Thingadong-1复杂高压气井大尺寸套管固井技术

Cementing Technology in Large Casings of High Pressure Gas Well Thingadong-1

Thingadong-1井是缅甸D区块上的一口预探井,在钻至井深1 712.32 m处时发生了气侵溢流,用密度为1.48 g/cm3的钻井液建立了井下压力平衡。电测解释有水层14套、含气水层19套、气水同层1套、二开井底气层1套(裸眼测试)。下套管结束后循环钻井液时发生了失返性漏失,低排量间断性地泵入堵漏浆264 m3后静止堵漏46 h,堵漏成功(未验证井下承压能力)。施工后的水泥浆在失重状态下,气侵、水窜等因素易影响固井质量。应用低黏度、低切力先导钻井液,加重隔离液,微膨胀、非渗透、多凝阶梯密度防漏防气窜水泥浆体系等技术措施,完成固井施工作业。在施工中漏失5 m3水泥浆,随着水泥浆的漏失,浆体中的橡胶堵漏剂和纤维堵漏剂发挥了防漏堵漏效果。产层段封隔优质,满足了测试要求。

The well Thingadong-1 is an exploration well in D Block Myanmar.The bit of φ444.5 mm is used in the second hole,and the depth of that is 1,720.52 m.When drilling to the depth of 1,712.32 m,the overflow is caused by gas invasion is encountered,and the balance pressure is established by drilling fluid with density of 1.48 g/cm3.The electric logging shows there are 14 sets of water layers,19 sets of gas-in-water layers,one set of gas and water with layer and one set of bottom 1,710.6-1,715.0 m gas layer.After set the casing of φ339.7 mm at the depth of 1,704.56 m,a heavy mud loss without mud on ground is encountered at the time of circulation.The lost circulation drilling fluid is intermittently pumped by 264 m3 with small volumetric rate,and kept stable for 46 h,then plugging successfully(No test of the lost pressure of the thief zone).Moreover,gas cut,water channeling and other factors affecting the quality of cementing in weightlessness.Therefore,the leading drilling fluid with low viscosity and gel,weighted spacer,micro-dilatancy and non-penetrative gas block cement slurry shall be used to operate.In the cementing operation,with the leakage of 5 m3 cement slurry,rubber and fiber blocking agents work well,and the cementing job quality is excellent.