The carbonate reservoir is characterized by complex evolution process,various pore structure and strong heterogeneity.Among these features,pore structure is an important factor affecting the heterogeneity of carbonate.It focused on a Jurassie Callovian-Oxfordian limestone gas reservoirs on the right bank block of Amu Darya River.Based on the study of pore structure,a number of techniques were used to characterize the micro pore structure of heterogeneous carbonate reservoirs,and the accurate prediction of gas reservoir was carried out.Rock composition and plane porosity was studied by rock thin section analysis,which proved that two types of pore structure,dissolution pore and structural fracture mainly developed in carbonate reservoir of this area.Rock internal stereo images including pore distributions and fluid filling states were obtained by CT scanning,which confirmed that a "gas-in-water" distribution exists in rocks with patchy saturation.It provided a basis for the rock physics modeling.The physics information such as velocity,density and porosity was got by core physics experiment.The P-wave impedance and vP/vS were chosen to be the sensitive parameters of fluid detection by multi-parameter crossplot analysis in this area.The rock physics template was built to predict reservoir porosity and gas saturation based on the equivalent medium theory.The predicted results matched with log data and gas testing data.%碳酸盐岩储集空间演化过程复杂、孔隙结构多样、非均质性强,孔隙结构是影响碳酸盐岩非均质性的重要因素.以阿姆河右岸中上侏罗统卡洛夫-牛津阶灰岩气藏为例,从孔隙结构的基础研究出发,对非均质碳酸盐岩储层微观孔隙结构进行了精细表征,并对气藏开展了精确预测:通过岩石镜下薄片对岩石成分、类型、面孔率等信息进行鉴定,证明该地区碳酸盐岩储层主要发育溶孔和裂缝两种类型孔隙结构;通过CT扫描得到岩石内部立体影像,统计孔隙分布与流体充填状态,证实了实际岩石中"水包气"的斑块状饱和状态,为岩石物理建模提供了依据;通过岩心实验测量得到岩石速度、密度、孔隙度等物理信息,根据多参数交会分析结果,优选纵波阻抗与纵横波速度比作为该地区流体检测的敏感参数;综合以上信息,选择基于双孔等效介质理论的岩石物理建模方法,结合地震数据制作岩石物理模板,预测了储层孔隙度与含气饱和度,预测结果与试气结果吻合.
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