强封堵有机盐钻井液在致密油水平井中的应用

Application on High Sealing Organic Salt Drilling Fluid System in Tight Oil Reservoir Horizontal Well

阿密1H井是华北油田针对致密油领域在二连油田部署的第1口预探水平井,完钻井深为2 700 m,水平位移长1 218 m,水平段长970 m,水平井段岩性以大段硬脆性泥岩或砂泥岩为主。用邻井泥岩掉块做实验发现,掉块在有机盐/聚胺高抑制性溶液中的回收率很高,但浸泡实验表明,岩屑块仍然在短时间内出现明显的裂纹,长时间浸泡后掉块水化分散明显;掉块在有机盐/铝合物封堵剂溶液中浸泡20 h后,铝合物在掉块表面或裂缝处析出白色沉淀,紧密附着在岩屑上。因此决定采用具有良好抑制性的有机盐钻井液钻井,并且引入了铝合物封堵剂封堵硬脆性泥页岩微裂缝。在现场施工中,该强封堵强抑制钻井液克服了井眼水平位移大、井壁易垮塌、井眼轨迹复杂、完井作业时间长等诸多难题,满足致密油特殊地层开发的钻井需求。

The well Ami1H is the first horizontal exploration well in Erlian Oilfield,with total depth of 2,700 m,horizontal displacement of 1,218m,and horizontallengthof 970m.Inhorizontal section,thick brittle mudstone form ationisencountered,and the laboratory test results show that even rolling recovery rate of cuttings in organic/polymer solution is very high,after soaking for a short time,fractures exist apparently.However,after soaking for 20 h in organic/ aluminum complex sealing fluid,white deposit exists apparently to protect cuttings from hydrating.The application of organic salt aluminum complex sealing drilling fluid system is successful,which meets the demands of drilling in special tight oil reservoirs.