Shale gas is one of the most important types of the unconventional natural gas resource which has received more and more attention in recent years. The accumulation mechanism, existing phase and the distribution characteristics of shale gas differ greatly from conventional natural gas and its reserve calculation methods are also different. This paper discusses the special characteristics of shale gas reservoirs. It is presented that the gas has a dual-storage-mode and reservoir accumulation mechanism is a mixed one. Based on this, this paper puts forward an effective reserve calculation volumetric method used in the early stage of shale gas exploration and development. The special gas storage includes both free gas mode and adsorbed gas mode. Free gas content was calculated in accordance to the method used in conventional natural gas reservoir; while the adsorbed gas content calculation referred to the coal-bed methane reserve calculation which was relatively mature nowadays. Finally, a successful real data application to Pearsall shale gas asset valuation of North America was introduced.%页岩气作为一种重要的非常规天然气资源,近年来受到越来越多的关注,页岩气的成因机理、赋存相态、分布特征等与常规天然气有着明显的区别,其特殊的气体蕴藏方式导致储量计算方法也有别于常规气藏.探讨页岩气藏的特殊性,其主要表现在气体具有双重赋存状态和成藏机理具有混合性等,在此基础上提出了在页岩气藏勘探开发初期计算地质储量的一种有效方法:容积法.页岩气特殊的蕴藏方式有游离气和吸附气两种,游离气储量按照常规天然气的方法来计算,吸附气储量则参考目前已有的相对成熟的煤层气地质储量计算方法.该计算方法在北美页岩气资产地质储量估算中得到成功应用.
展开▼
