鄂尔多斯盆地东南部致密砂岩气勘探开发关键技术创新及规模实践

Innovation and scale practice of key technologies for the exploration and development of tight sandstone gas reservoirs in Yan’an Gas Field of southeastern Ordos Basin

为了落实鄂尔多斯盆地东南部致密砂岩气成藏规律,解决陕西延长石油(集团)有限责任公司延安气田规模效益建产难题;采用产、学、研、用一体化联合攻关思路,多学科开展了盆地东南部上古生界沉积—储层—成藏地质理论研究,并在基于动态知识库的储层预测、混合井网立体动用模式、气藏动态优化调整等关键技术方面开展了系统研究,取得了地质理论和开发关键技术创新进展,总体实现规模效益建产。研究结果表明:①明确了盆地东南部二叠纪时期为三角洲前缘沉积,浅水环境岸线频繁迁移控制储集砂体发育,建立了致密砂岩气优质储层“甜点”发育模式;②形成了基于多要素、全过程天然气运聚模拟的目标优选技术,高效指导了勘探有利区的优选;③基于动态知识库提高了有效储层预测可靠性,建立了基于井网要素差异化设计的混合井网立体动用技术;④形成了以压力跟踪和产量智能优化为核心的气藏开发动态优化技术,实现了延安气田的规模有效动用和长期稳产。结论认为,取得的系列地质理论新认识和开发关键技术,支撑了延安气田7635×10^(8)m^(3)天然气探明储量发现和71.4×10^(8)m^(3)/a的产能建设,且为类似致密气藏勘探开发提供了借鉴,为保障国家能源安全做出了重要贡献。

In order to figure out the accumulation law of tight sandstone gas in the southeastern Ordos Basin and solve the problems in the large-scale benefit productivity construction of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,this paper carries out multidisciplinary studies on the geological theories of Upper Paleozoic sedimentation-reservoir-hydrocarbon accumulation in the southeastern Ordos Basin following the research idea of integrated production,learning,study and application.Then,key technologies are systematically studied,such as reservoir prediction based on dynamic knowledge base,three-dimensional production mode of hybrid well pattern,and dynamic optimization and adjustment of gas reservoirs.Thus,geological theories and key development technologies are innovatively improved and large-scale benefit productivity construction is achieved overall.And the following research results are obtained.First,it is determined that it was a deposit of delta front in the southeastern Ordos Basin during the Permian and the shoreline of the shallow water environment migrated frequently then,which controlled the development of reservoir sandbodies.A"sweet spot"development model of high-quality tight sandstone gas reservoir is established.Second,a target optimization technology based on multi-element full-process natural gas migration and accumulation simulation is developed,which provides efficient guidance for the selection of favorable exploration areas.Third,the prediction reliability of effective reservoir is improved based on dynamic knowledge base,and the hybrid well pattern for three-dimensional production technology based on the differentiated design of well pattern elements is established.Fourth,the dynamic optimization technology of gas reservoir development taking pressure tracking and intelligent production optimization as the cores is de-veloped.As a result,the scale effective production and long-term stable production is realized in Yan'an Gas Field.In conclusion,the new understanding of a series of geological theories and the application of key development technologies provide a support for the discovery of natural gas proved reserves of 7635×10^(8) m^(3) and the productivity construction of 71.4×10^(8) m^(3)/a in Yan'an Gas Field,as well as a refer-ence for the exploration and development of similar tight gas reservoirs and make an important contribution to national energy security.