不同岩性裂缝油气藏定量表征关键技术

Key techniques for quantitative characterization offractured reservoirs with different lithology

由于海上不同岩性裂缝油气藏的裂缝成因不同、发育规律比较复杂,难以定量预测裂缝。根据油气藏裂缝发育特征,应用多种研究方法,提出不同岩性裂缝油气藏定量表征关键技术:①砂砾岩裂缝油气藏定量表征技术,把沉积演化模拟和目标模拟相结合,预测砾内缝展布范围,实现砂砾岩微裂缝定量表征。②变质岩裂缝油气藏定量表征技术,在建模中引入非结构化网格剖分,实现大、中、小尺度裂缝及其与基质间耦合关系的精细表征。③碳酸盐岩油气藏定量表征技术,在开展多信息多手段融合储层评价基础上,应用双模迭代技术定量表征微裂缝分布。渤海3个油气田的应用结果表明,这一系列表征技术在开发方案研究中提供了坚实的定量依据,数值模拟拟合精度提高20%左右,在油田调整中成功指导10余口开发井高效实施,为类似裂缝油气藏的高效开发提供借鉴。

It is difficult to predict fractures quantitatively due to the different fracture genesis and complex development laws of fractures in offshore fractured oil and gas reservoirs with different lithologies.Techniques for quantitative characterization of fractured reservoirs with different lithology were proposed by many research methods based on fracture development characteristics of reservoirs:①Quantitative characterization technique of fractured glutenite reservoirs:the sedimentary evolution simulation and target simulation are combined to predict the distribution range of intra-gravel fractures and quantitatively characterize the micro-fractures of glutenite fractured reservoirs.②Quantitative characterization technique of fractured metamorphic rock reservoirs:an unstructured mesh subdivision was introduced in modeling to quantitatively characterize the large,medium and small fractures and their coupling relationships with matrix.③Quantitative characterization technique of carbonate reservoirs:the dual-mode iteration technique was used to quantitatively characterize the distribution of microfractures on the base of the multi-information and multimeans reservoir evaluation.The application of these techniques in three oil and gas fields in Bohai Sea shows that these characterization techniques provide a solid quantitative basis in the study on development schemes,with numerically simulated fitting accuracy improved by about 20%.These techniques have successfully guided the efficient implementation of more than 10 development wells during oilfield adjustment,providing a reference for efficient development of similar fractured reservoirs.