Two-phase slug flow is a common phenomenon observed in oil and gas wells and pipelines. Mechanist... more Two-phase slug flow is a common phenomenon observed in oil and gas wells and pipelines. Mechanistic modelling approaches used in industry for design and monitoring rely on closure relations (e.g. Taylor bubble rise velocity in a stagnant fluid) to approximate phase interactions. In this work, the phase-field lattice Boltzmann method (PFLBM) originally proposed by Fakhari et al. [4] and extended to three dimensions by Mitchell et al. [10] is employed to investigate the validity of some of these closure relations. The PFLBM solves the conservative phase-field equation to capture the interfacial dynamics while resolving the hydrodynamics through a velocity-evolution LBM. To assist with model stability at high density and viscosity ratios, a weighted-multiple-relaxation-time (WMRT) operator is incorporated in the hydrodynamic scheme. The model is first validated for Taylor bubble transport in vertical pipes at a range of Morton (Mo) and Eotvos (Eo) numbers. The effect of inclination in ...
Journal of Petroleum Science and Engineering, 1993
Abstract Two rigorous techniques for hyperbolic decline-curve analysis based on the fundamental e... more Abstract Two rigorous techniques for hyperbolic decline-curve analysis based on the fundamental equations are investigated. The parameter estimation is made more accurate and repeatable than type curve matching if linear regression is used to extract the unknowns D i q i and n from the data. Maximizing the regression coefficient is the criterion used to select the correct parameter values. In application to six field examples, it is seen that the two methods do not always give identical results if there is a lot of scatter in the data.
CO 2 capture and utilization caused more and more public attention because of its environmental i... more CO 2 capture and utilization caused more and more public attention because of its environmental impact. The objective of this work was to study the catalytic gasification of a sub-bituminous coal from the Powder River Basin (PRB) using a CO 2 and H 2 O mixture as the gasifying agent. Sodium and iron, in the form of inexpensive compounds, were chosen to catalyze the coal gasification. The experiments were conducted between 700 and 900 °C in a fixed-bed laboratory gasifier under the atmospheric pressure. Results show that the added catalysts had an effect on the composition of gas products in a way different from it in pure steam gasification. Fitting models for kinetic data were examined and the results show that addition of 3 wt% Na or 3 wt% iron led to a 28.0% or a 19.5% reduction in the activation energy of the gasification reaction, respectively. The sodium and iron in the coal char were characterized and the results show that sodium is more evenly distributed than iron during gasification. Suggestions for improving the catalysts' performance in coal gasification were proposed accordingly.
Proceedings of International Petroleum Technology Conference, 2008
Copyright 2008, International Petroleum Technology Conference This paper was prepared for present... more Copyright 2008, International Petroleum Technology Conference This paper was prepared for presentation at the International Petroleum Technology Conference held in Kuala Lumpur, Malaysia, 35 December 2008. This paper was selected for presentation by an IPTC ...
Copyright 2008, IADC/SPE Drilling Conference This paper was prepared for presentation at the 2008... more Copyright 2008, IADC/SPE Drilling Conference This paper was prepared for presentation at the 2008 IADC/SPE Drilling Conference held in Orlando, Florida, USA, 46 March 2008. This paper was selected for presentation by an IADC/SPE program committee following review ...
To describe the management and follow-up of women with initial minor Papanicolaou (Pap) smear abn... more To describe the management and follow-up of women with initial minor Papanicolaou (Pap) smear abnormalities by general practitioners (GPs) in metropolitan Sydney in 1990. One hundred women with cervical intraepithelial neoplasia grade 1 (CIN 1) and 121 women with mild squamous atypia (MSA) on Pap smears taken by GPs in 1990, who had not had Pap smear abnormalities in the previous two years, were sampled from the records of four Sydney pathology laboratories. A descriptive study. Information about the management of women after their Pap smear was obtained from GPs by telephone questionnaire. Of women with MSA, 19% were initially investigated by colposcopy, and 8% went on to have treatment. Of 82 women with MSA who were not initially investigated, 80% had follow-up Pap smears within 12 months. Of women with CIN 1, 84 underwent colposcopy with or without biopsy; 27% of these women had CIN 2/3 and 31% had CIN 1 confirmed by investigation. Overall, 51% of women with CIN 1 on their initial Pap smears were treated by excisional or ablative means, including 78% of women with confirmed CIN 2/3, and 69% of women with confirmed CIN 1. Two and a half years after the original Pap smear, only 46% of women with initial MSA and 51% of women with initial CIN 1 were known by their GP to be having follow-up. Most women with MSA were managed by initial observation, and those with CIN 1 were managed by initial investigation. However, the range of management practices described suggests a lack of consensus among practitioners about the most appropriate management for women with minor cervical abnormalities. A large randomised controlled trial would help elucidate preferred management guidelines. The difficulty individual GPs experience in following up women after abnormal Pap smears supports the establishment of centralised State cytology registers.
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Ab... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Abu Dhabi International Petroleum Exhibition & Conference held in Abu Dhabi, UAE, 14 November 2010. This paper was selected for presentation by an SPE program committee ...
Copyright 2008, Society of Petroleum Engineers This paper was prepared for presentation at the 20... more Copyright 2008, Society of Petroleum Engineers This paper was prepared for presentation at the 2008 SPE Annual Technical Conference and Exhibition held in Denver, Colorado, USA, 2124 September 2008. This paper was selected for presentation by an SPE program ...
Proceedings of SPE Annual Technical Conference and Exhibition, 2010
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SP... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in Florence, Italy, 1922 September 2010. This paper was selected for presentation by an SPE program committee following ...
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SP... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SPE EOR Conference at Oil & Gas West Asia held in Muscat, Oman, 1113 April 2010. This paper was selected for presentation by an SPE program committee following review of ...
Abu Dhabi International Petroleum Exhibition and Conference, 2010
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Ab... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Abu Dhabi International Petroleum Exhibition & Conference held in Abu Dhabi, UAE, 14 November 2010. This paper was selected for presentation by an SPE program committee ...
Two-phase slug flow is a common phenomenon observed in oil and gas wells and pipelines. Mechanist... more Two-phase slug flow is a common phenomenon observed in oil and gas wells and pipelines. Mechanistic modelling approaches used in industry for design and monitoring rely on closure relations (e.g. Taylor bubble rise velocity in a stagnant fluid) to approximate phase interactions. In this work, the phase-field lattice Boltzmann method (PFLBM) originally proposed by Fakhari et al. [4] and extended to three dimensions by Mitchell et al. [10] is employed to investigate the validity of some of these closure relations. The PFLBM solves the conservative phase-field equation to capture the interfacial dynamics while resolving the hydrodynamics through a velocity-evolution LBM. To assist with model stability at high density and viscosity ratios, a weighted-multiple-relaxation-time (WMRT) operator is incorporated in the hydrodynamic scheme. The model is first validated for Taylor bubble transport in vertical pipes at a range of Morton (Mo) and Eotvos (Eo) numbers. The effect of inclination in ...
Journal of Petroleum Science and Engineering, 1993
Abstract Two rigorous techniques for hyperbolic decline-curve analysis based on the fundamental e... more Abstract Two rigorous techniques for hyperbolic decline-curve analysis based on the fundamental equations are investigated. The parameter estimation is made more accurate and repeatable than type curve matching if linear regression is used to extract the unknowns D i q i and n from the data. Maximizing the regression coefficient is the criterion used to select the correct parameter values. In application to six field examples, it is seen that the two methods do not always give identical results if there is a lot of scatter in the data.
CO 2 capture and utilization caused more and more public attention because of its environmental i... more CO 2 capture and utilization caused more and more public attention because of its environmental impact. The objective of this work was to study the catalytic gasification of a sub-bituminous coal from the Powder River Basin (PRB) using a CO 2 and H 2 O mixture as the gasifying agent. Sodium and iron, in the form of inexpensive compounds, were chosen to catalyze the coal gasification. The experiments were conducted between 700 and 900 °C in a fixed-bed laboratory gasifier under the atmospheric pressure. Results show that the added catalysts had an effect on the composition of gas products in a way different from it in pure steam gasification. Fitting models for kinetic data were examined and the results show that addition of 3 wt% Na or 3 wt% iron led to a 28.0% or a 19.5% reduction in the activation energy of the gasification reaction, respectively. The sodium and iron in the coal char were characterized and the results show that sodium is more evenly distributed than iron during gasification. Suggestions for improving the catalysts' performance in coal gasification were proposed accordingly.
Proceedings of International Petroleum Technology Conference, 2008
Copyright 2008, International Petroleum Technology Conference This paper was prepared for present... more Copyright 2008, International Petroleum Technology Conference This paper was prepared for presentation at the International Petroleum Technology Conference held in Kuala Lumpur, Malaysia, 35 December 2008. This paper was selected for presentation by an IPTC ...
Copyright 2008, IADC/SPE Drilling Conference This paper was prepared for presentation at the 2008... more Copyright 2008, IADC/SPE Drilling Conference This paper was prepared for presentation at the 2008 IADC/SPE Drilling Conference held in Orlando, Florida, USA, 46 March 2008. This paper was selected for presentation by an IADC/SPE program committee following review ...
To describe the management and follow-up of women with initial minor Papanicolaou (Pap) smear abn... more To describe the management and follow-up of women with initial minor Papanicolaou (Pap) smear abnormalities by general practitioners (GPs) in metropolitan Sydney in 1990. One hundred women with cervical intraepithelial neoplasia grade 1 (CIN 1) and 121 women with mild squamous atypia (MSA) on Pap smears taken by GPs in 1990, who had not had Pap smear abnormalities in the previous two years, were sampled from the records of four Sydney pathology laboratories. A descriptive study. Information about the management of women after their Pap smear was obtained from GPs by telephone questionnaire. Of women with MSA, 19% were initially investigated by colposcopy, and 8% went on to have treatment. Of 82 women with MSA who were not initially investigated, 80% had follow-up Pap smears within 12 months. Of women with CIN 1, 84 underwent colposcopy with or without biopsy; 27% of these women had CIN 2/3 and 31% had CIN 1 confirmed by investigation. Overall, 51% of women with CIN 1 on their initial Pap smears were treated by excisional or ablative means, including 78% of women with confirmed CIN 2/3, and 69% of women with confirmed CIN 1. Two and a half years after the original Pap smear, only 46% of women with initial MSA and 51% of women with initial CIN 1 were known by their GP to be having follow-up. Most women with MSA were managed by initial observation, and those with CIN 1 were managed by initial investigation. However, the range of management practices described suggests a lack of consensus among practitioners about the most appropriate management for women with minor cervical abnormalities. A large randomised controlled trial would help elucidate preferred management guidelines. The difficulty individual GPs experience in following up women after abnormal Pap smears supports the establishment of centralised State cytology registers.
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Ab... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Abu Dhabi International Petroleum Exhibition & Conference held in Abu Dhabi, UAE, 14 November 2010. This paper was selected for presentation by an SPE program committee ...
Copyright 2008, Society of Petroleum Engineers This paper was prepared for presentation at the 20... more Copyright 2008, Society of Petroleum Engineers This paper was prepared for presentation at the 2008 SPE Annual Technical Conference and Exhibition held in Denver, Colorado, USA, 2124 September 2008. This paper was selected for presentation by an SPE program ...
Proceedings of SPE Annual Technical Conference and Exhibition, 2010
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SP... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Annual Technical Conference and Exhibition held in Florence, Italy, 1922 September 2010. This paper was selected for presentation by an SPE program committee following ...
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SP... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the SPE EOR Conference at Oil & Gas West Asia held in Muscat, Oman, 1113 April 2010. This paper was selected for presentation by an SPE program committee following review of ...
Abu Dhabi International Petroleum Exhibition and Conference, 2010
Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Ab... more Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Abu Dhabi International Petroleum Exhibition & Conference held in Abu Dhabi, UAE, 14 November 2010. This paper was selected for presentation by an SPE program committee ...
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