[PDF] Investigation Of Time Lapse 4d Seismic Tuning And Spectral Responses To Co2 Eor For Enhanced Characterization And Monitoring Of A Thin Carbonate Reservoir eBook

Author : Austin Krehel
Publisher :
Page : pages
File Size : 36,8 MB
Release : 2017
Category :
ISBN :

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Advancements, applications, and success of time-lapse (4D) seismic monitoring of carbonate reservoirs is limited by these systems' inherent heterogeneity and low compressibility relative to siliciclastic systems. To contribute to the advancement of 4D seismic monitoring in carbonates, an investigation of amplitude envelope across frequency sub-bands was conducted on a high-resolution 4D seismic data set acquired in fine temporal intervals between a baseline and eight monitor surveys to track CO2-EOR from 2003-2005 in the Hall-Gurney Field, Kansas. The shallow (approximately 900 m) Plattsburg 'C Zone' target reservoir is an oomoldic limestone within the Lansing-Kansas City (LKC) supergroup -- deposited as a sequence of high-frequency, stacked cyclothems. The LKC reservoir fluctuates around thin-bed thickness within the well pattern region and is susceptible to amplitude tuning effects, in which CO2 replacement of initial reservoir fluid generates a complex tuning phenomena with reduction and brightening of amplitude at reservoir thickness above and below thin-bed thickness, respectively. A thorough analysis of horizon snapping criteria and parameters was conducted to understand the sensitivity of these autonomous operations and produce a robust horizon tracking workflow to extend the Baseline Survey horizon data to subsequent Monitor Surveys. This 4D seismic horizon tracking workflow expedited the horizon tracking process across monitor surveys, while following a quantitative, repeatable approach in tracking the LKC and maintaining geologic integrity despite low signal-to-noise ratio (SNR) data and misties between surveys. Analysis of amplitude envelope data across frequency sub-bands (30-80 Hz) following spectral decomposition identified geometric features of multiple LKC shoal bodies at the reservoir interval. In corroboration with prior geologic interpretation, shoal boundaries, zones of overlap between stacked shoals, thickness variation, and lateral changes in lithofacies were delineated in the Baseline Survey, which enhanced detail of these features' extent beyond capacity offered from well log data. Lineaments dominated by low-frequency anomalies within regions of adjacent shoals' boundaries suggest thicker zones of potential shoal overlap. Analysis of frequency band-to-band analysis reveals relative thickness variation. Spectral decomposition of the amplitude envelope was analyzed between the Baseline and Monitor Surveys to identify spectral and tuning changes to monitor CO2 migration. Ambiguity of CO2 effects on tuning phenomena was observed in zones of known CO2 fluid replacement. A series of lineaments highlighted by amplitude brightening from the Baseline to Monitor Surveys is observed, which compete with a more spatially extensive effect of subtle amplitude dimming. These lineaments are suggestive of features below tuning thickness, such as stratigraphic structures of shoals, fractures, and/or thin shoal edges, which are highlighted by an increased apparent thickness and onset of tuning from CO2. Detailed analysis of these 4D seismic data across frequency sub-bands provide enhanced interpretation of shoal geometry, position, and overlap; identification of lateral changes in lithofacies suggestive of barriers and conduits; insight into relative thickness variation; and the ability of CO2 tuning ambiguity to highlight zones below tuning thickness and improve reservoir characterization. These results suggest improved efficiency of CO2 -EOR reservoir surveillance in carbonates, with implications to ensure optimal field planning and flood performance for analogous targets.

Author : David H. Johnston
Publisher : SEG Books
Page : 288 pages
File Size : 26,73 MB
Release : 2013
Category : Science
ISBN : 156080307X

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Time-lapse (4D) seismic technology is a key enabler for improved hydrocarbon recovery and more cost-effective field operations. This book shows how 4D data are used for reservoir surveillance, add value to reservoir management, and provide valuable insight on dynamic reservoir properties such as fluid saturation, pressure, and temperature.

Author : Julie Nicole Ditkof
Publisher :
Page : 0 pages
File Size : 44,8 MB
Release : 2013
Category :
ISBN :

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The Cranfield field, located in southwest Mississippi, is an enhanced oil recovery and carbon sequestration project that has been under a continuous supercritical CO2 injection by Denbury Onshore LLC since 2008. Two 3D seismic surveys were collected in 2007, pre-CO2 injection, and in 2010 after > 2 million tons of CO2 was injected into the subsurface. The goal of this study is to characterize a time-lapse response between two seismic surveys to understand where injected CO2 is migrating and to map the injected CO2 plume edge. In order to characterize a time-lapse response, the seismic surveys were cross equalized using a trace-by-trace time shift. A normalized root-mean-square (NRMS) difference value was then calculated to determine the repeatability of the data. The data were considered to have "good repeatability," so a difference volume was calculated and showed a coherent seismic amplitude anomaly located through the area of interest. A coherent seismic amplitude anomaly was also present below the area of interest, so a time delay analysis was performed and calculated a significant added velocity change. A Gassmann-Wood fluid substitution workflow was then performed at two well locations to predict a saturation profile and observe post-injection expected changes in compressional velocity values at variable CO2 saturations. Finally, acoustic impedance inversions were performed on the two seismic surveys and an acoustic impedance difference volume was calculated to compare with the fluid substitution results. The Gassmann-Wood fluid substitution results predicted smaller changes in acoustic impedance than those observed from acoustic impedance inversions. At the Cranfield field, time-lapse seismic analysis was successful in mapping and quantifying the acoustic impedance change for some seismic amplitude anomalies associated with injected CO2. Additional well log data and refinement of the fluid substitution workflow and the model-based inversion performed is necessary to obtain more accurate impedance changes throughout the field instead of at a single well location.

Author : Thomas L. Davis
Publisher : Cambridge University Press
Page : 391 pages
File Size : 11,84 MB
Release : 2019-05-09
Category : Business & Economics
ISBN : 1107137497

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An overview of the geophysical techniques and analysis methods for monitoring subsurface carbon dioxide storage for researchers and industry practitioners.

Author : Ajitabh Kumar
Publisher :
Page : pages
File Size : 13,28 MB
Release : 2010
Category :
ISBN :

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Production from a hydrocarbon reservoir is typically supported by water or carbon dioxide (CO2) injection. CO2 injection into hydrocarbon reservoirs is also a promising solution for reducing environmental hazards from the release of green house gases into the earth0́9s atmosphere. Numerical simulators are used for designing and predicting the complex behavior of systems under such scenarios. Two key steps in such studies are forward modeling for performance prediction based on simulation studies using reservoir models and inverse modeling for updating reservoir models using the data collected from field. The viability of time-lapse seismic monitoring using an integrated modeling of fluid flow, including chemical reactions, and seismic response is examined. A comprehensive simulation of the gas injection process accounting for the phase behavior of CO2-reservoir fluids, the associated precipitation/dissolution reactions, and the accompanying changes in porosity and permeability is performed. The simulation results are then used to model the changes in seismic response with time. The general observation is that gas injection decreases bulk density and wave velocity of the host rock system. Another key topic covered in this work is the data assimilation study for hydrocarbon reservoirs using Ensemble Kalman Filter (EnKF). Some critical issues related to EnKF based history matching are explored, primarily for a large field with substantial production history. A novel and efficient approach based on spectral clustering to select 0́optimal0́9 initial ensemble members is proposed. Also, well-specific black-oil or compositional streamline trajectories are used for covariance localization. Approach is applied to the Weyburn field, a large carbonate reservoir in Canada. The approach for optimal member selection is found to be effective in reducing the ensemble size which was critical for this large-scale field application. Streamline-based covariance localization is shown to play a very important role by removing spurious covariances between any well and far-off cell permeabilities. Finally, time-lapse seismic study is done for the Weyburn field. Sensitivity of various bulk seismic parameters viz velocity and impedance is calculated with respect to different simulation parameters. Results show large correlation between porosity and seismic parameters. Bulk seismic parameters are sensitive to net overburden pressure at its low values. Time-lapse changes in pore-pressure lead to changes in bulk parameters like velocity and impedance.

Author : Marcos Hexsel Grochau
Publisher : LAP Lambert Academic Publishing
Page : 136 pages
File Size : 31,36 MB
Release : 2010-06
Category :
ISBN : 9783838322117

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Time-lapse (4D) seismic is a modern technology for monitoring production-induced changes in and around hydrocarbon reservoirs. Perhaps the most important challenges related to this technology are to perform quantitative time-lapse and to interpret time-lapse effects in thin layers. This book presents an integrated study of saturation and pressure effects on elastic properties. A workflow is developed to test the validity of Gassmann fluid substitution in real geological environments and it is applied on a turbidite reservoir from the Campos Basin, offshore Brazil. The magnitude of pressure effects on compressional-wave velocities is investigated by using two different approaches: laboratory and well measurements. This book also shows a novel methodology to assess rock properties that result from centimeter scale depositional layering by using X-ray computed tomography images along with laboratory velocity measurements and borehole logs. Finally, the equivalent properties of a heterogeneous sandstone reservoir are investigated for modeling time-lapse effects. The combined seismic response of thin layers of sandstones and shales was computed for depletion and injection scenarios.

Author : Junzo Kasahara
Publisher : Gulf Professional Publishing
Page : 0 pages
File Size : 13,95 MB
Release : 2016-10-14
Category : Science
ISBN : 9780128035887

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Time Lapse Approach to Monitoring Oil, Gas, and CO2 Storage by Seismic Methods delivers a new technology to geoscientists, well logging experts, and reservoir engineers, giving them a new basis on which to influence decisions on oil and gas reservoir management. Named ACROSS (Accurately Controlled and Routinely Operated Signal System), this new evaluation method is presented to address more complex reservoirs, such as shale and heavy oil. The book also discusses prolonged production methods for enhanced oil recovery. The monitoring of storage zones for carbon capture are also included, all helping the petroleum and reservoir engineer to fully extend the life of a field and locate untapped pockets of additional oil and gas resources. Rounded out with case studies from locations such as Japan, Saudi Arabia, and Canada, this book will help readers, scientists, and engineers alike to better manage the life of their oil and gas resources and reservoirs.

Author : David Hervey Johnston
Publisher :
Page : 270 pages
File Size : 10,67 MB
Release : 2013
Category : Electronic books
ISBN : 9781560803126

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Time-lapse (4D) seismic technology is a key enabler for improved hydrocarbon recovery and more cost-effective field operations. Practical Applications of Time-lapse Seismic Data (SEG Distinguished Instructor Series No. 16) shows how 4D seismic data are used for reservoir surveillance, how they provide valuable insight on dynamic reservoir properties such as fluid saturation, pressure, and temperature, and how they add value to reservoir management. The material, based on the 2013 SEG Distinguished Instructor Short Course, includes discussions of reservoir-engineering concepts and rock physics critical to the understanding of 4D data, along with topics in 4D seismic acquisition and processing. A primary focus of the book is interpretation and data integration. Case-study examples are used to demonstrate key concepts and are drawn on to demonstrate the range of interpretation methods currently employed by industry and the diversity of geologic settings and production scenarios in which 4D is making a difference. Time-lapse seismic interpretation is inherently integrative, drawing on geophysical, geologic, and reservoir-engineering data and concepts. As a result, this book should be of interest to individuals from all subsurface disciplines.

Author : Carlos Eduardo Borges De Salles Abreu
Publisher :
Page : 337 pages
File Size : 20,45 MB
Release : 2008
Category :
ISBN :

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This thesis research aims at investigating seismic interpretation methodologies and techniques that will help on better characterizing time-lapse, or 4D, seismic signatures. These techniques and methodologies are used to evaluate the time-lapse repeatability and then to filter out undesirable artefacts that are non-related to the production, while enhancing the 4D signature. To achieve these goals, a methodology based on geostatistical tools, was developed. Typically, at least two time-interval windows are considered: one above and the other comprising the reservoir of interest. A statistical and variographic analysis, conducted on both windows and on all surveys, leads to an interpretation step where common or independent structures - in the variographic sense- can be pointed out. The structures interpreted as not related to the geology or to the production mechanism are filtered from the data by a multivariate factorial cokriging technique, based on the concept of Kriging Analysis developed by Matheron in 1982. Two real case time-lapse studies were used to test the methodology. The first case is a Canadian onshore heavy oil reservoir submitted to steam injection, where three different time-lapse surveys were shot to monitor the steam-chamber evolution. The noise present in the three surveys was first filtered using the technique described above; next, an unsupervised seismic facies analysis was conducted on both raw and filtered data in order to evaluate the filtering technique, and finally an interpretation, in terms of reservoir properties changes, of the time-shit observed between the campaigns was proposed. In the second case, the seismic data was acquired on a deepwater turbiditic oilfield from Brazil at two different times of reservoir life, before and after production and water injection. The two seismic surveys were filtered using the factorial kriging technique; the quality of the filtering was, in this case, evaluated by comparison with more common techniques.

Author : Satinder Chopra
Publisher : SEG Books
Page : 474 pages
File Size : 47,30 MB
Release : 2007
Category : Science
ISBN : 1560801417

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Introducing the physical basis, mathematical implementation, and geologic expression of modern volumetric attributes including coherence, dip/azimuth, curvature, amplitude gradients, seismic textures, and spectral decomposition, the authors demonstrate the importance of effective colour display and sensitivity to seismic acquisition and processing.