吉华1地区潜山变质岩储层裂缝发育特征及综合评价

天然裂缝是吉华1潜山变质岩储层重要储集空间和主要的渗流通道，其发育程度影响着潜山油气运移、聚集、保存和单井产能。利用岩心、薄片以及成像测井等资料，对吉华1潜山变质岩储层裂缝的分布特征进行了定量表征，明确了影响研究区变质岩储层裂缝发育的主控因素，最后运用多信息融合和数值模拟等方法对裂缝的分布进行了综合评价。吉华1潜山变质岩储层主要发育以中-高角度为主的构造裂缝，裂缝大多未充填或半充填，裂缝有效性好。岩心宏观裂缝线密度主要分布在8~14条/m之间，平均为12.39条/m。宏观裂缝孔隙度大多分布在0%~2%，微观裂缝孔隙度大多分布在0.6%~1.2%。宏观和微观裂缝增加了研究区变质岩储层的储集空间，同时增强了储层的连通性，充当油气充注的运移通道。岩石矿物成分和断层是影响研究区裂缝发育的主要因素。浅色矿物中的裂缝线密度高于深色矿物，同时随着距断层距离的增大，裂缝的线密度明显降低，裂缝的线密度随着距断面距离的增加呈负指数函数递减的趋势。通过岩心和成像测井标定，建立了多信息融合的常规测井裂缝识别方法，裂缝发育段比值与岩心裂缝密度正相关，裂缝识别吻合率达64.02%。结合应力场数值模拟，对裂缝分布规律进行综合评价。

Fracture development characteristics and comprehensive evaluation of buried hill metamorphic reservoir in Jihua 1 area

Natural fractures are important reservoir space and main seepage channel of metamorphic rock reservoir in Jihua 1 buried hill, and their development degree affects the migration, accumulation, preservation and productivity of buried hill oil and gas. Based on core, thin section and imaging logging data, the fracture distribution characteristics of metamorphic rock reservoir in Jihua 1 buried hill were quantitatively characterized, and the main controlling factors affecting the fracture development of metamorphic rock reservoir in the study area were identified. Finally, the fracture distribution was comprehensively evaluated by using multi-information fusion and numerical simulation methods. The buried hill of Jihua 1 metamorphic rock is mainly developed with medium-high dip angle structural fractures, which are mostly unfilled or half-filled and have good effectiveness. The macroscopic fracture linear density of core is mainly distributed between 8~14 fractures per meter, with an average of 12.39 fractures per meter. The macroscopic fracture porosity is mostly in 0~2%, and the microscopic fracture porosity is mostly in 0.6%~1.2%. Macro and micro fractures increase the reservoir space of the metamorphic rocks in the study area and enhance reservoir connectivity, acting as migration channels for oil and gas charging and expulsion. Rock mineral composition and fault are the main factors affecting fracture development in the study area. The fracture linear density in light minerals is higher than that in dark minerals. At the same time, the linear density of fractures decreases obviously with the increase of the distance from the fault. Through core and imaging logging calibration, a conventional logging fracture identification method based on multi-information fusion was established. The ratio of fracture development segments is positively correlated with core fracture density, and the coincidence rate of fracture identification reaches 64.02%. Combined with the numerical simulation of stress field, the fracture distribution is evaluated comprehensively.