相国寺储气库注采井完整性技术探索与实践

PROBE ON AND PRACTICE OF WELL INTEGRITY TECHNOLOGY FOR INJECTION-PRODUCTION WELLS AT XIANGGUOSI UNDERGROUND GAS STORAGE

相国寺储气库是比较典型的枯竭性气藏储气库,构造狭长、出露地层老、地层倾角大、储气层压力极低,新钻注采井必须穿越两个已开发的枯竭层以及两个易垮塌层段,构造主体部位地表0500 m之间有多个煤矿开采巷道。在这种复杂地质条件下建设储气库,新钻注采井完整性技术尤其重要。因此,如何经济安全完成新钻注采井的钻完井工作,且保证每口新钻注采井的完整性,难度极大。文章对揭开易塌盖层防卡钻、长段低压漏失段固井技术、建设过程管理以及后续注采完整性监测与评估等一系列实践进行浅析,充分阐述了枯竭气藏储气库注采井完整性关键技术。

Xiangguosi Underground Gas Storage is a typical depleted gas reservoir type,the structure being narrow and long,with ancient outcrops,high formation dip and extremely low reservoir pressure. The new injection-production wells must drill through 2 production formations already produced and 2 sloughing formations. In addition,quite a few coal mining channels are located within 0-500 m depth underground at the main part of the structure. Well integrity technology is extremely important for injection-production wells to be drilled. It is challenging to safely and economically drill and complete the new wells with well integrity guaranteed. Here in this paper discussion is made on how to open the cap rock section without pipe sticking,how to perform the cementing in long low-pressure thief zones,how the manage the whole operation,and subsequent injection-production integrity monitoring & evaluation. The critical well integrity technology for new wells to be drilled at depleted gas reservoir storage is elaborated.