We have developed the theory and synthetic tests of elastic least-squares reverse time migration (ELSRTM). In this method, a algorithm is used to image multicomponent seismic data based on first-order velocity-stress wave equation, in which linearized modeling equations are for forward its adjoint derived adjoint-state method back propagating residuals. Also, we another ELSRTM scheme wavefield separation technique, P-wave obtained using wavefields S-wave wavefields. way, crosstalk artifacts...

Elastic least-squares reverse time migration (ELSRTM) has the potential to provide improved subsurface reflectivity estimation. Compared with elastic RTM (ERTM), ELSRTM can produce images higher spatial resolution, more balanced amplitudes, and fewer artifacts. However, crosstalk between P- S-waves significantly degrade imaging quality of ELSRTM. We have developed an method suppress This includes three crucial points. The first is that forward backward wavefields are extrapolated based on...

Anelasticity of the earth subsurface medium, which is quantified by quality factor <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> , causes dissipation seismic energy. Strong attenuation effect resulting from geology such as gas clouds (gas-filled sandstone) a challenging problem for high-resolution imaging. To compensate effect, first we need to accurately estimate...

As the depth migration of multi-component seismic data can obtain better images subsurface structures with multi-wave information in records, an effective Gaussian beam method is presented this paper. Firstly, a detailed numerical analysis on local slant stack carried out, which demonstrates that has good directionality and computational efficiency through decomposing records into different outgoing directional plane waves. Then two prestack algorithms are presented, corresponding to PP-...

Elastic reverse time migration (ERTM) is a state-of-the-art imaging technique used for determining complicated subsurface structures. However, the migrated images often suffer from low spatial resolution, signal-to-noise ratio (S/N), and unbalanced amplitudes because theoretical hypothesis of ERTM cannot be satisfied in practice. Although elastic least-squares (ELSRTM) has been proposed to address issues ERTM, resulting are generally represented by parameter perturbations such as P-...

Elastic-wave migration in anisotropic media is a vital challenge, particularly for areas with irregular topography. Gaussian-beam (GBM) an accurate and flexible depth technique, which adaptable imaging complex surface areas. It retains the dynamic features of wavefield overcomes multivalued traveltimes caustic problems Kirchhoff migration. We have extended GBM method to work 2D multicomponent under conditions. use Gaussian beams calculate from topography, we two schemes derive down-continued...

Elastic angle-domain common-imaging gathers (ADCIGs) extracted from elastic reverse time migration (ERTM) play a pivotal part in velocity analysis, amplitude variation with angle, and attribute interpretation. In practice, however, ADCIGs often suffer unbalanced behavior, poor resolution, low-wavenumber artifacts because of insufficient information, limited recording aperture, uneven illumination, other inaccuracies the operator. We have developed new method to improve quality ERTM by posing...

Processing pressure shear (PS)-wave data is more challenging than PP-wave because of the asymmetry source-to-receiver ray paths, particularly for irregular surfaces and sparse acquisition. Gaussian beam summation (GBS) migration an effective method imaging seismic from surfaces. In this letter, we introduce a converted PS-wave using GBS, in which scalar wavefield used propagation imaging. Cross correlation performed forward-continued source wavefields calculated with P-wave reverse-continued...

ABSTRACT The direct prestack depth migration methods of nonplanar data provide effective ways to address the complex near‐surface problem. Based on study local slant stacks considering elevation and dip angle information an irregular surface, alternative method for multiwave Gaussian beam exploration‐scale seismic with effects is presented here. We first derive downward‐continued wavefield surface in terms beams, where we directly decompose records within a window into plane‐wave component....

AbstractThe transversely isotropic (TI) media approximation is commonly applied to assist in the processing of seismic data acquired sedimentary environments. Based on anisotropic kinematic and dynamic ray tracing systems, a P-wave Gaussian beam prestack depth migration (GB-PSDM) method for TI introduced this paper. The imaging principle GB-PSDM corresponding parameters are presented basis media. Tests synthetic field show that an accurate efficient media.Based demonstrate efficient. Key...

The deep reflection seismic technique is essential to detect the basement of petroliferous basins and fine structure lithosphere. traditional stacking or time migration usually adopted for imaging data, but accuracy too limited acquire precise profiles. Development an effective prestack depth method data urgent requirement in field lithosphere detection. Gaussian beam summation (GBS) requires no local slant phase approximation. It has higher precision better flexibility applicability...

The complex topography is a challenging issue in onshore seismic exploration. rugged terrain and lateral change of near-surface velocity pose significant obstacle to the accurate imaging data. adaptive focused beam migration method retains good applicability ray methods for calculating wavefield under surface conditions. It can effectively solve contradiction between accuracy deep shallow strata traditional Gaussian migration. We extend approach domain data Firstly, basic principles are...

Imaging PS-wave is essential for converted wave exploration, especially in tilted transversely isotropic (TTI) media. Compared with the relatively low imaging accuracy of anisotropic time migration complex structures, an accurate depth approach would be preferable. As effective technique, Gaussian beam summation (GBS) can provide high-precision geological structures. In this letter, we extend GBS to PS-waves media and present angle-domain method waves 2-D TTI We first introduce...

From a new view of financial distress concept drift, this paper attempts to put forward method for dynamic prediction modeling based on slip time window and multiple support vector machines (SVMs). A algorithm is designed dynamically select the proper handle then classifier selection used build combined model. With totally 642 samples from Chinese listed companies, which include ST companies 2001 2008 their paired non-ST empirical study carried out by simulating process passage. The results...

Brittleness is an important evaluation parameter in shale fracturing. Current methods of brittleness can be classified into two categories: elastic parameter-based and mineral content-based methods. However, both categories neglect the effect anisotropy on index (BI) computation resources. We have redefined a new BI by integrating failure criteria stress parameters estimated (BIac) from seismic waves. According to definition, at one analysis point varies with incident angle wave confining...

Summary Low resolution and poor amplitude-preservation are two key issues in the exploration of deeply-buried carbonate reservoirs Tarim Basin, China. The buried more than 6000 meters seismic signal encounters serious attenuation absorption. Though Kirchhoff migration is commonly used as routine method, its can hardly meet requirement for precise prediction reservoirs. By contrast, amplitude-preserved Q-compensation effectively compensate absorbed energy to enhance recovery amplitude deep...