Abstract:
Mimicking the structure and movement principles of earthworms, a peristaltic load transfer method for the drill-string has been proposed as an innovative approach to enhance the transfer efficiency of weight on bit in long horizontal well sections. This paper presents the development of a bionic peristaltic drilling tool, which uses a pulse generator to drive multiple vibration subs. This design enables the drill-string to perform peristaltic motion while reducing hydraulic pressure loss. Laboratory tests showed that at a flow rate of 30 L/s, the tool's pressure fluctuation amplitude reached nearly 2 MPa, with a vibration frequency of 6.5 Hz, and the displacement amplitude of the three vibration subs exceeded 5 mm. Field test was conducted in the horizontal section of the JHW8X-3X well in the Xinjiang oil field, where a single tool set achieved a drilling footage of 815 m with an average penetration rate of 12.48 m/h. Compared to adjacent wells in the same block that used oscillating screw and Agitator tools, the average penetration rate increased by 15.5%. The field test results indicate that the bionic peristaltic drilling tool alleviates the problem of drill-string friction, promotes the transfer of weight on bit, and offers an effective solution for improving the drilling efficiency of long horizontal sections in horizontal wells.