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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

Ⅰ. Equipment Definition The Drilling Mud Decanter Centrifuge is a critical solid-liquid separation device in oil and gas drilling operations. It is primarily used for high-efficiency centrifugal separation of drilling mud (also known as drilling fluid), achieving graded treatment of solid particles in the mud and recycling of the liquid phase. This optimizes mud performance, reduces waste discharge, and saves costs. Ⅱ. Core Functions Solid Phase Grading Treatment Separates solid particles of different sizes (such as cuttings and rock debris), typically capable of separating particles ≥2–5 microns (specific to equipment models and operating conditions).    Differentiates between "coarse solids" (to be discarded) and "fine solids" (retained in the mud to maintain performance). Liquid Phase Recycling Recovers the liquid phase in the mud (base fluid, chemical agents, etc.), reducing the amount of fresh mud preparation and material costs. For oil-based mud or environmentally sensitive scenarios, liquid recycling minimizes environmental pollution. Mud Performance Optimization Adjusts mud density, viscosity, and rheological properties by controlling solid content and particle size distribution to meet process requirements for different drilling stages (e.g., drilling, cementing). Ⅲ. Working Principle Centrifugal Separation Mechanism The equipment consists of a horizontal drum (rotating at high speed, 1,500–4,000 RPM) and an internal scroll conveyor. Drilling mud enters the drum center and, under centrifugal force , solid particles settle on the drum wall and are pushed to the conical end by the scroll conveyor; the liquid forms an inner liquid ring and discharges from the overflow port at the opposite end of the drum. Key Parameter Control Drum Speed: Higher speeds generate greater centrifugal force and higher separation precision (suitable for fine particle separation). Weir Height: Adjusts liquid residence time, affecting separation efficiency and liquid clarity. Differential Speed (Speed Difference Between Drum and Scroll): Controls solid conveying speed to avoid over-compression or blockage. Ⅳ. Typical Application Scenarios Land Drilling：Processes water-based and oil-based mud, separates cuttings, and recovers useful solids like bentonite and barite. Offshore Drilling：Meets environmental regulations (e.g., MARPOL Convention), reduces mud waste discharge, and adapts to space constraints on offshore platforms. Horizontal/Directional Drilling：Handles high-viscosity and high-solid-content mud, maintains wellbore cleanliness, and prevents stuck pipe risks. Waste Treatment：Reduces the volume of waste mud, lowering solid waste transportation and disposal costs. Ⅴ. Technical Advantages High Efficiency and Energy Saving:Processing capacity ranges from 30–150 m³/h (model-dependent), with energy consumption 30% lower than traditional filtration equipment. Automated Control:Integrated PLC control system real-time monitors mud parameters (e.g., density, flow rate) and automatically adjusts operating parameters like speed and differential speed. Wear-Resistant Design:Drums and scrolls are made of wear-resistant materials (e.g., tungsten carbide coatings, high-chromium cast iron) to extend service life and withstand high-sand-content mud environments. Environmental Compliance:Reduces harmful substances (e.g., heavy metals, oil) in mud waste, meeting environmental standards worldwide (e.g., EPA in the U.S., CLP Regulation in the EU). Ⅵ. Key Selection Parameters Drum Dimensions Diameter (e.g., 350mm, 450mm, 650mm): Larger diameters enable higher processing capacity, suitable for large-scale drilling operations. Length-Diameter Ratio (L/D): A higher ratio improves separation precision, ideal for fine particle separation. Processing Capacity Maximum mud processing capacity (m³/h): Must match the flow rate of the drilling fluid circulation system. Separation Precision Minimum separable particle size (microns): Selected based on solid control requirements for drilling processes (e.g., deeper wells require higher precision). Drive Mode Variable Frequency Drive (VFD): Enables flexible speed adjustment to adapt to different mud conditions. Ⅶ. Maintenance Considerations Daily Inspections Monitor bearing temperature and vibration values to prevent downtime due to mechanical failures. Clean solid deposits on the drum inner wall and scroll conveyor to reduce wear. Regular Maintenance Replace gearbox lubricating oil every 500–1,000 hours and check the clearance between the scroll and drum (adjust or replace if worn). Perform non-destructive testing (e.g., ultrasonic flaw detection) on wear-resistant components to assess wear levels. Ⅷ. Types Drilling mud decanter centrifuges can be classified into various types based on different criteria. Below are common classifications and their characteristics: By Separation Precision (Minimum Separable Particle Size) Medium-Speed Centrifuge（5–40 microns）：Primary separation for removing larger cuttings, commonly used in initial mud purification. High-Speed Centrifuge（2–5 microns）：Fine separation for mud containing fine particles (e.g., bentonite, barite), suitable for deep wells with high mud performance requirements. By Drum Structure 1.Cylindrical Centrifuge Features: Cylindrical drum offers large separation space and high processing capacity but lower separation precision. Application: Rapid processing of large mud volumes, suitable for primary solid control stages. 2.Conical Centrifuge Features: Conical tail enhances solid compression via centrifugal force, improving separation efficiency and solid dewatering. Application: Scenarios requiring high-dryness solid discharge (e.g., oil-based mud processing). 3.Cylindrical-Conical Composite Centrifuge Features: Combines the large capacity of the cylindrical section with the high dewatering efficiency of the conical section, balancing processing capacity and separation precision. Application: Most drilling scenarios, especially complex well conditions with high mud performance requirements. By Drive Mode 1.Single-Motor Drive Centrifuge Structure: Driven by a single motor, with differential speed between the scroll and drum achieved via mechanical transmission (e.g., planetary gearbox). Features: Simple structure and low cost, but limited differential speed adjustment range and flexibility. 2.Dual-Motor Drive Centrifuge Structure: Drum and scroll are driven by independent motors, with differential speed controlled via frequency conversion. Features: Real-time adjustment of differential speed based on mud characteristics, high adaptability, efficiency, and energy savings (e.g., with variable frequency motors). 3.Triple-Motor Drive Centrifuge Structure: Adds an auxiliary motor to the dual-motor system for precise control of scroll torque and differential speed. Features: Suitable for high-viscosity and high-solid-content mud, with higher reliability but increased cost. By Explosion-Proof Rating 1.Standard Centrifuge Application: Non-explosive environments (e.g., onshore conventional drilling). 2.Explosion-Proof Centrifuge Features: Key components (motors, control systems) use explosion-proof designs (e.g., flameproof, increased safety types), compliant with international standards (ATEX, IECEx) or domestic standards (GB 3836). Application: Explosive environments such as offshore drilling platforms and gas-containing well sites. By Processing Capacity Small Centrifuge(30–60 m³/h):Small drilling teams, laboratories, or low-flow mud circulation systems. Medium Centrifuge(60–120 m³/h):Conventional onshore drilling, matching most rig mud circulation requirements. Large Centrifuge(120–150 m³/h):Offshore platforms, large horizontal wells, or scenarios requiring rapid processing of large mud volumes. Selection Recommendations 1.Based on Well Depth: Shallow Wells (<3,000 meters): Choose medium-speed, cylindrical-conical composite centrifuges to balance cost and efficiency. Deep Wells (>3,000 meters): Require high-speed, dual-motor drive centrifuges to ensure fine separation and stable mud performance. 2.Based on Mud Type: Water-Based Mud: Standard centrifuges suffice. Oil-Based/Synthetic-Based Mud: Must use explosion-proof, corrosion-resistant centrifuges with heating systems. 3.Based on Environmental Requirements: Strict Environmental Areas (e.g., offshore drilling): Prioritize high-separation-precision centrifuges to reduce waste discharge, or use in conjunction with cutting dryers to further lower oil content.