Marchenko redatuming allows one to use surface seismic reflection data to generate the seismic response from sources at the surface to any point in the subsurface. Without requiring much information about the earth’s properties, the seismic response generated by Marchenko redatuming contains accurate estimates of not only the primaries but also the internal multiples. A target-oriented imaging method, referred to as Marchenko imaging, was implemented for imaging complex structures of the earth using the seismic response obtained through Marchenko redatuming. Taking account of the contribution of primaries and internal multiples, Marchenko imaging produces images that contain fewer artifacts than the images obtained using conventional imaging methods (e.g., reverse time migration) with the same input data. In this study, we applied Marchenko imaging to a field data set acquired at the Gulf of Mexico to produce an image of a subsalt area. We investigated two important and practical aspects of the Marchenko framework: (1) the missing near offsets in marine shot records and (2) the calibration of the reflection data. Finally, we suggested a workflow for processing the marine towed-streamer field data set acquired at the Gulf of Mexico, and we have developed a complete theoretical and practical framework to produce a target-oriented subsalt image using the Marchenko methods. The images obtained from Marchenko imaging are consistent and comparable, for the most part, with conventional migration methods. However, Marchenko imaging achieves improvements in the continuity of the geologic structures and in suppressing the artifacts that are caused by internal multiples.

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Marchenko redatuming allows one to use surface seismic reflection data to generate the seismic response at any point in the subsurface due to sources at the surface. Without requiring much information about the earth's properties, the seismic response generated by Marchenko redatuming contains accurate estimates of not only the primaries, but also internal multiples. A target-oriented imaging method, referred to as Marchenko imaging, was implemented for imaging complex structures of the earth using the seismic response obtained through Marchenko redatuming. Taking account of the contribution of both primaries and internal multiples, Marchenko imaging provides more accurate information about the earth's structures than standard imaging methods (e.g. Reverse Time Migration). In order to apply Marchenko redatuming and imaging to field seismic data, we investigate two important aspects of the Marchenko framework: 1) the missing near offsets in marine shot records, and 2) the calibration of the reflection data. With numerical experiments using a Gulf of Mexico salt model (inspired by a Gulf of Mexico field dataset), we present a criterion to determine whether the missing near offsets of the towed-streamer dataset need to be reconstructed. We also demonstrate the importance of proper calibration for the amplitudes of the reflection data in removing the artifacts caused by the mismatch between the amplitudes of the two inputs, the reflection response and the first arrival, for Marchenko redatuming. Finally, we suggest a work flow for processing the marine towed-streamer field dataset acquired at the Gulf of Mexico, and present a complete theoretical and practical framework to produce a target-oriented subsalt image using the Marchenko methods. The images obtained from Marchenko imaging are consistent and comparable, for the most part, with conventional migration methods. However, Marchenko imaging achieves improvements in the continuity of the geological structures and in suppressing the artifacts, which we think are caused by internal multiples.

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Sub-basalt imaging for hydrocarbon exploration faces challenges with the presence of multiple scattering, attenuation and mode-conversion as seismic waves encounter highly heterogeneous and rugose basalt layers. A combination of modern seismic acquisition that can record densely-sampled data, and advanced imaging techniques make imaging through basalt feasible. Yet, the internal multiples, if not properly handled during seismic processing, can be mapped to reservoir layers by conventional imaging methods, misguiding geological interpretation. Traditional internal multiple elimination methods suffer from the requirement of picking horizons of multiple generators and/or a top-down adaptive subtraction process. Marchenko imaging provides an alternative solution to directly remove the artifacts due to internal multiples, without the need of horizon picking or subtraction. In this paper, we present a successful application of direct Marchenko imaging for sub-basalt de-multiple and imaging with an offshore Brazil field dataset. The internal multiples in this example are generated from the seabed and basalt layers, causing severe artifacts in conventional seismic images. We demonstrate that these artifacts are largely suppressed with Marchenko imaging and propose a general work flow for data pre-processing and regularization of marine streamer datasets. We show that horizontally propagating waves can also be reconstructed by the Marchenko method at far offsets.