缝洞型储层中次生孔隙类型对胶结指数和饱和度指数影响的机理分析  

Analysis of the Mechanism of the Effects of Secondary Porosities on the Cementation Factor and Saturation Index in Reservoir Formation with Vuggs and Fractures

作　　者：沈金松[1,2,3] 刘子煊[1] 王素红 熊东方 

机构地区：[1]中国石油大学资源与信息学院地球物理系,北京102249 [2]中国石油集团公司物探重点实验室,北京102249 [3]中国石油大学油气资源与探测国家重点实验室,北京102249 [4]中国石油华北油田分公司,河北任丘062552

出　　处：《测井技术》2010年第1期9-15,共7页Well Logging Technology

基　　金：国家重点基础研究发展计划(973计划)(2007CB209607);国家高技术研究发展计划(863计划)(2007AA060502);中国石油天然气集团公司基础研究项目(07A10303)

摘　　要：缝洞型储层非均质性强烈、孔隙类型多且结构复杂,由中高孔隙度渗透率的均质砂岩实验数据建立的Archie公式失效。这类储层中,含水饱和度计算关系中的地层胶结指数和饱和度指数表现出复杂的变化特征。岩电实验观测到的地层胶结指数不仅与孔隙度相关,还出现异常大值或小值;同样,饱和度指数也表现类似特征。基于均匀分布的粒间孔基质中包含孔洞或裂缝的双孔隙储层模型,采用数学模拟方法,定量分析了孔洞型和裂缝型次生孔隙及次生孔隙的润湿性对地层胶结指数和饱和度指数的影响。明确了岩电实验中观测到的裂缝使胶结指数激剧减小,而孔洞使胶结指数增大这一结果的物理机制,有助于岩石物理学和测井处理解释相关人员对缝洞型储层含油气性评价的复杂性有一个基本的认识,也为缝洞型储层含水饱和度的准确计算奠定了理论基础。In general, reservoirs with vugs and fractures, such as carbonate reservoirs and volcanic reservoirs, are extremely inhomogeneous, and have various types of pores and complex pore structures. These factors result in the failure of the Archie equation which was founded on experimental data acquired on samples of homogeneous sand with average and high porosity. For the computation of water saturation, the most important parameters including cementation exponent and saturation exponent, demonstrate complex characteristics. The cementation exponent observed in petrophysical experiments is not only related to porosity, but also can be anomalously large or small, at the same time, the saturation exponent is dependent on saturation itself, and it also can be anomalously large and small. Based on the rock model with dual-porosity system which holds uniformly distributed intergranular pore as the porous matrix with vugs or fractures as its inclusions, this study has quantitatively and mathematically analyzed the effects of secondary pore system and their wettabilities on cementation and saturation exponents, and recognized the mechanism that how the cementation exponent is dramatically decreased by the fractures and how the cementation exponent is dramatically increased by the vugs. Also the modeling results provide petrophysists and log interpretors a sound understanding of the complexity of the hydrocarbon evaluation of reservoirs with vugs and fractures. And it sets a theoretical foundation for the evaluation of water saturation in reservoirs with rugs and fractures.

关 键 词：测井评价 缝洞型储层 次生孔隙类型 胶结指数 饱和度指数 润湿性 

分 类 号：P631.84[天文地球—地质矿产勘探]