Shale Oil Resource Assessment In The E₂s₃, Western Depression Of Liao He

Shale oil exploration and development in China is still in its infancy, and shale oil resource evaluation is not yet mature, Especially a large area of northern continental facies and transitional facies basins as the representative of the western Depression of Liaohe,which Shale are widely riched, high abundance of organic matter, have generated the material basis and organic geochemical conditions of shale oil. In this paper, E2S3 are studied and the current research in this area is basically still in the blank. Therefore, it is necessary to study the shale oil accumulation conditions, evaluation methods, and resources to provide a theoretical reference for shale oil exploration and development of Liaohe Depression.Western depression shale lithology is diverse, mainly deposited on deep lake-semi-deep lake facy of Shahejie formation, shallow lake, profan-delta and the frontal distribution bay is included. Shale formations are widely distributed,and mainly developed E2S3and E2S4 interval. E2S3 shale generally larger thickness, the maximum thickness to 1000 meters, organic matter type of Shale mainly contains type-Ⅱ,a certain amount of type-Ⅰ and less type-Ⅲ kerogen. Abundance of organic matter, organic carbon content gradually decreased from the center to the edge and from the bottom to the up; there is higher abundance of organic matter because of deep lake-semi-deep facy average TOC>2%, and chloroform bitumen "A" and oil-generation potential. In addition, the thermal evolution of shale is lower,0.4%<Ro <1%, is mainly in immature-low mature stage and reach the standard of shale oil development.Shale mineral is composed of clay of the E2S3 in western sag, generally more than 45%, followed by quartz and pyrite, Clay minerals mainly Consists of illite,smectite inter-layer illite and montmorillonite. smectite transition to smectite inter-layer illite and montmorillonite with increased depth. In addition, the development of tectoclases, there are a lot of dissolved pores and micro-cracks, and contains the nanoscale organic matter pores. The oil content is the most direct parameter oil-bearing, oil-bearing of Chenjia trap and its nearby in E2S3 isl better.By using the Western Depression shale oil resources evaluation system, shale oil favorable area have been optimized in the E2S3 of Liaohe West Depression by multi-factor analysis method. Geological resources and recoverable resources of shale oil of E2S3 and its three sub-paragraph have also been calculated, which shale oil geological resources is about 58973×104t of E2S3 and recoverable resources is about 5897×104t. The lower sub-paragraph of E2S3 is the focus of the development zones for its better geological and geochemical conditions. The middle sub-paragraph of E2S3 is the potential exploration and development strata because of its large area and huge thickness.