... This paper is an overview of the way geologic and seismic stratigraphic information of a regi... more ... This paper is an overview of the way geologic and seismic stratigraphic information of a region can ... Sclater, JG, and PAF Christie, 1980, Continental stretching: an explanation of the post-mid-Cretaceous ... 6) Perq Systems Corp., 2600 Liberty Ave., Pittsburgh, Pennsylvania 15230. ...
... First Page: 164. Last Page: 177. Title: Relationship Between Eustatic Sea Level Changes and B... more ... First Page: 164. Last Page: 177. Title: Relationship Between Eustatic Sea Level Changes and Basement Subsidence. Author(s): TM Guidish (2), I. Lerche (2), CG St. C. Kendall (3), JJ O'Brien (4). Article Type: Meeting abstract. ... Lovell (1982) cites Morton (1979) and Sutter. Fig. 11. ...
SPE Annual Technical Conference and Exhibition, 1989
In areas of rapid lithologic variations, the areal extent of sand and shale units usually cannot ... more In areas of rapid lithologic variations, the areal extent of sand and shale units usually cannot be inferred from sparse well data alone. Seismically derived interval velocity data can be used to help predict lithologic variations away from wells. However, in general, the overlap of the velocity ranges for sands and shales is such that seismic discrimination of lithology is ambiguous. We present a Monte Carlo technique for numerically simulating the spatial arrangement of sand/shale units. This technique accoimts for the ambiguous nature of the seismic velocity information. Rather than calculating a unique sand/shale model, the Monte Carlo method provides a family of alternative lithologic images, all of which are consistent with the data. The range of models reflects the uncertainty of the lithologic classification and is used to assess risk in reservoir development. The sand/shale simulation technique is illustrated using a data set from an oil-producing channel-sand reservoir. Sand/shale cross-sectional simulations are generated along a seismic traverse that intersects three wells. The simulated models reproduce the log-derived lithologic sequences at the wells; they are conditioned by interval velocities inverted from the seismic amplitude data and are consistent with the spatial autocorrelation and crosscorrelation structures of the seismic and well data. The seismically derived lithologic models of the reservoir are better spatially constrained than models solely conditioned by well data. However, in keeping with the inherent ambiguity of the seismic information, the exact location of the lateral truncation of the channel sand is not precisely defined in the Monte Carlo lithologic simulations.
A Bayesian technique, called the Maximum A Posteriori (MAP) method, is presented for generating c... more A Bayesian technique, called the Maximum A Posteriori (MAP) method, is presented for generating cross sectional lithologic models of the subsurface that (1) honor lithologic observations in wells, (2) are constrained by seismically derived impedance data and (3) are consistent with geological information expressed in the form of lithologic texture models. The MAP lithologic modeling technique is illustrated using a
SEG Technical Program Expanded Abstracts 1988, 1988
We present an analytic method based on the Hadamard-WKB expansion to calculate the self-force for... more We present an analytic method based on the Hadamard-WKB expansion to calculate the self-force for a particle with scalar charge that undergoes radial infall in a Schwarzschild spacetime after being held at rest until a time t = 0. Our result is valid in the case of short duration from the start. It is possible to use the Hadamard-WKB expansion in this case because the value of the integral of the retarded Green's function over the particle's entire past trajectory can be expressed in terms of two integrals over the time period that the particle has been falling. This analytic result is expected to be useful as a check for numerical prescriptions including those involving mode sum regularization and for any other analytical approximations to self-force calculations.
A geostatistical modelling technique called cokriging is used to describe the lateral variations ... more A geostatistical modelling technique called cokriging is used to describe the lateral variations of porosity, f, in a synthetic and a real reservoir. Using this method, an error-qualified porosity model is estimated for each of the two reservoirs from sparse well porosity measurements and seismically derived velocities. The method capitalizes on the high spatial density of the seismic measurements and on their correlation with f. Compared with conventional reservoir models derived solely from sparse well control, the seismically consistent models are better spatially constrained and, hence, provide more detailed and accurate reconstructions of the porosity variations.
Estimating pressure variability throughout a given field is one of the key parameters in determin... more Estimating pressure variability throughout a given field is one of the key parameters in determining fluid dynamics of a field. We utilize a unique patented process to relate rock stresses derived from seismic measurements to the pressure fields within the reservoir. ...
SEG Technical Program Expanded Abstracts 1987, 1987
... Permeability was determined using the permeability-l%ia results in a lateral change in the po... more ... Permeability was determined using the permeability-l%ia results in a lateral change in the polarity of porosity relationahfp baaed on the available core ... initially tnderaaturated with a bubble point pressure of ebou~ 9,650 kpa qt the reaervolr temperature of 30° C. ...
Description/Abstract Two independent reservoir models were constructed for an oil-bearing channel... more Description/Abstract Two independent reservoir models were constructed for an oil-bearing channel-sand reservoir in the Taber-Turin area, Alberta, Canada. The first reservoir description was based on log and core data from six producing and two dry wells drilled ...
Reservoir description away from well control can be improved by supplementing wire-line log and c... more Reservoir description away from well control can be improved by supplementing wire-line log and core data by petrophysical parameters estimated with seismic lithologic modeling techniques. Two independent reservoir models were constructed for an oil-bearing channel-sand reservoir in the Taber-Turin area, Alberta, Canada. The first reservoir description was based solely on log and core data from six producing and two dry wells drilled within a portion of the field on which a 3-D seismic survey was acquired. The second reservoir model was supplemented by petrophysical parameters derived from Seismic Lithologic Modeling (SLIM) of the 3-D seismic reflection data. A detailed model of the stratigraphically complex reservoir was constructed using the results of a forward lithologic parameter estimation process that produces a thin-layer solution from the band-limited, noise-contaminated seismic data. Based on the model results, and after calibration with log and core data, maps of reservoir thickness, porosity, and permeability are produced. Crossplots of seismically inferred parameters versus core-calibrated log interpretations exhibit a limited scatter in the data which, in turn, testifies to the accuracy of the seismic reservoir characterization. The improved accuracy in predicting reservoir variation attained by incorporating seismic control is also demonstrated by comparing the projections from the two separate models with the actual values observed at two new well locations that were not included in the modeling. The increased detail and confidence in reservoir description provided by the information obtained from Seismic Lithologic Modeling of 3-D survey data can dramatically reduce risk (cost) in field development programs, improve results of model simulation and, in turn, enhance reservoir management.
SEG Technical Program Expanded Abstracts 1999, 1999
A new method was developed to use core, well log, and post-stack seismic data to identify reservo... more A new method was developed to use core, well log, and post-stack seismic data to identify reservoir lithologies between wells. The method was based on a combination of rock physics modeling, seismic attribute generation and pattern recognition via neural network analysis. The result was a new lithologically calibrated attribute that showed the producing wells to be inside the indicated oil sand area and the non-producing wells to be outside this area.
... This paper is an overview of the way geologic and seismic stratigraphic information of a regi... more ... This paper is an overview of the way geologic and seismic stratigraphic information of a region can ... Sclater, JG, and PAF Christie, 1980, Continental stretching: an explanation of the post-mid-Cretaceous ... 6) Perq Systems Corp., 2600 Liberty Ave., Pittsburgh, Pennsylvania 15230. ...
... First Page: 164. Last Page: 177. Title: Relationship Between Eustatic Sea Level Changes and B... more ... First Page: 164. Last Page: 177. Title: Relationship Between Eustatic Sea Level Changes and Basement Subsidence. Author(s): TM Guidish (2), I. Lerche (2), CG St. C. Kendall (3), JJ O'Brien (4). Article Type: Meeting abstract. ... Lovell (1982) cites Morton (1979) and Sutter. Fig. 11. ...
SPE Annual Technical Conference and Exhibition, 1989
In areas of rapid lithologic variations, the areal extent of sand and shale units usually cannot ... more In areas of rapid lithologic variations, the areal extent of sand and shale units usually cannot be inferred from sparse well data alone. Seismically derived interval velocity data can be used to help predict lithologic variations away from wells. However, in general, the overlap of the velocity ranges for sands and shales is such that seismic discrimination of lithology is ambiguous. We present a Monte Carlo technique for numerically simulating the spatial arrangement of sand/shale units. This technique accoimts for the ambiguous nature of the seismic velocity information. Rather than calculating a unique sand/shale model, the Monte Carlo method provides a family of alternative lithologic images, all of which are consistent with the data. The range of models reflects the uncertainty of the lithologic classification and is used to assess risk in reservoir development. The sand/shale simulation technique is illustrated using a data set from an oil-producing channel-sand reservoir. Sand/shale cross-sectional simulations are generated along a seismic traverse that intersects three wells. The simulated models reproduce the log-derived lithologic sequences at the wells; they are conditioned by interval velocities inverted from the seismic amplitude data and are consistent with the spatial autocorrelation and crosscorrelation structures of the seismic and well data. The seismically derived lithologic models of the reservoir are better spatially constrained than models solely conditioned by well data. However, in keeping with the inherent ambiguity of the seismic information, the exact location of the lateral truncation of the channel sand is not precisely defined in the Monte Carlo lithologic simulations.
A Bayesian technique, called the Maximum A Posteriori (MAP) method, is presented for generating c... more A Bayesian technique, called the Maximum A Posteriori (MAP) method, is presented for generating cross sectional lithologic models of the subsurface that (1) honor lithologic observations in wells, (2) are constrained by seismically derived impedance data and (3) are consistent with geological information expressed in the form of lithologic texture models. The MAP lithologic modeling technique is illustrated using a
SEG Technical Program Expanded Abstracts 1988, 1988
We present an analytic method based on the Hadamard-WKB expansion to calculate the self-force for... more We present an analytic method based on the Hadamard-WKB expansion to calculate the self-force for a particle with scalar charge that undergoes radial infall in a Schwarzschild spacetime after being held at rest until a time t = 0. Our result is valid in the case of short duration from the start. It is possible to use the Hadamard-WKB expansion in this case because the value of the integral of the retarded Green's function over the particle's entire past trajectory can be expressed in terms of two integrals over the time period that the particle has been falling. This analytic result is expected to be useful as a check for numerical prescriptions including those involving mode sum regularization and for any other analytical approximations to self-force calculations.
A geostatistical modelling technique called cokriging is used to describe the lateral variations ... more A geostatistical modelling technique called cokriging is used to describe the lateral variations of porosity, f, in a synthetic and a real reservoir. Using this method, an error-qualified porosity model is estimated for each of the two reservoirs from sparse well porosity measurements and seismically derived velocities. The method capitalizes on the high spatial density of the seismic measurements and on their correlation with f. Compared with conventional reservoir models derived solely from sparse well control, the seismically consistent models are better spatially constrained and, hence, provide more detailed and accurate reconstructions of the porosity variations.
Estimating pressure variability throughout a given field is one of the key parameters in determin... more Estimating pressure variability throughout a given field is one of the key parameters in determining fluid dynamics of a field. We utilize a unique patented process to relate rock stresses derived from seismic measurements to the pressure fields within the reservoir. ...
SEG Technical Program Expanded Abstracts 1987, 1987
... Permeability was determined using the permeability-l%ia results in a lateral change in the po... more ... Permeability was determined using the permeability-l%ia results in a lateral change in the polarity of porosity relationahfp baaed on the available core ... initially tnderaaturated with a bubble point pressure of ebou~ 9,650 kpa qt the reaervolr temperature of 30° C. ...
Description/Abstract Two independent reservoir models were constructed for an oil-bearing channel... more Description/Abstract Two independent reservoir models were constructed for an oil-bearing channel-sand reservoir in the Taber-Turin area, Alberta, Canada. The first reservoir description was based on log and core data from six producing and two dry wells drilled ...
Reservoir description away from well control can be improved by supplementing wire-line log and c... more Reservoir description away from well control can be improved by supplementing wire-line log and core data by petrophysical parameters estimated with seismic lithologic modeling techniques. Two independent reservoir models were constructed for an oil-bearing channel-sand reservoir in the Taber-Turin area, Alberta, Canada. The first reservoir description was based solely on log and core data from six producing and two dry wells drilled within a portion of the field on which a 3-D seismic survey was acquired. The second reservoir model was supplemented by petrophysical parameters derived from Seismic Lithologic Modeling (SLIM) of the 3-D seismic reflection data. A detailed model of the stratigraphically complex reservoir was constructed using the results of a forward lithologic parameter estimation process that produces a thin-layer solution from the band-limited, noise-contaminated seismic data. Based on the model results, and after calibration with log and core data, maps of reservoir thickness, porosity, and permeability are produced. Crossplots of seismically inferred parameters versus core-calibrated log interpretations exhibit a limited scatter in the data which, in turn, testifies to the accuracy of the seismic reservoir characterization. The improved accuracy in predicting reservoir variation attained by incorporating seismic control is also demonstrated by comparing the projections from the two separate models with the actual values observed at two new well locations that were not included in the modeling. The increased detail and confidence in reservoir description provided by the information obtained from Seismic Lithologic Modeling of 3-D survey data can dramatically reduce risk (cost) in field development programs, improve results of model simulation and, in turn, enhance reservoir management.
SEG Technical Program Expanded Abstracts 1999, 1999
A new method was developed to use core, well log, and post-stack seismic data to identify reservo... more A new method was developed to use core, well log, and post-stack seismic data to identify reservoir lithologies between wells. The method was based on a combination of rock physics modeling, seismic attribute generation and pattern recognition via neural network analysis. The result was a new lithologically calibrated attribute that showed the producing wells to be inside the indicated oil sand area and the non-producing wells to be outside this area.
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Papers by Tom Guidish