Thermal maturity indices and modelling based on Arrhenius-equation reaction kinetics have played an important role in oil and gas exploration and provided petroleum generation insight for many kerogenrich source rocks...Thermal maturity indices and modelling based on Arrhenius-equation reaction kinetics have played an important role in oil and gas exploration and provided petroleum generation insight for many kerogenrich source rocks.Debate continues concerning how best to integrate the Arrhenius equation and which activation energies(E)and frequency factors(A)values to apply.A case is made for the strong theoretical basis and practical advantages of the time-temperature index(∑TTIARR)method,first published in 1998,using a single,carefully selected E-A set(E?218 kJ/mol(52.1 kcal/mol);A?5.45Et26/my)from the well-established A-E trend for published kerogen kinetics.An updated correlation between ∑TTIARR and vitrinite reflectance(Ro)is provided in which the P TTIARR scale spans some 18 orders of magnitude.The method is readily calculated in spreadsheets and can be further enhanced by visual basic for application code to provide optimization.Optimization is useful for identifying possible geothermal gradients and erosion intervals covering multiple burial intervals that can match calculated thermal maturities with measured Ro data.A memetic optimizer with firefly and dynamic local search memes is described that flexibly conducts exploration and exploitation of the feasible,multi-dimensional,thermal history solution space to find high-performing solutions to complex burial and thermal histories.A complex deep burial history example,with several periods of uplift and erosion and fluctuating heat flow is used to demonstrate what can be achieved with the memetic optimizer.By carefully layering in constraints to the models specific insights to episodes in their thermal history can be exposed,leading to better characterization of the timing of petroleum generation.The objective function found to be most effective for this type of optimization is the mean square error(MSE)of multiple burial intervals for the difference between calculated and measure Ro.The sensitively-scaled P TTIARR methodology,coupled with the memetic optimizer,is well suited for rapidly conducting basin-wide thermal maturity modelling involving multiple pseudo-wells to provide thermal maturity analysis at fine degrees of granularity.展开更多
Results of this study are based on core materials description,thin sections,Cathodoluminescence(CL),and Scanning Electron Microscope(SEM)examinations.The Lower Cretaceous over the Euphrates Graben area was characteriz...Results of this study are based on core materials description,thin sections,Cathodoluminescence(CL),and Scanning Electron Microscope(SEM)examinations.The Lower Cretaceous over the Euphrates Graben area was characterized by carbonate sedimentation in shallow marine environments.The low energy lagoonal to inner shelf sediments of the Judea Formation includes micritic mudstone to wackestone texture,dolomitic limestones and dolostones.Two types of dolomites recognized in the carbonates of the Judea Formation,the preserving microcrystalline dolomites which commonly founded in the partially dolomitized micritic limestones,and the destructive coarsely crystalline dolomites which commonly founded in the dolostones and dolomitic limestones.Petrographic examinations indicate that the preserving microcrystalline dolomites represent subtidal cycles developed in a shoal to open marine depositional environments,they probably formed under conditions of the shallow burial diagenesis.The destructive coarsely crystalline dolomites may develop in more basinward,open marine environments under conditions of the deep burial diagenesis that accompanied by rising in temperature,pressure,and burial depth.It is believed that evolution of the diagenetic history of the Judean Formation sediments occurred in two diagenetic stages;the shallow burial diagenesis,and the deep burial diagenesis.Compaction processes,early fracturing,micritization,early calcite,and the early phase of dolomitization were part of the multiple diagenetic alterations during the shallow burial diagenesis.The deep burial diagenesis was marked by dissolution,late stage of dolomitization and replacement,mechanical and chemical compaction,and the late calcite precipitation.It is believed that dolomitization of the Judea Formation carbonates in the Euphrates Graben has contributed to improving the reservoir properties by increasing the porosity and thus the permeability.展开更多
The Dongpu depression,like other depressions in the Bohai Bay Basin,is characterized by overpressure,however,the published studies have not clearly given the overpressure formation mechanism and paleo-pressure evoluti...The Dongpu depression,like other depressions in the Bohai Bay Basin,is characterized by overpressure,however,the published studies have not clearly given the overpressure formation mechanism and paleo-pressure evolution history in the Dongpu depression.In addition,the current researches are mainly focused on the northern Dongpu depression,while rare investigation has been conducted in the southern part.In this context,it is urgent to explore the comprehensive overpressure evolution and formation mechanism in the Dongpu depression in academic and industrial fields.This paper provided a systematic analysis of fluid inclusions,including fluid inclusion petrography,microthermometry,vapor phase filling degree measurement and PVT-x modeling.By using homogenization temperature-burial history projection,the trapping time of the oil inclusions are determined.Four pressure evolution stages are identified in both the northern and the southern Dongpu depression.The results indicate that the pressure accumulation stage is derived by disequilibrium compaction and hydrocarbon generation in the northern part because of the salt rock distribution,while the stage is only derived by hydrocarbon generation in the southern part because of no salt rock distribution.The pressure release stages are mainly caused by the tectonic uplifting movements at the end of Dongying and Minghuazhen Formation.The overpressure in most areas in the northern part has been preserved till now,which is considered as a result of the good plasticity and sealing ability of salt rock that prevent the pressure leakage by smearing on the fault.Areas without salt rock distribution show normal pressure,which means the salt rock is an important factor that contributes to the overpressure preservation.However,there are exceptions that in Baimiao and Qiaokou,the overpressure still exists even without salt rock distribution,which is due to fault closure.展开更多
Thermal maturation and petroleum generation modeling of shales is essential for successful exploration and exploitation of conventional and unconventional oil and gas plays. For basinwide unconventional resource plays...Thermal maturation and petroleum generation modeling of shales is essential for successful exploration and exploitation of conventional and unconventional oil and gas plays. For basinwide unconventional resource plays such modeling, when well calibrated with direct maturity measurements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A misconception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite reflectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index(∑TTI ARR), as proposed by Wood(1988), is flawed. This claim was initially made by Sweeney and Burnham(1990) in promoting their "Easy R o" method, and repeated by others. This paper demonstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ∑TTI ARR and "Easy R o" methods that this is not the case. The ∑TTI ARR method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies(e.g., "Easy Ro"). Through simple expressions the ∑TTI ARR method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ∑TTI ARR method than the "Easy R o" method. Analysis indicates that the "Easy R o" method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realistically model observed kerogen behaviour and transformation factors over geologic time scales.展开更多
文摘Thermal maturity indices and modelling based on Arrhenius-equation reaction kinetics have played an important role in oil and gas exploration and provided petroleum generation insight for many kerogenrich source rocks.Debate continues concerning how best to integrate the Arrhenius equation and which activation energies(E)and frequency factors(A)values to apply.A case is made for the strong theoretical basis and practical advantages of the time-temperature index(∑TTIARR)method,first published in 1998,using a single,carefully selected E-A set(E?218 kJ/mol(52.1 kcal/mol);A?5.45Et26/my)from the well-established A-E trend for published kerogen kinetics.An updated correlation between ∑TTIARR and vitrinite reflectance(Ro)is provided in which the P TTIARR scale spans some 18 orders of magnitude.The method is readily calculated in spreadsheets and can be further enhanced by visual basic for application code to provide optimization.Optimization is useful for identifying possible geothermal gradients and erosion intervals covering multiple burial intervals that can match calculated thermal maturities with measured Ro data.A memetic optimizer with firefly and dynamic local search memes is described that flexibly conducts exploration and exploitation of the feasible,multi-dimensional,thermal history solution space to find high-performing solutions to complex burial and thermal histories.A complex deep burial history example,with several periods of uplift and erosion and fluctuating heat flow is used to demonstrate what can be achieved with the memetic optimizer.By carefully layering in constraints to the models specific insights to episodes in their thermal history can be exposed,leading to better characterization of the timing of petroleum generation.The objective function found to be most effective for this type of optimization is the mean square error(MSE)of multiple burial intervals for the difference between calculated and measure Ro.The sensitively-scaled P TTIARR methodology,coupled with the memetic optimizer,is well suited for rapidly conducting basin-wide thermal maturity modelling involving multiple pseudo-wells to provide thermal maturity analysis at fine degrees of granularity.
基金supported by the Ministry of Science and Higher Education of the Russian Federation under agreement No.075-15-2020-931 within the framework of the development program for a world-class Research Center"Efficient development of the global liquid hydrocarbon reserves"。
文摘Results of this study are based on core materials description,thin sections,Cathodoluminescence(CL),and Scanning Electron Microscope(SEM)examinations.The Lower Cretaceous over the Euphrates Graben area was characterized by carbonate sedimentation in shallow marine environments.The low energy lagoonal to inner shelf sediments of the Judea Formation includes micritic mudstone to wackestone texture,dolomitic limestones and dolostones.Two types of dolomites recognized in the carbonates of the Judea Formation,the preserving microcrystalline dolomites which commonly founded in the partially dolomitized micritic limestones,and the destructive coarsely crystalline dolomites which commonly founded in the dolostones and dolomitic limestones.Petrographic examinations indicate that the preserving microcrystalline dolomites represent subtidal cycles developed in a shoal to open marine depositional environments,they probably formed under conditions of the shallow burial diagenesis.The destructive coarsely crystalline dolomites may develop in more basinward,open marine environments under conditions of the deep burial diagenesis that accompanied by rising in temperature,pressure,and burial depth.It is believed that evolution of the diagenetic history of the Judean Formation sediments occurred in two diagenetic stages;the shallow burial diagenesis,and the deep burial diagenesis.Compaction processes,early fracturing,micritization,early calcite,and the early phase of dolomitization were part of the multiple diagenetic alterations during the shallow burial diagenesis.The deep burial diagenesis was marked by dissolution,late stage of dolomitization and replacement,mechanical and chemical compaction,and the late calcite precipitation.It is believed that dolomitization of the Judea Formation carbonates in the Euphrates Graben has contributed to improving the reservoir properties by increasing the porosity and thus the permeability.
基金supported by the National Natural Science Foundation of China(No.41730421)Major Science and Technology Project of SINOPEC during the 13th Five-Year Plan Period(No.ZDP1705)。
文摘The Dongpu depression,like other depressions in the Bohai Bay Basin,is characterized by overpressure,however,the published studies have not clearly given the overpressure formation mechanism and paleo-pressure evolution history in the Dongpu depression.In addition,the current researches are mainly focused on the northern Dongpu depression,while rare investigation has been conducted in the southern part.In this context,it is urgent to explore the comprehensive overpressure evolution and formation mechanism in the Dongpu depression in academic and industrial fields.This paper provided a systematic analysis of fluid inclusions,including fluid inclusion petrography,microthermometry,vapor phase filling degree measurement and PVT-x modeling.By using homogenization temperature-burial history projection,the trapping time of the oil inclusions are determined.Four pressure evolution stages are identified in both the northern and the southern Dongpu depression.The results indicate that the pressure accumulation stage is derived by disequilibrium compaction and hydrocarbon generation in the northern part because of the salt rock distribution,while the stage is only derived by hydrocarbon generation in the southern part because of no salt rock distribution.The pressure release stages are mainly caused by the tectonic uplifting movements at the end of Dongying and Minghuazhen Formation.The overpressure in most areas in the northern part has been preserved till now,which is considered as a result of the good plasticity and sealing ability of salt rock that prevent the pressure leakage by smearing on the fault.Areas without salt rock distribution show normal pressure,which means the salt rock is an important factor that contributes to the overpressure preservation.However,there are exceptions that in Baimiao and Qiaokou,the overpressure still exists even without salt rock distribution,which is due to fault closure.
文摘Thermal maturation and petroleum generation modeling of shales is essential for successful exploration and exploitation of conventional and unconventional oil and gas plays. For basinwide unconventional resource plays such modeling, when well calibrated with direct maturity measurements from wells, can characterize and locate production sweet spots for oil, wet gas and dry gas. The transformation of kerogen to petroleum is associated with many chemical reactions, but models typically focus on first-order reactions with rates determined by the Arrhenius Equation. A misconception has been perpetuated for many years that accurate thermal maturity modeling of vitrinite reflectance using the Arrhenius Equation and a single activation energy, to derive a time-temperature index(∑TTI ARR), as proposed by Wood(1988), is flawed. This claim was initially made by Sweeney and Burnham(1990) in promoting their "Easy R o" method, and repeated by others. This paper demonstrates through detailed multi-dimensional burial and thermal modeling and direct comparison of the ∑TTI ARR and "Easy R o" methods that this is not the case. The ∑TTI ARR method not only provides a very useful and sensitive maturity index, it can reproduce the calculated vitrinite reflectance values derived from models based on multiple activation energies(e.g., "Easy Ro"). Through simple expressions the ∑TTI ARR method can also provide oil and gas transformation factors that can be flexibly scaled and calibrated to match the oil, wet gas and dry gas generation windows. This is achieved in a more-computationally-efficient, flexible and transparent way by the ∑TTI ARR method than the "Easy R o" method. Analysis indicates that the "Easy R o" method, using twenty activation energies and a constant frequency factor, generates reaction rates and transformation factors that do not realistically model observed kerogen behaviour and transformation factors over geologic time scales.
