摘要
鄂尔多斯盆地西部的乌拉力克组海相页岩气藏有利含气富集区面积达9000 km^(2),但气藏埋藏较深,地层压力系数低,且总有机碳含量与含气性等指标较低,压裂提产的难度较大。为此,分析了乌拉力克组页岩气储层地质特征和压裂技术难点,针对该类深层海相页岩气储层裂缝延伸和加砂难度大的问题,优化多段少簇裂缝设计,同时将井筒井口压力等级提高至140 MPa;针对低压条件下大液量压后连续排采的要求,通过增加液氮伴注或者前置液态CO_(2)增加地层能量,室内模拟和矿场数据拟合优化了压后控压排液生产制度。开展了直井高压混合压裂、水平井分段多簇增能体积压裂现场试验,单井压裂用液强度、加砂量及排量等关键参数达到四川页岩气水平,井下微地震监测裂缝带长579 m、带宽266 m,试气无阻流量直井突破10×10^(4) m^(3),水平井超过20×10^(4) m^(3),实现了大规模体积改造提高产量的目的。鄂尔多斯盆地海相深层页岩气压裂技术为该地区页岩气勘探开发提供了技术支持。
The marine shale gas reservoir of Wulalike Formation in the western Ordos Basin covers a favorable gas enrichment area of approximately 9,000 km^(2).However,the reservoir is deep buried,has a low formation pressure coefficient,and exhibits low indicators in terms of total organic carbon content(TOC)and gas-bearing properties,making hydraulic fracturing for production more challenging.This work conducted a comparison and analysis of geological characteristics and fracturing difficulties of Wulalike shale gas,and the problem of fracture propagation and sand-adding of deep marine shale gas has been solved by optimizing more stages and fewer clusters fractures and upgrading the wellhead pressure level to 140 MPa.In response to the requirement of continuous drainage after fracturing with large liquid volume under low formation pressure conditions,by liquid nitrogen injection or pre-loading liquid CO_(2) to enhance formation energy,the post-fracturing pressure-controlled drainage production system was optimized through laboratory simulation and field data fitting.On site tests of high-pressure hybrid fracturing of vertical wells and multi-cluster energized volume fracturing technology of horizontal wells were conducted,the key parameters such as operation liquid capacity,sand amount,and discharge rate of energized fracturing of horizontal wells have reached the level of shale gas in Sichuan.The length and width of fracture zone is 579 m and 266 m according to the microseismic monitoring results,respectively.The absolute open flow has exceeded 10×10^(4) m^(3) for vertical wells and 20×10^(4) m^(3) for horizontal wells,suggesting that the production has been improved with large scale volume stimulation.The hydraulic fracturing technology for deep marine shale in Ordos Basin has provided technical support for the exploration and development of shale in Ordos Basin.
作者
赵振峰
王文雄
徐晓晨
叶亮
李鸣
ZHAO Zhenfeng;WANG Wenxiong;XU Xiaochen;YE Liang;LI Ming(PetroChina Changqing Oilfield Company,Xi’an,Shaanxi,710018,China;Oil and Gas Technology Research Institute,PetroChina Changqing Oilfield Company,Xi’an,Shaanxi,710018,China;National Engineering Laboratory for Exploration and Development of Low Permeability Oil&Gas Fields,Xi’an,Shaanxi,710018,China)
出处
《石油钻探技术》
CAS
CSCD
北大核心
2023年第5期23-32,共10页
Petroleum Drilling Techniques
基金
国家科技重大专项“鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程”(编号:2016ZX05050)资助。
关键词
页岩气
水平井
体积压裂
增能压裂
控压排液
鄂尔多斯盆地
shale gas
horizontal well
volume fracturing
energized fracturing
managed pressure drainage
Ordos Basin
