鄂尔多斯盆地低渗透岩性气藏型地下储气库地质评价关键技术  

Key technologies for geological evaluation of UGSs rebuilt from low-permeability lithological gas reservoirs in the Ordos Basin

作　　者：张建国[1,2] 夏勇[1,2] 赵晨阳[1,2] 王蕾蕾[1,2] ZHANG Jianguo;XIA Yong;ZHAO Chenyang;WANG Leilei(Exploration and Development Research Institute,PetroChina Changqing Oilfield Company,Xi'an,Shaanxi 710018,China;National Engineering Laboratory of Low-permeability Oil&Gas Exploration and Development,Xi'an,Shaanxi 710018,China)

机构地区：[1]中国石油长庆油田公司勘探开发研究院 [2]低渗透油气田勘探开发国家工程实验室

出　　处：《天然气工业》2023年第10期55-63,共9页Natural Gas Industry

摘　　要：鄂尔多斯盆地是我国最大的天然气生产基地和陆上管网枢纽中心,具有优越的地下储气库(以下简称储气库)建库地质资源、地理位置和气源等优势。为解决低渗透强非均质岩性气藏侧向封闭不明确、单井产能低等带来的储气库选址评价难、方案优化设计难等诸多问题,开展了岩溶型碳酸盐岩气藏和辫状河三角洲砂岩气藏侧向封闭性评价、碳酸盐岩储层裂缝表征与三维地质建模、大面积强非均质气藏局部甜点建库模式优化以及储气库注采井网优化设计等研究,并形成了低渗透岩性气藏型储气库地质评价关键技术。研究结果表明:①碳酸盐岩气藏侵蚀沟槽形成地层遮挡、致密层形成岩性遮挡,侧向封闭性良好,砂岩气藏储层内部阻流带发育、压力波及范围有限,设置过渡带可以实现边界的动态封闭;②裂缝是低渗透气藏的主要渗流通道,其精细表征是裂缝型碳酸盐岩气藏优化注采井位部署和储气库快速达容达产的基础;③核心注采区、中间过渡区、外围监测区的“三区带”建库模式,可以有效提升气库运行效率、降低天然气外溢风险;④基于强非均质气藏的储层地质特点优化注采气井井网井型,能够降低施工风险、提高气井产能和库容控制。结论认为,形成的低渗透岩性气藏型储气库地质评价关键技术有效解决了储气库选址和设计等难题,支撑了鄂尔多斯盆地气藏储气库的建设,为同类型低渗透岩性气藏改建储气库提供了有益参考和借鉴。The Ordos Basin is widely recognized as the largest natural gas production base and an onshore gas pipeline network hub in China.It has advantages in geological resources,geographical location and gas sources for the construction of underground gas storage(hereinafter referred to as UGS).The lithological gas reservoirs with low permeability and strong heterogeneity have an unclear lateral sealing capacity and a low single-well productivity,which bring challenges to UGS site selection and evaluation and scheme optimization and design.In order to solve these problems,this paper evaluates the lateral sealing capacity of karst carbonate gas reservoirs and braided river delta sandstone gas reservoirs,characterizes the fractures in carbonate reservoirs,and performs three-dimensional geological modeling.A UGS construction model of local sweet spot in large,strongly heterogeneous gas reservoirs and the design of injection–production well patterns are optimized.In addition,key technologies for geological evaluation of UGSs rebuilt from low-permeability lithological gas reservoirs are developed.And the following research results are obtained.First,carbonate gas reservoirs exhibit a good lateral sealing capacity with erosional groove as the stratigraphic barrier and tight layer as the lithological barrier.Sandstone gas reservoirs have developed internal flow blocking zones,which result in limited pressure range,so the dynamic sealing of boundaries can be achieved by setting transition zones.Second,fractures are the primary seepage channels in low-permeability gas reservoirs.Therefore,the fine characterization of fractures lays a foundation for optimizing the deployment of injection and production wells in fractured carbonate gas reservoirs and ensuring the rapid achievement of UGS capacity and production.Third,the"three-zone"UGS construction model,which involves injection and production in the core zone,transition in the intermediate zone and monitoring in the peripheral zone,can effectively improve UGS's operation effici

关 键 词：鄂尔多斯盆地 地下储气库 低渗透 岩性气藏 侧向封闭性 甜点区优选 水平井 

分 类 号：TE972.2[石油与天然气工程—石油机械设备]