Relationships between salt diapirism, faulting, and sedimentation on a Gulf of Mexico 3‐D data set

We have developed a new trace-based, warping least-squares inversion method to quantify 4D velocity changes. There are two steps to solve for these velocity changes: (1) dynamic warping with phase constraints to align the baseline and monitor traces and (2) least-squares inversion for 4D velocity changes incorporating the time shifts and 4D amplitude differences (computed after trace alignment by warping). We have demonstrated this new inversion workflow using simple synthetic layered models. For the noise-free case, phase-constrained warping is superior to standard, amplitude-based warping by improving trace alignment, resulting in more accurate inverted velocity changes (less than 1% error). For synthetic data with 6% rms noise, inverted velocity changes are reasonably accurate (less than 10% error). Additional inversion tests with migrated finite-difference data shot over a realistic anticline model result in less than 10% error. The inverted velocity changes on a 4D field data set from the Gulf of Mexico are more interpretable and consistent with the dynamic reservoir model than those estimated from the conventional time-strain method.

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A practical workflow using quantitative interpretation of seismic amplitudes to derisk infill wells in deepwater Gulf of Mexico: The Auger example

The Leading Edge ◽

10.1190/tle38100754.1 ◽

2019 ◽

Vol 38 (10) ◽

pp. 754-761 ◽

Cited By ~ 1

Author(s):

Liqin Sang ◽

Uwe Klein-Helmkamp ◽

Andrew Cook ◽

Juan R. Jimenez

Keyword(s):

Gulf Of Mexico ◽

Time Lapse ◽

Quantitative Interpretation ◽

Efficient Manner ◽

Data Set ◽

Seismic Amplitude ◽

Imperfect Data ◽

Avo Inversion ◽

Fluid Saturation ◽

Single Well

Seismic direct hydrocarbon indicators (DHIs) are routinely used in the identification of hydrocarbon reservoirs and in the positioning of drilling targets. Understanding seismic amplitude reliability and character, including amplitude variation with offset (AVO), is key to correct interpretation of the DHI and to enable confident assessment of the commercial viability of the reservoir targets. In many cases, our interpretation is impeded by limited availability of data that are often less than perfect. Here, we present a seismic quantitative interpretation (QI) workflow that made the best out of imperfect data and managed to successfully derisk a multiwell drilling campaign in the Auger and Andros basins in the deepwater Gulf of Mexico. Data challenges included azimuthal illumination effects caused by the presence of the Auger salt dome, sand thickness below tuning, and long-term production effects that are hard to quantify without dedicated time-lapse seismic. In addition, seismic vintages with varying acquisition geometries led to different QI predictions that further complicated the interpretation story. Given these challenges, we implemented an amplitude derisking workflow that combined ray-based illumination assessments and prestack data observations to guide selection of the optimal seismic data set(s) for QI analysis. This was followed by forward modeling to quantify the fluid saturation and sand thickness effects on seismic amplitude. Combined with structural geology analysis of the well targets, this workflow succeeded in significantly reducing the risk of the proposed opportunities. The work also highlighted potential pitfalls in AVO interpretation, including AVO inversion for the characterization of reservoirs near salt, while providing a workflow for prestack amplitude quality control prior to inversion. The workflow is adaptable to specific target conditions and can be executed in a time-efficient manner. It has been applied to multiple infill well opportunities, but for simplicity reasons here, we demonstrate the application on a single well target.

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Investigation of deep-water Gulf of Mexico subsalt imaging using anisotropic model, data set and RTM — Tempest

Geophysics ◽

10.1190/geo2011-0043.1 ◽

2011 ◽

Vol 76 (5) ◽

pp. WB21-WB26 ◽

Cited By ~ 1

Author(s):

Fatmir Hoxha ◽

Jacqueline O’Connor ◽

Jeff Codd ◽

David Kessler ◽

Alex Bridge ◽

...

Keyword(s):

Gulf Of Mexico ◽

Deep Water ◽

Model Building ◽

Earth Model ◽

Anisotropic Model ◽

Model Data ◽

Data Set ◽

Depth Imaging ◽

The Tempest ◽

Time Migration

Performing accurate depth-imaging is an essential part of deep-water Gulf of Mexico exploration and development. Over the years, depth-imaging technology has provided reliable seismic images below complicated salt bodies, and has been implemented in workflows for both prospect generation as well as reservoir development. These workflows include time domain preprocessing using various multiple elimination techniques, anisotropic model building, and depth-imaging using anisotropic reverse time migration (RTM). However, the accuracy of the depth-migrated volumes is basically unknown because they are tested only in the locations where a well is drilled. In order to learn about the accuracy of anisotropic deep water Gulf of Mexico model building, and depth-imaging tools which are used for processing and imaging of field acquired data, we created a 3D vertical transverse isotropic (VTI) anisotropic earth model and a 3D seismic data set representing subsalt Gulf of Mexico geology. The model and data set are referred to as the Tempest data set, the original being created several years ago. The recent model and data set were created incorporating upgraded technology to reflect recent developments in data acquisition, model building and depth-imaging. Our paper presents the new Tempest anisotropic model, data set, and RTM prestack depth-migration (PSDM) results. The Tempest RTM PSDM is being used to learn about the differences between the exact geological model and the RTM PSDM image, helping in the interpretation of real RTM prestack depth-migrated data.

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Characterization of layered anisotropic media from prestack PS-wave-reflection data

Geophysics ◽

10.1190/1.2335419 ◽

2006 ◽

Vol 71 (5) ◽

pp. D171-D182 ◽

Cited By ~ 7

Author(s):

Jason E. Gumble ◽

James E. Gaiser

Keyword(s):

Gulf Of Mexico ◽

Seismic Data ◽

Equivalent Model ◽

Time Shift ◽

Layer By Layer ◽

Converted Wave ◽

Data Set ◽

Fracture Characterization ◽

Anisotropic Models ◽

Hti Media

Anisotropy and fracture characterization in individual layers is realized through iterative layer stripping corrections of four, converted-wave (PS-wave) synthetic reflection seismic data sets, generated from azimuthally anisotropic (HTI and TTI) models, and a four component (4-C) data set from the Teal South, Gulf of Mexico. The corrections were applied on a layer-by-layer basis to evaluate the efficacy of constant polarization rotation and time-shift operators. Equivalent isotropic models were compared to anisotropic models after layer-stripping corrections using rms amplitude and shear-wave-splitting time-difference maps to quantify and identify inherent errors in estimating seismic polarization parameters. For HTI media radial and transverse components of PS data that have had layer-stripping corrections applied, exhibit incorrect symmetry and orientations. This may adversely affect inversion and/or amplitude-variation with angle offset (AVO) and amplitude versus azimuth (AVA)analysis. Layer-stripping corrections applied to fast and slow ([Formula: see text] and [Formula: see text], respectively) components exhibit the correct symmetry and orientation. Time differences between PS1 and PS2 are computed using crosscorrelation. Previous studies have addressed some of the problems associated with layer-stripping corrections for the case of vertical fractures (HTI media) and poststack layer-stripping analyses. This study includes an equivalent model with dipping fractures (TTI media) and extends the scope to encompass the effects of anisotropy on prestack data. The results from an application of the same technique are also applied to a limited set of 4-C data from the Teal South project in the Gulf of Mexico. Results are consistent with those of previous studies involving solely poststack 4-C rotation analysis in terms of average, or zero offset, time differences and symmetry orientation. Offset and azimuth amplitude/traveltime variations, however, indicate that there is more information contained in prestack seismic data than 4-C rotation can comprehend.

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AVO inversion of a Gulf of Mexico bright spot—A case study

Geophysics ◽

10.1190/1.1444652 ◽

1999 ◽

Vol 64 (5) ◽

pp. 1480-1491 ◽

Cited By ~ 5

Author(s):

Patrice Nsoga Mahob ◽

John P. Castagna ◽

Roger A. Young

Keyword(s):

Gulf Of Mexico ◽

Poisson’S Ratio ◽

Poisson's Ratio ◽

Bright Spot ◽

Inversion Algorithm ◽

Seismic Line ◽

Data Set ◽

The Real ◽

Hydrocarbon Saturation ◽

Initial Starting

An iterative and linearized inversion algorithm carried out in the x-t domain has been applied to a prestack seismic data set from the central Gulf of Mexico, offshore Louisiana. Sonic and density curves from a well located close to the seismic line are used to generate the initial starting models for the inversion. We tested the geologically realistic hypothesis that the starting models have an accurate impedance structure outside of the potential pay zone and that the prospective pay zone will have mechanical properties consistent with the presence or absence of hydrocarbons. The inversion, performed with starting models with pay zones with a Poisson’s ratio appropriate for 100% brine saturation or with a Poisson’s ratio intermediate between expected values for full brine and hydrocarbon saturation, does not converge to the real seismic gather. However, with a starting model having a Poisson’s ratio appropriate for hydrocarbon saturation in the target zone, there is convergence from the initial to the real seismic gather.

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Protocol for Building a Reference Standard Sequence Library for DNA-Based Seafood Identification

Journal of AOAC International ◽

10.5740/jaoacint.14-111 ◽

2014 ◽

Vol 97 (6) ◽

pp. 1626-1633 ◽

Cited By ~ 12

Author(s):

Jonathan R Deeds ◽

Sara M Handy ◽

Frederick Fry ◽

Hudson Granade ◽

Jeffrey T Williams ◽

...

Keyword(s):

United States ◽

Gulf Of Mexico ◽

Dna Sequencing ◽

The United States ◽

Reference Standard ◽

Data Set ◽

Standard Sequence ◽

Seafood Products ◽

Reference Specimens ◽

The U.S

Abstract With the recent adoption of a DNA sequencing-based method for the species identification for seafood products by the U.S. Food and Drug Administration (FDA), a library of standard sequences derived from reference specimens with authoritative taxonomic authentication was required. Provided here are details of how the FDA and its collaborators are building this reference standard sequence library that will be used to confirm the accurate labeling of seafood products sold in interstate commerce in the United States. As an example data set from this library, information for 117 fish reference standards, representing 94 species from 43 families in 15 orders, collected over a 4-year period from the Gulf of Mexico, U.S., that are now stored at the Smithsonian Museum Support Center in Suitland, MD, are provided.

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Chemistry and transport of pollution over the Gulf of Mexico and the Pacific: Spring 2006 INTEX-B Campaign overview and first results

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-363-2009 ◽

2009 ◽

Vol 9 (1) ◽

pp. 363-409 ◽

Cited By ~ 13

Author(s):

H. B. Singh ◽

W. H. Brune ◽

J. H. Crawford ◽

F. Flocke ◽

D. J. Jacob

Keyword(s):

Air Quality ◽

Gulf Of Mexico ◽

Transport Model ◽

Chemical Transport ◽

Second Phase ◽

Pollution Transport ◽

Aerosol Composition ◽

Data Set ◽

The Pacific ◽

Two Phases

Abstract. Intercontinental Chemical Transport Experiment-B (INTEX-B) was a major NASA1 led multi-partner atmospheric field campaign completed in the spring of 2006 (http://cloud1.arc.nasa.gov/intex-b/). Its major objectives aimed at (i) investigating the extent and persistence of the outflow of pollution from Mexico; (ii) understanding transport and evolution of Asian pollution and implications for air quality and climate across western North America; and (iii) validating space-borne observations of tropospheric composition. INTEX-B was performed in two phases. In its first phase (1–21 March), INTEX-B operated as part of the MILAGRO campaign with a focus on observations over Mexico and the Gulf of Mexico. In the second phase (17 April–15 May), the main INTEX-B focus was on the trans-Pacific Asian pollution transport. Multiple airborne platforms carrying state of the art chemistry and radiation payloads were flown in concert with satellites and ground stations during the two phases of INTEX-B. Validation of Aura satellite instruments (TES, OMI, MLS, HIRDLS) was a key objective within INTEX-B. Satellite products along with meteorological and 3-D chemical transport model forecasts were integrated into the flight planning process to allow targeted sampling of air parcels. Inter-comparisons were performed among and between aircraft payloads to quantify the accuracy of data and to create a unified data set. Pollution plumes were sampled over the Gulf of Mexico and the Pacific several days after downwind transport from source regions. Signatures of Asian pollution were routinely detected by INTEX-B aircraft, providing a comprehensive data set on gas and aerosol composition to test models and evaluate pathways of pollution transport and their impact on air quality and climate. This overview provides details about campaign implementation and a context within which the present and future INTEX-B/MILAGRO publications can be understood. 1 Acronyms are provided in Appendix A.

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Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico ◽

10.47886/9781888569971.ch2 ◽

2007 ◽

Keyword(s):

Time Series ◽

Gulf Of Mexico ◽

Mississippi River ◽

Red Snapper ◽

Survey Area ◽

Lutjanus Campechanus ◽

Data Set ◽

Stock Size ◽

Central Texas ◽

The U.S

Abstract.—Eleven taxa of snappers were found among the 20,301 snapper larvae examined from over 14,000 bongo and neuston samples collected during SEAMAP surveys, 1982 to 2003. During that time series, a total of 639 red snapper Lutjanus campechanus larvae were identified in bongo samples and 1053 larvae in neuston samples. Red snapper larvae first appeared in May and were present as late as November. Months of highest occurrence and abundance were July and September when larvae were taken in 12.7% and 11.0% of bongo samples, and in 7.6% and 8.4% of neuston samples. Mean abundance in those months was 1.18 and 0.82 larvae under 10 m2 of sea surface for bongo samples and 0.36 larvae per 10 min for neuston samples. By November, percent occurrence was less than or equal to 0.2% and mean abundance was less than 0.01 larvae in samples from either gear. Larvae identifiable as red snapper ranged in body length from 2.4 to 19.2 mm (mean = 5.12, median = 4.60) in bongo net samples; and 2.7–24.0 mm (mean = 4.37, median = 4.00) in neuston net samples. Over 95% of larvae in bongo samples were less than or equal to 8.3 mm and in neuston samples were less than or equal to 5.6 mm. Larvae were captured throughout the survey area but were consistently observed in greatest abundance at stations on the mid-continental shelf west of the Mississippi River, especially off western Louisiana and central Texas. This time series of observations is the data set from which annual estimates of larval red snapper abundance were derived for use as a fishery independent index of adult stock size.

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