王龙庄油田天83断块低孔低渗储层裂缝识别及建模验证

Fracture identification and the model validation of low porosity and low permeability reservoir of Tian 83 block,Wanglongzhuang Oilfield

裂缝性低渗透砂岩油藏的非均质性、渗流特征复杂多变,给油藏的开发和管理带来较大难度.天83断块储层为常规的低孔低渗储层,储层内以人工裂缝为主.结合岩心、测井、微观、动态等地质与开发资料,发现研究区存在大量非人工裂缝,并采用构造、沉积约束裂缝的方法对裂缝的方向性、发育规律及发育程度进行研究,认为裂缝以北东向的低角度不规则裂缝为主,裂缝开度为20～100μm,靠近南部和北部断层附近,裂缝发育较密集.针对以上特征,建立了裂缝的离散网络模型（DFN 模型）,来验证前期裂缝识别的准确性,较为准确地预测研究区平面裂缝的分布及属性,并形成了-套针对该类油藏裂缝的地质、测井、地震、开发相结合的描述识别方法及相应的模型验证方法,为研究区后续的开发提供有效的依据.

Fractured low permeability sandstone reservoir is complex in reservoir heterogeneity and seepage characteristics,so reservoir development and management are difficult.Predecessors believed that Tian 83 was a conventional reservoir of low permeability and the artificial fracture was the main fracture in reservoir.Combination with the geological and development data such as core,logging,microscopic,and dynamic,many artificial fracture were found in the study area.The fracture direction,rule and degree of development were conditioned to sedimentary and tectonic factors and thought that north-east is the main direction of the fracture,the fracture aperture is 20-100μm,the fracture network is comparatively dense near the northern fault.According to these data,the fracture model of Discrete Fracture Network(DFN model)were established,the distribution of fractures in the study area were relatively accurate predicted and the accuracy of the fracture identification was verified.A set of discriminating method combining geology,logging and development suitable for this kind of reservoir and the corresponding method of model validation were formed,which provide effective basis for the subsequent development of study area.