富台油田碳酸盐岩潜山裂缝充填特征及其控制因素

Filling Characteristics of Fractures in Carbonate Buried Hill of Futai Oilfield and Their Controlling Factors

为研究富台潜山油田有效裂缝分布区域,利用岩心、薄片、流体包裹体分析等资料对富台潜山储层进行系统分析。综合研究结果表明:富台潜山裂缝充填成因主要是深层热液作用;裂缝充填物主要为方解石,少量为硬石膏;裂缝充填受围岩岩性、裂缝性质、热液温度和流速、与断层距离等多种因素控制。富台潜山的裂缝纵向上冶里-亮甲山组、凤山组的白云岩储层充填程度低,上、下马家沟组灰岩充填程度高;平面上背斜轴部远离埕南大断层及二台阶断层的部分充填程度低,靠近这2条断层区域充填程度高;低充填程度区为有效裂缝分布范围。

In order to identify the distribution of the effective fractures in the buried hill reservoirs of Futai Oilfield,the fractured reservoirs were systematically studied based on core observation,thin section and fluid inclusion analysis data.The results show that the main cause why the fractures in the buried hill reservoirs were filled is deep hydrothermal action;the fracture fillings are mainly calcite and a small amount of anhydrite.The fracture filling is influenced mainly by the lithology of surrounding rock,the features of fractures,the temperature and flow velocity of hydrothermal solution and the distance of fractures from faults.Vertically the fractures in the dolomite reservoirs of YeliLiangjiashan Formation and Fengshan Formation have a low filling degree,whereas the fractures in the limestone of the upper Majiagou Formation and lower Majiagou Formation have a high filling degree.Horizontally a part of the fractures in the anticline axis far away from Chengnan fault and Ertaijie fault have lower filling degree,and the fractures near two faults have higher filling degree.The effective fractures distribute in the areas of low filling degree.