关键词: 岩性油气藏, 低渗透储层, 沉积微相, 成岩作用, 层序地层, 优质储层, 分布规律

Abstract: The low-permeability reservoirs are dominated in the lithostratigraphic oil-gas pools.The origin of low-permeability reservoir and distribution of favorable reservoir in several typical lithostratigraphic oil-gas pools were studied.It is found that sedimentation is a basic factor for generating low-permeability reservoirs,and the strong compaction and cementation are the key factors for forming low-porosity and low-permeability reservoirs.The formation and distribution of the favorable reservoirs were controlled by sequence boundary,favorable facies and dissolution of organic acid water.Generally,favorable reservoirs were vertically distributed in the lower and middle parts of Ⅲ-order sequence and laterally distributed in the stacked channels of delta plain or delta front. These places kept more primary porosity during generation of organic acid water which was easy removing into primary porosity and dissolving lots of cement and feldspar to form the secondary porosity.Then the favorable reservoirs can be generated.

Key words: lithostratigraphic oil-gas pool low-permeability reservoir, sedimentary micro-facies, diagenesis, sequence stratigraphy, favorable reservoir, distribution law