摘要
南川区块页岩气资源丰富,平桥、东胜两个构造带目前已探明储量近2000×10^(8) m^(3),以常压页岩气藏为主,构造、应力双复杂,资源品质相对较差。受保存条件、埋深、地应力、复杂构造、裂缝发育不均以及压裂改造效果的影响,同平台单井产能差异较大,部分井测试产量、产能、单井EUR(最终可采储量)未达预期,极大地限制了规模上产和效益开发。开展地质、开发、工程多维度典型井生产效果对比分析,认为在资源落实区,地层压力系数、天然缝网发育程度、局部复杂构造、地应力是影响常压页岩气开发的主要因素。压力系数表征了地层的驱动能量,一定程度的天然缝网可有效改善开发效果。局部复杂构造导致优质页岩钻遇率低,挤压变形,埋深增加,水平段方位与最小主应力方位夹角过大产生的应力增加,会在一定程度上限制人造缝网的复杂程度。根据主控因素平面差异分布特征,甜中选优,局部优化调整是提高常压页岩气开发效果的基础。
Nanchuan Block is rich in shale gas resources,and the proven reserves of Pingqiao and Dongsheng structural belts are nearly 2000×10^(8) m^(3),mainly in normal pressure shale gas reservoir,with complex structure and stress,and relatively poor resource quality.Affected by the preservation conditions,burial depth,in-situ stress,complex structure,uneven fracture development and fracturing effect,the productivity of single wells on the same platform is quite different,and the test production,productivity and single well EUR of some wells have not been able to meet the expectation,all these above greatly limit the scale production and benefit development.By the comparative analysis of production effects of typical wells in geology,development and engineering,it is considered that formation pressure coefficient,development degree of natural fracture network,local complex structure and insitu stress are the main factors affecting normal pressure shale gas development in resource implementation area.The pressure coefficient represents the driving energy of the formation,and a certain degree of natural fracture network can effectively improve the development effects.The local complex structure leads to a low drilling rate of high-quality shale,and the stress increase caused by extrusion deformation,deepening burial depth and excessive angle between horizontal section azimuth and minimum principal stress azimuth will limit the complexity of artificial fracture network to a certain extent.According to the plane difference distribution characteristics of main controlling factors,the basis of improving the development effects of normal pressure shale gas is to select the best from sweet spot and adjust the local optimization.
作者
胡春锋
梅俊伟
李仕钊
卢比
马军
钱劲
HU Chunfeng;MEI Junwei;LI Shizhao;LU Bi;MA Jun;QIAN Jin(Research insititute of Exploration and Development,Sinopec East China Oil and Gas Company,Nanjing,Jiangsu 210000,China;Sinopec Chongqing Shale Gas Co.,Ltd.,Chongqing 408400,China)
出处
《油气藏评价与开发》
CSCD
2021年第4期559-568,共10页
Petroleum Reservoir Evaluation and Development
基金
中国石化科技开发部项目“四川盆地及周缘常压页岩气勘探开发关键技术研究”(P21087-4)。
关键词
常压页岩气
压力系数
裂缝发育程度
地应力
开发效果
normal pressure shale gas
pressure coefficient
fracture development degree
crustal stress
development effect
