Durable Drilling Drawworks For Deep And Ultra-Deep Well Drilling

Five Core Functions of the Drilling Drawworks (Full Coverage of the Entire Drilling Process)

The drilling drawworks runs through the entire drilling life cycle — spudding in, drilling ahead, making connections, tripping, running casing, well completion, raising/lowering, and accident handling. Five core functions support the normal operation of the entire drilling process.

1. Heavy-Load Tripping of Drill String and Running of Casing (Core Main Function)

During drilling operations, the drawworks undertakes all lifting, lowering, transfer, and suspension of drill pipe, drill collars, bits, downhole tool assemblies, and casing strings. In deep-well drilling, the total weight of the string can reach several hundred tons, all borne by the drawworks wire rope and drum. Relying on the high-torque output of the drawworks for smooth lifting and uniform lowering, the frequent tripping procedures are completed. This is the core function with the greatest workload and highest usage frequency in drilling.

2. Precise Weight-on-Bit Control and Automatic Drilling (Auto-Feed) During Drilling

Under normal drilling conditions, the drawworks does not lift or lower at full speed; instead, it feeds in at micro-speed, constant torque, and constant pressure. By dynamically releasing the string weight through hook-load control, it delivers a stable weight on bit to the bit with precision, allowing the bit to uniformly penetrate the formation and break rock steadily. Modern variable-frequency drawworks are equipped with automatic drilling (auto-feed) systems, enabling fully automatic constant-weight drilling and constant-speed feed, greatly reducing manual operation errors and improving drilling uniformity, wellbore quality, and rate of penetration (ROP).

3. Integral Raising and Folding/Storage

Throughout rig relocation, installation, and positioning, the raising, lowering, and section adjustments are all completed by pulling with the main drawworks. The drawworks provides large pulling force, working with the hoisting sheave system to safely raise weighing hundreds of tons — it is the core power equipment for rig installation and commissioning.

4. Wellhead Auxiliary Cathead Operations

Both ends of the drawworks are equipped with front and rear cathead shafts, capable of auxiliary pulling for making up and breaking out connections, pipe handling, pulling drill pipe, pipe alignment/centralization, lifting small tools, wellhead positioning, and auxiliary tensioning — high-frequency wellhead auxiliary operations and an important auxiliary power source for mechanized wellhead work.

5. Downhole Emergency Safety Handling

In the event of stuck pipe, drilling stalls, drill string obstruction, or complex downhole conditions, the drawworks can instantly deliver a huge overpull load, completing upward jarring to release stuck pipe, shock-release load relief, and emergency suspension and locking, preventing buried bits, stuck pipe, and drill string drop-off. It is the key safety equipment for downhole accident prevention and emergency escape.

Technical parameter:

System rated pressure　　　　　　　　　　　　　　　　6.5MPa

Rated flow of system　　　　　　　　　　　　　　　　15L/minX2

Maximum brake moment of normally open tong　　　　77kN.m

Maximum brake moment of normally closed tong　　　　80kN.m

Maximum brake moment of emergent brake　　　　　　157kN.m

Brake disc size( thickness×diameter)　　　　　　　　40×1500mm

Center height of assy　　　　　　　　　　　　　　　　745mm