大庆油田侧钻小井眼水平井固井施工压力设计与应用

DESIGN AND APPLICATION OF CEMENTING OPERATION PRESSURE ON SIDETRACKING HORIZONTAL WELL IN DAQING OILFIELD

针对大庆油田侧钻水平井环空间隙比常规井眼和小井眼环空间隙小得多、侧钻水平井尾管内径小,这样造成循环摩阻大,固井施工压力高,固井质量不易保证的实际,开展了注水泥设计,确立了环空压耗与井眼长度的关系及钻井液性能对压耗的影响。通过偏心环空时的压降计算施工压力研究及注替过程的速度、压力分析,开发与应用了侧钻水平井固井施工设计软件。通过两口井的实践,证实了设计的可靠性,地面施工一次成功。

In view of the annular clearance of sidetracking horizontal well is much smaller than that of conventional well and slim hole, and the inside diameter of liner is small, which heighten the circulating friction and cementing operation pressure, and increase the difficulty of cementing operation, and the cement job quality can′t ensure. By studying of cementing documentation, the relation between annular loss and borehole length, and the influence of drilling fluid properties on annular loss were determined. Through the study of calculation of differential pressure in eccentric annulus, and the analysis of velocity and pressure in fill/vent process, the design software of cementing operation in sidetracking horizontal well was developed. Field practice confirmed the design software is dependable.