延长探区古生界页岩气水平井一次上返高效封隔固井技术  

High-efficiency sealing and cementing technology of Paleozoic shale gas horizontal wells in Yanchang exploration area

作　　者：王涛 申峰 杨超 王海柱[3] 杨谋[4] 窦倩 石鲁杰 WANG Tao;SHEN Feng;YANG Chao;WANG Haizhu;YANG Mou;DOU Qian;SHI Lujie(Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an 710075,China;Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation,Xi’an 710075,China;China University of Petroleum(Beijing),Beijing 102249,China;Southwest Petroleum University,Chengdu 610500,China;Xinjiang Xinchun Petroleum Development Co.,Ltd.,Sinopec,Xinjiang Tacheng 834700,China)

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,西安710075 [2]陕西省陆相页岩气成藏与开发重点实验室,西安710075 [3]中国石油大学(北京),北京102249 [4]西南石油大学,成都610500 [5]中石化新疆新春石油开发有限责任公司,新疆塔城834700

出　　处：《非常规油气》2023年第1期122-129,共8页Unconventional Oil & Gas

基　　金：国家科技重大专项课题“陆相页岩气水平井高效低成本钻完井技术”(2017ZX05039003);延长石油科技项目“化子坪油区CO_(2)注采井水泥环封隔失效机理、评价及预测技术”(ycsy2022jcts-B-19);陕西省自然科学基础研究计划项目“改性碳纳米管开发功能性油井水泥浆研究”(2022KJXX-31)。

摘　　要：为提高延长探区古生界页岩气易漏水平井固井质量和水泥环层间封隔效果,在详细分析技术难点的基础之上,通过注替工艺、水泥浆体系及封隔能力评价方法创新,形成了系列固井技术,并进行了两口井现场实施。结果表明:1)陆相页岩气水平井最优化注水泥浆柱结构为钻井液/隔离顶替浆/冲洗液/低密度水泥浆/常规密度水泥浆,可提高顶替效率;2)选取国产人造微珠A为减轻材料、微硅为体系的稳定剂,可研制体系配方“油井水泥+77%微珠+35%微硅+4.0%降失水剂+10%早强剂”,最低可配置密度为0.95 g/cm^(3);3)采用尿素改性碳纳米管配置纳米封隔水泥浆,与未改性碳纳米管体系相比,抗压强度、抗拉强度分别提高32.3%和36.4%;4)采用三轴应力加载装置,对改性碳纳米管加量为0.04%的水泥环进行封隔能力测试,在110 MPa套管内压、11次循环加载作用下,水泥环的密封性仍然保持完好。该技术可以提高水平井一次上返固井成功率和水泥环压后完整性,为区域高效开发提供支撑,也为同类井固井提供了借鉴。In order to improve the cementing quality of leaky horizontal wells and the sealing effect between the cement rings of the Paleozoic shale gas in the Yanchang exploration area,based on the detailed analysis of technical difficulties,a series of cementing technologies had been formed by the injection replacement technology,the cement slurry systemand the sealing ability evaluation method.And then,two wells had been implemented.The results showed that:1)The optimal cementing slurry column structure for continental shale gas horizontal wells was drilling fluid/isolation displacement slurry/flushing fluid/low density cement slurry/conventional density cement slurry,which can improve displacement efficiency.2)The domestic artificial microbead A had been selected as the lightening material and microsilica as the stabilizer of the system to develop system formula.The formula was“oil well cement+77% microbeads+35% microsilica+4.0% fluid loss reducer+10% early strength agent”and the minimum configurable density was 0.95 g/cm^(3).3)Compared with unmodified carbon nanotube system,the compressive strength and tensile strength of nano-sealing cement slurry with urea-modified carbon nanotubes had been increased by 32.3% and 36.4%.4)A triaxial stress loading device had been used to test the sealing capacity of the cement sheath with the addition of 0.04% modified carbon nanotubes.The sealing performance of the cement sheath remained intact under the condition of 110 MPa casing internal pressure and 11 cycles of loading.This technology can improve the cementing success rate of horizontal wells and the integrity after cement ring pressure,which had provided support for efficient regional development and reference for similar cementing wells.

关 键 词：浆柱结构 低密度 改性碳纳米管 评价装置 纳米封隔 

分 类 号：TE256[石油与天然气工程—油气井工程]