The sandstones of the paleogene in the Huimin Depression have undergone numerous diagenetic processes, such as compaction, cementation, dissolution, metasomasis and recrystallization. The first three — compaction, ...The sandstones of the paleogene in the Huimin Depression have undergone numerous diagenetic processes, such as compaction, cementation, dissolution, metasomasis and recrystallization. The first three — compaction, cementation and dissolution — affect reservoir properties most intensively. An average porosity loss due to compaction is 0.78% per 100 meters, slightly higher in the central and southern parts and lower in the northern. Cementation has resulted in the porosity loss from 8% to 20% at a depth below 1,500 meters. Dissolution, which in most cases is the dissolution of feldspar and of carbonate cement, primarily occurs in two depth intervals, from 1,400 to 2,500 meters and 2,700 to 4,000 meters respectively. New porosity is created through dissolution from 4% to 14%. The sandstones experienced stage A and stage B of early diagenesis and stage A of late diagenesis. At present, most of them are experiencing Phase A2 of late diagenesis. The types of pores in the sand reservoir can be grouped into primary and secondary ones.展开更多
The reservoir conditions,oil and gas charge history and accumulation phases were studied for Yingshan Formation of Yuqi block,and an oil and gas accumulation model was established by using the techniques of reservoir ...The reservoir conditions,oil and gas charge history and accumulation phases were studied for Yingshan Formation of Yuqi block,and an oil and gas accumulation model was established by using the techniques of reservoir prediction,fluorescence thin section and fluid inclusion analysis under the guidance of the theories of oil and gas accumulation.The results indicate that the main rock types in Yingshan Formation are micrite and calcarenite.The carbonate reservoirs are of cave,fracture-pore and fracture types,and their physical properties are intermediate;there are at least four oil/gas charges,i.e.late Hercynian,Yanshanian,early Himalayan and middle Himalayan(Cenozoic).The most important charge periods are late Hercynian,early Himalayan and middle Himalayan;the oil and gas accumulation model is self source-lateral expulsion of hydrocarbon-multistage accumulation,or hydrocarbon sourced from and preserved in the same old rocks-long term expulsion of hydrocarbon-multistage accumulation.展开更多
The prospect of employing Light Amplification by Stimulated Emission of Radiation(LASER) for well drilling in oil and gas industry was examined.In this work,the experimental works carried out on various oil well drill...The prospect of employing Light Amplification by Stimulated Emission of Radiation(LASER) for well drilling in oil and gas industry was examined.In this work,the experimental works carried out on various oil well drilling operations was discussed.The results show that,LASER or LASER-aided oil and gas well drilling has many potential advantages over conventional rotary drilling,including high penetration rate,reduction or elimination of tripping,casing,bit costs,enhanced well control,as well as perforating and side-tracking capabilities.The investigation also reveals that modern infrared LASERs have a higher rate of rock cuttings removal than that of conventional rotary drilling and flame-jet spallation.It also reveals that LASER can destroy rock without damaging formation permeability but rather,it enhances or improves permeability and that permeability and porosity increases in all rock types.The paper has therefore provided more knowledge on the potential value to drilling operations and techniques using LASER.展开更多
Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containi...Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containing-exploitation. Oil exploitation from vertical wells is becoming more and more inefficient. The reservoir type, with water displacing oil and the remaining oil distribution are specifically studied in order to improve the efficiency of the recovery ratio. An integrated scheme for adjusting horizontal wells has been designed and the key technique of the scheme optimized. The study shows that: 1) the positive rhythm of fluvial depositional features is the internal cause of the flooding of oil reservoirs while water injection, injection-production patterns and accumulative petroleum production are the external causes; 2) oil-water driving patterns have transferred from edge water advancing to bottom-water-coning; distribution of the remaining oil mainly concentrates in the upper rhythm and top of the middle rhythm in Ng33 members; 3) a great deal of remaining oil is enriched in high positions of faults, in axes of tiny structures, in stagnation areas among water-injection wells and oil-wells and in tectonic saddle areas with sparse wells. Compared with vertical wells, horizontal wells have advantages such as high recovery, high off-take potential, high critical output, large controlling areas and long time of bottom-water breakthrough.展开更多
Nowadays, it becomes very urgent to find remain oil under the oil shortage worldwide.However, most of simple reservoirs have been discovered and those undiscovered are mostly complex structural, stratigraphic and lith...Nowadays, it becomes very urgent to find remain oil under the oil shortage worldwide.However, most of simple reservoirs have been discovered and those undiscovered are mostly complex structural, stratigraphic and lithologic ones. Summarized in this paper is the integrated seismic processing/interpretation technique established on the basis of pre-stack AVO processing and interpretation.Information feedbacks occurred between the pre-stack and post-stack processes so as to improve the accuracy in utilization of data and avoid pitfalls in seismic attributes. Through the integration of seismic data with geologic data, parameters that were most essential to describing hydrocarbon characteristics were determined and comprehensively appraised, and regularities of reservoir generation and distribution were described so as to accurately appraise reservoirs, delineate favorite traps and pinpoint wells.展开更多
Foreland basins on the western edge of Ordos are characterized by typical loess geomorphologic features. Its surface is severely cut, and its underground geological structures are complicated.Making use of the advanta...Foreland basins on the western edge of Ordos are characterized by typical loess geomorphologic features. Its surface is severely cut, and its underground geological structures are complicated.Making use of the advantage of CEMP in exploration in frontland as well as successful multi-year exploration experiences in West China, we first employed the CEMP method to conduct exploration on the western edge of the Ordos basin and its surrounding areas. The practices proved that rich and reliable geological results have been achieved with the CEMP method in complicated areas covered with loess. This can provide important evidence for researching the contact relationship among basins and mountains, structural feature of target layers and predict favourable areas.展开更多
The Dongpu depression has experienced a complicated evolution of structure since Mesozoic. The Paleozoic carbonate rock has been strongly reformed and the buried hills with different characteristics of structure are d...The Dongpu depression has experienced a complicated evolution of structure since Mesozoic. The Paleozoic carbonate rock has been strongly reformed and the buried hills with different characteristics of structure are developed in the depression. There exist lots of groups of fault structures with strikes of NNE(or NE),NW, near NS and EW etc., of which the faults with strikes of NNE and NW play an important controlling role on present-day structural framework of the depression. The faults with near NS-striking and EW-striking deeply affect the establishment of structural framework of basement of the depression. Although most of the fractures are filled by calcite and other minerals, under the action of later structural stress, the earlier fractures could change their features into tensional ones. Therefore, much attention should be paid to the exploration and exploitation of Paleozoic oil and gas in Dongpu depression.展开更多
The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniqu...The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.展开更多
In 2011, petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re- alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pal 61 well, with 855.7 949.6 m se...In 2011, petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re- alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pal 61 well, with 855.7 949.6 m section, in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa. s （50 ℃）. The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.展开更多
The concern on formation damage control of high permeability sandstone reservoir has been growing in oil industry in recent years. The invasion of particles and the filtrate of drilling fluid are proven as one of the ...The concern on formation damage control of high permeability sandstone reservoir has been growing in oil industry in recent years. The invasion of particles and the filtrate of drilling fluid are proven as one of the key factors accounting for reservoir damage. Based on the ideal packing theory, the practical software has been developed to optimize the blending proportion of several bridging agents, and the core flooding tests were conducted to evaluate return permeability of core samples contaminated with different drilling fluids. Experimental results show that the ideal packing approach can reduce the dynamic filtration rate, improve the return permeability and drawdown the breakthrough pressure, indicating that this kind of drilling fluids can meet the demands of formation damage control for high permeability sandstone reservoirs. Some applying procedures for formation damage control are also proposed in this paper.展开更多
文摘The sandstones of the paleogene in the Huimin Depression have undergone numerous diagenetic processes, such as compaction, cementation, dissolution, metasomasis and recrystallization. The first three — compaction, cementation and dissolution — affect reservoir properties most intensively. An average porosity loss due to compaction is 0.78% per 100 meters, slightly higher in the central and southern parts and lower in the northern. Cementation has resulted in the porosity loss from 8% to 20% at a depth below 1,500 meters. Dissolution, which in most cases is the dissolution of feldspar and of carbonate cement, primarily occurs in two depth intervals, from 1,400 to 2,500 meters and 2,700 to 4,000 meters respectively. New porosity is created through dissolution from 4% to 14%. The sandstones experienced stage A and stage B of early diagenesis and stage A of late diagenesis. At present, most of them are experiencing Phase A2 of late diagenesis. The types of pores in the sand reservoir can be grouped into primary and secondary ones.
基金Project(P05009) supported by the Item of Science and Technology and Development of SINOPEC Stock Limited Company of China
文摘The reservoir conditions,oil and gas charge history and accumulation phases were studied for Yingshan Formation of Yuqi block,and an oil and gas accumulation model was established by using the techniques of reservoir prediction,fluorescence thin section and fluid inclusion analysis under the guidance of the theories of oil and gas accumulation.The results indicate that the main rock types in Yingshan Formation are micrite and calcarenite.The carbonate reservoirs are of cave,fracture-pore and fracture types,and their physical properties are intermediate;there are at least four oil/gas charges,i.e.late Hercynian,Yanshanian,early Himalayan and middle Himalayan(Cenozoic).The most important charge periods are late Hercynian,early Himalayan and middle Himalayan;the oil and gas accumulation model is self source-lateral expulsion of hydrocarbon-multistage accumulation,or hydrocarbon sourced from and preserved in the same old rocks-long term expulsion of hydrocarbon-multistage accumulation.
文摘The prospect of employing Light Amplification by Stimulated Emission of Radiation(LASER) for well drilling in oil and gas industry was examined.In this work,the experimental works carried out on various oil well drilling operations was discussed.The results show that,LASER or LASER-aided oil and gas well drilling has many potential advantages over conventional rotary drilling,including high penetration rate,reduction or elimination of tripping,casing,bit costs,enhanced well control,as well as perforating and side-tracking capabilities.The investigation also reveals that modern infrared LASERs have a higher rate of rock cuttings removal than that of conventional rotary drilling and flame-jet spallation.It also reveals that LASER can destroy rock without damaging formation permeability but rather,it enhances or improves permeability and that permeability and porosity increases in all rock types.The paper has therefore provided more knowledge on the potential value to drilling operations and techniques using LASER.
基金Projects 2003CB214603 supported by the National Basic Research Program of ChinaDMSM200803 by the Open Fund of Key Laboratory of Deposi-tional Mineralization & Sedimentary Mineral, Shandong Province
文摘Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containing-exploitation. Oil exploitation from vertical wells is becoming more and more inefficient. The reservoir type, with water displacing oil and the remaining oil distribution are specifically studied in order to improve the efficiency of the recovery ratio. An integrated scheme for adjusting horizontal wells has been designed and the key technique of the scheme optimized. The study shows that: 1) the positive rhythm of fluvial depositional features is the internal cause of the flooding of oil reservoirs while water injection, injection-production patterns and accumulative petroleum production are the external causes; 2) oil-water driving patterns have transferred from edge water advancing to bottom-water-coning; distribution of the remaining oil mainly concentrates in the upper rhythm and top of the middle rhythm in Ng33 members; 3) a great deal of remaining oil is enriched in high positions of faults, in axes of tiny structures, in stagnation areas among water-injection wells and oil-wells and in tectonic saddle areas with sparse wells. Compared with vertical wells, horizontal wells have advantages such as high recovery, high off-take potential, high critical output, large controlling areas and long time of bottom-water breakthrough.
文摘Nowadays, it becomes very urgent to find remain oil under the oil shortage worldwide.However, most of simple reservoirs have been discovered and those undiscovered are mostly complex structural, stratigraphic and lithologic ones. Summarized in this paper is the integrated seismic processing/interpretation technique established on the basis of pre-stack AVO processing and interpretation.Information feedbacks occurred between the pre-stack and post-stack processes so as to improve the accuracy in utilization of data and avoid pitfalls in seismic attributes. Through the integration of seismic data with geologic data, parameters that were most essential to describing hydrocarbon characteristics were determined and comprehensively appraised, and regularities of reservoir generation and distribution were described so as to accurately appraise reservoirs, delineate favorite traps and pinpoint wells.
文摘Foreland basins on the western edge of Ordos are characterized by typical loess geomorphologic features. Its surface is severely cut, and its underground geological structures are complicated.Making use of the advantage of CEMP in exploration in frontland as well as successful multi-year exploration experiences in West China, we first employed the CEMP method to conduct exploration on the western edge of the Ordos basin and its surrounding areas. The practices proved that rich and reliable geological results have been achieved with the CEMP method in complicated areas covered with loess. This can provide important evidence for researching the contact relationship among basins and mountains, structural feature of target layers and predict favourable areas.
文摘The Dongpu depression has experienced a complicated evolution of structure since Mesozoic. The Paleozoic carbonate rock has been strongly reformed and the buried hills with different characteristics of structure are developed in the depression. There exist lots of groups of fault structures with strikes of NNE(or NE),NW, near NS and EW etc., of which the faults with strikes of NNE and NW play an important controlling role on present-day structural framework of the depression. The faults with near NS-striking and EW-striking deeply affect the establishment of structural framework of basement of the depression. Although most of the fractures are filled by calcite and other minerals, under the action of later structural stress, the earlier fractures could change their features into tensional ones. Therefore, much attention should be paid to the exploration and exploitation of Paleozoic oil and gas in Dongpu depression.
基金This work is sponsored by the Major Program in the Ninth-five Year Plan, National Natural Science Foundation of China （No.498894190 - 4）.
文摘The analysis of strata between wells is fundamental in the study of oil and gas reservoirs. Automatic analysis of strata between wells, based on stratigraphic division of well logs, is realized using computer techniques. We use a technique of dynamic waveform matching to build cross-well stratigraphic correlation relationships and automatically draw a path diagram of the cross-well stratigraphic contrast through piecewise line fitting, log character extraction, match cost calculation, and etc.. After analyzing many structure path diagrams between wells, 30 path patterns for normal faults, reverse faults, unconformities, synsedimentary faults, listric faults, pinch-outs, and so on were summarized and the path diagram patterns and correlation conceptions are presented. The application analysis in Dagang Oil Field shows that this method is effective.
基金National Planed Major S&T Projects(No.2011ZX05002-002)Scientific Research Project of Sinopec(No.P03011)Key Technology Tacking Project,Shengli Oilfield Company,Sinopec(No.YKK0808)
文摘In 2011, petroleum exploration of shallow marine deposits Carboniferous and volcanic tuff reservoir re- alized breakthroughs at Chepaizi slope in the western margin of Junggar Basin. Pal 61 well, with 855.7 949.6 m section, in the conventional test oil obtained 6 t/d industrial oil flow. The surface viscosity is 390 mPa. s （50 ℃）. The marine deposit of Carboniferous are deep oil source rocks and high-quality reservoir. Magma volcanic activity provides the basis for volcanic reservoir development and distribution. The weathering crust and secondary cracks developed volcanic tuff by strong rock weathering and dissolution of organic acids which has become top quality reservoir. Deep Permian oil-gas migrated and accumulated to high parts along Hong-Che fault belt and stratigraphic unconformity stripping. Permian and Triassic volcanic rocks or dense mudstone sedimentary cover as a regional seal for the late Carboniferous oil-gas to save critically. The seismic pre-stack time migration processing technologies for the problem of poor inner structures of Carboniferous were developed. Response of volcanic rock seismic and logging are obvious. The application imaging logging and nuclear magnetic technology achieved the qualitative identification and quantification of fracture description.
文摘The concern on formation damage control of high permeability sandstone reservoir has been growing in oil industry in recent years. The invasion of particles and the filtrate of drilling fluid are proven as one of the key factors accounting for reservoir damage. Based on the ideal packing theory, the practical software has been developed to optimize the blending proportion of several bridging agents, and the core flooding tests were conducted to evaluate return permeability of core samples contaminated with different drilling fluids. Experimental results show that the ideal packing approach can reduce the dynamic filtration rate, improve the return permeability and drawdown the breakthrough pressure, indicating that this kind of drilling fluids can meet the demands of formation damage control for high permeability sandstone reservoirs. Some applying procedures for formation damage control are also proposed in this paper.
