The Characterization Of Fracture Rock Elastic Model And Its Application

As we know most oil and gas reservoirs mainly explore from carbonate rocks.Complex digenesis and pore system created a complex carbonate rock structure. Dueto the complexity of carbonate rock pore structure system, the porosity of rocks, poregeometry have an effect on elastic properties of carbonate rocks that is very big, soin-further study of the pore system is bound to promote the understanding ofcarbonate seismic attributes. It can be assumed that that the pores in carbonate scalingof seismic waves is much higher than long premise, through the differential equivalentmedium theory, established porosity, pore geometry, and the connection between theelastic properties of the three. Through the establishment of physical model, estimatethe equivalent elastic modulus of complex porous medium, characterization ofearthquake response of the carbonate rock.Assuming carbonate pore characteristic scale is much smaller than thewavelength of the premise of the earthquake, by the differential effective mediumtheory. It can be builded between the rock porosity, pore geometry and elasticproperties relationship Through the establishment of the physical model to estimatethe equivalent porous media complex elastic modulus, it can be described carbonateseismic response.The equivalent medium theory can simulate the medium of double pore byadding the inclusion into the rock framework. The type of inclusion contain two kindof pore type: stiff pore and soft pore. The procedure of method contain two course: atfirst, it add the small scale stiff pore into the mineral medium until reach the desiredconcentration. Then it add the large pore into the medium which get by the previouslystep until reach the desired concentration. The two kind of inclusion can be describeby similar sphere and ellipsoid.By the differential effective medium theory it can obtain the correspondingmodel results. Through analysis of the simulation results, the soft porous presenceschange the overall elastic properties of the rock, while the difference in pore shape exacerbated differentiation. we combined with logging data were compared with theresults of theoretical simulation and real log data consistent between the two is better,the results confirm the correctness of the theoretical model. At the same time, Givenporosity of the premise, through theoretical calculations of equivalent medium andlogging the difference between the measured vertical and horizontal wave velocity itcan be inversed average porosity of rock type and porosity.