超深井多压力系统一次性上返固井技术  

OneTrip Cementing Technology for Ultra-deep Well with Multiple Pressure Systems

作　　者：丁志伟 阳强 李成全[3] 李斌[4] 徐明 周琛洋 DING Zhiwei;YANG Qiang;LI Chengquan;LI Bin;XU Ming;ZHOU Shenyang(CNPC Engineering Technology R&D Co.,LTD.,Beijing 102206,China;Sichuan Shale Gas Exploration and Development Co.,LTD.,Chengdu,Sichuan 610056,China;Development Department,PetroChina Southwest Oil and Gas Field Company,Chengdu,Sichuan 610017,China;Engineering Technology Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu,Sichuan 610017,China)

机构地区：[1]中国石油集团工程技术研究院有限公司 [2]四川页岩气勘探开发有限责任公司 [3]中国石油西南油气田分公司开发事业部 [4]中国石油西南油气田公司工程技术研究院

出　　处：《钻采工艺》2021年第6期31-35,共5页Drilling & Production Technology

基　　金：中国石油天然气集团有限公司“深层与复杂地层钻完井新技术新方法研究”课题4“复杂工况条件下深井固井密封力学机理及控制技术研究”(编号:2019A-3910)。

摘　　要：针对西南油气田风险探井双探6井采用Φ177.8 mm+Φ184.15 mm尾管固井存在井深达7833 m、封固段长达4585 m、安全密度窗口窄(0.05 g/cm^(3))、漏失层分布广、气层显示活跃、温差大(74℃)、油基钻井液与水泥浆相容性差等固井难题,通过采用精细控压平衡法固井工艺设计、固井前降低钻井液密度、设计防漏防窜的浆柱结构、优化三凝高强防窜大温差水泥浆体系等固井工艺技术措施,解决了窄密度窗口下长封固段水泥浆一次性上返难、封固段顶部水泥浆强度发展慢等技术难题。其中,领浆顶部静胶凝43 h起强度,中间浆顶部静胶凝29.9 h起强度,尾浆底部静胶凝5.8 h起强度,水泥浆综合性能满足固井施工要求。固井质量合格率90.4%,优质率47.9%,创造了川渝地区Φ241.3 mm井眼固井套管最长、井斜角最大、窗口密度最窄等多项新纪录,为西南油气田超深井窄密度窗口长封固段固井提供了技术支撑。In view of such cementing problems encountered in Φ177.8 mm+Φ184.15 mm liner cementing in risk exploration Well Shuangtan 6 of Southwest Oil and Gas Field Company as well depth of 7833 m,sealing section of 4585 m,narrow density window of 0.05 g/cm^(3),wide distribution of leakage layers,gas-layer activity,temperature difference of 74℃,poor compatibility between oil-based drilling fluid and cement slurry,the cementing technology measures such as cementing design of the precise managed pressure balance method,reducing drilling fluid density before cementing,designing slurry column structure to prevent leakage and channeling,optimizing cement slurry system with triple setting,high strength,channeling prevention and large temperature difference,etc,the technical problems such as the one-time upturn difficulty of cement slurry in long sealing section under narrow density window and the slow development of cement slurry strength at the top of sealing section have been overcome.The results of the optimization experiment are as follows:the static gelling strength at the top of the column slurry is 43 h,the static gelling strength at the top of the intermediate slurry is 29.9 h,and the static gelling strength at the bottom of the tail slurry is 5.8 h.The comprehensive performance of cement slurry meets the cementing requirements.The qualified rate of cementing quality is 90.4%,and the excellent rate is 47.9%.It has created many new records such as the longest casing,the largest inclination angle and the narrowest density window in Φ241.3 mm hole cementing in Sichuan-Chongqing region,which provides technical support for ultra-deep well with narrow density window and long sealing segment cementing in Southwest Oil and Gas Field Company.

关 键 词：超深井 尾管固井 精细控压 密度窗口窄 长封固段 

分 类 号：TE256[石油与天然气工程—油气井工程]