渤海深层变质岩潜山油藏裂缝主控因素及预测

渤中13-2大型潜山地区是渤海海域发现的首个亿吨级深层变质岩潜山油藏。通过已钻井的岩心、薄片、测试、测井等资料，从构造演化、成岩作用、古地貌特征等方面，阐述了研究区潜山储集空间类型、裂缝发育主控因素及分布规律，为研究区的高效开发奠定基础。研究结果表明：①多期次构造运动是导致裂缝形成的主控因素，风化淋滤和裂缝充填是造成储层纵向差异的主要原因。②利用结构张量场与绕射波耦合属性可以有效指导研究区储层平面预测，根据最大似然属性体能够较好地预测潜山裂缝走向。③平面上靠近大断层附近裂缝发育较好，纵向上风化带裂缝好于内幕带裂缝，渤中13-2地区主力层段风化带储层可划分为4类，Ⅰ类储层最好，主要位于构造高部位；Ⅱ类储层次之，主要位于构造腰部； Ⅲ类储层较差，主要位于距离断层较近区域的构造翼部； Ⅳ类储层最差，主要位于距离大断层较远处。

Main controlling factors and prediction of fractures in deep metamorphic buried hill reservoirs in Bohai Sea

Bozhong 13-2 area is the first deep metamorphic buried hill reservoir with 100 million-ton reserves discovered in Bohai Sea. Based on the data of drilled cores，thin sections, test and logging, the buried hill reservoir space，main controlling factors and distribution of fractures in the study area were expounded from the aspects of structural evolution，diagenesis and paleogeomorphic characteristics，which lays a foundation for the efficient development of the study area. The results show that： （1）Multi-stage tectonic movements are the main controlling factors of fracture formation，weathering， leaching and fracture filling are the main reasons for the vertical difference of reservoirs.（2）The coupling properties of structure tensor field and diffraction wave can effectively guide the prediction of reservoir on the plane in the study area， and the maximum likelihood attributes can be used to effectively predict the fracture trend in buried hills.（3）The fractures are well developed near the large faults on the plane， and the fractures developed in the weathered zone are better than those in the inner zone in the vertical direction. The reservoirs in the weathered zone of Bozhong 13-2 area can be divided into four types. The type Ⅰ reservoirs are the best and mainly located in the high parts of the structure，type Ⅱ reservoirs are mainly located at the waist of the structure，type Ⅲ reservoirs are mainly located in the structural wings near the faults, and type Ⅳreservoirs are the poorest and mainly located far away from the large faults.