川西坳陷油气圈闭类型分析

ANALYSIS OF THE TYPES OF OIL AND GAS TRAPS IN THE WEST SICHUAN DEPRESSION

在川西坳陷这个致密砂岩领域,圈闭和气藏的形成机理相当复杂,其根本原因在于盆地有着相当复杂的形成与演化史。即使在同一构造形变带内,在不同的构造部位或层位,含油气情况也存在较大的差异,制约圈闭条件和气藏富集的地质因素也不相同,既有依赖于构造活动促成油气富集的各种构造圈闭类型,同时也发现了需由构造配合岩性、岩相、沉积环境等条件而形成的地层、岩性圈闭。即古构造-岩性型、古构造-成岩型、构造-岩性型等多种多样的非构造圈闭类型。

In the West Sichuan Depression with tight sand, the formation mechanism of traps and gas reservoir is quite complicated, resulted from the basin's complex evolution. Even in different structural part or horizon of the same structural deformation band, there exists distinct difference in both oil-and-gas bearing condition and geological factors restricting trap and gas enrichment. There are structural traps where structural activities enrich oil and gas. There are also non-structural stratum and lithologic traps, such as palaeostructural-lithologic trap, palaeostructural-diagenetic trap, and structural-lithologic trap, where structural activities cooperate with lithology, lithofacies, and sedimentary environment.