桩1-支平1井钻井液工艺技术

Drilling fluid technology for well Zhuang1-ZP1

桩1-支平1井位于胜利长堤油田桩1块中部构造较高位置,目的层是馆陶组上段9小层。该井是胜利油田第一口分支井,钻探目的是利用分支水平井技术控制更大面积储量,抑制底水锥进,增大泄油面积,提高采收率。针对分支水平井对钻井液的特殊要求,及分支井施工钻井液在裸眼井段静止时间长,要求钻井液具有很强的悬浮携带能力、稳定性能、流变性能和油层保护性能,采用聚合醇防塌钻井液体系。聚合醇钻井液以聚合醇为主要处理剂,正电胶、两性离子聚合物为辅助处理剂。经现场应用表明,聚合醇在钻井液中加量为3％时,具有很强的润滑性、抑制性和防塌性能;携岩能力和保护油气层能力强;生物毒性小,LC50值大于30800g/mL,利于环境保护,满足了该水平井钻井的要求。

Well Zhuang1-ZP1 was the first multilateral well of Shengli oilfield, it was drilled to develop more reservoirs, control the bottom water coning, increase oil drainage area and enhance oil recovery. The anti- collapsing polyol drilling fluid system was selected, as special requirements on drilling fluid were needed for multilateral drilling; and because of long static time of drilling fluid in the open hole, very good suspension and cuttings transportation, borehole stability, rheology and reservoir protection were also required. This drilling fluid system was mainly based on polyol, and such additives as MMH and zwitterionic polymer were also added into. Field using showed that when the dosage of polyol is 3% , the drilling fluid exhibited good lubricity, good shale controlling and anti-collapsing abilities, better cuttings transportation and formation protection. At the same time, the biological toxicity was minimized and the value of LC50 is higher than 30800 g/mL, which was safe for the environment.