【摘要】 准噶尔盆地吉木萨尔凹陷东斜坡二叠系梧桐沟组发育多套厚薄不等的砂砾岩体,是研究区重要的含油气储集体。通过岩心描述、薄片观察、重矿物及粒度分析,结合测井及地震资料解释,从该套砂砾岩体的古地理特征、物源条件及岩石学特征等方面,确定其为湖底扇相沉积。通过研究吉17井区梧桐沟组一段湖底扇相标志、相类型及砂体展布,认为研究区主要为内扇亚相和中部扇亚相,以及主沟堤微相、漫溢微相、辫状沟道微相、主沟道微相等沉积微相。结合储层物性和构造特征分析,认为湖底扇相具备形成岩性油气藏的条件,油气藏形成于辫状河三角洲前缘的外围半深湖区,其沉积厚度大,分布相对稳定,储集物性好,油源充足,油气侧向和纵向上运移通道良好,运移距离较短,是发育在凹陷斜坡区半深湖相中主要的岩性油藏勘探目标。更多还原

【Abstract】 As important hydrocarbon-bearing reservoirs in the study area,multiple sets of glutenite with different thicknesses are developed in Permian Wutonggou Formation on the east slope of Jimsar sag,Junggar Basin.Through core description,slice observation,heavy mineral and grain size analysis in combination with well logging and seismic data,this region was identified as sublacustrine fan facies sediments in terms of the paleo-geographic characteristics,provenance conditions and petrological characteristics of glutenites.According to the analyses on sublacustrine fan facies marks,facies types and sand body distribution in Member 1 of Wutonggou Formation,Well Ji-17,it is considered that the study area is dominated by inner-fan subfacies and middle-fan subfacies with sedimentary microfacies,such as main levee microfacies,overflow microfacies,braided channel microfacies and main channel microfacies.Based on the analyses on physical properties and tectonic characteristics of reservoirs,it is regarded that sublacustrine fan facies has favorable conditions for the formation of lithologic reservoirs.The reservoirs were formed in the semi-deep lake area in the periphery of braided river delta front,characterized by large sediment thickness,stable distribution,favorable reservoir physical properties,sufficient oil sources,good lateral and vertical migration channels for oil and gas,as well as short migration distance.These reservoirs are the main target of lithologic reservoir exploration and development in the semi-deep lake facies of sag slope area.更多还原