致密砂岩气藏高渗透带与古构造关系探讨—以川中川南过渡带内江—大足地区上三叠统须二段致密砂岩气藏为例

通过对川中川南过渡带内江—大足地区上三叠统须二段低渗透致密砂岩气藏的研究,指出:该区高产井呈带状分布并与古构造有密切的关系;沉积作用中古构造带顶部及两翼为水体的高能带,沉积了成熟度较高的粗颗粒，并且在成岩过程中由差异压实作用形成了裂缝,使古构造带顶部及两翼变为有利的油气聚集区带;远离古构造带翼部的沉积成岩条件相对较差,储层物性变差，于是在古构造带上就形成了岩性油气藏.

Relationship between High Permeability Zones and Palaeostructures in Tight Gas Reservoirs

Research of the T3x^2 tight gas reservoir of Neijiang-Dazu Region in the transitional zone of Chuanzhong and Chuannan reveals that high capacity wells are in zonal distribution and are closely related to palaeostructures. In the process of deposition, because of the water bodies with high-energy on both sides of the palaeotectonic belt, the higher maturity coarse particles were deposited. In the diagenesis, cracks were formed by differential compaction. These make the top and two wings of the palaeotectonic belt to be favorable oil and gas accumulation zones. Due to the relatively poor conditions of sedimentation and diagenesis away from the palaeotectonic belt, physical properties of the reservoirs became poor, so that a lithologic reservoir was formed on the palaeotectonic belt.