Carl Sondergeld | University of Oklahoma (original) (raw)

Papers by Carl Sondergeld

Interpretation

Mississippian Meramec reservoirs of the Sooner Trend in the Anadarko (Basin) in Canadian and King... more Mississippian Meramec reservoirs of the Sooner Trend in the Anadarko (Basin) in Canadian and Kingfisher Counties (STACK) play are comprised of silty limestones, calcareous siltstones, argillaceous calcareous siltstones, argillaceous siltstones, and mudstones. We found that core-defined reservoir lithologies are related to petrophysics-based rock types derived from porosity-permeability relationships using a flow-zone indicator approach. We classified lithologies and rock types in noncored wells using an artificial neural network (ANN) with overall accuracies of 93% and 70%, respectively. We observed that mudstone-rich rock type 1 exhibits high clay and relatively low calcite, whereas calcareous-rich rock type 3 has high calcite and low clay content with rock type 2 falling in between as a balance between rock types 1 and 3. Results of the ANN were applied to a suite of well logs in noncored wells in which we generated lithology and rock-type logs for the Meramec. We identified that ...

Marine and Petroleum Geology

Proceedings of the 8th Unconventional Resources Technology Conference

SPWLA 61st Annual Online Symposium Transactions, 2020

Day 3 Wed, October 28, 2020, 2020

This study demonstrates the application of an interpretable (or explainable) machine learning wor... more This study demonstrates the application of an interpretable (or explainable) machine learning workflow using surface drilling data to identify fracable, brittle and productive rock intervals along horizontal laterals in the Marcellus shale. The results are supported by a thorough model-agnostic interpretation of the input-output relationships to make the model explainable to users. The methodology described here can easily be generalized to real-time processing of surface drilling data for optimal landing of laterals, placing of fracture stages, optimizing production and minimizing frac hits. In practice, this information is rarely available in real-time and requires tedious and time-consuming processing of logs (including image logs), core, microseismic data and fiber optic sensor data to provide post-job validation of frac- and well-placement. Post-completion analyses are generally too late for corrective action leading to wells with a low probability of success and increasing ris...

Journal of Petroleum Science and Engineering, 2017

Highlights: • Nitrogen adsorption-desorption measurements are analyzed to estimate pore size dist... more Highlights: • Nitrogen adsorption-desorption measurements are analyzed to estimate pore size distribution and certain parameters characterizing the pore connectivity in shale samples. • Percolation theory and bimodal fractal model are used to estimate pore size distribution, probability of drainage, and fractal dimension. • Estimates from Eagle Ford and Wolfcamp samples were analyzed under various petrophysical conditions, such as TOC, porosity, maturity, and ashing. • Eagle Ford samples have better connectivity compared to Wolfcamp samples.

SPE Reservoir Evaluation & Engineering, 2017

Summary Pore connectivity controls fluid flow in porous media. Well-established methods such as p... more Summary Pore connectivity controls fluid flow in porous media. Well-established methods such as permeability measurements or mercury-injection porosimetry are used to evaluate pore connectivity. However, these methods have limits in unconventional shale formation mainly because of the presence of different-wettability pores with large capillary pressures associated with them. In the present study, we have used the sequential spontaneous imbibition of brine and dodecane to study pore connectivity in shales. The present study shows the presence of water-wet pores, hydrocarbon-wet pores, and mixed-wettability pores. The water-wet pores are the continuous phase, and are controlled by the amount and distribution of inorganic water-wet minerals. The hydrocarbon-wet pores are essentially contained within the organic matter and require a minimum amount of total organic carbon (TOC), ≈3 wt%, to form a connected network of hydrocarbon wet pores. The ≈3 wt% of TOC is a necessary, but not suffi...

Bulletin of the Seismological Society of America, Apr 1, 1977

... BY CARL H. SONDERGELD, BRYAN L. ISACKS, MUAWIA BARAZANGI, AND SELENA BILLINGTON ... The earth... more ... BY CARL H. SONDERGELD, BRYAN L. ISACKS, MUAWIA BARAZANGI, AND SELENA BILLINGTON ... The earthquakes were relocated by means of the method of Joint Hypocenter Determination (JHD) (Dewey, 1972; Billington and Isacks, 1975). ...

Fluid substitution is an important part of seismic attribute work, because it provides the interp... more Fluid substitution is an important part of seismic attribute work, because it provides the interpreter with a tool for modeling and quantifying the vari-ous fluid scenarios which might give rise to an ob-served amplitude variation with offset (AVO) or 4D response. The most commonly used technique for doing this involves the application of Gassmann’s equations. Modeling the changes from one fluid type to another requires that the effects of the starting fluid first be re-moved prior to modeling the new fluid. In practice, the rock is drained of its initial pore fluid, and the moduli (bulk and shear) and bulk density of the porous frame are calculated. Once the porous frame properties are properly determined, the rock is saturated with the new pore fluid, and the new effective bulk modulus and den-sity are calculated. A direct result of Gassmann’s equations is that the shear modulus for an isotropic material is independent of pore fluid, and therefore remains constant during the fluid...

SPWLA 61st Annual Online Symposium Transactions, 2020

SPE Reservoir Evaluation & Engineering, 2019

Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays.... more Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays. Common laboratory protocols for measuring rock strength, Young's modulus, and Poisson's ratio typically do not account for moisture content in rocks, yet these parameters are critical in fracture designs and are greatly affected by rock moisture content. The process of water weakening is particularly complicated in shales because of the presence of both organic matter and inorganic minerals, such as clays, silica, and calcite. We study the effects of spontaneous fluid imbibition (brine and dodecane) on Young's modulus and hardness in shales using nanoindentation. The shales studied include Marcellus, Woodford, Eagle Ford, and Wolfcamp. A key objective was to compare the weakening effects of 2.5 and 7.5% KCl brine solutions vs. dodecane. Our measurements show that irrespective of the shale wettability, brine led to a greater reduction in Young's modulus (45% reduction in ...

SPE Reservoir Evaluation & Engineering, 2019

Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays.... more Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays. Common laboratory protocols for measuring rock strength, Young's modulus, and Poisson's ratio typically do not account for moisture content in rocks, yet these parameters are critical in fracture designs and are greatly affected by rock moisture content. The process of water weakening is particularly complicated in shales because of the presence of both organic matter and inorganic minerals, such as clays, silica, and calcite. We study the effects of spontaneous fluid imbibition (brine and dodecane) on Young's modulus and hardness in shales using nanoindentation. The shales studied include Marcellus, Woodford, Eagle Ford, and Wolfcamp. A key objective was to compare the weakening effects of 2.5 and 7.5% KCl brine solutions vs. dodecane. Our measurements show that irrespective of the shale wettability, brine led to a greater reduction in Young's modulus (45% reduction in ...

Mississippian deposits and reservoirs in the STACK play (Sooner Trend in the Anadarko [Basin] in ... more Mississippian deposits and reservoirs in the STACK play (Sooner Trend in the Anadarko [Basin] in Canadian and Kingfisher counties) of central Oklahoma are comprised of silty limestones, calcareous siltstones, argillaceous-calcareous siltstones, argillaceous siltstones and mudstones. Using core-derived X-ray fluorescence (XRF) data and established environmental proxies, the occurrence of specific elements is evaluated and their stratigraphic variability is illustrated. Other proxies are developed for indicator elements based on correlation to established proxies as well as background knowledge on how elements are associated with different minerals, rocks, and organic matter. For the Meramec, six indicator elements or element ratios serve as proxies for clay, detrital sediment, carbonate deposits and calcite cement, and biogenic and continentally derived quartz. Detailed core descriptions and an unsupervised K-means classification were used to cluster elemental data to develop three c...

This paper summarizes experimental studies using Nuclear Magnetic Resonance (NMR) to evaluate cem... more This paper summarizes experimental studies using Nuclear Magnetic Resonance (NMR) to evaluate cement porosity, pore size distribution, and other characteristics such as Calcium Silicate Hydrate (CSH) gel structure and morphology. The first known paper on NMR experiments to investigate cement pastes was published in 1978. Two main NMR parameters, the so-called longitudinal T1 and transverse T2 relaxation times, are commonly measured and analyzed, representing the water response which is trapped in the cement. The hydration process reported in this paper was found to be monitored from as low as 10 min to longer than 365 days. Other studies conducted experiments by using NMR, especially during the 1980s. These studies employed variations in methodologies and frequencies, making data comparison difficult. Additionally, different spectrometers and NMR concepts, as well as operating characteristics, were used. Therefore, it is challenging to reconcile results from previous NMR studies on ...

SEG Technical Program Expanded Abstracts 2016, 2016

SEG Technical Program Expanded Abstracts 1996, 1996

Interpretation

Mississippian Meramec reservoirs of the Sooner Trend in the Anadarko (Basin) in Canadian and King... more Mississippian Meramec reservoirs of the Sooner Trend in the Anadarko (Basin) in Canadian and Kingfisher Counties (STACK) play are comprised of silty limestones, calcareous siltstones, argillaceous calcareous siltstones, argillaceous siltstones, and mudstones. We found that core-defined reservoir lithologies are related to petrophysics-based rock types derived from porosity-permeability relationships using a flow-zone indicator approach. We classified lithologies and rock types in noncored wells using an artificial neural network (ANN) with overall accuracies of 93% and 70%, respectively. We observed that mudstone-rich rock type 1 exhibits high clay and relatively low calcite, whereas calcareous-rich rock type 3 has high calcite and low clay content with rock type 2 falling in between as a balance between rock types 1 and 3. Results of the ANN were applied to a suite of well logs in noncored wells in which we generated lithology and rock-type logs for the Meramec. We identified that ...

Marine and Petroleum Geology

Proceedings of the 8th Unconventional Resources Technology Conference

SPWLA 61st Annual Online Symposium Transactions, 2020

Day 3 Wed, October 28, 2020, 2020

This study demonstrates the application of an interpretable (or explainable) machine learning wor... more This study demonstrates the application of an interpretable (or explainable) machine learning workflow using surface drilling data to identify fracable, brittle and productive rock intervals along horizontal laterals in the Marcellus shale. The results are supported by a thorough model-agnostic interpretation of the input-output relationships to make the model explainable to users. The methodology described here can easily be generalized to real-time processing of surface drilling data for optimal landing of laterals, placing of fracture stages, optimizing production and minimizing frac hits. In practice, this information is rarely available in real-time and requires tedious and time-consuming processing of logs (including image logs), core, microseismic data and fiber optic sensor data to provide post-job validation of frac- and well-placement. Post-completion analyses are generally too late for corrective action leading to wells with a low probability of success and increasing ris...

Journal of Petroleum Science and Engineering, 2017

Highlights: • Nitrogen adsorption-desorption measurements are analyzed to estimate pore size dist... more Highlights: • Nitrogen adsorption-desorption measurements are analyzed to estimate pore size distribution and certain parameters characterizing the pore connectivity in shale samples. • Percolation theory and bimodal fractal model are used to estimate pore size distribution, probability of drainage, and fractal dimension. • Estimates from Eagle Ford and Wolfcamp samples were analyzed under various petrophysical conditions, such as TOC, porosity, maturity, and ashing. • Eagle Ford samples have better connectivity compared to Wolfcamp samples.

SPE Reservoir Evaluation & Engineering, 2017

Summary Pore connectivity controls fluid flow in porous media. Well-established methods such as p... more Summary Pore connectivity controls fluid flow in porous media. Well-established methods such as permeability measurements or mercury-injection porosimetry are used to evaluate pore connectivity. However, these methods have limits in unconventional shale formation mainly because of the presence of different-wettability pores with large capillary pressures associated with them. In the present study, we have used the sequential spontaneous imbibition of brine and dodecane to study pore connectivity in shales. The present study shows the presence of water-wet pores, hydrocarbon-wet pores, and mixed-wettability pores. The water-wet pores are the continuous phase, and are controlled by the amount and distribution of inorganic water-wet minerals. The hydrocarbon-wet pores are essentially contained within the organic matter and require a minimum amount of total organic carbon (TOC), ≈3 wt%, to form a connected network of hydrocarbon wet pores. The ≈3 wt% of TOC is a necessary, but not suffi...

Bulletin of the Seismological Society of America, Apr 1, 1977

... BY CARL H. SONDERGELD, BRYAN L. ISACKS, MUAWIA BARAZANGI, AND SELENA BILLINGTON ... The earth... more ... BY CARL H. SONDERGELD, BRYAN L. ISACKS, MUAWIA BARAZANGI, AND SELENA BILLINGTON ... The earthquakes were relocated by means of the method of Joint Hypocenter Determination (JHD) (Dewey, 1972; Billington and Isacks, 1975). ...

Fluid substitution is an important part of seismic attribute work, because it provides the interp... more Fluid substitution is an important part of seismic attribute work, because it provides the interpreter with a tool for modeling and quantifying the vari-ous fluid scenarios which might give rise to an ob-served amplitude variation with offset (AVO) or 4D response. The most commonly used technique for doing this involves the application of Gassmann’s equations. Modeling the changes from one fluid type to another requires that the effects of the starting fluid first be re-moved prior to modeling the new fluid. In practice, the rock is drained of its initial pore fluid, and the moduli (bulk and shear) and bulk density of the porous frame are calculated. Once the porous frame properties are properly determined, the rock is saturated with the new pore fluid, and the new effective bulk modulus and den-sity are calculated. A direct result of Gassmann’s equations is that the shear modulus for an isotropic material is independent of pore fluid, and therefore remains constant during the fluid...

SPWLA 61st Annual Online Symposium Transactions, 2020

SPE Reservoir Evaluation & Engineering, 2019

Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays.... more Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays. Common laboratory protocols for measuring rock strength, Young's modulus, and Poisson's ratio typically do not account for moisture content in rocks, yet these parameters are critical in fracture designs and are greatly affected by rock moisture content. The process of water weakening is particularly complicated in shales because of the presence of both organic matter and inorganic minerals, such as clays, silica, and calcite. We study the effects of spontaneous fluid imbibition (brine and dodecane) on Young's modulus and hardness in shales using nanoindentation. The shales studied include Marcellus, Woodford, Eagle Ford, and Wolfcamp. A key objective was to compare the weakening effects of 2.5 and 7.5% KCl brine solutions vs. dodecane. Our measurements show that irrespective of the shale wettability, brine led to a greater reduction in Young's modulus (45% reduction in ...

SPE Reservoir Evaluation & Engineering, 2019

Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays.... more Summary Hydraulic fracturing is the completion method of choice in unconventional resource plays. Common laboratory protocols for measuring rock strength, Young's modulus, and Poisson's ratio typically do not account for moisture content in rocks, yet these parameters are critical in fracture designs and are greatly affected by rock moisture content. The process of water weakening is particularly complicated in shales because of the presence of both organic matter and inorganic minerals, such as clays, silica, and calcite. We study the effects of spontaneous fluid imbibition (brine and dodecane) on Young's modulus and hardness in shales using nanoindentation. The shales studied include Marcellus, Woodford, Eagle Ford, and Wolfcamp. A key objective was to compare the weakening effects of 2.5 and 7.5% KCl brine solutions vs. dodecane. Our measurements show that irrespective of the shale wettability, brine led to a greater reduction in Young's modulus (45% reduction in ...

Mississippian deposits and reservoirs in the STACK play (Sooner Trend in the Anadarko [Basin] in ... more Mississippian deposits and reservoirs in the STACK play (Sooner Trend in the Anadarko [Basin] in Canadian and Kingfisher counties) of central Oklahoma are comprised of silty limestones, calcareous siltstones, argillaceous-calcareous siltstones, argillaceous siltstones and mudstones. Using core-derived X-ray fluorescence (XRF) data and established environmental proxies, the occurrence of specific elements is evaluated and their stratigraphic variability is illustrated. Other proxies are developed for indicator elements based on correlation to established proxies as well as background knowledge on how elements are associated with different minerals, rocks, and organic matter. For the Meramec, six indicator elements or element ratios serve as proxies for clay, detrital sediment, carbonate deposits and calcite cement, and biogenic and continentally derived quartz. Detailed core descriptions and an unsupervised K-means classification were used to cluster elemental data to develop three c...

This paper summarizes experimental studies using Nuclear Magnetic Resonance (NMR) to evaluate cem... more This paper summarizes experimental studies using Nuclear Magnetic Resonance (NMR) to evaluate cement porosity, pore size distribution, and other characteristics such as Calcium Silicate Hydrate (CSH) gel structure and morphology. The first known paper on NMR experiments to investigate cement pastes was published in 1978. Two main NMR parameters, the so-called longitudinal T1 and transverse T2 relaxation times, are commonly measured and analyzed, representing the water response which is trapped in the cement. The hydration process reported in this paper was found to be monitored from as low as 10 min to longer than 365 days. Other studies conducted experiments by using NMR, especially during the 1980s. These studies employed variations in methodologies and frequencies, making data comparison difficult. Additionally, different spectrometers and NMR concepts, as well as operating characteristics, were used. Therefore, it is challenging to reconcile results from previous NMR studies on ...

SEG Technical Program Expanded Abstracts 2016, 2016

SEG Technical Program Expanded Abstracts 1996, 1996