Considering the pore deformation and permeability changes during dilation-recompaction in cyclic steam stimulation(CSS),an existing geomechanical model is improved and thermo-mechanically coupled with the flow equatio...Considering the pore deformation and permeability changes during dilation-recompaction in cyclic steam stimulation(CSS),an existing geomechanical model is improved and thermo-mechanically coupled with the flow equations to form a coupled flow-geomechanical model.The impacts of dilation-recompaction parameters can be quantified through sensitivity analysis and uncertainty assessment utilizing the synergy between Latin hypercube designs and response surface methodology.The improved coupled flow-geomechanical model allows a more reasonable history-matching of steam injection pressure and volume and oil/water production volume.In both the linear and quadratic models,the rise in recompaction pressure has the most significant effect on the rise in the volumes of steam injection and water production,both rock compressibility and recompaction pressure are positively correlated with steam injectivity and oil/water production,and the dilation pressure is negatively correlated with steam injectivity and oil/water production.In the linear model,dilation pressure has the most significant negative impact on the cumulative oil production,and compressibility and recompaction pressure are positively correlated with oil production.In the quadratic model,the rise in recompaction pressure has the most significant effect on the rise in the cumulative volumes of oil/water production and steam injection.The interactions between the dilation/recompaction pressures and spongy-rock compressibility negatively affect the cumulative volumes of oil/water production and steam injection.展开更多
A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam“stimulatio...A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam“stimulation”methods for enhanced oil recovery.The new distribution system consists of a swirler,spiral dividing baffles,and critical flow nozzles.Numerical simulations are used to analyze the flow-field and degree of steam homogeneity obtained with such an approach.The results indicate that a higher inlet pressure leads to better results.Additionally,the internal flow field becomes more stable,and the deviation from an even distribution reduces to±4.0%even when the resistance of each branch is inconsistent.Furthermore,field tests have yielded satisfactory results.展开更多
Cyclic steam stimulation(CSS)is widely used for production from heavy oil reservoirs where oil viscosity is manipulated by heat.Many analytical models have been developed to predict the temperature evolution in the re...Cyclic steam stimulation(CSS)is widely used for production from heavy oil reservoirs where oil viscosity is manipulated by heat.Many analytical models have been developed to predict the temperature evolution in the reservoir and estimate the oil recovery.However,they often suffer from a number of assumptions which ultimately reduce their efficiency in providing a realistic prediction.In this study,a numerical solution was proposed for two-dimensional heat conduction in heavy oil reservoirs to obtain the temperature evolution during the soaking period.For a better comparison,an industry widely accepted analytical model,knows as the Boberg and Lantz steam stimulation model,together with its modified version later proposed by Bensten and Donohue were considered to examine temperature changes in a synthetic case study.The results obtained indicated that the analytical solutions overestimate the average temperature of the reservoir by 42%after 300 days of injection while the numerical formulation can provide a close prediction.This numerical approach could be a useful tool to estimate the temperature and oil production from heavy oil reservoirs.展开更多
To address the problems existing in testing steam injection profiles in a steam-stimulated well during steam injection and production periods, this paper proposes that the temperature profile in the completion interva...To address the problems existing in testing steam injection profiles in a steam-stimulated well during steam injection and production periods, this paper proposes that the temperature profile in the completion interval could be tested during the soak period. A mathematical model for calculating the vertical distribution of temperature in a single layer reservoir is established based on the temperature characteristics of steam stimulated reservoirs, and the vertical distribution of temperature in a single layer reservoir could be obtained and heat loss could be calculated. The temperature, which is disturbed by thermal conduction in a multilayer reservoir, and heat loss could be derived based on the superposition principle of temperature potential. This paper establishes a multilayer testing temperature profile interpretation method and interprets the actual test temperature profile of Well Gao 3-7-66. The results indicate that the temperature profile in the soak period can reflect the thermal absorption conditions in various reservoir beds.展开更多
文摘Considering the pore deformation and permeability changes during dilation-recompaction in cyclic steam stimulation(CSS),an existing geomechanical model is improved and thermo-mechanically coupled with the flow equations to form a coupled flow-geomechanical model.The impacts of dilation-recompaction parameters can be quantified through sensitivity analysis and uncertainty assessment utilizing the synergy between Latin hypercube designs and response surface methodology.The improved coupled flow-geomechanical model allows a more reasonable history-matching of steam injection pressure and volume and oil/water production volume.In both the linear and quadratic models,the rise in recompaction pressure has the most significant effect on the rise in the volumes of steam injection and water production,both rock compressibility and recompaction pressure are positively correlated with steam injectivity and oil/water production,and the dilation pressure is negatively correlated with steam injectivity and oil/water production.In the linear model,dilation pressure has the most significant negative impact on the cumulative oil production,and compressibility and recompaction pressure are positively correlated with oil production.In the quadratic model,the rise in recompaction pressure has the most significant effect on the rise in the cumulative volumes of oil/water production and steam injection.The interactions between the dilation/recompaction pressures and spongy-rock compressibility negatively affect the cumulative volumes of oil/water production and steam injection.
基金The authors would like to acknowledge the support provided by Supported By Open Fund of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University),YQZC202309.
文摘A new approach and a new related distribution system are proposed to address the issue of uneven steam injection caused by the different suction capacities of the used wells during the application of steam“stimulation”methods for enhanced oil recovery.The new distribution system consists of a swirler,spiral dividing baffles,and critical flow nozzles.Numerical simulations are used to analyze the flow-field and degree of steam homogeneity obtained with such an approach.The results indicate that a higher inlet pressure leads to better results.Additionally,the internal flow field becomes more stable,and the deviation from an even distribution reduces to±4.0%even when the resistance of each branch is inconsistent.Furthermore,field tests have yielded satisfactory results.
文摘Cyclic steam stimulation(CSS)is widely used for production from heavy oil reservoirs where oil viscosity is manipulated by heat.Many analytical models have been developed to predict the temperature evolution in the reservoir and estimate the oil recovery.However,they often suffer from a number of assumptions which ultimately reduce their efficiency in providing a realistic prediction.In this study,a numerical solution was proposed for two-dimensional heat conduction in heavy oil reservoirs to obtain the temperature evolution during the soaking period.For a better comparison,an industry widely accepted analytical model,knows as the Boberg and Lantz steam stimulation model,together with its modified version later proposed by Bensten and Donohue were considered to examine temperature changes in a synthetic case study.The results obtained indicated that the analytical solutions overestimate the average temperature of the reservoir by 42%after 300 days of injection while the numerical formulation can provide a close prediction.This numerical approach could be a useful tool to estimate the temperature and oil production from heavy oil reservoirs.
文摘To address the problems existing in testing steam injection profiles in a steam-stimulated well during steam injection and production periods, this paper proposes that the temperature profile in the completion interval could be tested during the soak period. A mathematical model for calculating the vertical distribution of temperature in a single layer reservoir is established based on the temperature characteristics of steam stimulated reservoirs, and the vertical distribution of temperature in a single layer reservoir could be obtained and heat loss could be calculated. The temperature, which is disturbed by thermal conduction in a multilayer reservoir, and heat loss could be derived based on the superposition principle of temperature potential. This paper establishes a multilayer testing temperature profile interpretation method and interprets the actual test temperature profile of Well Gao 3-7-66. The results indicate that the temperature profile in the soak period can reflect the thermal absorption conditions in various reservoir beds.
