Research On Methods Of Shale Oil Formation Evaluation In Jiyang Depression

Shale oil reservoirs in jiyang depression are mainly distributed in the paleogene shahejie formation. Reservoir lithology are mainly calcareous mudstone, calcareous oil mudstone, mudstone, oil mudstone and oil shale. Organic matter types are mainly kerogen type I and kerogen type Ⅱ1. Organic matter abundance is in a various range; the total organic carbon content in reservoirs with low organic mater abundance is about 1.5% while the total organic carbon content in reservoirs with high organic mater abundance is about 3.4%. Most of the organic matter in shale oil reservoir are in low-mature (0.5%< Ro< 0.8%) or mature stage (0.8%< Ro< 1.3%). Reservoir porosity is distributed in a various range, with an average of 4.58%. Reservoir permeability is mainly distributed between 0.01-200 mD. Reservoir oil saturation is quite high, with an average of 72.1%.Based on the analysis of reservoir characteristics above, the main study contents of this paper is achieved as follows:Both activity function method and inflection point method are used to perform automatic layering from well logs and the application of these two methods are quite efficient and consistent.Quantitative evaluation of geochemical parameters of shale oil reservoirs in Jiyang depression is accomplished based on well logging data. Effective evaluation of vitrinite reflectance is conducted by linear fitting it with buried depth. Current methods of evaluating TOC content from conventional well logging data are summarized and applied in quantitative evaluation of total organic carbon content of shale oil reservoirs in jiyang depression. Neural network method is proposed to calculate rock free hydrocarbon content S1 from well logging data. Appraisal model of rock pyrolysis hydrocarbon content S2 is established with TOC content.Multimineral model of the shale oil reservoirs in jiyang depression and improved mineral inversion method are proposed, which have improved the accuracy of mineral content calculation Porosity in shale oil reservoirs are quantitatively evaluated by different methods, including linear fitting method, neural network method and multimineral inversion method. Permeability in shale oil reservoirs are quantitatively evaluated by linear fitting method and neural network method. Oil and water saturation in shale oil reservoirs are quantitatively evaluated by different methods, including Archie method, linear fitting method and neural network method.Finally, well logging evaluation method for mechanical parameters of shale oil reservoirs are studied, which include elastic parameters, strength parameters and brittleness index.There are two innovations in this paper. Neural network method is proposed to calculate free hydrocarbon content for the first time, and the application effect is quite well. Besides, a multi-minerals volume model with improved inversion method for shale oil reservoirs in Jiyang depression is proposed for the first time, which also works well in field application.