哈萨克斯坦南图尔盖盆地油气地质特征及勘探潜力分析

南图尔盖盆地是哈萨克斯坦中南部重要的含油气盆地,为中生代裂谷盆地,具有垒堑相间结构,南部阿尔斯库姆坳陷是盆地的沉积中心和主要的生烃灶,自西向东由4 个北西-南东向展布的地堑组成,已发现的十余个油田均位于地堑间的次级隆起与斜坡部位。盆地主要沉积侏罗系-白垩系地层,由下至上发育了几个大型的区域不整合。直接覆盖在前侏罗系变形基底之上的是下、中侏罗统泥岩为主的生油层系,上侏罗统河道砂体及下白垩统一套广泛发育的席状砂是主要储层,其上一套稳定的湖泊相页岩成为区域盖层,生储盖配置关系合理。该盆地虽然经历了20 多年的勘探历程,大规模的优质储量大部分已被发现,但仍具勘探潜力,除构造圈闭外,斜坡部位的地层岩性圈闭和基底裂缝型风化壳都是未来的勘探方向。

Oil-gas geological features and its exploration potential in South Turgay Basin, Kazakhstan

South Turgay Basin is an important oil-bearing basin in central south Kazakhstan, which is a rift basin of Mesozoic. The struct ure character is grabens separating horsts. Aryskum Trough in the south is the main depression and oil kitchen , including four NW-SE direction grabens from west to east. The oil fields found are located in the arches and slopes. The main genetic unit is Jurassic-Cretaceous series , and several regional unconformities exist through the sediments. Lower-Middle Jurassic mudstones are mainly source rocks, the principal reservoirs are the clastics of the Middle-Upper Jurassic and the Lower Cretaceous Formation, and early Cretaceous mudstone is regional seal. Although during more than 20 years exploration course, most large-size reserves have been found , there are many exploration potential fields. Except for the structure traps, the stratigraphic traps of Jurassic-Cretaceous Formations at the graben flanks and the basement weathered crust of Paleozoic are the future exploration directions.