Abstract: The foreland basin is dominated by structural reservoirs, and generally it is difficult for lithostratigraphic reservoirs to form large-scale resource fields. Based on the case study of the Mesozoic in the eastern Kuqa depression, as well as the superposition analysis of a large number of outcrop, drilling, seismic and logging data, it is obtained that the large-scale Tugeerming anticline in the eastern Kuqa depression was formed by successive basement thrusting in Paleocene and Pliocene with NNE-SSW trending main compressive stress field of deformation. Yiqikelike anticline is a basement-involved thrust structure. Its southern wing is the Dibei slope with simple topography, while the northern wing incline to the north at a low angle with NNW-SSE trending main compressive stress field. In the Middle and Lower Jurassic and Upper Triassic, sapropelic source rocks with huge thick layers of humic and dark mudstone in coal measures were developed in the eastern Kuqa depression. The sedimentary centers are distributed in Kuqa River, Dibei and Tudong areas. The total organic carbon content is 2.1% to 3.3%, and the R_o is 1.0% to 2.0%, indicating the mature and high-mature stages of reservoirs with large hydrocarbon generation potential. Middle- and thin-layered sandbodies of the braided river delta plain and delta front is widely developed, with the cumulative thickness of 200 m to 280 m. The sand body is discontinuous in the vertical direction and lenticular in the transverse direction, and the extension distance is up to 4 km. There are three types of large-scale favorable areas for oil and gas accumulation. Structural-lithologic reservoirs are developed in the large anticline slope, large area of tight sand structural-lithologic reservoirs are developed in Yangxia sag and the gentle zone of the deep anticline, as well as the structural-stratigraphic onlap reservoirs are developed in the south slope of Yangxia sag.

Key words: Kuqa depression, Middle and Lower Jurassic, Upper Triassic, structural-lithologic strata, reservoir

摘要： 前陆盆地以蕴藏构造油气藏为主，岩性地层油气藏在以往被认为难以形成规模资源量。以库车坳陷东部中生界为例，在大量露头、钻井、地震和测井资料叠合分析的基础上，分析出吐格尔明大型背斜构造为古新世和上新世继承性基底冲断作用的产物，其变形主压应力场的方位为NNE—SSW向；依奇克里克背斜构造为基底卷入的冲断构造，其褶皱南翼相对简单，为迪北斜坡带，北翼呈低角度北倾，变形主压应力场的方位为NNW—SSE向。库车坳陷东部中—下侏罗统和上三叠统发育巨厚层煤系腐殖型和暗色泥岩腐泥型烃源岩，沉积中心分布在库车河地区、迪北地区和吐东地区，TOC含量为2.1%~3.3%，R_o为1.0%~2.0%，处于成熟—高成熟阶段，生烃潜力大；广泛发育中层—薄层辫状河三角洲平原—前缘砂体，累计厚度为200~280 m，砂体在垂向上不连续加积，在横向上呈透镜状，延伸距离最大可达4 km。油气藏主要发育在3个有利区带：构造-岩性油气藏发育在大型背斜围斜部位，大面积致密砂岩构造-岩性型油气藏发育在阳霞凹陷和深部背斜平缓带，构造-地层超覆油气藏发育在阳霞凹陷南斜坡。

关键词: 库车坳陷, 中—下侏罗统, 上三叠统, 构造-岩性地层, 油气藏