柴窝堡盆地的石油地质特征

THE CHARACTERISTICS OF PETROLEUM GEOLOGY IN CHAIWOPU BASIN

柴窝堡盆地面积2880km^2,是一个小型的山间构造盆地。它与准噶尔盆地之间隔有大断裂带和石炭系基岩凸起,其下可能存在前寒武基底硬块。中石炭世至二叠纪,柴窝堡地区为博格达裂谷和博格达残留海湖泊的一部分,侏罗纪末期因博格达山隆升而演变为山间盆地。柴窝堡盆地分为4个一级构造单元,其中达北凹陷面积1200km^2,是石油勘探的远景区,其内的圈闭类型以背斜为主。盆地内发育两套生储盖组合,油、气资源量十分丰富。盆地内的局部构造被评价排队,分为4类,有3个可供优先勘探的有利构造。

Chaiwopu Basin, covering an ares of 2880 Km^2, is a small intermontane structural basin. The basin and Junggar Basin are separated by an important big fault zone and an uplift of Carboniferous base rocks. It is likely that there is a firm block of Precambrian base under Chaiwopu Basin. During from Middle Carboniferous to Permian, Chaiwopu region was a part of the Bogda rift and the Bogda lake of survived sea. Bogda Mountain uprose in the last phase of Jurassic, there fore Chaiwopu Basin was formed. Chaiwopu Basin is divided into four structural units of first—order.Among the four units, Dabei Depression, with an area of 1200 km^2, is the prospective region for petroleum prospecting in the basin. The traps for oil in Dabei Depression are mainly the type of anticline. In Chaiwopu Basin, there are two suites of combination for source bed, reservoir bed and cap bed and the resources of oil and gas are very yich. This paper appraises and lines up the local structures in Chaiwopu Basin into four types and raises three advantageous st(?)uctures that can be drilled preferentially.