河北省邯邢地区煤系气成藏特征及其共生组合模式

为揭示煤系气共生成藏作用,寻找分布有利区,实现共探共采,利用统计分析、测井分析、压汞实验、有机碳含量、有机质成熟度等实验方法,对河北省邯邢地区太原组和山西组煤系气成藏特征及其组合关系开展研究,并划分煤系气分布有利区.研究区煤层和暗色泥页岩为主要烃源岩,有机质类型为Ⅲ型,有机质成熟度介于0.61％ ～2.85％;致密砂岩孔隙度平均值为5.14％,渗透率平均值为0.03 mD,煤系气储层总体以砂-泥混合储层为主.煤层、泥页岩、致密砂岩和灰岩互为盖层,发育7种岩相组合类型.煤系气共生组合有3种类型,6种组合模式,包括自生共储型、自生自储型和共生共储型.山西组下部和太原组中下部为煤系气主要发育层段.研究区东部和南部构造简单,埋深较大,利于煤系气的成藏,西北部构造复杂,地层抬升,不利于煤系气的成藏.

Accumulation characteristics of coal measures gas and its symbiosis combination models in Hanxing area of Hebei Province

In order to reveal the cogeneration of coal measures gas, find favorable distribution areas and realize co-exploration and co-production, using statistical analysis, logging analysis, mercury intrusion experiment, organic carbon content, organic matter maturity and other experimental methods. The interbedded features of coal beds, mud shales, tight sandstones and limestones developed in the coal measures gas of the Taiyuan and Shanxi formations, the characteristics of coal measure gas accumulation and their combination relationship are studied, and the favorable coal measure gas distribution areas are divided. The results show that the coal beds and dark mud shale are the main source rocks. The type of organic matter is type III, and organic matter maturity is between 0.61-2.85%. The average porosity of tight sandstone is 5.14%, permeability average is 0.03mD. The coal measures gas reservoirs are mainly sand-mud mixed reservoirs. Coal seam, mud shale, tight sandstone and limestone are caprocks, and there are 7 types of lithofacies. There are three types of coal measures gas symbiosis combinations, including self-generation and co-storage type, self-generation and self-storage type, and symbiosis-storage type, and six combination patterns. The lower part of Shanxi Formation and the middle and lower part of Taiyuan Formation are the main development zones of coal measures gas. The eastern and southern parts of the study area have simple structures and large burial depths, which are beneficial to the accumulation of coal measure gas. The northwestern structure is complex and the stratum is uplifted, which is not conducive to the accumulation of coal measure gas.