Enhance Seismic Quality With A Fast, Robust and Economic Solution Using Broadband Technology

2020 ◽  
Author(s):  
M. Syarif
Keyword(s):  
Time Window ◽  
Time Budget ◽  
Dominant Frequency ◽  
Seismic Processing ◽  
Kirchhoff Migration ◽  
Seismic Resolution ◽  
Original Dataset ◽  
Resolution Problem ◽  
Solution Focused ◽  
Thin Reservoir

Often many companies doing seismic reprocessing project with the latest advanced seismic processing technology to handle their seismic problems. This kind of solution might work for some companies but certainly will not for many others. Innovative solutions are required to overcome seismic problem or issue considering time, budget and technical robustness. The objective of this paper is to demonstrate a seismic processing project that was run in a relatively low oil price condition, to handle a low seismic resolution problem in thinly bedded reservoirs. In addition to budget and technical constraints, timing and schedule is also an issue since the updated interpretation is required to be used for updating a static model in less than a 3 months time window. A broadband processing method on 100 km2 post-stack 3D seismic data was applied to enhance frequency content which leads to enhanced seismic resolution to resolve objective reservoirs. This method is considered fast, robust and economical. The procedure would be enhancing the spectrum by designing a unique filter into the dataset after inverse Kirchhoff migration application. After some iterations, forward Kirchhoff migration and multi spatial time-variant filter was applied to generate the desired output. Overall processing time was completed within budget in a one-month period only. As a result, forty percent (40%) increase in dominant frequency was achieved as final deliverables from 25Hz to 35Hz. The original dataset with 25Hz dominant frequency can only resolve reservoirs with thickness greater than 20m. The thickness of individual objective sandstone reservoirs in the study area was ranging from 1.5m to 20m with average thickness around 6-10m. However, stacked reservoir thickness within the same flooding surface interval of the same unit is relatively thicker than 10m. The 35Hz dominant frequency data from broadband processing can resolve reservoir with thickness greater than 14m and better resolve stacked reservoirs even though very thin reservoir below resolution remains unresolved. Broadband seismic technology on post-stack dataset offers a fast, robust and economical solution focused on target which can be duplicated in other area/data to provide successful interpretation projects.

FLUVIAL RESERVOIR ARCHITECTURE INTERPRETATION BELOW THE SEISMIC RESOLUTION IN AN OFFSHORE OILFIELD

2021 ◽  
pp. 1-49
Author(s):  
Dong Zhang ◽  
Xuri Huang ◽  
Ting’en Fan ◽  
Haifeng Wang ◽  
Feng Ding ◽  
...  
Keyword(s):  
Time Window ◽  
Seismic Attributes ◽  
Gradient Algorithm ◽  
Bohai Bay ◽  
Reservoir Heterogeneity ◽  
Reservoir Architecture ◽  
Fluvial Reservoir ◽  
Seismic Resolution ◽  
Infill Drilling ◽  
Bounding Surfaces

Reservoir discontinuity is a practical representation of reservoir heterogeneity, which leads to the non-uniformed flow of hydrocarbons during production and to the increase in the difficulties of producing the remaining oil in clastic reservoirs. A feasible solution is to detect the internal bounding surfaces of the reservoir based on infill drilling data. However, for offshore oilfields, reservoir discontinuity analysis will have to rely on seismic data due to their sparse well spacings. Moreover, from the interpretation of a fluvial reservoir system in Chinaapos;s Bohai Bay, it turns out that the thickness of the sandstone is usually smaller than the seismic tuning thickness. In order to interpret a fluvial reservoir architecture which is below the seismic resolution, we elaborated a hierarchy of the fluvial reservoir architectures and classified the compound sandstones as different architectural elements according to their sedimentary periods. Forward models were designed to analyze the seismic responses of the architectures. The results demonstrate that amplitude-related seismic attributes could be sensitive to different reservoir architectures below the seismic resolution. The amplitude-related seismic attributes can be extracted through a time window guided by the horizons. The horizon-based attributes can be treated as digital images which may contain the information of compound sandstones with hidden discontinuity boundaries. We propose a direction-adaptive mathematical morphology gradient algorithm that can detect the boundaries of reservoir architectures in different directions on horizon-based seismic attributes. The application to field data demonstrates that the boundaries detected by the proposed algorithm have a good consistency with well logs. This method could enhance our capability to visualize and understand the complexity of reservoir heterogeneity.

See the Unseen through Target-Oriented Dip-Steered Seismic Resolution

2021 ◽  
Author(s):  
Muhammad Sajid ◽  
Ahmad Riza Ghazali
Keyword(s):  
Reservoir Characterization ◽  
Resolution Enhancement ◽  
Dominant Frequency ◽  
Seismic Inversion ◽  
Seismic Resolution ◽  
Geological Features ◽  
Spectral Enhancement ◽  
Enhancement Method ◽  
Layer Velocity ◽  
Seismic Volumes

Abstract Seismic resolution plays an important role not only in interpretation and reservoir characterization but also in seismic inversion and seismic attributes analysis. The resolution depends on several factors, including seismic frequency bandwidth, dominant frequency, and layer velocity. This paper presents a spectral resolution enhancement approach that is based on Non-stationary Differential Resolution (NSDR) that honors the local structural dip, better preserves amplitude and improves target-oriented seismic interpretation. The proposed technology is applied to both 2D and 3D seismic volumes and findings are compared with the oil industry common spectral enhancement algorithms. We demonstrate the target-oriented dip steering spectral enhancement method on two 3D field datasets and compare the resulting outcome with those obtained by conventional techniques. It is found that thinly layered subsurface geological features with steeply dipping beds are better defined, with artifacts from the conflicting dips removed.

Efficient Cluster-Based Heuristics for the Team Orienteering Problem with Time Windows

2019 ◽  
Vol 36 (01) ◽  
pp. 1950001 ◽  
Author(s):  
Damianos Gavalas ◽  
Charalampos Konstantopoulos ◽  
Konstantinos Mastakas ◽  
Grammati Pantziou
Keyword(s):  
Execution Time ◽  
Time Window ◽  
Time Budget ◽  
Time Windows ◽  
Experimental Tests ◽  
Orienteering Problem ◽  
Solution Quality ◽  
Routing Problem ◽  
Team Orienteering Problem ◽  
Team Orienteering

In the Team Orienteering Problem with Time Windows (TOPTW), a variant of the Vehicle Routing Problem with Profits, a set of locations is given, each associated with a profit, a visiting time and a time window. The aim is to maximize the overall profit collected by a number of routes, while the duration of each route must not exceed a given time budget. TOPTW is NP-hard and is typically used to model the Tourist Trip Design Problem. The latter deals with deriving near optimal multiple-day tours for tourists visiting a destination with several points of interest (POIs). The most efficient known heuristic approach to TOPTW which yields the best solution quality versus execution time, is based on Iterated Local Search (ILS). However, the ILS algorithm treats each node separately, hence it tends to overlook highly profitable areas of nodes situated far from the current solution, considering them too time-expensive to visit. We propose two cluster-based extensions to ILS addressing the aforementioned weakness by grouping nodes on separate clusters (based on geographical criteria), thereby making visits to such nodes more attractive. Our approaches improve ILS with respect to solutions quality and execution time as evidenced by experimental tests exercised on both existing and new TTDP-oriented benchmark instances.

scholarly journals Real-time Approximate Routing for Smart Transit Systems

2021 ◽  
Vol 5 (2) ◽  
pp. 1-30
Author(s):  
Noémie Périvier ◽  
Chamsi Hssaine ◽  
Samitha Samaranayake ◽  
Siddhartha Banerjee
Keyword(s):  
Real Time ◽  
Time Window ◽  
Time Budget ◽  
High Capacity ◽  
Constant Factor ◽  
Planning Problem ◽  
Randomized Rounding ◽  
Exact Methods ◽  
Line Planning ◽  
Transit Systems

We study real-time routing policies in smart transit systems, where the platform has a combination of cars and high-capacity vehicles (e.g., buses or shuttles) and seeks to serve a set of incoming trip requests. The platform can use its fleet of cars as a feeder to connect passengers to its high-capacity fleet, which operates on fixed routes. Our goal is to find the optimal set of (bus) routes and corresponding frequencies to maximize the social welfare of the system in a given time window. This generalizes the Line Planning Problem, a widely studied topic in the transportation literature, for which existing solutions are either heuristic (with no performance guarantees), or require extensive computation time (and hence are impractical for real-time use). To this end, we develop a 1-1/e-ε approximation algorithm for the Real-Time Line Planning Problem, using ideas from randomized rounding and the Generalized Assignment Problem. Our guarantee holds under two assumptions: (i) no inter-bus transfers and (ii) access to a pre-specified set of feasible bus lines. We moreover show that these two assumptions are crucial by proving that, if either assumption is relaxed, the łineplanningproblem does not admit any constant-factor approximation. Finally, we demonstrate the practicality of our algorithm via numerical experiments on real-world and synthetic datasets, in which we show that, given a fixed time budget, our algorithm outperforms Integer Linear Programming-based exact methods.

scholarly journals An integrated petrophysical-based wedge modeling and thin bed AVO analysis for improved reservoir characterization of Zhujiang Formation, Huizhou sub-basin, China: A case study

2020 ◽  
Vol 12 (1) ◽  
pp. 256-274
Author(s):  
Wasif Saeed ◽  
Hongbing Zhang ◽  
Qiang Guo ◽  
Aamir Ali ◽  
Tahir Azeem ◽  
...  
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Dominant Frequency ◽  
Well Logs ◽  
Amplitude Versus Offset ◽  
Avo Attributes ◽  
Thin Reservoir ◽  
Amplitude Versus

AbstractThe main reservoir in Huizhou sub-basin is Zhujiang Formation of early Miocene age. The petrophysical analysis shows that the Zhujiang Formation contains thin carbonate intervals, which have good hydrocarbon potential. However, the accurate interpretation of thin carbonate intervals is always challenging as conventional seismic interpretation techniques do not provide much success in such cases. In this study, well logs, three-layer forward amplitude versus offset (AVO) model and the wedge model are integrated to analyze the effect of tuning thickness on AVO responses. It is observed that zones having a thickness greater than or equal to 15 m can be delineated with seismic data having a dominant frequency of more than 45 Hz. The results are also successfully verified by analyzing AVO attributes, i.e., intercept and gradient. The study will be helpful to enhance the characterization of thin reservoir intervals and minimize the risk of exploration in the Huizhou sub-basin, China.

Multiwavelet prestack Kirchhoff migration

Geophysics ◽  
2016 ◽  
Vol 81 (3) ◽  
pp. S79-S85
Author(s):  
Luchun Lin ◽  
Baoping Shi ◽  
Ping An
Keyword(s):  
Reservoir Characterization ◽  
Computational Cost ◽  
Dominant Frequency ◽  
Seismic Section ◽  
Kirchhoff Migration ◽  
Novel Approach ◽  
Alternative Approach ◽  
Specific Interpretation ◽  
Outer Iteration ◽  
Dominant Frequencies

The problems of stretching and aliasing usually occur in prestack Kirchhoff migration. A multiwavelet-based approach is proposed to provide an alternative approach to resolve these problems. Two steps are involved in the multiwavelet-based algorithm: The first step is the decomposition of the seismic traces with a series of wavelets of different dominant frequencies. This step is based on the principle of basis pursuit and is enhanced for more accurate and sparse decomposition by adding an adaptive subdictionary that is associated with the minima and maxima of a seismic trace. The second step is wavelet migration based on the Kirchhoff formulation using a novel approach. The outer iteration is the wavelets of the input seismic traces, which ensures that an input wavelet is only used once in the entire migration process. This enables output of multiple migrated images of different wavelets of dominant frequency ranges, elimination of noisy images, and composition of images for specific interpretation and reservoir characterization purposes with very little extra computational cost. The stretching and aliasing problems are naturally resolved because interpolation on the seismic trace is not required in the migration. We tested the algorithm using a synthetic model with a dipping layer and a 2D real seismic section. We compared our results with results obtained by conventional Kirchhoff migration.

Similarity attributes from differential resolution components

2017 ◽  
Vol 5 (1) ◽  
pp. T65-T73 ◽  
Author(s):  
Bruno César Zanardo Honório ◽  
Ulisses Miguel da Costa Correia ◽  
Marcílio Castro de Matos ◽  
Alexandre Campane Vidal
Keyword(s):  
Color Space ◽  
Dominant Frequency ◽  
Seismic Attribute ◽  
Frequency Bands ◽  
Conventional Procedure ◽  
Seismic Resolution ◽  
Campos Basin ◽  
Spectral Enhancement ◽  
Analysis Window ◽  
Enhancement Method

Seismic resolution plays an important role in the delineation of structural and stratigraphic features. The resolution improvement directly affects the seismic attributes and, consequently, the interpretation of a given feature. However, the broadband data do not necessarily provide the best insight for seismic attribute evaluation. Particularly, geologic discontinuities, such as karsts, faults, and fractures, can have different seismic expressions according to their intrinsic scales, and, therefore, they are better illuminated in a given frequency range. To extract dissimilar characteristics in different frequency bands, we have combined a recently developed spectral enhancement method based on differential resolution (DR) and similarity attributes. The DR algorithm is simultaneously used for frequency enhancement and acting as a pseudofilter, allowing us to compute similarity attributes at different frequency bands. The similarity computation follows the reflector dip of each DR subband and adjusts its analysis window accordingly to the dominant frequency within the subbands. Then, the subband similarities are combined in the red-green-blue-alpha color space, allowing a more detailed view of the geology under investigation. Although more expensive in terms of processing time because of all the steps needed for each subband, the proposed strategy proved to be a great improvement over the conventional procedure of detecting and delineating discontinuities in fault and karst structures when treating seismic data from an offshore carbonate field in Campos Basin, Brazil.

Revisit Seismic Attenuation Attributes: Influences of the Spectral Balancing Operation on Seismic Attenuation Analysis

2021 ◽  
pp. 1-50
Author(s):  
Fangyu Li ◽  
Rongchang Liu ◽  
Yihuai Lou ◽  
Naihao Liu
Keyword(s):  
Seismic Data ◽  
Seismic Attenuation ◽  
Estimation Methods ◽  
Gaussian Shape ◽  
Seismic Processing ◽  
Seismic Resolution ◽  
Attribute Analysis ◽  
Specific Source ◽  
Ricker Wavelet ◽  
Apparent Attenuation

Seismic attenuation analysis is important for seismic processing and quantitative interpretation. Nevertheless, the classic quality factor estimation methods make certain assumptions that may be invalid for a given geologic target and seismic volume. For this reason, seismic attenuation attribute analysis, which reduces some of the theoretical assumptions, can serve as a practical alternative in apparent attenuation characterization. Unfortunately, most of the published literature defines seismic attenuation attributes based on a specific source wavelet assumption, such as the Ricker wavelet, rather than wavelets that exhibit a relatively flat spectrum produced by modern data processing workflows. One of the most common processing steps is to spectrally balance the data either explicitly in the frequency domain, or implicitly through wavelet shaping deconvolution. If the post-stack seismic data have gone through the spectral balancing/whitening to improve the seismic resolution, the wavelet would exhibit a flat spectrum instead of a Ricker or Gaussian shape. We address the influence of the spectral balancing on seismic attenuation analysis. Our mathematical analysis shows that attenuation attributes are still effective for the post-stack seismic data after certain types of spectral balancing. More importantly, this analysis explains why seismic attenuation attributes work for real seismic applications with common seismic processing procedures. Synthetic and field data examples validate our conclusions.

Abstract 15890: Spatiotemporal Analysis of Phase and Frequency Dynamics in Human Persistent Atrial Fibrillation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Nawshin Dastagir ◽  
Frederique J Vanheusden ◽  
Gavin S Chu ◽  
João L Salinet ◽  
Xin Li ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Time Window ◽  
Persistent Atrial Fibrillation ◽  
Spatiotemporal Analysis ◽  
Detection Algorithm ◽  
Dominant Frequency ◽  
Jude Medical ◽  
The Hilbert Transform ◽  
Two Parameters ◽  
Opposite Chirality

There is increasing focus on understanding the substrates that maintain persistent atrial fibrillation (persAF) based on dominant frequency (DF) sources and phase singularity points (PS). In this study we aimed to combine these two parameters and study the relationship between them to depict the complex spatiotemporal patterns of fibrillation. For 9 patients with longstanding persAF (duration: 34 ± 25 months) undergoing left atrial (LA) ablation, noncontact array catheter (EnSite Array, St. Jude Medical) was used to collect virtual unipolar electrograms (EGMs) simultaneously from 2048 nodes on the LA. After QRST subtraction, 3D DF maps were obtained through the fast Fourier Transform applied simultaneously to each individual EGM. DF was defined within the range of 4-10Hz (4s time window; 87.5% overlap; 30s/patient). Highest DF (HDF) regions for each individual window were defined as any LA geometry nodes where the calculated DF was within 0.25 Hz of the maximum DF value registered in the window. In order to correlate these HDF locations with PS, phase maps were constructed using the Hilbert transform approach and the locations of PS and its respective chirality (+ clockwise; - anticlockwise) were identified applying an automatic PS detection algorithm. A statistical majority of PSs (92.5%, p<0.001) were distributed outside the HDF regions. There was a relationship between PSs and the HDF regions such that PSs of opposite chirality influence the propagation of HDF. This was observed for all patients and in 72.1 (± 10.5) % of the total windows. The influence of direction of HDF movement by PSs of opposite chirality was observed 12 (±9) times for each window. A case illustration is presented on Figure 1. Our analysis suggests an organised behaviour of PS of opposite chirality and HDF regions travelling between them. Once an electrophysiological relationship is established, the spatiotemporal behaviour of PS and HDF could provide alternative ablation strategies for AF.

Coaching Care Partners Who Support Loved Ones With MCI

2014 ◽  
Vol 19 (2) ◽  
pp. 50-56 ◽  
Author(s):  
Kerry Mills ◽  
Jennifer Brush
Keyword(s):  
Cognitive Functioning ◽  
Educational Program ◽  
Social Withdrawal ◽  
Quality Care ◽  
Critical Role ◽  
Family Care ◽  
Speech Language Pathologists ◽  
Care Partners ◽  
Provide Quality Care ◽  
Solution Focused

Speech-language pathologists can play a critical role in providing education and intervention to prevent social withdrawal, prevent premature disability, and maximize cognitive functioning in persons with MCI. The purpose of this article is to describe positive, solution-focused educational program that speech-language pathologists can implement with family care partners to improve relationships and provide quality care for someone living with MCI.

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