任平4井固井技术

Cementing Technology in Well Renping-4.

任平4井是位于冀中坳陷饶阳凹陷任丘构造带任6山头任469x井区的一口水平井,井深为3851.24m。该井二开用φ241.3mm钻头钻至井深3272.85m,下入φ177.8mm套管,要求水泥返至井深2000m。由于封固段长1200m,水泥浆"失重"时易发生气窜,加之该井后效严重,增加了气窜的可能性;此外,该井段井斜大,套管居中困难,也影响封固质量,该区块任平3井固井质量没有达到优质。对任平4井固井技术进行了研究。根据研究结果,该井选用了驱油效率大于90%的S104冲洗液以及双凝、低失水、低析水、高强度防气窜水泥浆体系和其它配套的工程措施,使水泥浆返至井深1775.5m,固井质量达到了优质。

Located in Block Ren469x,Renqiu Structure,Jizhong XXX,Well Renping-4 is a horizontal well with a depth of 3,851.24m.The second interval of this well was drilled with 241.3mm(diameter)bits to 3,272.85m. 177.8mm casing strings were run into this interval and the cement was required to return to the depth of 2,000m, that is to say,the cement column was about 1,200m in length.Gas channeling would be encountered if the ce- ment slurry was in'weightlessness'.The aftereffect of the well made it much more possible for the gas channeling to take place.Furthermore,the high angle of this interval made it very difficult for the casing strings to be central- ized in the hole.All these factors contributed to the difficulties in well cementing.Well Renping-3 in the same block had a cementing job that was not satisfactory.Based on laboratory studies,a flushing fluid having a displace- ment efficiency of greater than 90%,and an anti-channeling cement slurry having double setting points,low filter loss,low free water and high strength were chosen,combined with appropriate engineering procedures,to cement this interval,and the cement returned to a well depth of 1,775.5m,and the cement job quality was satisfactory.