Digital Core Modelling Method Based On CT Image And MC Algorithm

With the high-speed development of national economy,oil,as one of the important energy in our country,has been in short supply,the exploitation of oil and has become an urgent problem how to improve the recovery rate,due to the reservoir core complex internal structure,early detection of two-dimensional far short of the demand of people,now,using the digital core technology forecast core inside one of the indispensable means,with the gradually mature and application of numerical simulation,based on the three dimensional digital core physical simulation research has developed into the best way to rock physics research.Due to the heterogeneity of the actual core,only through a simple two-dimensional CT image and a simple algorithm of cores is difficult to reflect the actual reality,unable to accurately describe the internal complex pore structure,therefore,based on the core 2D information,using different algorithms to build digital cores with real similar pore structure,made on the basis of this research has more value and reference significance.Firstly,according to the processed CT core section and other core data,the methods of establishing digital core by CT scanning method,process simulation method and mixed method were studied,and the advantages and disadvantages of each method were analyzed.Secondly,the development and characteristics of MC algorithm are introduced and modified on the basis of the algorithm to solve the ambiguity problem and rebuild the digital core.Then,using the lattice boltzmann method for the above three methods to establish the digital core is evaluated,quantitative calculation of the reconstruction of 3D digital core of the autocorrelation function and partial porosity distribution function and average percolation probability function parameters and are compared with those of the real core,the results show that based on two-dimensional CT image,using the MC algorithm to reconstruct 3D digital core pore size,distribution and heterogeneity is similar to real core,and the reconstruction of cores in terms of connectivity and real closer;Finally,the flow simulation of the 3D digital core reconstructed by MC algorithm on the residual oil distribution is carried out to predict the built core.Prediction results with the digital core analysis results and the corresponding core physical simulation experiment results match height,suggests that this paper puts forward that construction of digital core and the validity and reliability of pore network model method,with the pore structure parameters for establishing a continuous change of 3D digital core provides a new method,At the same time,it can also provide relevant theoretical and data basis for subsequent mining and research.