埕北326 A-7大位移井钻井液技术

The Drilling Fluid Technology about Chengbei 326 A-7 Extended Reach Well

埕北326 A-7井上部地层沉积大段易水化泥岩,沙河街组发育油泥岩和油页岩,古生界地层压力系数低,近5000 m斜井段定向过程中岩屑易沉降在下井壁形成岩屑床,定向施工中钻井液井壁稳定、井眼净化及润滑防卡技术难度大。通过使用聚胺低活度固壁防塌钻井液体系和海水无固相润滑防塌钻井液体系,辅助相应的现场钻井液维护处理工艺,施工中井壁稳定、井眼净化良好、定向顺畅,全井平均机械钻速24.86 m/h,取得了优快钻井的良好效果。

The upper part of the Chengbei 326 A-7 well has a large sedimentary section of easily hydrated mudstone,while the Shahejie Formation develops oil mudstone and oil shale.The pressure coefficient of the Paleozoic formation is low,and during the directional process of the nearly 5000 meter inclined well section,rock debris is prone to settle on the lower wellbore wall,forming a rock debris bed.The stability of the drilling fluid wellbore wall,the difficulty of wellbore purification,and lubrication anti jamming technology during directional construction are significant.By using a low activity polyamine solid wall anti collapse drilling fluid system and a seawater solid-free lubrication anti collapse drilling fluid system,corresponding on-site drilling fluid maintenance and treatment processes were assisted.During construction,the wellbore was stable,the wellbore was well purified,and the orientation was smooth.The average mechanical drilling speed of the entire well was 24.86 m/h,achieving good results in fast drilling.