Optimized Log Interpretation And Rock Physics Research Of Organic Shale

Compared with conventional reservoirs, the shale gas reservoirs have so complex compositions of rock matrix, so low porosity and permeability and so various fluid types that the conventional log interpretation theories and methods cannot be used in organic shale reservoirs. Rock physics characters of organic shales are the basis and bridge of well logging and seismology, and the researches are not enough in China and abroad. To realize log interpretation and seismic reservoir prediction, the study about optimized log interpretation and rock physics research has significant theoretical sense and application value.This thesis is based on geologic features and log responses of organic shales, and studies the optimized log interpretation methods and rock physics modeling methods. First of all, the theory and algorithm of optimized log interpretation are researched, and the theories and implement steps of trust region algorithm, pattern search method and genetic algorithm are studied. The rock physics models and the optimized log interpretation of organic shales are established and completed, and the mineral contents are computed. The research shows that the accuracy of pattern search algorithm is higher than other algorithms, and the effect is better when five log curves are used. Then, the rock physics modeling theory and method of organic shales are studied, and the method estimating velocities of compressive and shear waves and elastic moduli using the mineral contents by optimized log interpretation is realized. The method is used in organic shales, and the results agree well with log responses which demonstrate the reliability of rock modeling method and prove the estimating methods correct again. Again, the relationship between elastic moduli and total organic carbon content is studied, and the preliminary conclusions have obtained. Finally, the methods above all are used in some shale wells, and mineral contents, velocities of compressive and shear waves and elastic moduli are all agreed well with log response, which demonstrate the correctness and feasibility of proposed methods.The thesis realizes optimized log interpretation and rock modeling methods by establishing rock physics model of organic shales, and analyzes elastic properties. The achievements establish a good foundation for further research of log interpretation and rock physics in organic shales.