根据FMI资料分析大庆油田徐家围子断陷构造应力场

现今构造应力场及古构造应力场最大主应力方向的准确判断对成矿地质研究，尤其是石油、天然气勘探和开发具有重要的意义。利用FMI(全井壁微电阻率成像测井)资料，以大庆油田徐家围子断陷下白垩统营城组为研究对象，对该断陷的构造应力方向进行分析。对FMI资料识别出的裂缝走向进行统计，结果表明：钻井伴生缝受现今应力场控制，构造成因的高导缝和高阻缝的形成则受古地应力控制，可指示古地应力场的方向；徐家围子断陷下白垩统营城组现今最大水平主应力方向为近东西向；在地质演化中，研究区域的构造应力场曾经发生多次变化，根据发育的裂缝组判断留下明显迹象的有3个方向，即近南北向、北东向和近东西向。

Analysis on Tectonic Stress Field of Xujiaweizi Rift in Daqing Oilfield with FMI

The directions of maximum horizontal stresses of the present tectonic stress field and palaeostress field are of great significance to mineralization analysis,especially to the exploration and development of oil and gas.Fractures induced by drilling are controlled by present stress field,while the high-conductive and high-resistant fractures caused by tectonic genesis are closely related to palaeostress and can be the indications of the directions of palaeostress fields.After the statistics analyses of fractures identified from FMI images in groups,it is drawn to the conclusion that the current direction of the maximum horizontal major stress of the Lower Cretaceous Yingcheng Formation in Xujiaweizi Rift,Daqing Oilfield is identified to be nearly eastwest,and has changed frequently in the geological history,with obvious three directions of NS,NE and WE.