基岩油气藏裂缝性储层的成像测井评价及裂缝预测

Evaluation of imaging logging and fracture prediction in fractured basement reservoirs

基岩油气藏裂缝性储层具有复杂的储集空间和储层非均质性,为了实现对基岩油气藏的储层精细评价和裂缝预测,以岩心分析资料为基础,将常规测井、成像测井、地震资料与地质理论相结合,对研究区的7口井进行了裂缝及孔洞分析、现今地应力与裂缝有效性分析和储层裂缝定量评价,综合预测了裂缝发育带。分析结果表明,研究区古生界变质岩地层中基本以基岩内幕油气藏为主;现今最大水平主应力方向主要呈北东—南西向和北东东—南西西向;裂缝的主要走向与古潜山主断层走向大致平行,属纵裂缝;裂缝主要发育在东西两侧靠近断层、近源的构造陡坡上的硬脆性变质岩段。此解释结果与试油资料、地质情况吻合较好。

The fractured basement reservoirs are of the complicated storage space and heterogeneity.On the basis of core data,the conventional logging,imaging logging and seismic data were combined with geological theories and used to analyze the fracture,vugs,current stress and fracture effectiveness of seven wells.The reservoir fractures were quantitatively evaluated,and the fractured zones in the studied area were predicted.The analysis results show that the main type of basement reservoirs in the Palaeozoic metamorphic formation is the inside reservoirs,and the main current maximum horizontal principal stress is in directions of NE-SW and NEE-SWW.The main fracture strike is approximately parallel to the main fault,and the fractures are developed in the brittle hard metamorphic rock on the steep structural slope near the fault and the oil source.The interpreted results of this method are matchable very well with the well test data and the actual geologic state.