焦石坝工区页岩气整体固井技术

Overall cementing technologies used for shale gas wells in Jiaoshiba block

马小龙

MA Xiaolong

中石化中原石油工程有限公司固井公司 中国石油大学(华东)石油工程学院

Well Cementing Company, SINOPEC Zhongyuan Petroleum Engineering Co. Ltd., Puyang 457001, He'nan, China College of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong, China

焦石坝工区海相页岩气井现已成为中石化勘探开发的重点，该工区上部地层溶洞裂缝发育，并伴随有浅层气，下部为微裂缝渗透性漏失且气层活跃，井漏和压稳矛盾突出，油基钻井液条件下长水平段固井质量不易保证以及大型压裂对水泥石破坏严重易造成井口带压。通过优化导管下入深度，研发高强低密度水泥浆体系和韧性水泥浆体系，使用可控胶凝堵漏技术，应用防漏、压稳、提高顶替效率等固井工艺，形成了焦石坝工区整体固井技术，提高了固井质量，满足了焦石坝工区开发的需要，为同类井固井提供了一定的借鉴作用。

The marine shale gas wells in Jiaoshiba block is now the focus of SINOPEC'S exploration and development. In this block, caverns, pores and fractures are developed and associated with shallow gas in the upper strata. In the lower strata, micro-fracture permeable circulation loss happens and gas layers are active, so the conflict between circulation loss and pressure stabilization is obvious. It is difficult to guarantee the cementing quality of long horizontal sections in the surroundings of oil-based drilling fluids. And wellhead pressure is induced for set cement is seriously damaged during large-scale fracturing. To deal with these difficulties, a series of overall cementing technologies suitable for Jiaoshiba block were established by optimizing the setting depth of conductors, developing high-intensity low-density cement slurry system and tough cement slurry system, adopting controllable gel plugging technology and applying well cementing technologies (e.g. circulation loss prevention, pressure stabilization and displacement efficiency improvement). And consequently cementing quality is improved, satisfying the development requirements of Jiaoshiba block. The research results can be used as the reference for well cementing of the same type.

10.13639/j.odpt.2017.01.011