Seismic Wave Field Forward Modeling And Migration For The Complex Reservoir

The paper concentrates on seismic wave-field forward modeling and migration for the fractured reservoir. It researches the wavefield extrapolation operator for lateral variation of velocity, design four theoretical models and seven practical models with fracture and cavity. Base on the progenitor, in the frequency-wavenumber domain with the PSPI wavefield extrapolation operator and arithmetic of forward modeling and migration that applied lateral variation of velocity which is strong, the paper obtains the result of numerical simulation and the wavefield characteristic by the way of the forward modeling and depth migration of poststack seismic wavefield.Firstly, the paper starts from the one-way wave equation of wavefield extrapolation, research the relationship and transform condition of wavefield extrapolation operators, and improves on the wavefield extrapolation operator and so heightens the operation efficiency, and chooses the PSPI that fits to the lateral variation of velocity to resolve the wave-equation, which lay a foundation of the theoretic study.Secondly, the paper discusses and analyses the characteristic of the seismic wavefield of fractural reservoir and the influence caused by fracture density, property of the filled material, the strike of fracture and so on. And then discusses the problem of the design of the fractured model.Finally, in term of the analysis the characteristic of the seismic wavefield of fractural reservoir, the paper adopts the numerical simulation. The first step, designs the four fractured reservoir models which bases on the geological characters of the analysis field, with the forward modeling and depth migration of poststack seismic wavefield gains the record of the forward and the profile of the migration. The second step, on the base of the first step, the paper designs seven practical models which bases on the practical information of the seismic, by the same way the paper gets the record of the forward and the profile of the migration. The third step, on the base of the anterior steps gets the characters of the seismic response. Generally speaking, when the fractural reservoir is complex, the record of the forward is disorder, the event is interrupted and the difference of its' energy is great, the other way round, the record of the forward is...