石灰岩、白云岩储层孔隙度-渗透率关系研究

Porosity-permeability interrelation of limestone and dolomite reservoirs

白云石化作用对储层特征的影响是碳酸盐岩储层研究中的一个重要主题。最重要也是最普遍的发现可能是在深埋藏条件下,白云岩的孔隙度和渗透率要比石灰岩高,然而,目前表明这种差异的定量信息却很少。虽然大多数研究实例表明白云岩的孔隙度更高,但是也有少量的不同观点。利用来自不同沉积背景、不同年代、不同埋藏深度的5个碳酸盐岩台地岩心样品的孔隙度和渗透率的关系,分析了石灰岩和白云岩互层储层特征的相似性和差异。在浅埋藏的台地中,石灰岩和白云岩的平均孔隙度很接近,而白云岩的渗透率要比要比石灰岩的高。3个深埋藏的台地岩心的主要特征是石灰岩的平均孔隙度比相邻的白云岩要低很多,但是它们的孔隙度-渗透率关系却十分相近。

One of the important topics of the study on carbonate reservoirs is how dolomitization influences reservoir properties. The most important and most common understanding is that perhaps under deep burial, the porosity and permeability of dolomite are higher than that of limestone. Yet there are few quantitative evidences for this difference. Though most case studies show the porosity of dolomite is higher, there are some exceptions. Based on the interrelations between porosity and permeability of five core examples from carbonate platforms with different depositional settings, different geologic ages and different burial depths, this paper explores the similarities and differences between dolomite and limestone reservoirs. For cores sampled from shallow-buried platforms, the average porosity of dolomite is similar to that of limestone but permeability of dolomite is higher than that of limestone. While for cores sampled from deep burial platforms, the average porosity of limestone is much lower than that of the adjacent dolomite ,but their interrelations of porosity-permeability are almost the same.