Seismic Rock Physics Experiment And Modeling Of Complex Pore Structure Reservoir

Seismic exploration is a geophysical exploration method and is widely used in oil and gas resources exploration and development.Rock physics is an indispensable means of seismic exploration,and its research focus has also shifted to the seismic properties of rocks.Rock physics is a bridge connecting reservoir properties(porosity,density,saturation,fluid type,pressure,temperature,crack)and seismic properties(seismic wave velocity,travel time,impedance,amplitude,AVO response).Through petrophysical experimental data and petrophysical models,we can either derive reservoir seismic properties from reservoir properties or reverse reservoir properties from seismic properties to provide assistance in finding hydrocarbon reservoirs.With the increasing difficulty of conventional oil and gas resources development,the development center of gravity shifts to unconventional oil and gas resources.The pore structure of these reservoirs is complex.How to characterize reservoir pore structure is a difficult point in earthquake prediction.The petrophysical experiments were used to measure the porosity,permeability,elastic modulus and the longitudinal and transverse wave velocities of rocks in complex pore structure reservoirs.The variation of petrophysical properties and elastic parameters of rock was analyzed.The pore structure is related.The DEM analytical model was established to analyze the effect of the pore aspect ratio of the rock on the rock elastic modulus and the longitudinal and transverse wave velocity under the assumption of single and double holes.Compare the model prediction results with the core experimental data to analyze the soft and hard pore content in the cores of different lithologies.In addition to the pore structure(porosity aspect ratio),the effect of pore size on the phase velocity and elastic modulus of the rock is analyzed.Considering the multiple scattering of elastic waves in rocks,the wave field in the complex medium is regarded as the superposition of the average field and the disturbance field.The average field is regarded as the wave field propagating in the equivalent medium.The disturbance field is regarded as the complex medium.The wave field caused by the difference between the characteristics of the equivalent medium and the characteristics of the equivalent medium gives the expression of the phase velocity and the equivalent elastic modulus in the complex medium at low frequencies.The pore structure of rocks in underground reservoirs is very complex,and it is difficult to establish a universally applicable seismic petrophysical model.The seismic petrophysical model considering the pore structure established in this paper needs further discussion and verification.It is necessary to further improve the reservoir parameters in combination with laboratory data and logging data.