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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.