Abstract: There are two typical kinds of mechanisms and models for gas migration,accumulation and preservation,including deep basin or basin centered gas accumulations and generally trapped gas accumulations.By the use of the seepage mechanic principle and comparing method,the formation mechanisms of the two kinds of gas accumulations were discussed.The typical deep basin gas accumulation is usually of the properties of piston-typed migration way,up grow-typed accumulation and actively dynamic preservation models,while the typically normal trapped gases are generally of replacement-typed migration way,suspend-typed accumulation models and stabilization-typed preservation.The diversification results showed that some successive gas models happened between the two typical gas accumulations.The two typical models are always developed simultaneously in the tight sandstone reservoirs.

Key words: gas reservoir, tight sandstone reservoir, normal gas pools, deep basin gas, accumulation mechanism, successive gas model

摘要： 游离相天然气在从运移到聚集和保存的过程中,通常存在着深盆气藏和常规圈闭气藏两种机理模式.运用渗流力学基本原理和比较学研究方法,对两类典型天然气的成藏机理进行了分析,指出了天然气运移、成藏和保存过程中的两种基本方式.典型深盆气藏具有活塞式气水排驱模式、向上逐渐推进的生长方式和动态活跃式保存特点;常规圈闭气藏具有置换式气水排驱模式、悬浮式聚集的成藏方式和静态稳定式的保存特点.成藏机理分析表明,两种典型天然气藏之间存在着大量的递变过渡模式.在致密砂岩储层中,天然气成藏的两种机理模式同时发生,从而形成具有机理过渡特点的致密砂岩气藏.

关键词: 天然气藏, 致密砂岩, 常规气藏, 深盆气藏, 成藏机理, 成藏模式递变