深盆气成藏条件及其内部特征

FORMATION CONDITIONS AND INTERNAL FEATURES OF DEEP BASIN GAS ACCUMULATIONS

深盆气藏概念的提出和成藏机理研究的突破 ,尤其是这类气藏通常所蕴聚的巨大天然气储量 ,引起了中外地质学家的广泛关注。深盆气藏是一类在成藏机制、成因类型和分布规律上甚为特殊的非常规类型。深盆气藏的形成以低孔、低渗性致密储层的存在为发育条件 ,以流体倒置和异常地层压力分布为表现特征 ,在平面和剖面上表现出了一系列特殊性。本文对深盆气藏的基本特征进行了讨论 。

Deep basin gas accumulation (DBGA) has been followed with wind interests by petroleum geologists since the being put forward of the concept DBGA (deep basin gas trap by J. A. Masters)and the breakthrough of accumulation mechanism,especially its enormous reserves. Deep basin gas accumulations are distinct from normal ones in origin mechanism,genetic features and distribution rules. The formation and distribution of DBGAs are restricted by tight sand reservoirs with low porosity,low permeability and high saturation of water. The fundamental features of DBGAs are the overturning of formation fluids and occurring of abnormal pressures. DBGAs are distinguished from normal ones in their basic principles,general characteristics and genetic sequences. DBGA is discussed thoroughly in the paper to expect to be useful for the exploration of DBGA in China.