旋转下套管技术在川渝页岩气开发中的应用

Application of Top Drive Casing Running Technology in Sichuan and Chongqing Shale Gas Exploration and Development

旋转下套管技术是一种现代化的套管下入技术,该技术通过应用顶驱下套管装置,提高下套管作业生产效率并且保障作业安全,可以在套管下入遇阻时及时循环钻井液并旋转套管串,实现井眼轨迹不佳情况下套管安全高效下放到位。相比于常规"上提下放"的下套管方式,旋转下套管方式减小了套管与井壁间的摩擦系数,从而使套管避免了过大的轴向载荷,降低了后期套变的风险。从2018年开始,旋转下套管技术在川渝页岩气钻完井作业中大规模应用,已经有超过30%的井采用了旋转下套管方式下入生产套管,后期压裂套变率已降低25%以上。

Top-drive casing running is a modern casing driving technology which improves the efficiency of casing operations and guarantees the safety of operations by circulating the drilling fluid and rotating the casing string in time when the well trajectory is not good and casing running encounters obstacles.Compared with the conventional"pull and release"casing running method,the rotating casing method reduces the friction coefficient between the casing and the well-bore,thereby avoiding excessive axial load on the casing and reducing the later casing risk of change.Since 2018,top-drive casing running technology has been applied on a large scale in Sichuan&Chongqing shale gas exploration.More than 30%of wells have adopted this method to run production casings.Results from the hydraulic fracture indicate that the casing deformation has decreased significantly.