大位移井井眼清洁监测技术在大港油田的应用

Establishment of bore hole cleaning and monitoring technology andits application in Dagang oilfield（）

汪志明 翟羽佳 高清春

WANG Zhiming ZHAI Yujia GAO Qingchun

中国石油大学石油工程学院，北京　102249

Petroleum Engineering Institute, China University of Petroleum, Beijing 102249, China

随着大位移井及复杂结构井钻井技术的不断发展，井眼清洁及监测技术面临着新的困难和挑战。如何监测复杂地质条件、复杂井型条件下的岩屑运移状况，预测岩屑成床时间，帮助判断、处理井下复杂情况是现场迫切需要解决的问题。基于环空岩屑运移规律及岩屑床成床机理，采用岩屑运移多层模型，根据岩屑对环空压耗的影响以及环空压耗与循环钻井液当量密度的转换关系，建立了适合工程中监测井眼清洁状况的ECD曲线。并应用该技术对大港油区ES-H6井进行分析和指导。实例分析表明，ECD曲线是衡量井眼清洁与否的重要标准，应控制ECD曲线在合理的范围之内。另外，ECD主要与环空载荷、环空返速、钻井液性能等因素有关，对钻井液性能以及钻杆钻速的合理控制有利于大位移井的井眼清洁。

Bore hole cleaning is one of the key technologies of extended reach well drilling, with the law of annulus cutting transport as the core. With the technological development of extended reach wells and complex structural wells, the bore hole cleaning and monitoring technology faces new difficulties and challenges. The problems urgent to be resolved are how to monitor the cutting transport under complex geological condition and in complex structural well, and how to predict the time of cuttings forming bed, in order to help judge and solve the downhole problems. Based on the law of cutting transport and the forming mechanism of cutting bed, the multilayer cutting transport model is adopted, the ECD curve to monitor the conditions of bore hole cleaning is established, considering the effect of cuttings on annular pressure lost and the transformational relation between annular pressure lost and equivalent circulation density. It is used in Well ES-H6 of Dagang oilfield, and the application shows that the ECD curve is an important criterion for measuring the bore hole cleaning condition, and it should be controlled within a reasonable range. Besides, the ECD is related to such factors as annular loads, annular velocity, mud property, and so on. Reasonable control of mud property and rotational speed is beneficial to bore hole cleaning of extended reach wells.