Deepwater reservoir prediction using broadband seismic-driven impedance inversion and seismic sedimentology in the South China Sea

Abstract

In recent years, many important discoveries have been made in the marine deepwater hydrocarbon exploration in the South China Sea, which indicates the huge exploration potential of this area. However, the seismic prediction of deepwater reservoirs is very challenging because of the complex sedimentation, the ghost problem, and the low exploration level with sparse wells in deepwater areas. Conventional impedance inversion methods interpolate the low frequencies from well-log data with the constraints of interpreted horizons to fill in the frequency gap between the seismic velocity and seismic data and thereby recover the absolute impedance values that may be inaccurate and cause biased inversion results if wells are sparse and geology is complex. The variable-depth streamer seismic data contain the missing low frequencies and provide a new opportunity to remove the need to estimate the low-frequency components from well-log data. Therefore, we first developed a broadband seismic-driven impedance inversion approach using the seismic velocity as initial low-frequency model based on the Bayesian framework. The synthetic data example demonstrates that our broadband impedance inversion approach is of high resolution and it can automatically balance between the inversion resolution and stability. Then, we perform seismic sedimentology stratal slices on the broadband seismic data to analyze the depositional evolution history of the deepwater reservoirs. Finally, we combine the broadband amplitude stratal slices with the impedance inversion results to comprehensively predict the distribution of deepwater reservoirs. Real data application results in the South China Sea verify the feasibility and effectiveness of our method, which can provide a guidance for the future deepwater hydrocarbon exploration in this area.

Seismic-Geological Integrated Study on Sedimentary Evolution and Peat Accumulation Regularity of the Shanxi Formation in Xinjing Mining Area, Qinshui Basin

“…Seismic sedimentology studies the stratigraphic lithology, sedimentary genesis, basin filling history and sedimentary system through the integrated analysis of seismic lithology and seismic geomorphology [18,22]. It has played an important role in delineating thin sand bodies, predicting favorable reservoirs and comprehensively evaluating potential blocks in the hydrocarbon-bearing sedimentary basin [20,[23][24][25]. However, there are few studies on the sedimentary facies of coal-bearing series by seismic sedimentology, and previous studies have made preliminary attempts to investigate the sedimentary seal ability and the gas content of coal seams by means of seismic sedimentology [11,26].…”

Application of seismic sedimentology in a fluvial reservoir: A case study of the Guantao Formation in Dagang Oilfield, Bohai Bay Basin, China

“…Some researchers have attempted to decompose the original seismic volume into several spectral-decomposition seismic attributes with different dominant frequencies and then combine their seismic attributes using red-green-blue colour blending for visual analysis (Tomasso, Bouroullec, & Pyles, 2010;Bakke & Kane, 2013;Bitrus, Iacopini, & Bond, 2016;Naseer & Asim, 2017;Sun, Lin, Du, Bi, & Ren, 2019;Yue et al, 2019). Luo et al (2018) developed a broadband seismic-driven impedance inversion approach to improve the resolution of inversion and automatically balance between the inversion resolution and stability. Zeng et al (2018) also applied the stratigraphic slicing technique to the prediction of carbonate reservoirs and obtained well effect.…”