旋转导向钻井技术已经成为当前钻井必不可少的核心技术,主要根据静态推靠式旋转导向控制原理,结合工程实际要求,建立力学模型.根据有利区内支撑爪力最大、不利区内支撑爪力最小原则,提出120°和60°划分区域的2 种控制方案,在优化数学模型的基础上,分别将各支撑爪的应力分解到偏置合力的方向和垂直于偏置合力的方向,采用力学矢量分析法,建立不同偏置合力矢量下的力学方程,求解相应的方程,得出不同划分区域下各支撑爪的应力表达式.分析对比不同划分区域下各支撑爪应力变化,比较变化趋势,优选更为稳定的控制方案,从而增加仪器使用寿命,减少钻井事故,降低成本.
The rotary steering drilling technique has become an indispensable core technology in the present drilling operations. In this paper, a mechanical model was built according to the principle of static push-the-bit rotary steering control and in conjunction with the actual need of drilling engineering. According to the principle of maximum supporting claw force in the favorable area and minimum supporting claw force in the unfavorable force, this paper presents two control schemes: dividing the area by 120° and 60°. While optimizing the mathematical model, the stress on each supporting claw is decomposed to the bias resultant force direction and to the direction perpendicular to the bias resultant force. Using mechanics vector analytic method, a mechanic equation is built under different bias resultant vector, and then solves the related equation to ifnd the stress expressions of each supporting claw at different areas. This paper analyzes the stress changes of each supporting claw at different areas, compares the changing trend and optimizes the more steady control scheme so as to increase the service life of the instruments, reduce drilling accidents and reduce drilling costs.