天然气成藏动力学机制发展趋势分析

目的研究天然气成藏机理与分布规律。方法国内外相关文献综合分析。结果对天然气成藏动力学机制的研究主要围绕背斜圈闭气藏(含上倾型构造及地层圈闭)、向斜圈闭气藏(深盆气圈闭)及煤层气藏(源内气藏)3类气藏进行,但是,研究的侧重点差别很大。其中,对背斜气藏的研究主要侧重天然气初次运移、二次运移、聚集及保存机制的研究,对向斜圈闭气藏的研究主要侧重于气水倒置形成、气藏异常压力形成机制的研究,而对煤层气藏的研究则主要侧重煤孔隙的形成、煤层气富集及保存机制研究。存在问题:其一,把背斜气藏和向斜气藏当成两种成藏动力学机制完全不同的气藏类型,其动力学依据不充分;其二,没有解决气源岩内天然气初次运移机制和聚集机制的矛盾。结论建议应加强两方面的研究:其一,以盆地升降运动为动力学基础,研究天然气成藏的动力学机制;其二,以烃源岩—断裂—储气层为基本输导格架,研究不同输导介质中天然气成藏的动力学机制。上述研究有望解决不同类型天然气藏形成动力学存在的问题。

Analysis of developing tendency of gas accumulation dynamics mechanism

Aim To study gas accumulation mechanism and distribution rule.Methods Through reference reading and analysis.Results Gas accumulation dynamics researches focus on anticlinal trap(including updip structure and stratigraphic trap),synclinal trap(deep basin gas trap) and coalbed gas trap(hydrocarbon gas trap).The research emphases of anticlinal trap lie in primary migration,secondary migration,accumulation and preservation mechanism.As for synclinal trap are water and gas transition and abnormal pressure forming of gas pool.As for coalbed gas trap are coal pore forming,accumulation and preservation mechanism of coalbed gas.Problems: First,The origin contact between anticlinal gas pool and synclinal gas pool was weak.Second, there has a contradiction between gas primary migration mechanism and accumulation mechanism in gas source rock.Conclusion It is suggested to strengthen researches of two aspects.First,gas accumulation dynamics mechanism should be researched based on rise and drop movement of basin.Second,it should be researched in different mediums in hydrocarbon sourse rock-fracture-reservoir framework.