Improved Pulsed Neutron Capture Logging With Slim Carbon-Oxygen Tools: Methodology

Plasek, R.E.; Adolph, R.A.; Stoller, Ch.; Willis, D.J.; Bordon, Ernesto; Portal, M.G.

doi:10.2523/30598-ms

Cited by 23 publications

(18 citation statements)

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“…In contrast to the TDT-P signal model, the RST model utilizes a dynamic parameterization technique 6 . The RST tool response was recorded in a combination of over 1300 laboratory and 400 modeled formations and mapped to the formation sigma, formation porosity, salinity of the borehole fluid, and other formation property curves.…”

Section: Rst Processing Modelmentioning

confidence: 99%

“…Briefly, the RST tool uses the dual-burst measurement technique, in the sigma mode, with 126 measurement gates (Fig. 2), more efficient detectors, and a more powerful neutron source that generates over twice the neutron yield in neutrons/second of the existing TDT-P tool 6 . The depth of investigation for optimum sigma logging conditions is about 10 inches.…”

Section: Introductionmentioning

confidence: 99%

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Reservoir Monitoring with Pulsed Neutron Capture Logs

Morris

Quinlan

et al. 2005

All Days

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Efficient reservoir management requires that the latest pulsed neutron capture (PNC) tool technology be comparable with the older measurement results to provide continuity, precision, and accuracy in the monitoring program. A new sigma processing technique was developed for the dual-burst pulse neutron capture measurements that maintains the resolution and repeatability of the new-generation tools but provides results needed for reconciliation with the older generation tools used for more than 20 years in reservoir monitoring. The sigma processing technique is described relative to the old and new generation tools, which utilize radically different approaches. General considerations of repeatability and accuracy are discussed which apply to PNC logs and their use in both stand-alone and time-lapse techniques.More than 35 cases have been evaluated with the new processing technique. Examples are presented to show reservoir monitoring results obtained in a variety of formation lithologies, formation fluids, and borehole environments to illustrate the robustness of the technique. These cases include detailed analytic studies between the PNC tools. The results indicate that the new sigma processing can provide direct time-lapse reservoir monitoring continuity and yield accurate reservoir saturation analysis.

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Section: Rst Processing Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reservoir Monitoring with Pulsed Neutron Capture Logs

Morris

Quinlan

et al. 2005

All Days

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“…Pulsed neutron measurements are made using pulsed neutron bursts created by a minitron which, after losing energy by interactions with the formation and the fluids, will reach thermal energy level and can then be captured. The capture cross section, SIGMA (Σ), is measured, from which the quantitative amount of water and gas saturations can be determined (Plasek and al, 2005). For a quantitative interpretation effective porosity and lithology is needed.…”

Section: Reservoir Monitoringmentioning

confidence: 99%

Integrated Log Interpretation Approach for Underground Gas Storage Characterization

Cantini

Klopf

Revelant

et al. 2010

SPE EUROPEC/EAGE Annual Conference and Exhibition

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In the future natural gas will make a growing contribution to energy supply. Since gas production is constant during the year and its consumption almost seasonal, the importance of underground gas storage (UGS) is increasing because it acts as a buffer between production and consumption. This paper presents a workflow for reservoir and cap rock petrophysical and geomechanic characterization based on an integrated log interpretation, critically reviewing the value and reliability of information that can be gathered from the different log types. Geomechanical characterization is an essential trait in the UGS workflow, especially when the initial formation pressure is exceeded to increase the storage capacity and enhance gas deliverability or in the case of aquifer storages. The workflow consists in the following steps: 1) Conventional reservoir petrophysical characterization. This is achieved by means of gamma ray, neutron, density and resistivity logs, and nuclear magnetic resonance logs for verification of the nature and quantity of the pore fluids. 2) Cap rock petrophysical characterization. An innovative approach with nuclear magnetic resonance log is described.3) Reservoir and caprock geomechanical properties characterization. Information is provided by advanced sonic tools, allowing estimation of the stress profile magnitude, calibrated with micro-hydraulic fracturing tests (stress tests).The direction of the stresses is determined through image logs. 4) Well integrity assessment. Sonic and ultrasonic cement evaluation tools are recommended. 5) Reservoir monitoring. A pulsed neutron tool can be used in order to identify the position of the gas-water contact during gas injection and withdrawal cycles. Case studies are provided in order to complement the theoretical workflow description.

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“…Model the tool response with Monte Carlo techniques under the conditions measured in the laboratory to benchmark the model. 3. Develop interpretation procedures that quantitatively predict tool response using air to simulate gas.…”

Section: Threećphase Holdup Measurementmentioning

confidence: 99%

Measurement of Oil and Water Flow Rates in a Horizontal Well With Chemical Markers and a Pulsed-Neutron Tool

Roscoe

Lenn

Jones

et al. 1997

SPE Reservoir Engineering

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A new approach to obtaining oil and water flow rates in producing horizontal wells has been developed with a pulsed-neutron tool (PNT). This approach uses separate measurements of oil and water velocities in combination with separate holdup measurements to obtain the flow rates.The velocity measurement uses water-soluble and oil-soluble chemical markers, both of which are insoluble in the other fluid phase for the measurement. The markers are injected into the borehole by a logging tool at one location and detected by a PNT at a second location. The transit time between injection and detection of the marker gives a measurement of the fluid velocity. Because the markers are soluble in only one phase, the velocity of each phase can be measured separately. This measurement has been made under both laboratory and field conditions to measure velocities from 10 to 500 ft/min at horizontal and several degrees deviation from horizontal. The results of these tests show good linearity and repeatability of the measurement.The holdup measurement is performed with the inelastic data from a PNT. With these data, it is possible to obtain quantitatively the holdup of all three phases by combining information from the inelastic near/far (N/F) ratio with the near and far carbon/oxygen (C/O) ratios. This approach to the holdup measurement has been demonstrated by use of a combination of laboratory data, Monte Carlo modeling, and field data. The results of this study have demonstrated that the root-mean-square (RMS) accuracy of this measurement is about 6% on each of the three phases.

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Improved Pulsed Neutron Capture Logging With Slim Carbon-Oxygen Tools: Methodology

Cited by 23 publications

References 0 publications

Reservoir Monitoring with Pulsed Neutron Capture Logs

Reservoir Monitoring with Pulsed Neutron Capture Logs

Integrated Log Interpretation Approach for Underground Gas Storage Characterization

Measurement of Oil and Water Flow Rates in a Horizontal Well With Chemical Markers and a Pulsed-Neutron Tool

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