沁水盆地南部地区砂体与煤层空间叠置特征及其在煤层气和致密气合采开发中的意义

以沁水盆地南部煤层气和致密气共探合采研究区为例，详细解剖煤系地层砂体发育特征及其与煤层空间叠置关系，并探讨其对煤层气与致密气合采开发的影响。研究结果表明，煤系地层砂体成因类型丰富，砂体规模和形态特征各异。砂体结构特征主要受沉积相演化控制，形成五种主要空间叠置类型：孤立分散型、水平搭接型、垂向叠置型、错位叠置型和水平-错位复合叠置型。在沉积作用控制下，不同成因类型砂体与煤层可以形成多种空间叠置组合模式。砂体含气饱和度和压力及煤层含气量、物性和压力均受到两者空间叠置关系的显著影响。加强该方面研究，将对两气合采可行性评估及合采产气量预测具有重要意义。

The Characteristics of Spatial Superimposition between Sandbody and Coal seam and Its Implications to Commingling Production for CBM and Tight Gas

Taking the southern Qinshui basin as an example, the hot spot area for the study on co-exploration and commingled production for CBM and tight gas. Through detailed analysis of the spatial combination of sand body and superimposition relationship between sand body and coal seam, its implication to commingling production for CBM and tight gas was discussed. The study shows the sand bodies developed in coal-bearing strata with multiple genetic types, sand body scales and morphological characteristics. The characteristics of sand body architecture are mainly controlled by the sedimentary facies evolution. The spatial combination of sand bodies can be divided into five common types including isolated lenticular sand body, horizontal connection sand body, vertical superimposition sand body, lateral separation sand body and composite overlay sand body. Under the control of deposition, the multiple superimposition relationships between sand body and coal seam are formed. And the superimposition relationships have significant effects on gas saturation of sandstone, pressure in sandstone, coalbed gas content, properties of coal reservoirs and coal reservoir pressure, would control the feasibility and production of commingled production for CBM and tight gas.