Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Europe
Source-independent elastic least-squares reverse time migration
Fang, Jinwei (China University of Petroleum) | Zhou, Hui (China University of Petroleum) | Chen, Hanming (China University of Petroleum) | Wang, Ning (China University of Petroleum) | Wang, Yufeng (China University of Petroleum) | Sun, Pengyuan (BGP Research and Development Center) | Zhang, Jianlei (BGP Research and Development Center)
ABSTRACT Elastic least-squares reverse time migration (LSRTM) has been developed recently for its high accuracy imaging ability. The theory is based on minimizing the misfit between the observed and simulated data by an iterative algorithm to refine seismic images toward the true reflectivity. We have developed a new elastic LSRTM with the same modeling equations for source and receiver wavefield extrapolations, except for their source terms. The LSRTM has a natural advantage to solve the source and receiver wavefields using the same modeling system; thus, it is easy to implement LSRTM. In practice, it is difficult to obtain an accurate source wavelet, so a convolution-based objective function is used in our source-independent elastic LSRTM. Such an objective function can relax the requirement of an accurate wavelet, and improve the robustness of the inverse problem in the presence of noise. The numerical examples indicate that our method has the ability to recover the reflectivity models with an incorrect source wavelet from noisy data.
- Geophysics > Seismic Surveying > Seismic Processing > Seismic Migration (1.00)
- Geophysics > Seismic Surveying > Seismic Modeling > Velocity Modeling > Seismic Inversion (0.46)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Hod Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Hod Formation (0.99)
Application of LCSSI method in elastic impedance inversion based on orthogonal matching pursuit algorithm
Chen, Guang (China University of Petroleum–Beijing) | Zhou, Hui (China University of Petroleum–Beijing) | Liu, Mingdi (China University of Petroleum–Beijing) | Tao, Yonghui (China University of Petroleum–Beijing) | Wang, Haiyang (China University of Petroleum–Beijing)
ABSTRACT Elastic impedance inversion is an important prestack inversion method in reservoir prediction and fluid identification. Constrained sparse spike inversion (CSSI) used to be the most widely used method in poststack seismic inversion. Because of the relationship between the elastic impedance and the wave impedance, the CSSI can be directly applied to the prestack elastic impedance inversion. However, CSSI usually suffers from strongly ill-posed problem when using some local optimization algorithm, such as conjugate gradient (CG) method, and has a strong dependence on the initial model of reflection coefficient. Besides, conventional CSSI separately inverts the time locations and amplitudes of sparse-spikes, which increases the computational complexity. In this paper, we improve CSSI theory with a linear wave impedance constraint, which is named as LCSSI. We apply orthogonal matching pursuit (OMP) non-linear algorithm to linear constrained sparse spike prestack elastic impedance inversion. We derive a linear matrix equation from the cost function and use OMP algorithm to invert the sparse-spikes' time locations and amplitudes simultaneously. Due to OMP, this method can reduce dependence on initial model and obtain the inversion results precisely and quickly. Numerical examples indicate that our method can achieve a good performance even for noisy data, while the CG algorithm fails to get a desirable inversion result. Presentation Date: Wednesday, October 19, 2016 Start Time: 8:00:00 AM Location: 155 Presentation Type: ORAL
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Tofte Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Ile Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Garn Formation (0.99)
- (9 more...)
Robust source-independent elastic full-waveform inversion in the time domain
Zhang, Qingchen (China University of Petroleum) | Zhou, Hui (China University of Petroleum) | Li, Qingqing (China University of Petroleum) | Chen, Hanming (China University of Petroleum) | Wang, Jie (SINOPEC Geophysical Research Institute)
ABSTRACT Accurate estimation of source wavelet is crucial in a successful full-waveform inversion (FWI); however, it cannot be guaranteed in the case of real seismic data. We have developed time-domain source-independent elastic FWI using the convolution-based objective function that was originally developed for acoustic FWI. We have applied a new time window on the reference traces in the objective function to suppress the noises induced by the convolution and crosscorrelation operations. Also, we have adopted -, Huber-, and hybrid-norm objective functions to improve the antinoise ability of our algorithm. We implemented a multiscale inversion strategy to conduct the tests with a quasi-Newton limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) method to reduce the sensitivity to initial models and to improve the quality of inversion results. Synthetic tests verified that the new added time window can not only improve the inversion results, but also accelerate the convergence rate. Our method can be implemented successfully without a priori knowledge or accurate estimation of the source wavelet and can be more robust to Gaussian and spike noises, even for a Dirac wavelet. Finally, we applied our method to real seismic data. The similarity between the observed and modeled seismic data, the higher resolution of the migration image, and flatter common image gathers corresponding to the inverted models proved the relevance of our algorithm.
- Geophysics > Seismic Surveying > Seismic Processing (1.00)
- Geophysics > Seismic Surveying > Seismic Modeling > Velocity Modeling > Seismic Inversion (1.00)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/8 > Valhall Field > Hod Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Tor Formation (0.99)
- Europe > Norway > North Sea > Central North Sea > Central Graben > Block 2/11 > Valhall Field > Hod Formation (0.99)
Summary Prestack elastic parameter inversion (PEPI) is very helpful in quantitative estimation of reservoir properties. Sparse spike inversion (SSI) is the most widely used method in PEPI. However, SSI using some local optimization algorithms (e.g., conjugate gradient method, CG) usually suffers from a strongly ill-posed problem. The global optimization algorithms can avoid this problem effectively, in spite of a little extra computation cost. Besides, the usually used SSI separately inverts sparse-spike’s time locations and its amplitudes and it is low efficient. In this abstract, we adopt orthogonal matching pursuit (OMP) non-linear algorithm for SSI, and derive a linear matrix equation to invert the sparse-spike’s time locations and its amplitudes simultaneously (TLAS). We name the method as TLASSSI. The linear matrix equation is derived from the cost function without any constraint terms. In spite of no constraint terms, TLASSSI can still obtain exact inversion results including sparse-spike’s time locations and its amplitudes. Numerical examples indicate that our method can achieve a good performance even with an existence of some noise, while the CG algorithm fails to get a desirable inversion result.
- South America > Argentina > Patagonia > Golfo San Jorge Basin (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Tofte Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Ile Formation (0.99)
- (10 more...)