Multi GPU calculation based reverse time migration imaging method of 3D TTI medium

Abstract

The invention discloses a multi GPU calculation based reverse time migration imaging method of a 3D TTI medium. According to the method, a stable second-order coupling equation set serves as a calculation model, finite SV wave components are given to enhance the wave field spreading stability, an anisotropy parameter matching method is used to suppress interference of pseudo-transverse waves, uniform anisotropy boundaries corresponding to a random speed boundary and other parameters are introduced, storage of large amount of wave field data and frequency disk reading and writing are avoided, and a GPU-based CUDA platform is used to realize high-performance parallel calculation. According to the invention, a second-order coupling quasi-acoustic equipment in the TTI medium is solved in a difference method on the basis of multi-GPU parallel calculation technology, wave field spreading is stable, pseudo-transverse waves are suppressed effectively, application of the random boundary reduces wave field storage and disk reading and writing, a multi-asynchronous-flow high parallel strategy of multi GPU calculation is used, the calculation efficiency is improved obviously, and the imaging method meets requirements for industrialization of anisotropy reverse time migration.

Description

technical field [0001] The invention belongs to the technical field of reflection seismic data imaging, and in particular relates to a three-dimensional TTI medium reverse time migration imaging method based on multi-GPU computing. Background technique [0002] With the deepening of oil and gas exploration, the need to comprehensively describe reservoir lithology, stress, fractures and fluids presents a challenge to conventional P-wave seismic exploration. Multi-component seismic exploration can provide more abundant seismic information and can record the vector seismic wave field completely, thereby reducing the polysolution of P-wave exploration and meeting the needs of exploration and development. The pre-stack migration technology of multi-component data is the focus of research and development in the development of multi-component exploration technology in recent years, and it is the key to solving complex geology, structural imaging, and reservoir description problems....

AI Technical Summary

Problems solved by technology

[0004] 1. Inaccurate separation of surface wave types

For isotropic media, it is usually assumed that the recorded vertical component is a longitudinal wave, and the horizontal component is a transverse wave, or the wave field is decomposed on the surface by methods such as polarization analysis and τ-p transformation, but the seismic wave field propagated underground is coupled. Basically, it is difficult to achieve complete separation of longitudinal and transverse waves by wave field separation methods.

[0005] 2. The vector nature of the wave field is ignored

The multi-component seismic data records the vector wave field. The method of separating the wave field first, and then migrating the longitudinal wave and the converted wave separately based on the scalar migration method eliminates part of the information of the multi-component seismic wave field, and cannot fully reflect the wave in the underground medium. The rules and characteristics of propagation in

[0006] 3. Not conducive to subsequent analysis and interpretation

The second is that TTI medium reverse time migration has high-intensity computing requirements. At present, the industry often uses PC cluster technology to deal with the high-intensity computing problems of TTI reverse time migration. However, large-scale computer clusters need to occupy a lot of space in the computer room and waste a lot of power resources

The third is the problem of memory space. TTI reverse time migration needs to store the wave field information of each calculation step of the longitudinal wave field and the auxiliary wave field, so as to realize the simultaneous correlation imaging of the forward and backward wave fields, which requires A large amount of storage space overhead is limited by the memory capacity of the PC, and the TRON information needs to be stored in the hard disk, which leads to frequent data read and write operations between the PC memory and the hard disk, greatly increasing the IO time, and thus greatly Amplitude extends the time required for TTI reverse time migration

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