我国低孔渗储层天然气资源大型化成藏特征与分布规律

Large-scale accumulation characteristic and distribution law of low porosity and permeability reservoir in China

低孔渗储层天然气资源是目前和未来一段时间我国天然气勘探和开发的主体,具有大型化成藏的特点。集中讨论了这类天然气资源大型化成藏的特征和分布规律,认识到成藏要素具有大型化发育与规模变化的特征,是天然气大型化成藏的基础;薄饼式、集群式成藏是天然气大型化成藏的主要样式;气源灶埋藏期规模"蓄能"和抬升期规模排气是大型化成藏重要气源输入;体积流和扩散流充注是天然气大型化成藏的主要运聚方式。低孔渗储层天然气藏的成藏分布具有近源性,成藏组合以大面积和大范围两种类型为主,成藏类型以地层—岩性圈闭为主,主要分布在海相克拉通盆地古隆起围斜区、陆内坳陷盆地广大斜坡区和向斜区以及前陆盆地缓翼斜坡等地区。低孔渗储层天然气资源大型化成藏认识的提出,提升了我国天然气资源发现潜力,扩展了勘探范围,为客观评价我国天然气主体资源总量和分布、推动有效发现大气田提供了理论基础。

Natural gas resource of low porosity and permeability reservoir is the main body of natural gas exploration and development of current and future period in China, with the characteristics of large-scale hydrocar- bon accumulation. This paper focuses on the large-scale gas accumulation characteristics and distribution law of this type gas resource, and it is recognized that reservoir-forming factors have the characters of development and change in a large scale, which is the foundation of gas accumulation in a large scale. The main types of gas accumulation in a large scale are the ＂pancake type＂ outside and ＂cluster type＂ inside;the scale＂ energy storage＂ in burial peri- od and scale＂ exhausting gas＂ in uplift stage are the important gas source;the volume flow and diffusion flow filling are the main migration and accumulation modes. The distribution of low porosity and permeability gas reservoir is close to source , and reservoir combination mainly contains two types,which are large area and large scope types, and the stratigraphic and lithologic traps are the main type. The synclinal area of marine cratonic basin, the broad slope zone of intracontinental Down-Warped basin and slope slow wing area of foreland basin are the main areas of large scale accumulation of this kind of natural gas resources. The recognization of large scale gas accumulation of low porosity and permeability gas resources has been put forward, which prompts the discovery potential of natural gas resource, expands the range of exploration, provides the theoretical basis for objective evaluation of the total a- mount and distribution of natural gas resources, and promotes the large gas field effective discovery in China.