川西沙溪庙组高压气藏水平井固井技术

HORIZONTAL WELL CEMENTING TECHNOLOGY OF HIGH PRESSURE RESERVOIR IN CHUANXI SHAXIMIAO GROUP

川西沙溪庙组中浅层气藏为致密砂岩气藏,直井采收率低,而井网密集,增产措施困难,采用水平井分段压裂技术可提高裂缝钻遇率和致密砂岩气藏采出范围。该构造水平井套管下入难度大、套管居中度低、沙溪庙组钻井液密度高,固井难度大。为此,通过合理的扶正器选型与安放设计、优选前置液组合、优化固井液流变参数等技术措施,2013年在川西完成沙溪庙组高压水平井固井25口,其中优质井15口、良好井8口、合格井2口,沙溪庙组高压水平气井固井质量优良率达到92%,固井质量满足了后期作业的要求。

The shallow gas reservoir in Chuanxi Shaximiao group is the tight sandstone gas reservoir,the recovery ratio of straight well is low,the well network is dense,and it's difficult to increase production. In order to improve the recovery ratio,the staged fracturing technology of horizontal well was used. But the running casing was very difficult in horizontal well of Shaximiao structure,centralization of casing was low,and cementing was difficult for high density drilling fluid. To improve cementing quality,the type selection and setting of centralizer were redesigned,the ahead fluid and cementing fluid rheological parameter were optimized,the new cementing technologies suited forhorizontal well of Shaximiao group were formed and used successfully in 25 wells in 2013,the high grade rate for horizontal well cementing was 92%,the cementing quality could meet the requirement of late operation.