In the past few years, three-dimensional（3-D） seismogram has become an essential tool for the interpretation of subsurface stratigraphy and depositional systems. Seismic stratigraphy in conjunction with seismic geom...In the past few years, three-dimensional（3-D） seismogram has become an essential tool for the interpretation of subsurface stratigraphy and depositional systems. Seismic stratigraphy in conjunction with seismic geomorphology has elevated the degree to which seismic data can facilitate geological interpretation, especially in a deepwater environment. Technologies such as time slicing and interval attribute analysis can enhance geomorphological interpretations, and, when integrated with stratigraphic analyses, can yield insights regarding distribution of seal and reservoir facies. Multiple attributes corendering can further bring out features of geological interest that other technologies may overlook. This method involves corender spectral decomposition components（SDC） with semblance attributes to describe the distribution of deepwater channel elements and the boundaries of deepwater sinuous channel. Applying this technology to four elements is observed：（1） point-bars,（2） migration of channel meander loops,（3） channel erosion/cut, and（4） avulsion. The planview expression of the deepwater channel ranges from low sinuosity to high sinuosity. Furthermore, this technology has enabled interpreters to visualize details of complex depositional elements and can be used to predict net-to-gross ratio in channel systems, which can be incorporated into borehole planning for exploration as well as development needs to improve risk management significantly. The technology is applied to the study area in an effort to illustrate the variety of interpretation technologies available to the geoscientist.展开更多
Semblance,a measure of multi-trace coherence,has been used extensively in seismic data processing and interpretation such as velocity analysis and fault detection. The traditional algorithm has a difficulty at zero-cr...Semblance,a measure of multi-trace coherence,has been used extensively in seismic data processing and interpretation such as velocity analysis and fault detection. The traditional algorithm has a difficulty at zero-crossings of seismic recordings. This problem is alleviated by applying a smoothing window at the cost of losing vertical resolutions. In this paper,we improve the algorithm by computing semblance from complex traces. Our initial results show that the complex semblance is smooth at zero-crossings. Because the smoothing time window becomes unnecessary,the higher vertical resolution can be achieved by using small windows or none. Some geological features,like faults and unconformities,appear clearer and easier to identify with the complex semblance. As the advantages are obvious and the implementation is straight-forward with the Hilbert transform,this new algorithm may replace the traditional one in future applications.展开更多
Full-waveform inversion is a promising tool to produce accurate and high-resolution subsurface models.Conventional full-waveform inversion requires an accu-rate estimation of the source wavelet,and its computational c...Full-waveform inversion is a promising tool to produce accurate and high-resolution subsurface models.Conventional full-waveform inversion requires an accu-rate estimation of the source wavelet,and its computational cost is high.We develop a novel source-independent full-waveform inversion method using a hybrid time-and frequency-domain scheme to avoid the requirement of source wavelet estimation and to reduce the computational cost.We employ an amplitude-semblance objective function to not only effectively remove the source wavelet effect on full-waveform inver-sion,but also to eliminate the impact of the inconsistency of source wavelets among different shot gathers on full-waveform inversion.To reduce the high computational cost of full-waveform inversion in the time domain,we implement our new algorithm using a hybrid time-and frequency-domain approach.The forward and backward wave propagation operations are conducted in the time domain,while the frequency-domain wavefields are obtained during modeling using the discrete-time Fourier trans-form.The inversion process is conducted in the frequency domain for selected frequen-cies.We verify our method using synthetic seismic data for the Marmousi model.The results demonstrate that our novel source-independent full-waveform inversion pro-duces accurate velocity models even if the source signature is incorrect.In addition,our method can significantly reduce the computational time using the hybrid time-and frequency-domain approach compared to the conventional full-waveform inversion in the time domain.展开更多
基金The National Natural Science Foundation of China under contract Nos 41102059 and 91328201the National Science and Technology Major Project of China under contract No.2017ZX05032-001
文摘In the past few years, three-dimensional（3-D） seismogram has become an essential tool for the interpretation of subsurface stratigraphy and depositional systems. Seismic stratigraphy in conjunction with seismic geomorphology has elevated the degree to which seismic data can facilitate geological interpretation, especially in a deepwater environment. Technologies such as time slicing and interval attribute analysis can enhance geomorphological interpretations, and, when integrated with stratigraphic analyses, can yield insights regarding distribution of seal and reservoir facies. Multiple attributes corendering can further bring out features of geological interest that other technologies may overlook. This method involves corender spectral decomposition components（SDC） with semblance attributes to describe the distribution of deepwater channel elements and the boundaries of deepwater sinuous channel. Applying this technology to four elements is observed：（1） point-bars,（2） migration of channel meander loops,（3） channel erosion/cut, and（4） avulsion. The planview expression of the deepwater channel ranges from low sinuosity to high sinuosity. Furthermore, this technology has enabled interpreters to visualize details of complex depositional elements and can be used to predict net-to-gross ratio in channel systems, which can be incorporated into borehole planning for exploration as well as development needs to improve risk management significantly. The technology is applied to the study area in an effort to illustrate the variety of interpretation technologies available to the geoscientist.
基金supported by the National Natural Science Foundation of China (No. 41574134)the 100 Talents Program of the Chinese Academy of Science
文摘Semblance,a measure of multi-trace coherence,has been used extensively in seismic data processing and interpretation such as velocity analysis and fault detection. The traditional algorithm has a difficulty at zero-crossings of seismic recordings. This problem is alleviated by applying a smoothing window at the cost of losing vertical resolutions. In this paper,we improve the algorithm by computing semblance from complex traces. Our initial results show that the complex semblance is smooth at zero-crossings. Because the smoothing time window becomes unnecessary,the higher vertical resolution can be achieved by using small windows or none. Some geological features,like faults and unconformities,appear clearer and easier to identify with the complex semblance. As the advantages are obvious and the implementation is straight-forward with the Hilbert transform,this new algorithm may replace the traditional one in future applications.
基金supported by the U.S.Department of Energy(DOE)through the Los Alamos National Laboratory(LANL),which is operated by Triad National Security,LLC,for the National Nuclear Security Administration(NNSA)of U.S.DOE under Contract No.89233218CNA000001provided by the LANL Institutional Computing Program,which is supported by the U.S.DOE NNSA under Contract No.89233218CNA000001.
文摘Full-waveform inversion is a promising tool to produce accurate and high-resolution subsurface models.Conventional full-waveform inversion requires an accu-rate estimation of the source wavelet,and its computational cost is high.We develop a novel source-independent full-waveform inversion method using a hybrid time-and frequency-domain scheme to avoid the requirement of source wavelet estimation and to reduce the computational cost.We employ an amplitude-semblance objective function to not only effectively remove the source wavelet effect on full-waveform inver-sion,but also to eliminate the impact of the inconsistency of source wavelets among different shot gathers on full-waveform inversion.To reduce the high computational cost of full-waveform inversion in the time domain,we implement our new algorithm using a hybrid time-and frequency-domain approach.The forward and backward wave propagation operations are conducted in the time domain,while the frequency-domain wavefields are obtained during modeling using the discrete-time Fourier trans-form.The inversion process is conducted in the frequency domain for selected frequen-cies.We verify our method using synthetic seismic data for the Marmousi model.The results demonstrate that our novel source-independent full-waveform inversion pro-duces accurate velocity models even if the source signature is incorrect.In addition,our method can significantly reduce the computational time using the hybrid time-and frequency-domain approach compared to the conventional full-waveform inversion in the time domain.
