Digital Core Based Elastic Simulation Of Carbonate Rocks

Finding the exact correspondence between the pore structure and the elastic properties of natural reservoir rocks,especially carbonate rock,has always been a difficult problem to be solved in the oil and gas industry.This article starts with a digital core perspective to try to explore the solution to this problem.Digital core technology can be used to build real rock models by CT scanning imaging,and the elastic simulation based on this will be more accurate.The most critical step in the application of digital core technology in carbonate rock is image processing to establish an accurate and reliable digital core model.This paper proposes a set of image processing procedures for carbonate rock to solve this problem,and uses laboratory test porosity to verify the accuracy of the model.In terms of digital core elastic simulation,due to the heterogeneity of carbonate rock and complex pore structure,it is difficult to correlate with laboratory test data in both rock physics prediction and direct numerical simulation.This paper attempts to verify the trend line composed of digital core simulation data points and the measured data.It is found that the simulation results are very close to the ultrasonic data of a certain confining pressure in the laboratory,which verifies the effectiveness of the simulation work of the digital rock core of the carbonate rock.Using digital core simulation data,this paper uses the Sun's model inversion to obtain a structural compliance factor ? that can quantitatively reflect the influence of pore type on elasticity.The gamma can quantitatively divide the simulation data into three categories,each of which represents that the rock mainly contains a specific pore type.On the basis of the second,the relationship between the elastic parameters with better fitting degree and the porosity can be obtained.The successful application of this technique to prestack seismic inversion will greatly improve the accuracy of porosity prediction.