概率法在缝洞型碳酸盐岩油气藏储量评估中的应用:以塔中隆起北斜坡下奥陶统岩溶油气藏为例

缝洞型碳酸盐岩油气藏储量计算是目前国际研究的难点。中国近年来发现了这类规模巨大的油气藏，储量计算始终是一个难题而未能有效解决。通过对塔里木油田目前缝洞型碳酸盐岩油气藏储量评估方法的梳理，结合缝洞型碳酸盐岩油气藏认识及缝洞型油气藏识别技术的进展，认为缝洞型碳酸盐岩油气藏储量评估的发展趋势是强调缝洞单元雕刻（解决非均质性、合理的指导开发井部署）和储量参数的随机性。在了解缝洞型碳酸盐岩油气藏识别技术进展基础上，吸收国内外油气储量评估经验，提出了塔里木油田缝洞型碳酸盐岩油气藏概率法储量评估方法。评估思路是发挥缝洞雕刻油气面积置信度高的优势，充分利用孔隙度、饱和度样本点容量大的特点，合理建立其概率分布。缝洞雕刻和概率法的有机结合可以合理地评估缝洞型油气藏的储量。目前，缝洞型碳酸盐岩油气藏储量评估对象、裂缝处理方法、概率法储量计算高置信度确定性参数取值方法、概率法储量计算随机变量参数分布规律及合理性等方面的研究已取得一定的经验和进展。

The application of stochastic method in the evaluation of the fissure-cavern type carbonatite hydrocarbon reservoir： Taking Lower Ordovician karst hydrocarbon reservoir in the north slope of Tazhong Uplift as an example

The reserve calculation for a fissure-cavern type of carbonate reservoir is a difficult problem in the world.In recent years,a huge reservoir of this type was found in China and its reserve calculation has still been a challenge.An effective solution could not be obtained yet.According to the current reserve assessment methods for the fissure-cavern type of carbonate reservoir in Tarim Oilfield,the understanding of the fissure-cavern type carbonate reservoir,and the advances of reservoir recognition technology of this type,it is suggested that the trend of reserve assessment of a fissure-cavern type carbonate reservoir is to emphasize the fissure carved unit(for addressing heterogeneity and rationally guiding the deployment of development wells) and the randomness of storage parameters.On the basis of the advances in the technology of fissure-cavern type carbonate reservoir recognition and the experience of domestic and foreign oil and gas reserve assessment,the probability method of reserve assessment of fissure-cavern type carbonate reservoir of Tarim Oilfield was proposed.The idea of the assessment is to give full play to the advantages of high confidence of a fissure carved oil and gas area and to take advantage of big capacity of porosity and saturation sampling points so that a reasonable probability distribution can be established.The combination of the seam-hole carving and the probability law can make a more reasonable assessment of the reserve of a fissure-cavern type reservoir.