江汉盆地新沟嘴组泥质白云岩储集特征及勘探潜力

Reservoir Characteristics and Exploration Potential of Xingouzui Formation’s Argillaceous Dolomite in Jianghan Basin

江汉盆地新沟嘴组Ex下II油组主要为泥质白云岩,主要储集空间为晶间孔、粒间孔和溶蚀孔,裂缝提供主要的渗流通道;孔隙度平均13.6%,纵向上Ⅱ2层段孔隙发育相对较好;渗透率平均0.2md,为中-低孔、超低渗储层。综合运用录井、测井、试油试采及压汞资料,将泥质白云岩储层分成好、较好、差三类储层;结合储层含油性评价,Ex下Ⅱ油组三个层合计有利区14个,丫角新沟低凸起勘探潜力最好,潜力较好为陈沱口凹陷和沔阳凹陷。

Lower Ex II Oil Group of Xingouzui Formation consists mainly of argillaceous dolomite. Its main reservoir space contains inter-granular pores, inter-grain pores and corrosion pores. Its fractures are the main seepage channels. Its average porosity is 13.6% with better development of pores in vertical Ⅱ2 segment. Its average permeability is 0.2md, belonging to mid-low pore and super-low permeability reservoir. Based on the data of well logging, formation test and production test and mercury penetration, argillaceous dolomite reservoir is divided into three types: good one, common one and bad one. According to reservoir oil-bearing property evaluation, three layers of Lower Ex II Oil Group have 14 favourable areas with 117 million tons of resource quantity. The low bulges of Yajiao Area and Xingou Area have the best exploration potential followed by Chentuokou Sag and Mianyang Sag.