两种类型致密砂岩气藏对比

THE COMPARISON OF TWO TYPES OF TIGHT SAND GAS RESERVOIR

致密砂岩气是非常规天然气的一种,是常规天然气资源最重要的后备资源之一。在总结前人研究的基础上,结合构造演化历史背景,动态的研究致密砂岩气藏烃源岩生排烃高峰期与储层致密演化史二者之间的关系,将致密砂岩气藏划分为两种类型:储层先期致密深盆气藏型(“先成型”深盆气藏)与储层后期致密气藏型(“后成型”致密气藏)。对2类致密气藏成藏特征、成藏条件及成藏机理进行了详细的对比分析,总结出两种气藏的成藏模式和分布规律。“先成型”深盆气藏的成藏模式主要为凹陷中心对称分布、前陆侧缘斜坡分布及构造斜坡分布3种;“后成型”致密气藏为“早常规聚集-晚期改造”的成藏模式并划分为3个阶段,不同的阶段具有不同的成藏特点和成藏特征。准确判识两种类型致密砂岩气藏对于指导天然气勘探和合理制定开发方案均具有重要意义。

The tight sand gas is one of unconventional gas, it is also an important candidate resources of conventional gas. The opinion based on the research of predecessors. After fully thinking of the background of structural evolution, and dynamical analysis the relationships between the hydrocarbon generation and expulsion fastigium of source rock and tight evolution history of reservoir, divide the tight sand gas reservoir into two types. ＂pre-exiting deep gas＂ and ＂subsequent tight sand gas＂. According to the comparative analysis on reservoir forming conditions, reservoir forming characters and reservoir forming principle of this two types, generalize the reservoir forming patterns and distribution regulation. The reservoir forming patterns of ＂pre-exiting＂ deep basin gas reservoir is divided into three kinds： depression central symmetry distribution, foreland lateral margin slope distribution and structure slope distribution. ＂first is the conventional accumulation, but late is reconstruction＂ is the reservoir forming pattern of ＂subsequent＂ tight sand gas, and the pattern is divided into three phases with different reservoir forming characters and conditions. Correctively distinguish the two kinds of tight sand gas from each other is very important to guide natural gas exploration and make the right exploitation plan.