塔里木盆地库车山前超深气井砂垢堵塞成因及靶向解除技术  

Formation mechanism and targeted descaling technology of sand-scale composites in ultra-deep gas wells in the Kuqa piedmont of the Tarim Basin

作　　者：曹立虎[1,2,3,4] 江同文 潘昭才 孙涛[1,2,3,4] 张宝[1,2,3,4] 吴红军 易俊[1,2,3,4] CAO Lihu;JIANG Tongwen;PAN Zhaocai;SUN Tao;ZHANG Bao;WU Hongjun;YI Jun(PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China;CNPC R&D Center for Ultra-deep Complex Reservoir Exploration and Development,Korla,Xinjiang 841000,China;Xinjiang Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development,Korla,Xinjiang 841000,China;Xinjiang Key Laboratory of Ultra-deep Oil and Gas,Korla,Xinjiang 841000,China;PetroChina Company Limited,Beijing 100010,China)

机构地区：[1]中国石油塔里木油田公司 [2]中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心 [3]新疆维吾尔自治区超深层复杂油气藏勘探开发工程研究中心 [4]新疆超深油气重点实验室 [5]中国石油天然气股份有限公司

出　　处：《天然气工业》2024年第8期85-94,共10页Natural Gas Industry

基　　金：中国石油天然气股份有限公司油气和新能源分公司科技项目“三高井完整性风险量化评价技术研究与现场试验”(编号:2022KT1904);中国石油天然气股份有限公司塔里木油田公司科技项目“采油气提产稳产关键技术研究与试验”(编号:T201919)。

摘　　要：塔里盆地库车山前超深气田是西气东输主力气源地,具有超高温、超高压、高矿化度、储层裂缝非均质性强等特征,气井生产过程中砂垢堵塞问题突出,据统计最高影响气田产能达800×104 m^(3)/d。为实现超深气井高效解堵,通过气水两相结垢热力学预测模型、裂缝性储层岩石力学实验、井筒内气液固流动模拟等研究,揭示了超深气井砂垢复合堵塞成因,并形成了靶向解堵复产关键技术。研究结果表明:①“高温流动压降结垢、裂缝面破裂出砂”是超深气井出砂结垢的内在机理;②结垢固化松散砂桥形成复合堵塞是气井堵塞减产的主要原因,其中靶向除垢是解堵复产的关键所在;③靶向除垢解堵区域为井筒变径处和井周5 m内基质—裂缝系统,气井堵塞率30%~60%为最佳解堵时机;④非酸性除垢解堵液相比常用的酸性解堵液,在同级别溶垢能力的基础上,腐蚀速率降至0.49 g/(m^(2)·h),可同时满足低腐蚀和高效除垢的技术要求。结论认为,形成的超深气井靶向除垢解堵技术在塔里木盆地库车山前超深气田规模应用159井次,有效率达93.3%,累计增产天然气75.08×10^(8)m^(3),已成为西气东输主力气井快速解堵复产的“冬保良方”,可为国内外同类气田解堵复产提供技术借鉴。The ultra-deep gas field in the Kuqa piedmont of the Tarim Basin is the main gas source for the West-East Gas Pipeline,and it is characterized by ultra-high temperature,ultra-high pressure,high salinity,strong heterogeneity of reservoir fractures,etc.The problem of sand-scale composite is prominent during the production of gas wells,with the impact on the production capacity of gas field up to 800×104 m3/d.To achieve efficient descaling in ultra-deep gas wells,this paper reveals the formation mechanisms of sand-scale composite in ultra-deep gas wells using the thermodynamic prediction model of gas-water two-phase scaling,the rock mechanics experiments of fractured reservoirs,and the simulation of gas-liquid-solid flow in wellbore,and accordingly develops the key technologies for targeted descaling and production restoration.And the following research results are obtained.First,scaling along with flow pressure drop at high temperature and sand production due to fracturing of fracture surface are the internal formation mechanisms of the sand-scale composites in ultra-deep gas wells.Second,the formation of sand-scale composites due to the scale solidification and unconsolidated sand bridges is the main reason for the blockage and production reduction of gas well,and the targeted descaling technology is the key to descaling and production restoration.Third,the targeted descaling area is the wellbore diameter variation area and the martrix-fracture system within 5 m around the wellbore,and the optimal descaling occasion occurs when the gas well blockage rate is between 30%and 60%.Fourth,compared with the commonly used acidic descaling solutions,non-acidic descaling solutions have a corrosion rate of 0.49 g/(m^(2)·h)at the same level of descaling ability,which can meet the technical requirements of low corrosion rates and high descaling efficiency.In conclusion,the established targeted descaling technology for ultra-deep gas wells has been applied 159 well times in the ultra-deep gas field in the Kuqa piedmont of the

关 键 词：塔里木盆地 库车山前超深层 高温流动压降结垢 裂缝性储层出砂 砂垢复合堵塞 非酸性靶向除垢解堵 

分 类 号：TE37[石油与天然气工程—油气田开发工程]