| To improve the theoretical research of the fracture distribution affecting on CO2 flooding gas injection law, it can make the implementation of CO2 gas injection development reasonable and efficient. Selecting Hailaer Bei14-Block as the research object, to predict the distribution of natural and artificial fracture, the detailed study on the gas channeling reason of gas channeling wells are carried. In order to obtain the rock mechanics parameters, such as the rock elastic modulus, Poisson’s ratio and cohesion, the uniaxial and triaxial stress experiments are conducted. Through testing the magnitude and direction of the in-situ stress,the reservoir property parameters of Bei14-Block are achieved. Combined with the multi-field coupling mathematical model, three-dimensional seismic data and actual drilling data in the process of CO2 flooding, using the finite element numerical simulation method, a three-dimensional geological model of Bei14-Block is constructed and analyzed. Applying three-dimensional numerical simulation of stress field, a series of theories have been clearly explained, including the mutual influence between different layers, thickness variation of different formations and rock occurrence changes. The maximum and minimum principal stress distribution on a plane of the top and bottom layer is given by the corresponding three-dimensional simulation results, and the stress change of the vertical profile in this region is gotten. According to the stress field distribution model, the structural fracture distribution is predicted quantitatively. The development situation of natural fractures is predicted by failure criterion and the distribution characteristics of artificial fractures are obtained by the stress field distribution. Through the analysis on the gas channeling reasons of Bei14-X56-54 well,the influence law of fractures on gas injection is revealed, providing a more valid theoretical basis to improve the yield for Hailaer Bei14-Block. |
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