mud pumps), the battery and diesel engine supply power together, reducing the load fluctuation of the diesel engine and lowering fuel consumption. Core Advantage Fuel consumption is reduced by 20%-30% compared with pure diesel engines, and wear caused by frequent start-stop of the diesel engine is reduced, extending the equipment service life. Applicable Scenarios Onshore deep well drilling, workover operations, and other scenarios with frequent load fluctuations. Ⅳ. Maintenance Points For Diesel Engine Power 1.Regularly check the engine oil level and diesel filter element to prevent nozzle wear caused by impurities. 2.Replace the engine oil and air filter element every 200 hours to prevent high-temperature carbon deposition from affecting power output. 3.In cold environments, use anti-freezing diesel and add antifreeze to the water tank. For Electric Power 1.Regularly clean the cooling fan of the frequency converter and motor windings to prevent overheating caused by dust. 2.Test the motor insulation resistance monthly to avoid short circuits due to moisture. 3.After grid power interruption, check the battery capacity of the emergency generator to ensure normal emergency response.

Ⅰ. Surface Equipment Unit Mud Tank Function: A core container for storing, settling, and preparing drilling fluid, typically consisting of 3-5 independent tanks (suction tank, cleaning tank, reserve tank, weighting tank) with a single tank capacity of 50-100 m³. Mud Pump Function: Mostly a triplex single action reciprocating pump with an outlet pressure of 30-100 MPa and a displacement of 100-3000 L/min;It extracts drilling fluid from the suction tank, pressurizes it, and delivers it to the surface manifold, providing power for downhole circulation. Surface Manifold Function: A pipeline hub connecting the mud pump, swivel, and solids control equipment, composed of a standpipe, hose, mud gate valve, pressure gauge, etc.; It can switch the flow direction of drilling fluid via gate valves, and the pressure gauge monitors circulation pressure in real-time to prevent overpressure accidents. Swivel Function: A rotating sealing device installed under the traveling block, with the upper end connected to the hose and the lower end connected to the drill string; It enables synchronous rotation and fluid delivery, allowing the drill string to rotate at high speed while maintaining leak-free transportation of drilling fluid. Solids Control Equipment Function: A purification and filtration system for drilling fluid, classified into four levels by purification precision: 1.Shale shaker (removes large cuttings, screen size 0.2-1.5 mm); 2.Desander (removes sand particles, separation size 40-74 μm); 3.Desilter (removes mud particles, separation size 15-40 μm); 4.Centrifuge (removes colloidal particles, separation size 2-15 μm); It removes over 95% of solid particles from drilling fluid to ensure stable properties such as viscosity and density. Ⅱ. The Circulation Process of Drilling Fluid The circulation process of drilling fluid consists of three core stages, forming a complete closed loop, with specific procedures as follows: Stage 1: Drilling Fluid Descent (Surface → Bottom Hole, Power Delivery) 1.The mud pump extracts prepared drilling fluid from the suction tank, pressurizes it, and delivers it to the standpipe of the surface manifold; 2.The drilling fluid flows through the standpipe into the hose and then into the swivel; 3.The swivel guides the drilling fluid into the drill string bore through its rotating sealing structure, which flows downward along the hollow channels of the drill pipe and drill collar, eventually reaching the bottom hole bit; 4.The drilling fluid is ejected at high speed through the bit nozzles, forming a high-pressure jet to impact the bottom hole formation, assist the bit in breaking rock, and flush cuttings at the bottom. Stage 2: Drilling Fluid Ascent (Bottom Hole → Surface, Function Implementation) 1.The high-speed ejected drilling fluid wraps the broken cuttings at the bottom hole, forming a cuttings-mud mixture; 2.Driven by the continuous pressure of the mud pump, the mixture flows upward along the annulus, while completing three key tasks: Cooling the bit: Absorbing heat generated by bit rotation (bottom hole temperature can reach 150-200°C) and carrying it back to the surface through circulation; Stabilizing the wellbore: Clay particles in the drilling fluid form a 2-5 mm thick "mud cake" on the wellbore wall, plugging formation pores and preventing wellbore collapse; Balancing well pressure: Balancing formation pressure through drilling fluid column pressure to prevent blowouts or lost circulation; 3.After the cuttings-laden drilling fluid reaches the surface, it first enters the shale shaker for preliminary filtration of large cuttings larger than 0.2 mm in diameter. Stage 3: Purification and Regeneration (Surface Treatment, Recyclable Reuse) 1.The drilling fluid preliminarily filtered by the shale shaker flows into the desander, where sand particles with a diameter of 40-74 μm are separated by centrifugal force; 2.The drilling fluid with sand particles removed enters the desilter for further separation of mud particles with a diameter of 15-40 μm; 3.For high-requirement deep wells/complex wells, the drilling fluid needs to enter the centrifuge to separate colloidal particles with a diameter of 2-15 μm; 4.The purified drilling fluid flows into the cleaning tank, where technicians adjust its properties using testing instruments; 5.The qualified drilling fluid enters the suction tank, awaiting the next cycle to achieve zero or low-emission reuse. Ⅲ. Four Core Functions of the Circulation System 1.Carrying and removing cuttings: Preventing pipe sticking accidents 2.Cooling and lubricating the bit: Extending equipment service life 3.Stabilizing the wellbore and controlling well pressure: Ensuring wellbore safety 4.Transmitting downhole information: Supporting intelligent drilling

The rotary system is a typical component of a rotary drilling rig, whose function is to drive the drill string to rotate for rock breaking. It consists of the rotary table, swivel, and drill tools. The composition of drill tools varies depending on the type of well being drilled; generally, they include the kelly, drill pipe, drill collar, and bit, along with accessories such as stabilizers, shock absorbers, and adapter subs. Among these, the bit is the tool that directly breaks rock. The drill collar, featuring high weight and thick wall, is used to apply weight on bit (WOB). The drill pipe connects surface equipment to downhole equipment and transmits torque. The kelly typically has a square cross-section; the rotary table drives the entire drill string and bit to rotate via the kelly. The swivel is a classic component of rotary drilling rigs, which not only bears the weight of the drill tools and enables rotational movement but also provides a channel for high-pressure mud. Ⅰ. Key Components Rotary Table Composed of horizontal bearings, bevel gears, square kelly bushing (SKB), and a housing, it mostly adopts a gear transmission structure. 1.Serves as the executive core of the rotary system, driving the kelly or drill string to rotate through gear transmission; 2.Provides wellhead support and bears part of the drill string weight; 3.The square kelly bushing (SKB) fixes the kelly to ensure stable torque transmission. Swivel Consists of a gooseneck, center pipe, rotating bearings, sealing devices, and a suspension assembly. Its top is connected to the hook, and the bottom is connected to the kelly. 1.When the hook and traveling block are stationary, the swivel drives the kelly to rotate while preventing drilling fluid leakage; 2.The gooseneck is connected to the drilling fluid pipeline, and the center pipe guides the drilling fluid into the drill string; 3.Bears part of the drill string weight through the suspension assembly and coordinates with the hoisting system to adjust WOB. Kelly A thick-walled steel pipe with a square or hexagonal cross-section, usually 9-12 meters in length, with drill pipe joints at both ends. 1.Its upper end is connected to the swivel, and the lower end is connected to the drill string via a drill pipe joint, transmitting torque from the rotary table or top drive to the downhole drill string; 2.Its square cross-section matches the square kelly bushing of the rotary table to prevent slipping during rotation. Top Drive Composed of an electric motor (or hydraulic motor), gearbox, main shaft, drill pipe make-up/break-out device, and drilling fluid channel, it is installed below the traveling block. 1.Can directly drive the drill string to rotate without frequent joint making-up (reducing tripping time); 2.Equipped with a built-in make-up/break-out device, it can automatically tighten and loosen drill pipe threads, improving operational efficiency; 3.Suitable for deep wells, ultra-deep wells, and extended-reach wells, reducing drill string fatigue damage. Ⅱ. Core Functions Torque Provision Converts the energy of power equipment into the rotational torque of the drill string, driving the bit to rotate at high speed (typically 30-150 r/min) and enabling the bit cones to break rock formations. Drilling Fluid Circulation Support The rotary table and swivel of the rotary system are equipped with central through-holes. Drilling fluid can be injected into the drill string through these holes and finally sprayed out from the bit nozzles, fulfilling three key roles: cuttings carrying, bit cooling, and drill tool lubrication. Drill String Centering Maintenance Through the positioning function of components such as the rotary table and kelly bushing, it ensures the drill string always moves along the central axis of the wellbore during rotation, preventing wellbore deviation caused by drill string offset (especially critical for vertical well drilling). Downhole Tool Compatibility Can be compatible with directional drilling tools (e.g., progressive cavity drillers (PCD), measurement while drilling (MWD) tools). By adjusting the rotation speed or coordinating with downhole power tools, it achieves precise control of the wellbore trajectory (e.g., deviation building and hold for horizontal wells). Ⅲ. Working Principle Torque Transmission Process Diesel engine/Electric motor → Gearbox → Bevel gears → Rotary table rotation → Square kelly bushing driving kelly rotation → Kelly transmitting torque to downhole drill string via drill pipe joint → Bit rotating to break rock. Drilling Fluid Circulation Process Drilling pump → High-pressure pipeline → Swivel gooseneck → Swivel center pipe → Kelly → Inside of drill string → Bit nozzles → Annular space of wellbore → Wellhead return → Mud tank (for cuttings separation and recycling). Ⅳ. Daily Maintenance Rotary Table: Regularly clean the gearbox, replenish gear oil, and inspect bearing wear; Swivel: Clean the center pipe after each tripping operation and check the lubrication status of rotating bearings; Top Drive: Regularly calibrate the torque sensor, and inspect the motor insulation performance and hydraulic system pressure.

The hoisting system of a drilling rig is essentially a heavy-duty crane and serves as the core component of the rig. It mainly consists of the derrick, crown block, traveling block, hook, wire rope of the traveling system, drawworks, and auxiliary brake. The functions of the hoisting system primarily include hoisting and lowering the drill string, running casing, and controlling the bit feed. Ⅰ. Core Functions The functions of the hoisting system revolve around drill string operations, specifically including: Hoisting and Lowering the Drill String: During drilling, it is necessary to frequently replace the bit and handle downhole complex conditions (such as stuck pipe). The hoisting system lifts and lowers the drill string through equipment like the drawworks and wire rope, with a maximum lifting capacity of up to several hundred tons. Running Casing: After drilling is completed, casing needs to be run to reinforce the wellbore. The hoisting system steadily lifts long casing strings and accurately lowers them to the designed depth in the well. Controlling Weight on Bit (WOB) and Bit Feeding: During normal rotary drilling, the hoisting system adjusts the lowering speed of the drill string through the brake mechanism, converting 10%-50% of the drill string weight into "Weight on Bit (WOB)" which is applied to the bit to drive it in breaking rock formations. Meanwhile, it maintains stable WOB through the "bit feeding" action to prevent the bit from being overloaded (which may damage the bit) or underloaded (which reduces drilling efficiency). Ⅱ. Derrick The derrick is one of the important components of the drilling rig's hoisting system. Function: It is used to install and suspend the traveling system, elevator links, elevator, etc., and bears the weight of the drill string in the well. During tripping operations, it also stores drill pipes or casing. Structure: It is a metal truss structure with a certain height and space. Therefore, the derrick must have sufficient load-bearing capacity, strength, rigidity, and overall stability to ensure the hoisting and lowering of drill strings, casing, or tubing strings of a certain depth. Ⅲ. Traveling System The traveling system of a drilling rig consists of the crown block, traveling block, wire rope, and hook.In essence, it is a movable pulley system formed by connecting the crown block and traveling block with wire rope. It can greatly reduce the fast line tension, thereby significantly reducing the load on the drilling drawworks. The "structure of the traveling system" usually refers to the number of traveling block sheaves × the number of crown block sheaves. Crown Block The crown block is a fixed pulley block installed at the top of the derrick. It mainly consists of components such as the crown block frame, sheaves, bearings, bearing housings, and auxiliary sheaves. The crown block frame is a rectangular frame welded with steel beams, used to install the crown block sheave shafts and connect to the top of the derrick. Three basic structural forms of the crown block: Sheave shafts share a common axis, and all sheaves are parallel to each other; Sheave axes are parallel, with the fast line sheave on a separate shaft; Sheave shafts do not share a common axis, and the fast line sheave is offset. The parameters listed in the technical specifications of the crown block include: maximum hook load, number of sheaves, sheave size, weight, and installation dimensions. Traveling Block The traveling block is a movable pulley block suspended inside the derrick by wire rope and moves up and down reciprocally. Hook The hook is suspended below the traveling block. Generally, the drilling rig hook has three hooks: the main hook is used to suspend the swivel, and the auxiliary hooks are used to suspend the elevator links. The hook mainly consists of the hook body, hook rod, hook seat, bail, thrust bearing, and spring. Requirements for the hook in drilling operations: 1.It shall have sufficient strength and operational reliability; 2.The hook body shall rotate flexibly to facilitate making up and breaking out of joints; 3.The hook spring shall have a sufficient stroke to compensate for the vertical displacement of the drill pipe during making up and breaking out of joints; 4.The locking devices for the hook throat and side hooks shall be absolutely reliable, and easy to open and close; 5.It shall have a buffering and vibration-damping function to reduce the impact when disassembling stands. Ⅳ. Drawworks Components of the drilling drawworks: 1.Drum and drum shaft assembly: This is the core working component of the drawworks. The drum shall have a sufficient rope capacity to ensure good rope winding condition and extend the service life of the wire rope; 2.The drawworks is equipped with a sensitive and reliable main brake mechanism and a high-performance auxiliary brake, enabling it to accurately adjust the WOB, feed the drill string evenly, freely control the lowering speed during tripping out, and easily brake the heaviest drill string load; 3.Cathead and cathead shaft assembly: Used to meet the needs of making up and breaking out joints with tongs and other auxiliary lifting operations. Some cathead shafts are also equipped with sand reels for lifting core barrels.  

An oil drilling rig is a large-scale mechanical equipment used in oil and gas drilling operations. Its main function is to drive drilling tools to break underground rocks and drill wellbores, providing channels for subsequent exploitation and thereby realizing the exploration and development of oil and gas resources. Its core functions include hoisting and lowering drilling tools, rotary drilling, and circulating well cleaning. It is mainly composed of power machines, transmission mechanisms, working machines, and auxiliary equipment. Classified by operation scenarios, it can be divided into onshore oil drilling rigs and offshore oil drilling rigs, which are key infrastructure for ensuring global oil and gas supply. Core Component Systems A drilling rig consists of eight major systems: the hoisting system controls the lifting and lowering of drilling tools via drawworks and pulley blocks; the rotary system drives the drill bit to break rock formations; the circulation system uses high-pressure mud to remove cuttings; the power and transmission system provides power distribution; the control system coordinates equipment operation; the derrick and substructure provide support; and auxiliary equipment includes safety devices such as blowout preventers (BOP). Core components include the derrick, crown block, rotary table, and various types of drill bits. Top drive drilling rigs adopt top drive (power swivel) technology, which improves drilling efficiency and is suitable for deep well operations. During operation, mud pumps circulate mud to cool the drill bit, and braking mechanisms adjust drilling parameters. Ⅰ. Hoisting System The hoisting system is equipped to hoist and lower drilling tools, run casing, control weight on bit (WOB), and feed drilling tools. It includes the drawworks, auxiliary brakes, crown block, traveling block, hook, wire rope, and various tools such as elevator links, elevators, tongs, and slips. When hoisting, the drawworks drum winds the wire rope; the crown block and traveling block form a secondary pulley system. The hook rises to lift the drilling tools through tools like elevator links and elevators. When lowering, the drilling tools or casing string descends by its own weight, and the lowering speed of the hook is controlled by the drawworks' braking mechanism and auxiliary brakes. During normal drilling, the feed speed of the drilling tools is controlled by the braking mechanism, and a portion of the drilling tool weight is applied to the drill bit as WOB to break rock formations. Ⅱ. Rotary System The rotary system is a typical system of a rotary table drilling rig, whose role is to drive the drilling tools to rotate for breaking rock formations. It includes the rotary table, swivel, and drilling tools. The composition of drilling tools varies depending on the type of well being drilled; generally, it includes the kelly, drill pipe, drill collars, and drill bit, as well as stabilizers, shock absorbers, and adapter subs. Among them, the drill bit is the tool that directly breaks rock. Drill collars have high weight and wall thickness, used to apply WOB to the drill bit. Drill pipes connect surface equipment and downhole equipment and transmit torque. The kelly typically has a square cross-section; the rotary table drives the entire drill string and drill bit to rotate via the kelly. The swivel is a typical component of a rotary drilling rig: it not only bears the weight of the drilling tools but also enables rotational movement, while providing a channel for high-pressure mud. Ⅲ. Circulation System The rotary drilling rig is equipped with a circulation system to promptly carry cuttings broken by the downhole drill bit to the surface for continuous drilling, while cooling the drill bit, protecting the wellbore, and preventing drilling accidents such as wellbore collapse and lost circulation. The circulation system includes mud pumps, surface manifolds, mud tanks, and mud purification equipment. The surface manifolds include high-pressure manifolds, standpipes, and hose lines; the mud purification equipment includes shale shakers, desanders, desilters, and drilling mud centrifuges. The mud pump suctions mud from the mud tank; the mud, after being pressurized by the mud pump, flows through the high-pressure manifold, standpipe, and hose line, enters the swivel, and is lowered to the bottom of the well through the hollow drilling tools. It is ejected from the nozzles of the drill bit, then carries cuttings back to the surface through the annular space between the wellbore and the drilling tools. The mud returned from the bottom of the well passes through various levels of mud purification equipment to remove solid content, and then is reused. Ⅳ. Power Equipment The hoisting system, circulation system, and rotary system are the three major working units of the drilling rig, used to provide power. Their coordinated operation enables drilling operations. To supply power to these working units, the drilling rig needs to be equipped with power equipment. The power equipment of a drilling rig includes diesel engines, AC motors, and DC motors. Ⅴ. Transmission System The transmission system converts the force and motion provided by the power equipment, then transmits and distributes them to each working unit to meet the different power requirements of each unit. The transmission system generally includes a reduction mechanism, speed change mechanism, forward/reverse mechanism, and a coupling mechanism between multiple power machines. Ⅵ. Control System To ensure the coordinated operation of the three major working units of the drilling rig and meet the requirements of drilling technology, the drilling rig is equipped with a control system. Control methods include mechanical control, pneumatic control, electrical control, and hydraulic control. The commonly used control method on drilling rigs is centralized pneumatic control. The driller can complete almost all drilling rig controls through the driller's console on the rig, such as engaging/disengaging the main clutch; coupling multiple power machines; starting/stopping the drawworks, rotary table, and mud pumps; and controlling the high/low speed of the drawworks. Ⅶ. Derrick and Substructure The derrick and substructure are used to support and install various drilling equipment and tools, and provide a drilling operation site. The derrick is used to install the crown block, suspend the traveling block, hook, swivel, and drilling tools, bear drilling workloads, and stack stands. The substructure is used to install the power unit, drawworks, and rotary table, support the derrick, suspend the drilling tools via the rotary table, and provide height space between the rotary table and the ground for installing necessary BOPs and facilitating mud circulation. Ⅷ. Auxiliary Equipment To ensure the safety and normal progress of drilling, the drilling rig also includes other auxiliary equipment, such as a BOP stack for preventing blowouts, a generator set for providing lighting and auxiliary power for drilling, an air compression device for supplying compressed air, and water supply and oil supply equipment.  

Directional drilling technology is one of the most advanced drilling technologies in the global oil exploration and development field today. It relies on special downhole tools, measurement instruments, and process technologies to effectively control the wellbore trajectory, guiding the drill bit to reach the predetermined underground target along a specific direction. This technology breaks the limitation of vertical wells, which "can only develop resources directly below the wellhead". By adopting directional drilling technology, oil and gas resources restricted by surface or underground conditions can be developed economically and effectively, significantly increasing oil and gas production and reducing drilling costs. In essence, a directional well is a drilling method that guides the wellbore to reach the target formation along a pre-designed deviation angle and azimuth. There are three main types of its well profiles: (1) Two-section type: Vertical section + build-up section; (2) Three-section type: Vertical section + build-up section + tangent section; (3) Five-section type: Upper vertical section + build-up section + tangent section + drop-off section + lower vertical section A horizontal well is a type of directional well. Conventional oil wells penetrate the oil reservoir vertically or at a shallow angle, resulting in a short wellbore section passing through the reservoir. In contrast, after drilling vertically or at an angle to reach the oil reservoir, the wellbore of a horizontal well is turned to a near-horizontal direction to remain parallel to the oil reservoir, allowing long-distance drilling within the reservoir until completion. Equipped with high-strength heavy-weight drill pipes (HWDP) for horizontal sections and wear-resistant PDC (Polycrystalline Diamond Compact) bits, the length of the reservoir-penetrating section can range from hundreds of meters to over 2,000 meters. This not only reduces the flow resistance of fluids entering the well but also increases production capacity several times compared to conventional vertical or deviated wells, facilitating enhanced oil recovery. Ⅰ. Application Scenarios 1. Overcoming Surface/Underground Obstacles Surface obstacles: When there are buildings, railways, lakes, or ecological protection zones above the reservoir, directional wells can be drilled outside these obstacles to reach the reservoir at an angle (e.g., development of oil and gas reservoirs around cities). Underground obstacles: When bypassing hazardous geological features such as underground caves, salt domes, and faults, shock-resistant and collapse-proof drill collars and high-pressure blowout preventers (BOP) are used in coordination to avoid drilling accidents like pipe sticking and blowouts. 2. Enhancing Production Capacity of Unconventional Oil and Gas Reservoirs Unconventional reservoirs such as shale gas and tight oil have "extremely low permeability". Vertical wells can only access a small area of the reservoir, leading to limited production capacity. However, horizontal wells traverse the reservoir horizontally over a distance of several hundred meters, increasing the contact area with the reservoir by dozens of times. The daily gas production of a single horizontal well can be 5 to 10 times that of a vertical well, making it a core technology for unconventional oil and gas development. 3. Reducing Development Costs Offshore oil and gas fields: Drilling a cluster of wells from a single offshore platform is far less costly than building a separate platform for each target, resulting in a 30% to 50% reduction in development costs. Mature oil fields: Through "sidETracking" of directional wells (drilling branches from the wellbore of an old well to develop remaining oil reservoirs in the surrounding area), there is no need to drill new vertical wells, significantly reducing investment. Ⅱ. Advantages and Disadvantages Compared with Vertical Wells Advantages 1.Strong resource coverage capability: It can develop offset reservoirs and scattered reservoirs that are inaccessible to vertical wells, improving the production efficiency of oil and gas reservoirs. 2.High single-well production capacity: Horizontal wells, in particular, greatly increase the contact area between the wellbore and the reservoir, offering significant advantages in the development of unconventional oil and gas reservoirs. 3.Superior cost-effectiveness: Cluster wells and multi-lateral wells, supported by integrated drilling rigs and matched drilling equipment (such as top drives and mud pumps), reduce surface occupation and platform construction costs, making them suitable for offshore and intensive development scenarios. Disadvantages 1.High technical complexity: It requires professional directional drillers, rotary steerable systems (RSS), and MWD (Measurement While Drilling) equipment, resulting in a much higher technical threshold than vertical wells. 2.High costs: The investment in a single directional well is usually 20% to 50% higher than that of a vertical well of the same depth (due to increased costs of tools, equipment, and labor). 3.High risks: The complex trajectory leads to high circulating resistance of drilling fluid and increased difficulty in wellbore stability, resulting in a higher incidence of accidents such as pipe sticking and wellbore collapse compared to vertical wells. 4.Long construction cycle: Frequent trajectory adjustments and data measurements are required, leading to a 30% to 60% longer construction cycle than vertical wells of the same depth. Ⅲ. Conclusion In summary, directional drilling represents a milestone in the evolution of oil drilling from simple vertical development to complex and precise development. Currently, in global oil and gas resource development, the application proportion of directional wells has exceeded that of vertical wells, making it one of the core technologies for ensuring oil and gas supply.

Based on the geological, geographical conditions and engineering requirements of oil and gas exploration and development, wells are divided into two main types: vertical wells and directional wells. These two are core well types in the oil and gas drilling field, with the latter further categorized into conventional directional wells, horizontal wells, cluster wells, etc. The core difference between them lies in whether the wellbore trajectory is perpendicular to the ground, and they also differ significantly in design purposes, technical characteristics, application scenarios and construction difficulty. Next, we will discuss vertical wells. Ⅰ. Vertical Wells In drilling engineering terminology, a vertical well refers to a well type whose designed trajectory follows a vertical line, with the wellhead and bottomhole having the same geographical coordinates. Its total angle change rate is generally no more than 3°/30m. The wellbore verticality is ensured by drill string assemblies such as packed hole assemblies and pendulum assemblies, and it is suitable for scenarios such as coalbed methane development where geological units need to be divided. Vertical Well Drill String：The conventional drill string assembly consists of a rotary table rig + drill pipe + roller cone bit, which relies on the rigidity of the drill string itself to maintain verticality. Currently, the deviation prevention and straight drilling technology for vertical wells is mainly realized by improving the structural combination of the drill string: Deviation prevention: Rigid packed hole assemblies, tower-type assemblies, and square drill collar anti-deviation assemblies are mainly used. Deviation correction: Pendulum assemblies, flexible pendulum assemblies, eccentric weight drill collar assemblies, and downhole motor assemblies are mainly used. Ⅱ. Application Scenarios The application scenarios of vertical wells and directional wells are fully centered around three core needs: "resource distribution, surface conditions, and development efficiency". There is no absolute advantage or disadvantage between them, only differences in adaptability. Vertical wells are a cost-effective choice for simple scenarios. Their core advantages are "low cost and high efficiency", so they are suitable for scenarios with simple surface and underground conditions and concentrated resources. No complex design is required—only the target formation depth needs to be determined, and the drilling can be planned along a vertical path. The drilling process is carried out at a constant speed throughout, with only regular well deviation angle measurements required and no frequent adjustments. 1. Conventional Oil and Gas Reservoir Development When the oil and gas reservoir is directly below the wellhead, with a large reservoir thickness (>10 meters) and concentrated distribution, vertical wells can be drilled vertically to the target formation. The single-well productivity meets the demand, and there is no need for additional investment in directional costs. 2. Shallow Resource Exploration and Development For shallow oil and gas reservoirs, groundwater, and geothermal resources with a burial depth of <1000 meters, vertical wells do not require complex trajectories and can quickly complete drilling and production. 3. "Preliminary Exploration" with Exploration Wells In the early stage of oil and gas exploration, to obtain basic data such as underground formation lithology, porosity, and oil-gas bearing property, vertical wells (called parameter wells) are usually drilled. Due to their simple trajectory, vertical wells can more truly reflect the vertical formation sequence and provide a basis for the subsequent design of directional wells. Ⅲ. Advantages and Disadvantages Advantages 1.Low cost: The costs of equipment, construction, and maintenance are all lower than those of directional wells, and the single-well investment can be reduced by 30%~50%. 2.Simple technology: It has low technical requirements for the construction team, no need for professional directional engineers, and is easy to operate. 3.Short cycle: No frequent trajectory adjustments are required, and the construction cycle for the same depth is 30%~40% shorter than that of directional wells. 4.Low risk: The incidence of accidents such as wellbore collapse and pipe sticking is lower than that of directional wells (due to the simple trajectory, the drilling fluid circulation is more stable). Disadvantages 1.Trajectory limitation: It can only develop resources directly below the wellhead and cannot bypass obstacles or cover scattered reservoirs. 2.Low development efficiency: For unconventional oil and gas reservoirs, the contact area between the wellbore and the reservoir is small, resulting in low single-well productivity (e.g., the daily output of vertical shale gas wells is only 10,000~20,000 cubic meters). 3.Large land occupation: To develop multiple scattered reservoirs, multiple vertical wells need to be drilled, which consumes a large amount of land platform resources. Ⅳ.Conclusion With the advancement of oil and gas development towards "unconventional, deep-layer, and offshore" areas, the application proportion of directional wells continues to increase. However, vertical wells are still irreplaceable. In scenarios such as conventional oil and gas reservoirs, shallow resources, and exploration wells, vertical wells will exist for a long time due to their advantages of "low cost and high efficiency". In small and medium-sized oilfields in some regions, vertical wells remain the main development well type. The choice between the two is essentially a trade-off between "development needs and cost-effectiveness"—on the premise of ensuring the development target, vertical wells are selected for simple scenarios, and directional wells for complex scenarios, jointly supporting the efficient exploitation of global oil and gas resources.

Ⅰ.Pure Zirconia Liner Pure zirconia liners are made of high-purity zirconia material. The outer shell is constructed from 45# steel, while the inner sleeve typically has a zirconia content of ≥95% and a hardness of 92-94 HRC (Rockwell Hardness C Scale)—approximately 10 times that of traditional ceramics. With a service life of up to 8000 hours, this product features high hardness, excellent wear resistance and corrosion resistance, and long service life, making it suitable for offshore drilling operations. Ⅱ. ZTA Ceramic Liner Mud pump ZTA ceramic liners are engineered ceramic products. The outer shell is made of 45# steel, and the inner sleeve is composed of Zirconia Toughened Alumina (ZTA ), with the inner sleeve hardness reaching 92-94 HRC (Rockwell Hardness C Scale). By combining the properties of zirconia and alumina, a special material with integrated wear resistance, toughness, and thermal stability is formed. Specifically designed for the fluid ends of mud pumps, these liners boast high hardness, excellent wear resistance and corrosion resistance, and a long service life of up to 6000 hours, making them suitable for offshore drilling operations. Ⅲ. Differences Between Pure Zirconia Liners and ZTA Ceramic Liners Pure zirconia liners and ZTA ceramic liners differ in terms of material composition, performance characteristics, application scenarios, and cost, as detailed below: Material Composition Pure Zirconia Liner: Mainly composed of a single phase of zirconia grains. ZTA Ceramic Liner: A composite material of alumina and zirconia, generally containing 10%-20% zirconia, with the remainder being primarily alumina. Performance Characteristics Hardness: The hardness of ZTA ceramic liners is comparable to or slightly higher than that of pure zirconia liners, and both are harder than alumina ceramics. Toughness: ZTA ceramic liners achieve alumina toughening through zirconia, resulting in significantly higher toughness than ordinary alumina ceramics, but generally lower toughness than pure zirconia liners. Wear Resistance: Pure zirconia liners exhibit outstanding wear resistance; ZTA ceramic liners also have excellent wear resistance, reaching a level equivalent to that of pure zirconia liners. Thermal Stability: Pure zirconia liners have low thermal conductivity and better heat insulation performance, but may experience surface "pulverization" when used for a long time in humid conditions at 100-250°C. ZTA ceramic liners feature a low linear expansion coefficient and high thermal conductivity, which better inhibit thermal deformation and provide relatively superior dimensional stability in high-temperature environments. Chemical Stability: Both materials possess good chemical stability and can resist corrosion from most chemical substances. Application Scenarios Pure Zirconia Liner: Owing to its high hardness, high wear resistance, and corrosion resistance, it is suitable for oil and gas exploration and development scenarios such as deep oil reservoirs, harsh geological structures, and offshore oil and gas development. ZTA Ceramic Liner: In addition to being applicable to wear-resistant and corrosion-resistant scenarios similar to oil drilling mud pumps, it is also widely used in wear-resistant parts requiring cooling (e.g., abrasives, cutting tools) and components with high requirements for resistance to thermal deformation. Cost Pure Zirconia Liner: The overall cost is relatively high, as the raw material cost is high (zirconia powder preparation is complex), and the processing difficulty is greater—its higher toughness increases grinding complexity. ZTA Ceramic Liner: Since it contains a relatively high proportion of alumina (a raw material that is low-cost and easily available), the cost of ZTA ceramic liners is lower than that of pure zirconia liners.  

The mud pump ceramic liner is an improved version of the insert-type mud pump bi-metal liner, where the corrosion-resistant ceramic inner sleeve replaces the high-chromium alloy cast iron inner sleeve. Its technical principle lies in the application of modern phase transformation toughening technology, using high-toughness and high-strength toughened oxide ceramic materials to manufacture the integral inner sleeve of the liner—meeting the requirement for long service life. The production process of the outer sleeve is identical to that of the outer sleeve of bi-metal liners. Ⅰ. Materials of Ceramic Liners As the scope of global oil and gas resource exploitation continues to expand, frequent replacement of a large number of metal liners still fails to meet the high-pressure and anti-wear requirements of drilling rigs. However, ceramic liner materials—such as zirconia, alumina, and ZTA (Zirconia Toughened Alumina) composite ceramics—boast extremely high hardness, far exceeding that of metal materials. The raw materials (high-purity zirconia and alumina micropowders) undergo advanced cold pressing for one-time forming, high-temperature sintering, assembly, and final high-precision grinding and polishing. The resulting ceramic liners exhibit high flexural strength, high tensile strength, high fracture toughness, and excellent acid and alkali corrosion resistance. Ⅱ. Product Features of Ceramic Liners 1. Excellent Corrosion Resistance Ceramic materials have extremely high chemical stability and are less prone to chemical reactions in harsh environments such as acid, alkali, and salt spray. Neither chloride ions/hydrogen ions in drilling fluid nor acidic slurry in mining scenarios can easily cause corrosion damage to ceramic liners. For example, when handling drilling fluid with a pH value of 3-11, ceramic liners can maintain structural integrity for a long time; in contrast, bi-metal liners may suffer from wall thickness reduction and seal failure due to corrosion within a few months. 2. Good High-Temperature Resistance and Thermal Stability Ceramic materials have high melting points (e.g., approximately 2050℃ for alumina and 2715℃ for zirconia) and low thermal expansion coefficients, so they are not prone to deformation or cracking in high-temperature environments. During drilling operations, the local temperature generated by friction during pump operation may reach 150-200℃; ceramic liners can maintain dimensional stability, avoiding increased sealing gaps caused by thermal expansion and contraction. In contrast, metal liners are prone to thermal deformation at high temperatures, which may lead to drilling fluid leakage and reduced pump efficiency. 3. Low Friction and Energy-Saving Properties Ceramic materials have a high surface smoothness and an extremely low friction coefficient with pistons or plungers. For instance, the F-type mud pump ceramic liners feature a uniformly structured ceramic inner lining; their surfaces undergo multiple precision processing steps, resulting in excellent finish and gloss. This characteristic reduces frictional resistance between the liner and moving parts, lowering the power consumption of mud pumps—typically achieving an energy-saving effect of 5%-10%. Meanwhile, it further delays component aging and improves the operational stability of the entire equipment. Ⅲ. Comprehensive Cost Compared with traditional bi-metal liners, the service life of ceramic liners can reach 3000-4000 hours—more than 10 times longer than that of metal liners. This significantly improves cost-effectiveness, reduces comprehensive costs (including maintenance, labor, storage, and transportation), and ensures the stable progress of drilling operations.

In the oil drilling industry, the mud pump serves as the core power equipment of the drilling system, and the liner in its fluid end directly withstands the continuous impact of high-pressure and highly abrasive drilling fluid. Therefore, selecting a suitable liner is crucial. Mud pump liners are available in various materials, among which the mud pump bi-metal liner is the most common type. Its service life can usually reach 800 hours, and it is also one of the most widely used wearing parts of mud pumps. Structurally, it mainly consists of two layers: an outer sleeve and an inner sleeve. Ⅰ. Outer Sleeve 1. Structural Support As the core supporting component ensuring the overall performance, adaptability and durability of the liner, the outer sleeve is manufactured using centrifugal casting technology, with 45# forged steel as the material. It has a tensile strength of >610MPa and a hardness of HB180-200. This type of material exhibits excellent tensile, compressive and impact resistance. During drilling operations, the mud pump delivers drilling fluid at a pressure of 10-35MPa or even higher. The outer sleeve bears the impact of high-pressure fluid in the pump chamber and the lateral force generated by the reciprocating movement of the piston, preventing the liner from deformation or cracking due to excessive pressure. Meanwhile, acting as the "framework" of the liner, the outer sleeve supports the inner sleeve to prevent the inner sleeve from falling off or being damaged due to independent stress, thus ensuring the integrity of the bi-metal structure. 2. Installation Adaptability The dimensions of the outer sleeve directly determine whether the liner can perfectly match the liner bore of the fluid end. The outer diameter of the outer sleeve is precision-machined according to the pump body specifications to ensure transition fit with the liner bore of the pump body, avoiding radial looseness after installation. 3. Protection for the Inner Wear-Resistant Layer The inner sleeve of the bi-metal liner is the core wear-resistant layer, which directly comes into contact with sand and drill cuttings in the drilling fluid. However, the inner sleeve material (e.g., high-chromium cast iron) usually has high brittleness. The outer sleeve can buffer external mechanical impacts, preventing the inner sleeve from cracking due to direct stress. At the same time, the outer sleeve isolates the direct contact between the inner sleeve and the pump body metal, protecting the wear-resistant performance of the inner sleeve from additional damage. Ⅱ. Inner Sleeve 1. Resisting Wear and Erosion to Extend Overall Liner Life Drilling fluid often contains a large number of hard solid particles and flows at high pressure and high speed inside the pump, causing severe erosive wear to the inner wall of the liner. The inner sleeve is made of high-chromium material with high hardness and excellent wear resistance. Its hardness is much higher than that of the outer sleeve, enabling it to directly withstand the wear caused by drilling fluid and extend the overall service life of the liner. 2. Corrosion Resistance To meet different drilling requirements, drilling fluid may be acidic or alkaline. Long-term contact with such fluid can cause corrosion to metals. The inner sleeve material has excellent corrosion resistance, which can isolate the direct contact between the drilling fluid and the outer sleeve, and at the same time prevent corrosion products from mixing into the drilling fluid and affecting drilling quality. 3. Ensuring Sealing Performance The core function of the mud pump is to deliver drilling fluid to the bottom of the well at high pressure, and the sealing between the liner and the piston is the key to maintaining high pressure. If the inner wall of the liner has pits or deformations caused by wear and corrosion, it will lead to drilling fluid leakage, directly reducing the pump displacement and pressure and increasing energy consumption. The inner sleeve can fit tightly with the piston seal, reducing leakage and ensuring the mud pump operates stably at the rated pressure, thus avoiding drilling shutdowns caused by seal failure. 4. Reducing Comprehensive Costs Compared with mud pump ceramic liners, the inner sleeve of the bi-metal liner has lower cost, which can significantly reduce the overall material cost of the liner and improve the overall cost-effectiveness. In summary, the manufacturing process of bi-metal liners is relatively simple. Compared with ceramic or zirconia liners, bi-metal liners have a lower purchase price and are widely used in drilling operations. The adoption of bi-metal liners represents an important leap in the field of drilling mud pumps. They combine the strength of steel with excellent wear resistance, making them a highly attractive choice for various application scenarios. With the continuous advancement of technology, bi-metal liners are expected to play an increasingly important role in improving the efficiency of the mud pump industry and extending the service life of equipment.