Reverse-time migration (RTM) exhibits great superiority over other imaging algorithms in handling steeply dipping structures and complicated velocity models. However, low-frequency, high-amplitude noises commonly seen a typical RTM image have been one of the major concerns because they can seriously contaminate signals if are not handled properly. We propose new condition to effectively efficiently eliminate these specific from image. The method works by first decomposing source receiver...

In this paper, we decouple the P and SV wave components in an acoustic transversely isotropic media with vertical symmetric axis (VTI), construct independent pseudo‐differential equation for each mode. The resulted P‐wave is unconditionally stable. A scheme based on optimized separable approximation proposed their numerical implementation. We demonstrate theory some simple experiments.

In complex areas with large lateral velocity variations, wave-equation-based source plane-wave migration can produce images comparable to those from shot-profile migration, less computational cost. Image quality be better than in ray-theory-based Kirchhoff-type methods. This method requires the composition of sections all shot gathers. We provide a general framework evaluate prestack migration. Our analysis shows that section treated as encoded study provides theoretical justification for...

SUMMARY In this paper, we develop a new nearly analytic symplectically partitioned Runge–Kutta (NSPRK) method for numerically solving elastic wave equations. In method, first transform the equations into Hamiltonian system, and use discrete operator to approximate high-order spatial differential operators, then employ second-order symplectic solve resulted semi-discrete ordinary (ODEs). We investigate in great detail on properties of NSPRK that includes stability condition P–SV 2-D...

Knowledge of changes in reservoir properties resulting from extracting hydrocarbons or injecting fluid is critical to future production planning. Full-waveform inversion (FWI) time-lapse seismic data provides a quantitative approach characterize the by taking difference inverted baseline and monitor models. The sets can be either independently jointly. Time-lapse collected ocean-bottom cables (OBCs) Valhall field North Sea are suitable for such FWI practice because acquisitions long offset,...

Reverse‐time migration has the capability to image all dips including overturned structures. However, conventional imaging condition produces high‐amplitude noises in image, which often seriously mask shallow In this paper, we propose a new eliminate these works by decomposing full wavefields their one‐way components, and applying appropriate combinations of wavefield components. Numerical tests verify that successfully removes undesired noises.

Amplitude variation with offset/angle of incidence inversion has been playing a key role in hydrocarbon detection and reservoir characterization. Traditionally, it limited to elastic even viscoelastic cases. We investigated the reflectivity diffusive-viscous media. Our study demonstrated that magnitude reflection coefficients such media is not only related incident angle parameters medium but also strongly depends on frequency. first validity wave equation, proposed empirically, based...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2020Multi-channel dynamic matching full-waveform inversionAuthors: Jian MaoJames ShengYi HuangFeng HaoFaqi LiuJian MaoTGS, James ShengTGS, Yi HuangTGS, Feng HaoTGS, and Faqi LiuTGShttps://doi.org/10.1190/segam2020-3427610.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail AbstractWe propose a multi-channel fullwaveform inversion (DMFWI) for...

Full-waveform inversion (FWI) is firmly established within our industry as a powerful velocity model building tool. FWI carries significant theoretical advantages over conventional methods such refraction and reflection tomography. Specifically, by solving nonlinear inverse problem through the wave equation, able to recover broadband containing both high low spatial wavenumbers, thus extending approximation of residual moveout correction inherent in traditional approaches. Moreover, capable...

We present a least-squares solution for depth migration of the full reflected wavefield. The algorithm combines primary and high-order energy significantly enhances image illumination resolution compared to those conventional migration. Least-squares full-wavefield (LS-FWM) directly computes earth's reflectivity, thereby avoiding crosstalk noise often observed in imaging using reflections. Iteratively solving an inversion problem is computationally intensive can suffer from instability...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2002Plane wave source composition: An accurate phase encoding scheme for prestack migrationAuthors: Faqi LiuRobert H. StoltDouglas W. HansonRichard S. DayFaqi LiuConoco Inc., Robert StoltConoco Douglas HansonConoco and Richard DayConoco Inc.https://doi.org/10.1190/1.1816854 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Permalink:...

By minimizing the difference between synthetic and field data sets, full waveform inversion (FWI) can produce high resolution fidelity earth model parameters that are not resolvable by commonly used ray-based tomography. In this paper, we share our experience on applying 3-D acoustic time-domain to an OBC set collected over Valhall in North Sea.

In recent years, reverse time migration (RTM), the most powerful depth imaging method, has become preferred tool in many geologic settings because of its ability to handle complex velocity models including steeply dipping interfaces. Finite difference is one popular numerical methods applied RTM industry. However, it often encounters a serious issue dispersion, which typically suppressed by reducing propagation grid sizes, resulting large computation and memory increment. Recently, nearly...

A good starting model is imperative in full-waveform inversion (FWI) because it solves a least-squares problem using local gradient-based optimization method. suboptimal can result cycle skipping leading to poor convergence and incorrect estimation of subsurface properties. This especially crucial for salt models the strong velocity contrasts create substantial time shifts modeled seismogram. Incorrect bodies leads inaccuracies sediments gradient aims reduce traveltime differences without...

With the capability of handling complicated velocity models, reverse-time migration (RTM) has become a powerful imaging method. Improving accuracy and computational efficiency are two significant but challenging tasks in applications RTM. Despite being most popular numerical technique applied RTM, finite-difference (FD) methods often suffer from undesirable dispersion, leading to noticeable loss resolution. A new effective FD operator, called high-order stereo been developed approximate...

The acoustic wave equation has been widely used for the modeling and reverse‐time migration of seismic data. finite‐difference method long favored approach to solve this equation. To ensure quality results, accurate approximations are required spatial time derivatives. This can be achieved numerically by using either very fine computation grids or operators. Otherwise, numerical error, called dispersion, will present in data contaminate signals. However, increases cost dramatically. In...

Changes in reservoir properties resulting from extracting hydrocarbons and injecting fluid are critical to optimize production. These can be characterized using waveform inversions of time-lapse seismic data. The conventional approach for analysis tomography is take the difference inversion obtained baseline subsequent datasets that imaged independently. By contrast, double-difference (DDWI) jointly inverts changes. We use a 2D synthetic example demonstrate advantage DDWI mitigating spurious...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2002Prestack migration of areal shot records with phase encodingAuthors: Peiyong SunShulun ZhangFaqi LiuPeiyong SunDalian University Technology, China, Shulun ZhangDalian and Faqi LiuConoco Inc.https://doi.org/10.1190/1.1816858 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InReddit Permalink: https://doi.org/10.1190/1.1816858FiguresReferencesRelatedDetailsCited...

Plane wave migration can produce high quality images that are comparable to those of shot with much less computation cost. However, current acquisition geometries do not honor the optimal applications this technology. In paper, we discuss limitation pattern and show application plane algorithm requires split spread common receiver gathers. Using synthetic 2D Sigsbee data, demonstrate reciprocity principle generate gathers shows its impact on migration.

Full Waveform Inversion (FWI), as predominantly used in the petroleum industry today, solves a least-squares inversion problem by using local gradient-based optimization method which estimates an earth model iteratively updating starting model. Imaging salt body conventional FWI is very difficult task because of large velocity contrast and absence good Global methods have not been widely problems with number parameters due to dramatically increased computational cost even though they are...

Summary Least Squares RTM (LSRTM) is a powerful inversion-based imaging algorithm which minimizes the data misfit between observed seismic recordings and forward-modelled synthetic data. The algorithm, can be implemented in either or image domains, carries fundamental limitation because it based on linear inversion theory cannot accommodate velocity refinement as part of its model update process. Successful application LSRTM therefore requires highly accurate information, if significant...

PreviousNext No AccessThird International Meeting for Applied Geoscience & Energy Expanded AbstractsHigh-frequency FWI on Clair OBN dataset — Challenges and successesAuthors: Matvey RomanenkoLee SaxtonDan DaviesJames ShengFaqi LiuJan GromotkaYang HeMatvey RomanenkoTGS, Lee SaxtonTGS, Dan DaviesTGS, James ShengTGS, Faqi LiuTGS, Jan GromotkaTGS, Yang HeTGShttps://doi.org/10.1190/image2023-3910442.1 SectionsSupplemental MaterialAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack...