滨里海盆地东缘北特鲁瓦油田石炭系碳酸盐岩储层裂缝网络连通性评价

Connectivity of fracture networks of Carboniferous carbonate reservoirs in North Truva Oilfield,eastern margin of Precaspian Basin

基于岩心、成像测井及裂缝网络建模结果,应用拓扑学理论,对滨里海盆地东缘北特鲁瓦油田石炭系碳酸盐岩储层裂缝网络的连通性进行了评价,并分析了其对油田开发的影响。研究结果表明:(1)滨里海盆地东缘北特鲁瓦油田石炭系碳酸盐岩储层裂缝切割类型可划分为高高切割、高低切割和低低切割,研究区A2,A3,G1,G2,G3及G4小层裂缝切割较为发育,且主要分布在构造高部位。(2)裂缝网络连通性可通过连通体面积占比、裂缝体密度、裂缝的平均长度和平均节点数4个参数进行定量评价,根据连通体面积大小、裂缝体密度大小及裂缝类型可对裂缝连通体进行定性分析和命名,研究区A2小层主要发育低低大连通体、高中大连通体和高高大连通体。(3)裂缝网络连通性和储层物性的耦合作用是油田水窜的原因,裂缝网络连通性主要与裂缝长度和裂缝体密度有关。

Based on the data of core,imaging logging,and fracture network modeling,topology theory was ap-plied to evaluate the connectivity of fracture networks of Carboniferous carbonate reservoirs in North Truva Oil-field,the eastern margin of Precaspian Basin,and its impacts on oilfield development were analyzed.The results show that:(1)The types of fracture cutting of Carboniferous carbonate reservoirs in North Truva Oilfield of east-ern margin of Precaspian Basin can be divided into high-high cutting,high-low cutting,and low-low cutting.The fracture cutting in the sublayers A2,A3,G1,G2,G3,and G4 is relatively developed and mainly distri-buted in the high structural parts.(2)The connectivity of fracture networks can be quantitatively evaluated through four parameters:the proportion of connected area,fracture fracture volume density,average length of fractures,and average number of nodes.The connected area,fracture volume density,and fracture type can be used to qualitatively analyze and name the fracture connected units.The sublayer A2 in the study area mainly de-velops low-low large connected units,high-medium large connected units,and high-high large connected units.(3)The coupling effect of fracture network connectivity and reservoir properties is the origin of oilfield water channeling,and fracture network connectivity is mainly related to fracture length and fracture volume density.