井下可控变径稳定器工作机理及力学分析

石油钻井井眼轨迹控制是当今世界性技术难题之一,旋转导向钻井工具可控制井眼轨迹,但日租费昂贵,使用变径稳定器可有效解决该问题。针对目前国内可变径稳定器结构复杂、制造成本高等问题,设计了井下可控变径稳定器,详细介绍了工具的结构组成和工作原理。利用CAE技术对其关键部件进行力学分析;并利用CFD技术计算工具在三种工位时过流压降。综合考虑可变径稳定器受钻井液驱动力、节流套筒及导向体阻力、弹簧弹力等因素,对可调整支撑块进行力学分析,推导出可变径稳定器所受液压压降与工具直径的计算公式,同时实验论证该公式的合理性。该工具与防磨工具配套使用在钻井时可减少钻井时长,大大缩短钻井周期,降低钻井成本。

Working mechanism and mechanical analysis of variable diameter stabilizer for downhole controlled

Supporting the use of variable gauge stabilizer with screw drill tool could effectively control or adjust well trajectory. They have been applied overseas on a large scale due to its low cost and good control effects, while domestically some cases have also been successfully applied, but far from universal. According to the current domestic adjustable stabilizer complex structure, high manufacturing cost, the composition and working principle of downhole controlled stepless variable diameter stabilizer are introduced. The key mechanical analysis is carried out, by using CAE and CFD technology, which draws that the safety of the tool is higher and the flow pressure loss reasonable. Static analysis of adjustable stable block which by fluid driving force, throttle sleeve and guide body resistance and spring force is carried out. The formula about hydraulic pressure drop and tool diameter are derived, and the rationality of the formula experimental demonstration. The Drilling assembly for the stabilizer and the drag reduction tools is described in the paper, which reduce overall drilling times,thereby shortens the drilling cycle and decrease drilling cost.