页岩气井旋转式井壁取心器爬行机构设计与优化

为了解决页岩气井旋转式井壁取心器不能靠自重下至取心位置的问题,分析了取心器的工作要求,确定了取心器在水平井中所受阻力,设计了一种由行星齿轮、锥齿轮组合传动的旋转式井壁取心器爬行机构.建立了爬行轮正压力与各参数的函数关系、支撑臂伸出速度与各参数的函数关系;以支撑臂伸出速度和支撑臂推靠力为多目标优化函数,利用正交试验分析方...

Design and Optimization of the Crawling Mechanism of Rotary Sidewall Coring Device in Shale Gas Wells

With regard to the problem that the rotary sidewall coring device of shale gas wells cannot be lowered to the coring position with its own weight, the operating requirements of the coring device were analyzed, and the resistance to the coring device in the horizontal wells was determined. Then, a new crawling mechanism transmitted by planetary and bevel gears was designed for rotary sidewall coring device. The functional relationships of the positive pressure of the crawling wheel and the extension speed of the supporting arm with each parameter were established. With the extension speed and push-the-bit force of the supporting arm as the multi-objective optimization function, the order of priority of the influencing factors such as the length, rotation angle, and eccentricity of the crawling arm and the length of the supporting arm was determined through the orthogonal tests. Furthermore, the physical dimensions of the crawling arm and supporting arm were optimized. The analysis results demonstrated that the rotation angle of the crawling arm had the greatest influence on the extension speed and push-the-bit force of the supporting arm. When the rotation angle, length, and eccentricity of the crawling arm and the length of the supporting arm were 45°, 150 mm, 8 mm, and 140 mm, respectively, the extension speed and push-the-bit force of the crawling arm were optimal. The optimization of the lengths of the crawling and supporting arms facilitated the decline in the push-the-bit force needed by the supporting arm and the increase in the extension speed of the supporting arm. The crawling mechanism of the rotary sidewall coring device for shale gas wells provides a new driving method for the sidewall coring device.