Restech (United States)

The Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT) launched in Jan. 2009 has demonstrated accurate and precise CO2 and CH4 distribution measurements from space. The globally acquired data have contributed to reduce the uncertainties in global and regional flux inverse estimates. In response to the urgent need for monitoring carbon emissions from intense localized sources, such as cities and power plants, we have been developing a next generation instrument that should be able to detect and map plumes from the intense sources with a 1km spatial resolution. We design our system to implement both targeted observations for intense local sources with high spatial resolution and wide-swath observations for covering the earth’s entire surface with 2-axes pointing system and two telescopes. We have developed airborne imaging spectrometer suites with three imaging spectrometers: 0.47 µm for nitrogen dioxide (NO2), 0.76 µm for oxygen (O2) and solar-induced chlorophyll fluorescence (SIF) and 1.6 µm for carbon dioxide (CO2) and methane (CH4). The airplane observations successfully recorded CO2 and NO2 enhancements over a power plant in Greater Nagoya Area. In our presentation, we will present our first emission estimates based on the simultaneous CO2 and NO2 observation.

Abstract A new general correlation for estimating coal adsorption isotherms using log data has been developed. The "Langmuir Rank Equation," developed with the same dataset used for deriving Kim’s1 equation, provides an improved fit with the measurements. The Langmuir constants are derived from a coal rank indicator and adjusted for temperature. At elevated pressures, such as those in the San Juan basin, this approach may offer a substantial improvement in gas content estimates, as indicated in tests with a limited number of isotherms. The new correlation, adjusted for the effect of moisture, could be used with well logs alone in estimating gas content (saturated conditions) in coalbeds where no core samples are available. Since the equation provides the entire isotherm, it could also be used in the estimation of reserves. It could also be used when quality checking isotherms. It is important to note that both log-based models (Kim and Langmuir Rank) were developed based on isotherm data, and as such, assume the coal is saturated and cannot be used to identify undersaturated coals.

Estimating Coalbed Gas Content and Sorption Isotherm Using Well Log Data J.M. Hawkins; J.M. Hawkins ResTech Houston Search for other works by this author on: This Site Google Scholar R.A. Schraufnagel; R.A. Schraufnagel Gas Research Inst. Search for other works by this author on: This Site Google Scholar A.J. Olszewski A.J. Olszewski ResTech Pittsburgh Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Washington, D.C., October 1992. Paper Number: SPE-24905-MS https://doi.org/10.2118/24905-MS Published: October 04 1992 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Hawkins, J.M., Schraufnagel, R.A., and A.J. Olszewski. "Estimating Coalbed Gas Content and Sorption Isotherm Using Well Log Data." Paper presented at the SPE Annual Technical Conference and Exhibition, Washington, D.C., October 1992. doi: https://doi.org/10.2118/24905-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search SPE MembersAbstractA new general correlation for estimating coal adsorption isotherms using log data has been developed. The "Langmuir Rank Equation," developed with the same dataset used for deriving Kim's equation, provides an improved fit with the measurements. The Langmuir constants are derived from a coal rank indicator and adjusted for temperature. At elevated pressures, such as those in the San Juan basin, this approach may offer a substantial improvement in gas content estimates, as indicated in tests with a limited number of isotherms.The new correlation, adjusted for the effect of moisture, could be used with well logs alone in estimating gas content (saturated conditions) in coalbeds where no core samples are available. Since the equation provides the entire isotherm, it could also be used in the estimation of reserves. It could also be used when quality checking isotherms. It is important to note that both log-based models (Kim and Langmuir Rank) were developed based on isotherm data, and as such, assume the coal is saturated and cannot be used to identify undersaturated coals.IntroductionIsotherm data must accurately represent the coal reservoir. This is essential whether making simplified reserve calculations or more complex model-based projections. Properly done, this requires obtaining a number of isotherm samples statistically sufficient to characterize the coal seams of interest both vertically and laterally. Depending on isotherm variability, this number can be considerable. Two factors influencing isotherm character arc coal rank and ash content. Coal rank can vary vertically, from seam to seam at a given location. Laterally, maps of this parameter for a single coal seam show significant variation from township to township, and occasionally within a township. Ash content often shows significant vertical foot-to-foot variations within a well, particularly in the San Juan basin.Coal quality (as indicated by rank and ash content) is known to vary both vertically and laterally and it is expected that isotherm character will also exhibit variations. Therefore, gas resource evaluations would be improved if measured isotherm data were available for every foot of every coal seam in each well in the area to be evaluated. In practice, such extensive coring and testing are not done for operational and economic reasons; instead, the collection of measured isotherms is comparatively sparse. On the other hand, well log coverage is much more plentiful, and logs, particularly the bulk density log, have shown excellent correlations with the components of proximate analysis: ash content, fixed carbon, and volatile matter. A general correlation between proximate analysis and measured isotherms, if such could be found, could be used together with well logs to estimate isotherms where measurements are lacking. Such a correlation would also be useful in quality checking measured isotherms since there are currently no accepted industry standards for making these measurements.The two most common methods of determining gas content from logs are 1) relating ash content to gas content, and 2) the Kim equation. The ability to relate ash content to core-determined gas content has been documented by other authors. Although relationships based on ash content can provide reasonable estimates of gas contents, they are site specific and will vary from area to area. The Kim Equation is based on relationships among saturated gas content, coal rank (carbon/volatile ratio), pressure, and temperature.P. 491^ Keywords: coal bed methane, coal sample, proximate analysis, carbon, well logging, sorption isotherm, crossplot, log analysis, dataset, equation Subjects: Formation Evaluation & Management, Unconventional and Complex Reservoirs, Open hole/cased hole log analysis, Coal seam gas This content is only available via PDF. 1992. Society of Petroleum Engineers You can access this article if you purchase or spend a download.

ABSTRACT This paper presents a summary of the key observations and conclusions from the Gas Research Institute's (GRI's) Comprehensive Study Well (CSW) research program conducted in the Devonian Shales of the Appalachian Basin. Initiated in 1987, the CSW program was a series of highly instrumented study wells drilled in cooperation with industry partners. Seven wells were drilled as part of the program. Extensive data sets were collected and special experiments were run on the CSW's in addition to the operator's normal operations, with the objectives of identifying geologic production controls, refining formation evaluation tools, and improving reservoir description and stimulation practices in the Devonian Shales. This paper highlights the key results from the research conducted in the CSW program in the areas of geologic production controls, formation evaluation, stimulation and reservoir engineering, and field operations. The development of geologic, log analysis, and reservoir models for the Shales from the data gathered and analyzed during the research is discussed. In addition, on the basis of what was learned in the CSW program, GRI's plans for new research in the Devonian Shales are described.

Abstract Bypassed gas zones can be identified and developed by integrating advanced geologic methods and petrophysical techniques into field development strategies. These reservoirs may provide incremental gas reserve additions at relatively low cost to the operator. Seeligson field was studied as part of a Gas Research Institute-sponsored program designed to develop, test, and verity technologies and methodologies for maximizing the recovery of gas from conventional reservoirs in mature fields. Detailed geologic evaluation of middle Frio reservoirs in Seeligson field reveals a stratigraphic framework composed of multiple, stacked fluvial channel-fill and splay deposits interstratified with floodplain mudstones. Channel-fill deposits are 10 to 40 ft (3 to 12 m) thick and approximately 2,500 ft (750 m) wide. Splay deposits are up to 20 ft (6 m) thick proximal to channels and extend several thousand feet away from the channel. Channel-fill and crevasse-splay sandstones are reservoir fades; levee and floodplain mudstones are thought to be barriers to flow, separating individual reservoirs vertically and laterally. Recently developed cased-hole log evaluation techniques tested in Seeligson field demonstrate their superiority for locating bypassed gas. Based on geological and spatial considerations, 14 key wells within a 4 mi2 (10 km2) area of the field were selected for cased-hole petrophysical analyses. Pulsed-neutron and gamma-ray logs were recorded in these wells. After preliminary analyses, five wells were selected for full waveform acoustic logging. Porosity was calculated from the acoustic log and compared to pulsed-neutron porosity to determine gas effect. The logs were corrected for shaliness and combined with sigma (capture cross section) data to calculate water saturation. Long-normal resistivity curves from electric logs were digitized and integrated with the newly acquired data to calculate original open-hole water saturation. Plotting and comparing the logs graphically enabled gas-productive sands to be identified. Five successful recompletions were made as a result of this study. By estimating reserves from current and initial production, using net present value of the gas, and dividing by the cost of the project, a highly favorable return on investment is estimated.

SummaryThe in-situ stress contrast between a reservoir rock and the surrounding formations is important to the design and analysis of hydraulic fracture treatments. The stress contrast between layers controls the fracture's vertical (height) growth, which in turn affects the fracture length and width. As part of the Gas Research Inst.'s (GRI's) Comprehensive Study Well (CSW) program in the Devonian shales of the Appalachian basin, we measured in-situ stresses directly and used these values to calibrate acoustic log measurements to develop stress profiles across the Devonian shales. This discusses the measurement and interpretation of in-situ stresses, the use of acoustic logs to determine mechanical properties and a more complete stress profile, and the practical use of the stress profile in fracture-treatment design and analysis.In-situ stresses were measured directly throughout the Devonian shale interval with both openhole and cased-hole stress tests, conducted with nitrogen, a specially designed downhole shut-in tool, and a downhole quartz pressure gauge with surface readout. The paper describes the procedure used and presents interpreted stress-test results from two CSW's. Full-waveform acoustic tools were run to define elastic properties of the Devonian shales. These properties also were determined under both static and dynamic conditions from whole-core plugs taken in the shales. Logs were calibrated to core-measured values, and then elastic properties determined from the logs were used to compute an in-situ-stress profile, which was calibrated against field measurements of in-situ stresses. Finally, we discuss how these data are used to design and analyze hydraulic fracture treatments in CSW's.

It has long been recognized that grain size has a marked effect on the subsequent processing characteristics of metallic materials. Plasma cold hearth melting is a promising technique for the production of reactive and refractory metal ingots. A study has been conducted to determine the effect of melt parameters on the subsequent grain size and shape in plasma cold hearth withdrawal of Ti-6A1-4V ingots. In the study, a number of ingots were made in Retech's cold hqarth development furnace and sectioned for examination. The relative importance of operating parameters such as surface heat distribution and flux and of stirring on grain size and shape are reported.

ABSTRACT This paper presents an overall summary of the in-situ stress data obtained through the Gas Research Institute (GRI) Tight Gas Sands Research Program. Data of this type can be invaluable to anyone designing a hydraulic fracture treatment in a complex, multi-layered reservoir. Correlations are presented that allow the in-situ stress gradient to be calculated from openhole log data as a function of reservoir pressure. Results from thirty-four (34) stress tests in five wells in the Travis Peak formation of east Texas are presented. Twenty of these tests were conducted as part of the 1986 GRI Staged Field Experiment in the Waskom (Travis Peak) Field in Harrison County, Texas. The primary purpose of these tests was to determine the in-situ stresses of the various lithologies in this multi-layered, complex reservoir. Knowledge of the vertical stress profile can help to make estimates of vertical fracture growth as a function of excess pressure in the fracture. Formation pressures were obtained in many zones with either wireline formation testers or pressure buildup tests. These estimates of reservoir pressure were then correlated with the actual measured values of in-situ stress to determine the effects of pressure depletion on the in-situ stress. Calculated values of in-situ stress from logs were calibrated using the measured values of reservoir pressure and in-situ stress.