The Sedimentologic Characteristics And Potential Target Of Lacustrine Carbonate Reservoir In The Upper 4^Th Member Of Shahejie Formation(E₂ 2S₄^U),Luojia District, Zhanhua Depression

Lacustrine carbonate rocks are widely developed in Chinese continental oil and gas bearing basins. Such as the paleogene carbonate source rocks of Dongpu sag and Chaidamu basin, the cretaceous mussel-shrimp bearing carbonate rocks in Daqing oilfield and in Jurassic layer of the Sichuan basin, the palegene lacustrine carbonate in the Jiyang sag and Huanghua sag, which are not only the good petroleum reservoir, but also have great genetic potential. In a word, the study of lacustrine carbonate have great significance for the reservoir geology and the exploration and exploitation of continental oilfield.The research work is based on the subject of SinoPec Shenli oilfield-the E22S4u sedimentary character and reservoir distribution in lacustrine carbonate in Zhanhua sag and Chezhen sag.This paper is focused on the E22S4u sedimentary character and reservoir distribution in lacustrine carbonate in Luojia district. The main research work and achievements as follows:Firstly, based on the outcrop,core,thin section and the geochemical and geophysical test, we analysed the type of carbonate rocks, the rule of carbonate rocks distribution and the evolvement of the reservoir, and built the sedimentary mode.The next step is the analysis of the character of different types of reservoir, the reservoir spaces and the evolvement of the pores and fissures. On the basis of the above analysis, we choose the parameters for evaluation of the reservoir.What is the last, but is not least important step is the evaluation of the E22S4u lacustrine carbonate reservoir and prospect of the potential target. Because of the fast change in lacustrine facies and reservoir, the potential target of reservoir is not easy to be confirmed, and which is the main purpose of the paper. This research is combined with the macroscopical and microcosmic achievements, the key technology of this paper are the observation and analysis of the outcrop and thin sections, the geochemical and geophysical test. Based on all the above achievements, we can predict the location of the best reservoir.