元坝1井承压堵漏技术

元坝1井是位于四川盆地川东北巴中低缓构造带元坝岩性圈闭的一口重点区域探井,由于该井在嘉陵江组2段存在高压层,为满足下部井段安全快速钻进的需要,需对上部裸眼并段地层进行承压堵漏作业,使其承压能力达到2.15 kg/L以上.在室内试验的基础上,优选应用了凝胶复合堵漏剂NFJ-1,并给出了适用于不同漏失的堵漏浆配方及现场承压堵漏技术方案.该井须家河组、雷口坡组及嘉陵江组3段底部地层承压堵漏作业获得成功,地层承压能力均达到了设计要求,从而保证了该井的顺利完钻,并为该区块海相地层堵漏方案的确定积累了经验.介绍了该井承压堵漏技术研究、堵漏浆配方的确定、现场堵漏施工过程及效果等.

Leakage Control under Pressure in Well Yuanba-1

Well Yuanba-1 is a key well designed to explore Yuanba trap in Sichuan basin.Because of the high pressure formation in the Jialingjiang-2 section,leakage control was conducted in the upper open hole section under pressure over 2.15kg/L to meet the requirement of safe and rapid drilling in lower formation.Based on lab tests,the gelatin polymer lost circulation material(LCM) named NFJ-1 selected.Various drilling fluid formula and plugging plans were developed to meet demands for various lost circulation grade.Plugging jobs have been successfully conducted under pressure at three separate formations,the Xujiahe section,the Leikoupo section,and the Jialingjiang section.The formation strength of these formations all meet planned requirements so that the well was drilled to its planned depth.The leakage control technique,determination of plugging fluids,field application and its results were introduced in this paper.