下川东震旦系气井复杂处理技术实践与认识——以YT1井为例  

Complexity treatment technologies for Sinian gas wells in eastern Sichuan Basin:An example from YT1 well

作　　者：朱占林 敬婧 钟广荣 卓云 王荣 王栋 ZHU Zhanlin;JING Jing;ZHONG Guangrong;ZHUO Yun;WANG Rong;WANG Dong(Chuandong Drilling Company,CNPC Chuanqing Drilling Engineering Company Limited,Chongqing 400000,China)

机构地区：[1]中国石油川庆钻探工程有限公司川东钻探公司,重庆400000

出　　处：《天然气技术与经济》2024年第1期46-52,共7页Natural Gas Technology and Economy

摘　　要：为了安全有效开发四川盆地下川东地区震旦系气藏,保障川渝地区天然气能源的有效接替,需对震旦系气井的开发难点进行研究,解决易发生的故障复杂。以中国石油西南油气田公司重点探井YT1井为研究对象,分析了该井面临的地层多压力系统、压力系统窗口大、井漏严重、井壁易缩径等地质难点,从井身结构、堵漏技术、防溢流技术、防塌技术等方面开展复杂处理技术研究。研究结果表明:①优化井身结构为五开非标结构,能有效封隔必封点;②大井眼段下侏罗统自流井组—上二叠统龙潭组综合应用随钻堵漏、复合堵漏、水泥堵漏技术,可有效提升堵漏成功率,降低复杂时率;③241.3 mm井眼奥陶系十字铺组—上寒武统洗象池组优化钻具组合,综合治理溢、漏、塌等复杂,可有效提升作业效率。结论认为:①沙溪庙—凉高山地层采用空气/雾化钻进未发生故障复杂,防漏、提速效果显著;②龙潭组—下寒武统筇竹寺组地层优选“水力振荡器+复合钻头+MWD定向”技术,23趟钻完成3150.94 m长段膏盐层井段定向作业;③190 mm井眼开展185 mm双向微扩眼器试验,解决了长段膏盐层缩径问题,三次扩眼后下套管顺利到位;④通过复杂防控技术集成应用,YT1井复杂时率降低至17.47%,避免了恶性卡钻;⑤推广应用下川东地区震旦系气藏复杂防控技术对川渝地区后续震旦系气藏深井技术研究具有指导意义。For both active and safe development for Sinian gas reservoirs,eastern Sichuan Basin,and ensuring effective replacement of natural gas in Sichuan-Chongqing area,it is essential to figure out development challenges in Sinian gas wells to further deal with usual complexity and accidents.So,YT 1 well,the key exploration one which belongs to PetroChina Southwest Oil&Gasfield Company,was taken as an objective.And then,some geological difficulties existing in this drilling were put forward,including multiple sets of formation pressure,large window of pressure system,heavy lost circulation and wellbore shrinkage.Additionally,many treatment technologies were established for the complexity in terms of casing program,leakage stopping,anti overflow and anti collapse.Results show that(i)five-spud nonstandard program should be optimized as an optimal one for setting position in effective package;(ii)three schemes of leakage stopping while drilling,compound leakage stopping and cement plugging should be employed at big hole from the Lower Jurassic Ziliujing Formation to the Upper Permian Longtan Formation.As a result,the success ratio of leakage stopping can be improved with effect to decrease the complexity's incidence rate;and(iii)bottom hole assembly should be chosen at the hole of 241.3 mm from the Ordovician Shizipu Formation to the Upper Cambrian Xixiangchi Formation.And some complexity,like overflow,lost circulation and collapse,is treated to increase drilling efficiency.Five conclusions are made.First,there are no complexity or accidents during air and mist drilling from Shaximiao to Lianggaoshan formations,obtaining an obvious effect in anti-leakage and ROP increase. Second, hydroscillator + compound bit + MWD directional drilling, as the best technol ogy for Longtan to the Lower Cambrian Qiongzhusi formations, runs 23 trips in the gypsum salt bed with the well interval of 3150.94 m. Third, 185 mm bidirectional microreamer is tested after drilling 190 mm hole, which may solve hole shrink age in long gypsum salt bed an

关 键 词：下川东 震旦系气井 复杂处理 井漏 膏盐层 定向 

分 类 号：TE37[石油与天然气工程—油气田开发工程]