春光油田古近系砂体成因类型及控制因素

Genetic types and controlling factors of Paleogene sand bodies in Chunguang Oilfield

春光油田位于准噶尔盆地西缘车排子凸起,由于其砂体厚度薄、成因类型多样,导致储层预测难度加大。综合利用三维地震、测井、岩心及分析测试资料,运用高分辨率层序地层学方法,建立了春光油田古近系层序地层格架,并对其砂体的成因类型进行了划分,从岩性特征、沉积厚度及分布特征等方面总结了各类砂体的识别标志,又从水体深度、物源供给、水动力条件及地层发育样式等4个方面,探讨了砂体类型及分布规律的控制因素,并建立了春光油田古近系砂体成因模式。研究结果表明:春光油田古近系地层以辫状河三角洲及湖相沉积为主,发育辫状河三角洲前缘、前三角洲及滨浅湖亚相;砂体成因类型主要为水下分流河道砂体、前缘席状砂体和滩坝砂体。平缓的地形、丰富的物源、湖平面的频繁变化及波浪的侧向改造均是春光油田古近系砂体成因的主要控制因素。

Chunguang Oilfield is located at Chepaizi uplift in western Junggar Basin, and its thin sand body and various genetic types made the reservoir distribution hard to predict. Based on composite analyses of three dimensional seismic, well logging, core and analysis assay data, combined with high resolution sequence stratigraphy method, this paper established sequence stratigraphy framork of Paleogene, divided the genetic types of sand bodies, and concluded the identification signs of different types of sand bodies from the aspects of lithologies, sedimentary thickness and distribution features. Through the control effects of water depth, sediment supply, hydrodynamic conditions and formation development style, the sand body types and distribution rule were discussed and the genetic model of Paleocene sand bodies in Chunguang Oilfield were established. The results show that the Paleogene in Chunguang Oilfield developed braided fiver delta and lake facies, braided fiver delta front, front delta and coastal shallow-lake subfacies are developed,and the genetic types of sand bodies mainly are underwater distributary channel, front sheet terrain, abundant source rocks, changes of lake-level and wave transformation are the main genesis of Paleogene sand bodies. sand and bank bars. Flat controlling factore for the genesis of Paleogene sand bodies.