Analysis Of Error On Geological Interpretation Based On Wave Equation Numerical Simulation

With the continuous development of seismic acquisition technology, seismic profile contained on more abundant information, much of the information of which method to use physiognomy is observed on seismic profiles cannot be detected in. For some complex structure of the boundary, location and other details of the top and bottom (Such as reefs, buried hill, pinch, and other special geological phenomenon), still need to fine interpretation. At present, the latest fine structure based on interpretation of seismic data visualization technology is mainly used, coherent seismic attribute analysis such as calculation, the only advantage of the post-stack seismic shift, or solution of a strong subjective element.In this paper, two-way wave equation pre-stack seismic numerical simulation of synthetic seismograms, pre-stack seismic records of the time offset and depth migration, the corresponding structural section, used to verify the interpretation of results, and proposes a combination of forward and inverse results to verify the interpretation of seismic structural interpretation to reduce thinking and multiple solutions of wave equation based on geological interpretation process, in order to better seismic data processing and interpretation, mainly for the following aspects of work and achieved certain results:First, to achieve the numerical simulation of the wave equation, finite difference method to solve the wave equation, this method has the speed, small memory, etc. For the near to far field and the complex boundary has broad applicability, can accurately simulate wave propagation in various media and the formation of complex structures in the propagation.Second, proposed based on numerical simulation of seismic wave equation Fine Structural Interpretation Technology, using the frequency-wavenumber domain one-way seismic wave equation numerical simulation, by comparing the simulation with the offset recorded before and after the main seismic reflection profile characteristics, successive seismic structural interpretation of the model changes, resulting in fine structure of the final interpretation of the results. The technology uses the frequency-wavenumber domain one-way wave field continuation operator is calculated, not only computationally high efficiency, and high signal to noise ratio recorded wave field simulation, easy target reflected wave field geological characteristics of an effective contrast. The technology make full use of shift before and after the seismic reflection characteristics, help to reduce the seismic structural interpretation of the multiple solutions, access to detailed structural interpretation of seismic models.Third, derived and implemented a one-way wave equation of the frequency-wave number domain numerical simulation, of the speed of the impact of errors on the geological interpretation, migration velocity analysis of the case there is error, depth migration is more sensitive to the velocity error. Geological model through the triangular test, speed is too large and too small from the two aspects of migration velocity errors on the depth migration errors and quantitative research, and summarizes the relevant laws, statistics and obtained the variation of the thickness of top and bottom to change the amount of concrete, for example, increasing the proportional ratio of migration velocity ratio of migration velocity decreases the thickness of the offset error caused by larger,110% of the migration velocity shift caused by the thickness of the offset error rate of greater than 90%. Offset error of speed, but will also affect the reflection characteristics of the bottom stratum. When the offset is faster than the speed of less than 80% of the real, there will not be clear imaging below the ground. Model by practical experiments to verify the reef, so we have deeper their understanding of guidance from the quantitative point of view the actual seismic data processing and interpretation.Fourth, derived and implemented a two-way wave equation finite difference method for numerical simulation, from a practical point of view, by two-way wave equation pre-stack seismic numerical modeling synthetic seismic records, records of pre-stack time migration and depth migration, the corresponding structural section, used to verify the interpretation of results, and analyzed the horizon to explain the impact of errors on the geological interpretation, note wave equation pre-stack depth migration is to solve complex structures and sharp lateral velocity changes in the region ideal for seismic data imaging technology, high accuracy for the structural interpretation of complex areas and provide a reliable guarantee of geological interpretation, interpretation of seismic exploration has played a certain role in guiding the interpretation of the future and has some reference value.