华北地台上古生界煤成气藏的主要类型及特征

华北地台上古生界天然气藏的类型划分问题是关系到下一步勘探思路的关键之一。为此，从天然气藏与气源岩的空间关系着手，将华北地台上古生界石炭-二叠系煤系地层作为主要气源岩的煤成气藏分为两类：烃源岩气藏和非烃源岩气藏。烃源岩气藏是由于烃源岩的储集性能得到改善而形成的气藏类型，它可以发育在背斜构造中，也可以发育在向斜构造中。非烃源岩气藏按照储集层的构造形态及其与气源岩的接触关系可以分为背斜型气藏、断层型气藏、向斜型气藏（深盆气藏）以及地层型气藏。从煤成气藏发育层位来看，华北地台上古生界煤成气藏发育在上古生界烃源岩、煤系烃源岩的上覆地层以及下伏地层中。烃源岩气藏与非烃源岩气藏在垂向上的分布具有互补性。

MAIN TYPES AND CHARACTERISTICS OF UPPER PALEOZOIC COAL-DERIVED GAS POOLS IN NORTH CHINA PLATFORM

Classification of the Upper Paleozoic natural gas pools in North China Platform is one of the key issues concerning future exploration direction. Based on analysis of the spatial relationship between the gas pools and source rocks, the coal-derived gas pools with gas mainly sourced from the Upper Paleozoic Permo-carboniferous coalbeds in North China Platform are divided into two groups, i.e. source rock gas pools and non-source rock gas pools. The source rock gas pools are formed as a result of improvement of the poroperm characteristics of the source rocks. It can occur both in anticline and syncline structures. The non-source rock gas pools can be further divided into anticline type, fault type, syncline type (basin-centered gas pool) and stratigraphic type according to the structural features of reservoirs and their contact with source rocks. In respect of the horizons of coal-derived gas pools, the Upper Paleozoic coal-derived gas pools in North China platform are developed in the Upper Paleozoic source rocks and the overlying and underlying strata of coal measure source rocks. The complementarity of vertical distributions can be easily seen between source rock and non-source rock gas pools.