静态推靠式旋转导向工具造斜率预测分析

旋转导向钻井技术是目前钻井工程技术领域研究的热点之一。为准确认识静态推靠式旋转导向工具在给定导向力等钻进参数作用下的造斜能力,根据工具导向特点,对翼肋推靠井壁进行受力分析,考虑翼肋随非旋转套转动时所受的切向阻力作用,修正了翼肋导向合力计算模型;在钻进趋势预测模型的基础上,进一步建立了推靠式旋转导向工具造斜率预测方法。通过采用纵横弯曲梁法求解静态推靠式旋转导向底部钻具组合钻头力学特性,并考虑钻头切削各向异性指数,编程实现了静态推靠式旋转导向工具造斜率的定量预测计算。与现场试验数据对比发现:建立的造斜率预测误差在±0.5°以内,方位变化率预测值较不考虑翼肋与井壁间摩擦时更加符合实际方位变化率,预测结果与实钻井眼轨迹数据的对比验证了造斜率预测方法的合理可行性,为下一步进行井眼轨迹调控指令的准确制定提供了依据。

Buildup Rate Prediction of a Static Push-the-Bit Rotary Steerable Tool

Rotary steerable drilling technology is currently one of the hotspots in the field of drilling engineering technology.To accurately understand the buildup ability of the static push-the-bit rotary steerable tool under the given steering force and other drilling parameters,the force analysis of the steering rib pushing against the wellbore is carried out according to the tool steering characteristics.Considering the steering rib tangential resistance caused by the rotation of non-rotating sleeve,the steering rib steering resultant force calculation model is revised.Based on the drilling trend prediction model,a push-the-bit rotary steerable tool buildup rate prediction method is further established.The vertical and horizontal bending beam method is used to solve the mechanical characteristics of the bit on the static push-the-bit bottom hole assembly.Considering the cutting anisotropy index of the drill bit,the quantitative prediction calculation of the static push-the-bit rotary steerable buildup rate is programmed.Compared with field test data,the established buildup rate prediction error is within±0.5°.The azimuth change rate prediction value is more in line with the actual azimuth change rate than that without considering the friction between the steering rib and the wellbore.The comparison with the well trajectory data verifies the reasonable feasibility of the buildup rate prediction method,and provides a basis for the accurate formulation of the well trajectory control commands for the next step.