黔西比德——三塘盆地多层叠置独立含煤层气系统发育规律与控制机理

发布时间：2018-06-16 04:44

本文选题：黔西 + 多层叠置独立含煤层气系统　；参考：《天然气地球科学》2017年04期

【摘要】：在多煤层含煤地层中,往往形成垂向上叠置发育的多个独立含煤层气系统,严重影响了多煤层合排效果。以黔西比德—三塘盆地为对象,运用含气量梯度和压力系数的变异系数定量表征独立含气系统的发育程度,揭示其平面分布规律,并从构造、沉积、水文等3个方面综合分析其地质控制因素。研究认为:研究区周缘主干断裂以及由此形成的三角形构造控制了区内应力应变特点和聚煤作用,由西缘断裂带向盆地内部应力应变逐渐减弱,煤层厚度和稳定性逐渐增加,泥岩顶板渐趋发育;沉积相带呈NE向展布,并随着海水作用的增强,由西向东沉积特征发生规律性变化,砂泥比降低,沉积旋回渐趋发育,并易于形成黄铁矿、高岭石等成岩矿物充填孔隙;地下水总体由NW向SE方向径流,流动过程中渗流阻力增大,滞留程度增加。在构造、沉积、水文的耦合控制之下,独立含气系统由盆地NW向SE方向渐趋发育。依此进行了叠置含气系统发育程度分区,勘探开发实践在一定程度上佐证了分区的客观性。
[Abstract]:In the multi-seam coal-bearing strata, many independent coal-bed methane systems developed vertically and vertically are often formed, which seriously affect the effect of multi-seam combination and drainage. In this paper, the variation coefficient of gas content gradient and pressure coefficient is used to quantitatively characterize the development degree of independent gas-bearing system, and its plane distribution law is revealed. The geological control factors are comprehensively analyzed in three aspects such as hydrology. It is considered that the main faults around the studied area and the triangle structure formed from them control the characteristics of stress and strain and coal accumulation in the study area. The stress and strain gradually weaken and the thickness and stability of coal seam increase gradually from the fault zone of the western margin to the basin. The mudstone roof gradually develops, the sedimentary facies zone distributes in NE direction, and with the increase of seawater action, the sedimentary characteristics change regularly from west to east, the ratio of sand to mud decreases, the sedimentary cycle gradually develops, and pyrite is easily formed. The porosity is filled with diagenetic minerals such as kaolinite, and the groundwater flows from NW to SE, the seepage resistance increases and the retention degree increases during the flow process. Under the coupled control of structure, sedimentation and hydrology, the independent gas-bearing system gradually develops from basin NW to SE. The development degree of superimposed gas-bearing system has been partitioned, and the exploration and development practice has proved the objectivity of the zone to some extent.
【作者单位】：西安科技大学地质与环境学院;
【基金】：国家科技重大专项项目(编号:2011ZX05034) 西安科技大学博士启动基金项目(编号:2016QDJ028);西安科技大学科研培育基金项目(编号:201718)联合资助
【分类号】：P618.13

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