A total of 6 oil samples were systematically selected from six Asmari Reservoir wells in the Cheshmeh-Khush Oilfield for geochemical evaluation of the hydrocarbon system,based on reservoir geochemistry and oil fingerp...A total of 6 oil samples were systematically selected from six Asmari Reservoir wells in the Cheshmeh-Khush Oilfield for geochemical evaluation of the hydrocarbon system,based on reservoir geochemistry and oil fingerprints.An investigation of the distribution patterns of normal alkanes and tricyclic and tetracyclic terpanes along with characteristic biomarkers of the depositional environment and sedimentary facies,indicated that the source rock of the studied hydrocarbons was deposited in a reducing aquatic environment with a low input of terrigenous material and predominantly carbonate lithology derived from organic algal matter.The studied oil samples exhibited moderate maturity,as was further confirmed by the parameters extracted from the light hydrocarbons.Statistical clustering based on different biomarker parameters indicated the presence of two oil families.Additionally,the application of branched and cyclic compounds in the light hydrocarbons(C5–C11)to evaluate lateral continuity of the Asmari reservoir further supported the presence of the two oil families.Other evidence proved the presence of a NE–SW trending fault separating wells X5 and X6 from the other wells in the field.In other wells across the field,good lateral reservoir continuity was observed,despite the presence of faults on the northern and southern plunges of the structure.展开更多
Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added dur...Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added during the process. Geochemistry of formation water is used for aquifer identification, pollution problems, water compatibility studies, corrosion monitoring, water-quality control, water flooding, exploration, and to diagnose wellbore integrity issues. The current study investigates the spatial and temporal variation of produced water geochemistry from one of the largest conventional oil field, Ghawar field, Saudi Arabia. Produced water from different wellheads were collected and analyzed for different geochemical characteristics. Sixteen wells from ABQQ, nineteen wells from ANDR and twenty wells from SDGM area were selected for the current study. Sampling and analysis were performed as per the standard procedures. Results indicated that the pH of the sample varied from 6.0 to 7.4, and Electrical conductivity from 94200 to 102690 μS/cm. The spatial variation of major cations and anions were also recorded and represented by graphical plots. Metal analysis indicated the highest concentration for boron, which is 20.5 mg/L at ABQQ area, whereas all other metals are very low in concentration. Temporal variation of a single well at SDGM area indicated drastic change in the ionic concentration, whereas the geochemistry remains same as indicated by Tickler plot. The water type of the respective area was studied by tickler plots, which indicated same source of formation water in different wells at ABQQ, ANDR and SDGM areas. The ionic concentration is also used to predict corrosion and scaling issues. By Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the sample from all the wells showed higher scaling potential. The study concludes that the water type in different areas under Ghawar field remains same regardless of drastic changes in the ionic concentration, which can be used to diagnose wellbore integrity issues.展开更多
Based on the extensive studies of conventional and unconventional hydrocarbon accumulations,the concept,classification and formation as well as distribution of petroleum reservoirs are discussed.The revised concept de...Based on the extensive studies of conventional and unconventional hydrocarbon accumulations,the concept,classification and formation as well as distribution of petroleum reservoirs are discussed.The revised concept defined the petroleum reservoir as a continuous hydrocarbon accumulation in a single or a set of reservoirs with an independent or uniform pressure system.In terms of the pattern of hydrocarbon accumulation and distribution,the hydrocarbon accumulations are classified into three basic types,i.e.,the continuous accumulation,the quasi-continuous accumulation and the discontinuous accumulation.The hydrocarbon accumulation was demonstrated as a process from continuous accumulation to discontinuous accumulation,and therefore these three basic types of hydrocarbon accumulations were identified.The continuous hydrocarbon accumulation is principally formed in source rocks,and typical examples are shale hydrocarbon reservoirs and coal-bed methane reservoirs;it is mainly characterized by tight-ultra tight reservoirs with permeability of nanodarcy to millidarcy;the hydrocarbons occurred in free,adsorbed or dissolved state;a continuous accumulation comprises actually only a single reservoir,and hydrocarbons are extensively and continuously distributed within the scope of effective source rocks;the accumulation has neither defined boundaries nor bottom or edge water;oil and gas mainly accumulate in situ or near the generation of hydrocarbons with no prominent migration;this hydrocarbon accumulation process is basically not controlled by traps.The quasicontinuous hydrocarbon accumulation mostly occurs in the tight reservoirs adjacent to source rocks,and typical examples are most of tight hydrocarbon reservoirs;the hydrocarbons are distributed quasicontinuously in large areas,and each quasi-continuous hydrocarbon accumulation includes numerous adjacent small-to medium-size reservoirs;reservoirs of this kind of hydrocarbon accumulation have no defined boundaries,no or only local edge and bottom water distribution,and no regional oil-gas-water inversion;hydrocarbons are pervasively charged in large areas,and oil and gas accumulation is caused by primary migration and short-distance secondary migration;the hydrocarbon migration and accumulation is principally driven by non-buoyant forces in non-Darcy flow;and the hydrocarbon accumulation is basically not controlled by anticline traps,but largely by non-anticline traps,especially lithological traps.The discontinuous hydrocarbon accumulation is also named as the hydrocarbon accumulation of the conventional-trap type,and typically occurs in conventional reservoirs,but some tight hydrocarbon reservoirs,coalbed methane reservoirs and even possible shale hydrocarbon reservoirs also belong to this kind of hydrocarbon accumulation;the hydrocarbon reservoirs are distributed discontinuously,and have clear boundaries and complete edge water or bottom water;the hydrocarbon migration and accumulation is mainly driven by buoyancy and secondary migration is usually indispensable;the hydrocarbon accumulation is strictly controlled by various traps,especially structural traps.In a petroliferous basin,above three types of hydrocarbon accumulation may coexist,andhydrocarbons are often derived from a common source kitchen(s).Therefore,these three types of hydrocarbon accumulation should be considered and studied as a whole to maximize hydrocarbon exploration efficiencvy.展开更多
基金the Exploration Directorate of the National Iranian Oil Company for providing the research team with the required funding for performing the analysis utilized in this project。
文摘A total of 6 oil samples were systematically selected from six Asmari Reservoir wells in the Cheshmeh-Khush Oilfield for geochemical evaluation of the hydrocarbon system,based on reservoir geochemistry and oil fingerprints.An investigation of the distribution patterns of normal alkanes and tricyclic and tetracyclic terpanes along with characteristic biomarkers of the depositional environment and sedimentary facies,indicated that the source rock of the studied hydrocarbons was deposited in a reducing aquatic environment with a low input of terrigenous material and predominantly carbonate lithology derived from organic algal matter.The studied oil samples exhibited moderate maturity,as was further confirmed by the parameters extracted from the light hydrocarbons.Statistical clustering based on different biomarker parameters indicated the presence of two oil families.Additionally,the application of branched and cyclic compounds in the light hydrocarbons(C5–C11)to evaluate lateral continuity of the Asmari reservoir further supported the presence of the two oil families.Other evidence proved the presence of a NE–SW trending fault separating wells X5 and X6 from the other wells in the field.In other wells across the field,good lateral reservoir continuity was observed,despite the presence of faults on the northern and southern plunges of the structure.
文摘Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added during the process. Geochemistry of formation water is used for aquifer identification, pollution problems, water compatibility studies, corrosion monitoring, water-quality control, water flooding, exploration, and to diagnose wellbore integrity issues. The current study investigates the spatial and temporal variation of produced water geochemistry from one of the largest conventional oil field, Ghawar field, Saudi Arabia. Produced water from different wellheads were collected and analyzed for different geochemical characteristics. Sixteen wells from ABQQ, nineteen wells from ANDR and twenty wells from SDGM area were selected for the current study. Sampling and analysis were performed as per the standard procedures. Results indicated that the pH of the sample varied from 6.0 to 7.4, and Electrical conductivity from 94200 to 102690 μS/cm. The spatial variation of major cations and anions were also recorded and represented by graphical plots. Metal analysis indicated the highest concentration for boron, which is 20.5 mg/L at ABQQ area, whereas all other metals are very low in concentration. Temporal variation of a single well at SDGM area indicated drastic change in the ionic concentration, whereas the geochemistry remains same as indicated by Tickler plot. The water type of the respective area was studied by tickler plots, which indicated same source of formation water in different wells at ABQQ, ANDR and SDGM areas. The ionic concentration is also used to predict corrosion and scaling issues. By Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the sample from all the wells showed higher scaling potential. The study concludes that the water type in different areas under Ghawar field remains same regardless of drastic changes in the ionic concentration, which can be used to diagnose wellbore integrity issues.
基金This work was supported by National Science and Technology Major Project of China(Grant No.2011ZX05007-004 and Grant No.2011ZX05018001-004)National Natural Science Foundation of China(Grant No.41402121 and Grant No.41502132)+1 种基金Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2013JM5007)Shaanxi Provincial Natural Science Foundation of China(Grant No.2013JQ503).
文摘Based on the extensive studies of conventional and unconventional hydrocarbon accumulations,the concept,classification and formation as well as distribution of petroleum reservoirs are discussed.The revised concept defined the petroleum reservoir as a continuous hydrocarbon accumulation in a single or a set of reservoirs with an independent or uniform pressure system.In terms of the pattern of hydrocarbon accumulation and distribution,the hydrocarbon accumulations are classified into three basic types,i.e.,the continuous accumulation,the quasi-continuous accumulation and the discontinuous accumulation.The hydrocarbon accumulation was demonstrated as a process from continuous accumulation to discontinuous accumulation,and therefore these three basic types of hydrocarbon accumulations were identified.The continuous hydrocarbon accumulation is principally formed in source rocks,and typical examples are shale hydrocarbon reservoirs and coal-bed methane reservoirs;it is mainly characterized by tight-ultra tight reservoirs with permeability of nanodarcy to millidarcy;the hydrocarbons occurred in free,adsorbed or dissolved state;a continuous accumulation comprises actually only a single reservoir,and hydrocarbons are extensively and continuously distributed within the scope of effective source rocks;the accumulation has neither defined boundaries nor bottom or edge water;oil and gas mainly accumulate in situ or near the generation of hydrocarbons with no prominent migration;this hydrocarbon accumulation process is basically not controlled by traps.The quasicontinuous hydrocarbon accumulation mostly occurs in the tight reservoirs adjacent to source rocks,and typical examples are most of tight hydrocarbon reservoirs;the hydrocarbons are distributed quasicontinuously in large areas,and each quasi-continuous hydrocarbon accumulation includes numerous adjacent small-to medium-size reservoirs;reservoirs of this kind of hydrocarbon accumulation have no defined boundaries,no or only local edge and bottom water distribution,and no regional oil-gas-water inversion;hydrocarbons are pervasively charged in large areas,and oil and gas accumulation is caused by primary migration and short-distance secondary migration;the hydrocarbon migration and accumulation is principally driven by non-buoyant forces in non-Darcy flow;and the hydrocarbon accumulation is basically not controlled by anticline traps,but largely by non-anticline traps,especially lithological traps.The discontinuous hydrocarbon accumulation is also named as the hydrocarbon accumulation of the conventional-trap type,and typically occurs in conventional reservoirs,but some tight hydrocarbon reservoirs,coalbed methane reservoirs and even possible shale hydrocarbon reservoirs also belong to this kind of hydrocarbon accumulation;the hydrocarbon reservoirs are distributed discontinuously,and have clear boundaries and complete edge water or bottom water;the hydrocarbon migration and accumulation is mainly driven by buoyancy and secondary migration is usually indispensable;the hydrocarbon accumulation is strictly controlled by various traps,especially structural traps.In a petroliferous basin,above three types of hydrocarbon accumulation may coexist,andhydrocarbons are often derived from a common source kitchen(s).Therefore,these three types of hydrocarbon accumulation should be considered and studied as a whole to maximize hydrocarbon exploration efficiencvy.
