Geology topics

T.R. Carr

Publications and source records attributed to T.R. Carr.

12 recordsLinked to original sources

USGS2009

A national look at carbon capture and storage-National carbon sequestration database and geographical information system (NatCarb)

The US Department of Energy's Regional Carbon Sequestration Partnerships (RCSPs) are responsible for generating geospatial data for the maps displayed in the Carbon Sequestration Atlas of the United States and Canada. Key geospatial data (carbon sources, potential storage sites, transportation, land use, etc.) are required for the Atlas, and for efficient implementation of carbon sequestration on a national and regional scale. The National Carbon Sequestration Database and Geographical Information System (NatCarb) is a relational database and geographic information system (GIS) that integrates carbon storage data generated and maintained by the RCSPs and various other sources. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO 2 emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project is working to provide all stakeholders with improved online tools for the display and analysis of CO 2 carbon capture and storage data. NatCarb is organizing and enhancing the critical information about CO 2 sources and developing the technology needed to access, query, model, analyze, display, and distribute natural resource data related to carbon management. Data are generated, maintained and enhanced locally at the RCSP level, or at specialized data warehouses, and assembled, accessed, and analyzed in real-time through a single geoportal. NatCarb is a functional demonstration of distributed data-management systems that cross the boundaries between institutions and geographic areas. It forms the first step toward a functioning National Carbon Cyberinfrastructure (NCCI). NatCarb provides access to first-order information to evaluate the costs, economic potential and societal issues of CO 2 capture and storage, including public perception and regulatory aspects. NatCarb online access has been modified to address the broad needs of a spectrum of users. NatCarb includes not only GIS and database query tools for high-end user, but simplified display for the general public using readily available web tools such as Google Earth???and Google Maps???. Not only is NatCarb connected to all the RCSPs, but data are also pulled from public servers including the U.S. Geological Survey-EROS Data Center and from the Geography Network. Data for major CO 2 sources have been obtained from U.S. Environmental Protection Agency (EPA) databases, and data on major coal basins and coalbed methane wells were obtained from the Energy Information Administration (EIA). ?? 2009 Elsevier Ltd. All rights reserved.

Conference Paper↗

USGS2007

The NatCarb geoportal: Linking distributed data from the Carbon Sequestration Regional Partnerships

The Department of Energy (DOE) Carbon Sequestration Regional Partnerships are generating the data for a "carbon atlas" of key geospatial data (carbon sources, potential sinks, etc.) required for rapid implementation of carbon sequestration on a broad scale. The NATional CARBon Sequestration Database and Geographic Information System (NatCarb) provides Web-based, nation-wide data access. Distributed computing solutions link partnerships and other publicly accessible repositories of geological, geophysical, natural resource, infrastructure, and environmental data. Data are maintained and enhanced locally, but assembled and accessed through a single geoportal. NatCarb, as a first attempt at a national carbon cyberinfrastructure (NCCI), assembles the data required to address technical and policy challenges of carbon capture and storage. We present a path forward to design and implement a comprehensive and successful NCCI. ?? 2007 The Haworth Press, Inc. All rights reserved.

Journal of Map & Geography Libraries↗

USGS2007

Geostatistical three-dimensional modeling of oolite shoals, St. Louis Limestone, southwest Kansas

In the Hugoton embayment of southwestern Kansas, reservoirs composed of relatively thin (<4 m; <13.1 ft) oolitic deposits within the St. Louis Limestone have produced more than 300 million bbl of oil. The geometry and distribution of oolitic deposits control the heterogeneity of the reservoirs, resulting in exploration challenges and relatively low recovery. Geostatistical three-dimensional (3-D) models were constructed to quantify the geometry and spatial distribution of oolitic reservoirs, and the continuity of flow units within Big Bow and Sand Arroyo Creek fields. Lithofacies in uncored wells were predicted from digital logs using a neural network. The tilting effect from the Laramide orogeny was removed to construct restored structural surfaces at the time of deposition. Well data and structural maps were integrated to build 3-D models of oolitic reservoirs using stochastic simulations with geometry data. Three-dimensional models provide insights into the distribution, the external and internal geometry of oolitic deposits, and the sedimentologic processes that generated reservoir intervals. The structural highs and general structural trend had a significant impact on the distribution and orientation of the oolitic complexes. The depositional pattern and connectivity analysis suggest an overall aggradation of shallow-marine deposits during pulses of relative sea level rise followed by deepening near the top of the St. Louis Limestone. Cemented oolitic deposits were modeled as barriers and baffles and tend to concentrate at the edge of oolitic complexes. Spatial distribution of porous oolitic deposits controls the internal geometry of rock properties. Integrated geostatistical modeling methods can be applicable to other complex carbonate or siliciclastic reservoirs in shallow-marine settings. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

American Association of Petroleum Geologists Bulle↗

USGS2006

Neural network prediction of carbonate lithofacies from well logs, Big Bow and Sand Arroyo Creek fields, Southwest Kansas

In the Hugoton Embayment of southwestern Kansas, St. Louis Limestone reservoirs have relatively low recovery efficiencies, attributed to the heterogeneous nature of the oolitic deposits. This study establishes quantitative relationships between digital well logs and core description data, and applies these relationships in a probabilistic sense to predict lithofacies in 90 uncored wells across the Big Bow and Sand Arroyo Creek fields. In 10 wells, a single hidden-layer neural network based on digital well logs and core described lithofacies of the limestone depositional texture was used to train and establish a non-linear relationship between lithofacies assignments from detailed core descriptions and selected log curves. Neural network models were optimized by selecting six predictor variables and automated cross-validation with neural network parameters and then used to predict lithofacies on the whole data set of the 2023 half-foot intervals from the 10 cored wells with the selected network size of 35 and a damping parameter of 0.01. Predicted lithofacies results compared to actual lithofacies displays absolute accuracies of 70.37-90.82%. Incorporating adjoining lithofacies, within-one lithofacies improves accuracy slightly (93.72%). Digital logs from uncored wells were batch processed to predict lithofacies and probabilities related to each lithofacies at half-foot resolution corresponding to log units. The results were used to construct interpolated cross-sections and useful depositional patterns of St. Louis lithofacies were illustrated, e.g., the concentration of oolitic deposits (including lithofacies 5 and 6) along local highs and the relative dominance of quartz-rich carbonate grainstone (lithofacies 1) in the zones A and B of the St. Louis Limestone. Neural network techniques are applicable to other complex reservoirs, in which facies geometry and distribution are the key factors controlling heterogeneity and distribution of rock properties. Future work involves extension of the neural network to predict reservoir properties, and construction of three-dimensional geo-models. ?? 2005 Elsevier Ltd. All rights reserved.

Computers & Geosciences↗

USGS2005

Integrated core-log petrofacies analysis in the construction of a reservoir geomodel: A case study of a mature Mississippian carbonate reservoir using limited data

Small independent operators produce most of the Mississippian carbonate fields in the United States mid-continent, where a lack of integrated characterization studies precludes maximization of hydrocarbon recovery. This study uses integrative techniques to leverage extant data in an Osagian and Meramecian (Mississippian) cherty carbonate reservoir in Kansas. Available data include petrophysical logs of varying vintages, limited number of cores, and production histories from each well. A consistent set of assumptions were used to extract well-level porosity and initial saturations, from logs of different types and vintages, to build a geomodel. Lacking regularly recorded well shut-in pressures, an iterative technique, based on material balance formulations, was used to estimate average reservoir-pressure decline that matched available drillstem test data and validated log-analysis assumptions. Core plugs representing the principal reservoir petrofacies provide critical inputs for characterization and simulation studies. However, assigning plugs among multiple reservoir petrofacies is difficult in complex (carbonate) reservoirs. In a bottom-up approach, raw capillary pressure (Pc) data were plotted on the Super-Pickett plot, and log- and core-derived saturation-height distributions were reconciled to group plugs by facies, to identify core plugs representative of the principal reservoir facies, and to discriminate facies in the logged interval. Pc data from representative core plugs were used for effective pay evaluation to estimate water cut from completions, in infill and producing wells, and guide-selective perforations for economic exploitation of mature fields. The results from this study were used to drill 22 infill wells. Techniques demonstrated here can be applied in other fields and reservoirs. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

American Association of Petroleum Geologists Bulle↗

USGS2005

Use of relational databases to evaluate regional petroleum accumulation, groundwater flow, and CO2 sequestration in Kansas

Large-scale relational databases and geographic information system tools are used to integrate temperature, pressure, and water geo-chemistry data from numerous wells to better understand regional-scale geothermal and hydrogeological regimes of the lower Paleozoic aquifer systems in the mid-continent and to evaluate their potential for geologic CO2 sequestration. The lower Paleozoic (Cambrian to Mississippian) aquifer systems in Kansas, Missouri, and Oklahoma comprise one of the largest regional-scale saline aquifer systems in North America. Understanding hydrologic conditions and processes of these regional-scale aquifer systems provides insight to the evolution of the various sedimentary basins, migration of hydrocarbons out of the Anadarko and Arkoma basins, and the distribution of Arbuckle petroleum reservoirs across Kansas and provides a basis to evaluate CO2 sequestration potential. The Cambrian and Ordovician stratigraphic units form a saline aquifer that is in hydrologic continuity with the freshwater recharge from the Ozark plateau and along the Nemaha anticline. The hydrologic continuity with areas of freshwater recharge provides an explanation for the apparent underpressure in the Arbuckle Group. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

American Association of Petroleum Geologists Bulle↗

USGS2002

Sequence stratigraphic and sedimentologic significance of biogenic structures from a late Paleozoic marginal- to open-marine reservoir, Morrow Sandstone, subsurface of southwest Kansas, USA

Integrated ichnologic, sedimentologic, and stratigraphic studies of cores and well logs from Lower Pennsylvanian oil and gas reservoirs (lower Morrow Sandstone, southwest Kansas) allow distinction between fluvio-estuarine and open marine deposits in the Gentzler and Arroyo fields. The fluvio-estuarine facies assemblage is composed of both interfluve and valley-fill deposits, encompassing a variety of depositional environments such as fluvial channel, interfluve paleosol, bay head delta, estuary bay, restricted tidal flat, intertidal channel, and estuary mouth. Deposition in a brackish-water estuarine valley is supported by the presence of a low diversity, opportunistic, impoverished marine ichnofaunal assemblage dominated by infaunal structures, representing an example of a mixed, depauperate Cruziana and Skolithos ichnofacies. Overall distribution of ichnofossils along the estuarine valley was mainly controlled by the salinity gradient, with other parameters, such as oxygenation, substrate and energy, acting at a more local scale. The lower Morrow estuarine system displays the classical tripartite division of wave-dominated estuaries (i.e. seaward-marine sand plug, fine-grained central bay, and sandy landward zone), but tidal action is also recorded. The estuarine valley displays a northwest-southeast trend, draining to the open sea in the southeast. Recognition of valley-fill sandstones in the lower Morrow has implications for reservoir characterization. While the open marine model predicts a "layer-cake" style of facies distribution as a consequence of strandline shoreline progradation, identification of valley-fill sequences points to more compartmentalized reservoirs, due to the heterogeneity created by valley incision and subsequent infill. The open-marine facies assemblage comprises upper, middle, and lower shoreface; offshore transition; offshore; and shelf deposits. In contrast to the estuarine assemblage, open marine ichnofaunas are characterized by a high diversity of biogenic structures representing the activity of a benthic fauna developed under normal salinity conditions. Trace fossil and facies analyses allow environmental subdivision of the shoreface-offshore successions and suggest deposition in a weakly storm-affected nearshore area. An onshore-offshore replacement of the Skolithos ichnofacies by the Cruziana ichnofacies is clearly displayed. The lower Morrow fluvio-estuarine valley was incised during a drop of sea level coincident with the Mississippian-Pennsylvanian transition, but was mostly filled during a subsequent transgression. The transgressive nature of the estuarine infill is further indicated by the upward replacement of depauperate brackish-water trace fossil assemblages by the open-marine Cruziana ichnofacies. Additional stratal surfaces of allostratigraphic significance identified within the estuary include the bayline surface, the tidal ravinement surface, the wave ravinement surface, and a basinwide flooding surface recording inundation of the valley interfluves. A younger sequence boundary within the lower Morrow is also recorded in the Gentzler field at the base of a forced regression shoreface, demarcated by the firmground Glossifungites ichnofacies, indicating a rapid basinward facies migration during a sea-level drop. Trace fossil models derived from the analysis of Mesozoic and Cenozoic reservoirs are generally applicable to the study of these late Paleozoic reservoirs. Pennsylvanian brackish-water facies differ ichnologically from their post-Paleozoic counterparts, however, in that they have: (1) lower trace fossil diversity, (2) lower degree of bioturbation, (3) scarcity of crustacean burrows, (4) absence of firmground suites, and (5) absence of ichnotaxa displaying specific architectures designed to protect the tracemaker from salinity fluctuations. Morrow open-marine ichnofaunas closely resemble their post-Paleozoic equivalents. ?? 2002 Elsevier Science B.V. All rights reserved.

Sedimentary Geology↗

USGS2002

Coalbed gas play emerges in eastern Kansas basins

Coalbed gas from Middle Pennsylvanian rocks in eastern Kansas is an emerging new energy play. Many of the critical geological parameters that will prove to be the major controls on the production fairways of this potential new resource have yet to be determined. Nevertheless, preliminary analyses indicate that recent leasing and exploration may translate into long-term production of new gas resources in what was hitherto considered a supermature petroleum province.

Kansas↗

USGS2000

Schaben field, Kansas: Improving performance in a Mississippian shallow-shelf carbonate

Schaben field (Kansas), located along the northeastern shelf of the Hugoton embayment, produces from Mississippian carbonates in erosional highs immediately beneath a regional unconformity. Production comes from depths of around 4400 ft (1342 m) in partially dolomitized shelf deposits. A detailed reservoir characterization/simulation study, recently performed as part of a Department of Energy Reservoir Class Oil Field Demonstration Project, has led to important revision in explanations for observed patterns of production. Cores recovered from three new data wells identify three main facies: Spicule-rich wackestone-packstone, echinoderm wackestone/packstone/grainstone, and dolomitic mudstone-wackestone. Reservoir quality is highest in spicule-rich wackestone/packstones but is subject to a very high degree of vertical heterogeneity due to facies interbedding, silification, and variable natural fracturing. The oil reservoir is underlain by an active aquifer, which helps maintain reservoir pressure but supports significant water production. Reservoir simulation, using public-domain, PC-based software, suggests that infill drilling is an efficient approach to enhanced recovery. Recent drilling directed by simulation results has shown considerable success in improving field production rates. Results from the Schaben field demonstration project are likely to have wide application for independent oil and exploration companies in western Kansas.Schaben field (Kansas), located along the northeastern shelf of the Hugoton embayment, produces from Mississippian carbonates in erosional highs immediately beneath a regional unconformity. Production comes from depths of around 4400 ft (1342 m) in partially dolomitized shelf deposits. A detailed reservoir characterization/simulation study, recently performed as part of a Department of Energy Reservoir Class Oil Field Demonstration Project, has led to important revision in explanations for observed patterns of production. Cores recovered from three new data wells identify three main facies: spicule-rich wackestone-packstone, echinoderm wackestone/packstone/grainstone, and dolomitic mudstone-wackestone. Reservoir quality is highest in spicule-rich wackestone/packstones but is subject to a very high degree of vertical heterogeneity due to facies interbedding, silification, and variable natural fracturing. The oil reservoir is underlain by an active aquifer, which helps maintain reservoir pressure but supports significant water production. Reservoir simulation, using public-domain, PC-based software, suggests that infill drilling is an efficient approach to enhanced recovery. Recent drilling directed by simulation results has shown considerable success in improving field production rates. Results from the Schaben field demonstration project are likely to have wide application for independent oil and exploration companies in western Kansas.

Kansas↗

USGS1998

Petrofacies Analysis - A Petrophysical Tool for Geologic/Engineering Reservoir Characterization

Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measurements of a reservoir. The word "petrofacies" makes an explicit link between petroleum engineers' concerns with pore characteristics as arbiters of production performance and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations are reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types (size and connectedness) for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production, such as bypassed pay behind pipe and in old exploration wells, or to assess zonation and continuity of the reservoir. Petrofacies analysis in this study was applied to distinguishing flow units and including discriminating pore type as an assessment of reservoir conformance and continuity. The analysis is facilitated through the use of colorimage cross sections depicting depositional sequences, natural gamma ray, porosity, and permeability. Also, cluster analysis was applied to discriminate petrophysically similar reservoir rock.

AAPG Memoir↗

USGS1997

Kansas geological survey's Digital Petroleum Atlas (DPA) project

The Kansas Digital Petroleum Atlas (DPA) is a new approach to generating and publishing petroleum reservoir, field, play and basin studies. Atlas products are available anywhere in the world using a standard point-and-click World-Wide-Web interface. All information and technology in the DPA can be accessed, manipulated and downloaded in order to provide efficient transfer of the technology for client-defined solutions. The DPA design provides a dynamic product that is constantly evolving through new information structures, the latest research results, and incorporation of additional data. Through complete and flexible user access to both interpretative products and underlying reservoir and well data, the DPA significantly alters the relationship between research results, data access, and the transfer of technology.

Proceedings - SPE Annual Technical Conference and ↗

USGS1997

The future of scientific communication in the earth sciences: The impact of the internet

Publication on paper of research results following peer-review and editing has been the accepted means of scientific communication for several centuries. Today, the continued growth in the volume of scientific literature, the increased unit costs of archiving paper publications, and the rapidly increasing power and availability of electronic technology are creating tremendous pressures on traditional scientific communication. The earth sciences are not immune from these pressures, and the role of the traditional publication as the primary means of communication is rapidly changing. Electronic publications and network technology are radically altering the relationship between interpretative result and the underlying data. Earth science research institutions, including the Kansas Geological Survey, are experimenting with new forms of on-line publication that assure broad access to research and data and improve application of research results to societal problems. ?? 1997 Elsevier Science Ltd.

Computers & Geosciences↗