Abstract
Multiple reflections contain abundant structural information about the subsurface because of their smaller reflection angles and wider coverage. Multiple imaging has increasingly attracted attention. However, the imaging of multiples first needs to separate the multiples, which is a time-consuming and high-cost job. Therefore, the simultaneous imaging of primaries and multiples, which can make good use of multiple reflections with no need for multiple separation, has increasingly attracted attention. However, there are still some challenges to the conventional method, including wavelet selection and image artifacts suppression. In this paper, an improved method of the simultaneous imaging of primaries and multiples is proposed by introducing two creative strategies. First, considering that the wavelet, which is usually estimated by signal analysis under certain assumptions, is crucial to the simultaneous imaging, we propose to estimate the wavelet by iterative SRME (surface-related multiple elimination) using the original data containing multiples based on wave equation theory instead of signal analysis. Second, the stereographic imaging condition is introduced to suppress the crosstalk artifacts in the image. According to the numerical examples and field data test, the feasibility and effectiveness of our approach is verified.
Highlights
When a seismic wave propagates in the subsurface and encounters formation interfaces, reflection or transmission occurs
To better describe and balance the contribution of the primary image and multiple image, we suggest to estimate the wavelet through iterative surface-related multiple elimination (SRME) based on wave equation theory to effectively guarantee the accuracy of wavelet estimation for data with multiples, and use the estimated wavelet together with the recorded data as the source wavefield, which is quite different from selecting an arbitrary wavelet in conventional simultaneous imaging
In this paper, we first analyze the main challenges in the conventional simultaneous imaging of primaries and multiples through theoretical derivation, and it is concluded that one of the most important issues is the inaccurate wavelet, and the another issue is the artifacts that should be avoided by a proper imaging condition
Summary
When a seismic wave propagates in the subsurface and encounters formation interfaces, reflection or transmission occurs. To better describe and balance the contribution of the primary image and multiple image, we suggest to estimate the wavelet through iterative SRME based on wave equation theory to effectively guarantee the accuracy of wavelet estimation for data with multiples, and use the estimated wavelet together with the recorded data as the source wavefield, which is quite different from selecting an arbitrary wavelet in conventional simultaneous imaging. Structural images can be obtained by extrapolating the source wavefield and the receiver wavefield into the earth interior on the basis of the one-way wave equation migration first, the imaging condition [34] can be applied to obtain the related reflectivity information from the forward-extrapolated source wavefield and backwardextrapolated receiver wavefield at each depth-step [20]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
