The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle m...The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle model. With the new model, the statistical correspondence between the production decline stage and the reserve-production imbalance is clarified,and the correlation of water cut with the recovery percent of recoverable reserves is discussed, providing quantitative basis of reservoir engineering for dividing development stages of oilfield and defining mature oilfields. According to the statistics of oilfields in eastern China, the time point corresponding to the reserve-production balance coefficient dropping to less than 1dramatically is well correlated the beginning point of production decline, thus the time when the reserve-production balance coefficient drops dramatically can be taken as the initiation point of production decline stage. The research results show that the water cut and the recovery percent of recoverable reserves have a good statistical match in the high water cut stage, and it is more rational to take both the start point of production decline stage and the water cut of 90%(or the recovery percent of recoverable reserves of 80%) as the critical criteria for defining a mature oilfield. Five production evolution patterns can be summarized as follows: growth–peak plateau–stepped decline, growth–stepped stabilizing–stepped decline, growth–stepped stabilizing–rapid decline, growth–peak plateau–rapid decline, and growth–continuous decline.展开更多
The reservoirs in the seventh member of the Triassic Yanchang Formation (Chang 7 Member) in the Qingcheng Oilfield of the Ordos Basin are characterized by thin sandbody, tight rocks, high heterogeneity, low formation ...The reservoirs in the seventh member of the Triassic Yanchang Formation (Chang 7 Member) in the Qingcheng Oilfield of the Ordos Basin are characterized by thin sandbody, tight rocks, high heterogeneity, low formation pressure coefficient, and complex geomorphology. Through the efforts in the stages of exploration, appraisal, pilot testing and development, a series of key technologies have been formed, including “sweet spot” optimization, differentiated three-dimensional well deployment, fast drilling and completion of large-cluster horizontal well, intensively-staged volume fracturing in long horizontal well, and optimization of rational production system. Furthermore, a production organization mode represented by factory-like operations on loess platform has been implemented. Application of these technologies has enabled to significantly improve the single-well production of the Qingcheng Oilfield, reduce the investment cost, and realize a large-scale and beneficial development at a full cost below $55 per barrel. In 2022, the annual production of Chang 7 shale oil in the Ordos Basin reached 221×10^(4) t, accounting for 70% of the annual shale oil production of China. The practice of development technologies in the Qingcheng Oilfield provides valuable references for efficient development of continental shale oil.展开更多
To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, Chin...To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, China, the main strike-slip faults in and around well FD1 in the basin were analyzed in terms of sedimentary facies, sequence stratigraphy, intraplatform shoal reservoir property, and oil and gas origins, based on drilling data. The Yingshan Formation intraplatform shoal between the main strike-slip faults is superimposed with low-order faults to form a new type of hydrocarbon play. Firstly, hydrocarbons generated from the Lower Cambrian Yuertusi Formation source rocks vertically migrated into the second member of Yingshan Formation through the main strike-slip faults, and then migrated laterally until they were accumulated. A small amount of oil from Well FD1 came from the Yuertusi Formation source rocks in the mature stage, and a large amount of gas originated from oil cracking in the ultra-deep reservoirs. Therefore, the secondary gas condensate reservoir in Well FD1 is characterized by high gas to oil ratio, dry gas (dryness coefficient being 0.970) and hybrid origin. This new type of hydrocarbon play characterized by intraplatform shoal and low-order fault suggests a prospect of continuous hydrocarbon-bearing area in Fuman Oilfield, which will expand the ultrap-deep oil and gas exploration in the oilfield.展开更多
The Ordos Basin is the largest continental multi-energy mineral basin in China,which is rich in coal,oil and gas,and uranium resources.The exploitation of mineral resources is closely related to reservoir water.The ch...The Ordos Basin is the largest continental multi-energy mineral basin in China,which is rich in coal,oil and gas,and uranium resources.The exploitation of mineral resources is closely related to reservoir water.The chemical properties of reservoir water are very important for reservoir evaluation and are significant indicators of the sealing of reservoir oil and gas resources.Therefore,the caprock of the Chang 6 reservoir in the Yanchang Formation was evaluated.The authors tested and analyzed the chemical characteristics of water samples selected from 30 wells in the Chang 6 reservoir of Ansai Oilfield in the Ordos Basin.The results show that the Chang 6 reservoir water in Ansai Oilfield is dominated by calcium-chloride water type with a sodium chloride coefficient of generally less than 0.5.The chloride magnesium coefficients are between 33.7 and 925.5,most of which are greater than 200.The desulfurization coefficients range from 0.21 to 13.4,with an average of 2.227.The carbonate balance coefficients are mainly concentrated below 0.01,with an average of 0.008.The calcium and magnesium coefficients are between 0.08 and 0.003,with an average of 0.01.Combined with the characteristics of the four-corner layout of the reservoir water,the above results show that the graphics are basically consistent.The study indicates that the Chang 6 reservoir in Ansai Oilfield in the Ordos Basin is a favorable block for oil and gas storage with good sealing properties,great preservation conditions of oil and gas,and high pore connectivity.展开更多
The Ordovician reservoirs in the Tahe oilfield are dominated by fractured-vuggy carbonate reservoirs, of which fault-karst reservoirs are a hot topic in recent years. Fault-karst reservoirs feature high production, la...The Ordovician reservoirs in the Tahe oilfield are dominated by fractured-vuggy carbonate reservoirs, of which fault-karst reservoirs are a hot topic in recent years. Fault-karst reservoirs feature high production, large burial depth, and strong heterogeneity under the control of faulting and karstification. Based on geological, logging, and seismic data, this study classified the Ordovician fault-karst reservoirs in the Yuejin block of the Tahe oilfield into three types, namely karst-cave, dissolved-vug, and fractured types, and established the integrated identification criteria of the three types of reservoirs. This study characterized karst caves, dissolved vugs, and multi-scale faults through seismic wave impedance inversion and frequency-domain detection of multi-scale faults. 3D geological models of different types of reservoirs were built using the combined deterministic and stochastic methods and characterized the spatial distribution of multi-scale faults, karst caves, dissolved vugs, and physical property parameters of reservoir. This study established the method for the geological modeling of fault-karst reservoirs, achieved the quantitative characterization and revealed the heterogeneity of fault-karst reservoirs. The karst-cave and dissolved-vug types are high in porosity and act as reservoirs, while the fractured type is high in permeability and act as flow pathway. This study lays the foundation for the development index prediction, well emplacement, and efficient development of the fault-karst carbonate reservoirs.展开更多
About 88. 1% of the proven reserves in the Tahe Oilfield in the Tarim Basin of Northwest China are trapped in Ordovician carbonate reservoirs. These reservoirs are formed by unconnected and interconnected networks of ...About 88. 1% of the proven reserves in the Tahe Oilfield in the Tarim Basin of Northwest China are trapped in Ordovician carbonate reservoirs. These reservoirs are formed by unconnected and interconnected networks of karstic porosity forming a heterogeneous and complex reservoir system. Oil, water and gas characteristics vary significantly in different portions of the Ordovician reservoir. There is no uniform oil/water contact in the field, adding to its complexity.An acid fracture treatment is beneficial in 76% of the wells, stimulating nonproductive wells and enhancing production in other wells by fracturing into unconnected reservoirs and enhancing flow pathways with acid. Acid fracture treatments should be a standard procedure for developing this and similar oil fields.展开更多
A collection of data obtained from analytical methods in geochemistry along with the reservoir engineering and geologic data were used to investigate the reservoir continuity in the Cretaceous Fahliyan, Gadavan, Kazhd...A collection of data obtained from analytical methods in geochemistry along with the reservoir engineering and geologic data were used to investigate the reservoir continuity in the Cretaceous Fahliyan, Gadavan, Kazhdumi and Sarvak reservoirs of the super-giant Azadegan oilfield, SW Iran. The geochemical data indicate that the oil samples, with medium to high level of thermal maturity, have been generated from the anoxic marine marl/carbonate source rock(s). The Sargelu(Jurassic) and Garau(Cretaceous) formations are introduced as the main source rocks for the studied oils. The dendrogram obtained from the cluster analysis of high-resolution gas chromatography data introduces two main oil groups including Fahliyan reservoir, and Kazhdumi along with Sarvak/Gadvan reservoirs. This is confirmed by C7 Halpern star diagram, indicating that, the light oil fraction from Fahliyan reservoir is distinct from the others. Also, different pressure gradient of the Fahliyan Formation(over-pressured) relative to other reservoirs(normally-pressured) show the presence of compartments. The relation between toluene/n-heptane and n-heptane/methylcyclohexane represents the compartmentalization due to maturation/evaporative fractionation for Fahliyan and water washing for other studied reservoirs. Also, the impermeable upper part of the Fahliyan Formation and thin interbedded shaly layers in the Kazhdumi, Sarvak and Gadvan formations have controlled reservoir compartmentalization.展开更多
Located in Iranian sector of the Persian Gulf, Foroozan Oilfield has been producing hydrocarbons via seven different reservoirs since the 1970 s. However, understanding fluid interactions and horizontal continuity wit...Located in Iranian sector of the Persian Gulf, Foroozan Oilfield has been producing hydrocarbons via seven different reservoirs since the 1970 s. However, understanding fluid interactions and horizontal continuity within each reservoir has proved complicated in this field. This study aims to determine the degree of intra-reservoir compartmentalization using gas geochemistry, light hydrocarbon components, and petroleum bulk properties, comparing the results with those obtained from reservoir engineering indicators. For this purpose, a total of 11 samples of oil and associated gas taken from different producing wells in from the Yammama Reservoir were selected. Clear distinctions, in terms of gas isotopic signature and composition, between the wells located in northern and southern parts of the reservoir(i.e. lighter δ13 C1, lower methane concentration, and negative sulfur isotope in the southern part) and light hydrocarbon ratios(e.g. nC 7/toluene, 2,6-dmC7/1,1,3-tmcyC5 and m-xylene/4-mC8) in different oil samples indicated two separate compartments. Gradual variations in a number of petroleum bulk properties(API gravity, V/Ni ratios and asphaltene concentration) provided additional evidence on the reservoir-filling direction, signifying that a horizontal equilibrium between reservoir fluids across the Yammama Reservoir is yet to be achieved. Finally, differences in water-oil contacts and reservoir types further confirmed the compartmentalization of the reservoir into two separate compartments.展开更多
The geochemical characteristics of crude oils from Zao\|Ⅴ oil measures in the Shenjiapu oilfield are systematically described in terms of the fractional composition of crude oils, GC characteristics of saturated hydr...The geochemical characteristics of crude oils from Zao\|Ⅴ oil measures in the Shenjiapu oilfield are systematically described in terms of the fractional composition of crude oils, GC characteristics of saturated hydrocarbon fraction of crude oils and the characteristics of their biomarkers. The depositional environment, type and evolution of the biological source are also discussed. All pieces of evidence such as low saturated hydrocarbon fraction, high resin and asphalt, high isoprenoid alkane, weak odd\|carbon number predominance (CPI ranging from \{1.23\} to \{1.29\}, OEP ranging from \{1.14\} to \{1.16\}) and low sterane and terpane maturity parameters show these crude oils are immature oils. Low Pr/Ph ratios (\{0.66\}-\{0.88\}) and high gammacerance/C\-\{31\} hopane ratios (\{0.59\}-\{0.86\}) indicate the source rocks were formed in a slightly saline to brackish reducing lake depositional environment. Gas chromatographic characteristics of the saturated hydrocarbon fraction and the predominance of C\-\{30\} hopane in terpane series and C\-\{29\} sterane in sterane series indicate the biological source of the crude oils is composed mainly of bacterial and algal organic matter, and some algae are perhaps the main contributor of organic matter to the source rocks.展开更多
Xin’anbian Oilfield of the Ordos Basin is the large tight oilfield to be first exploration discovery in china.The production of tight oil increased significantly in recent years.It shows great exploration potential o...Xin’anbian Oilfield of the Ordos Basin is the large tight oilfield to be first exploration discovery in china.The production of tight oil increased significantly in recent years.It shows great exploration potential of Chang 7 tight oil.But the physical property and hydrocarbon enrichment characteristics of Chang 7 tight oil reservoirs were rarely studied,The forming conditions of tight oil reservoirs are systematically summarized and analyzed through the study of hydrocarbon generation,sedimentary reservoirs and hydrocarbon migration and accumulation based on production and core experimental data.The result shows that,The porosity of the Chang 7_(2)reservoir mainly distributed in 5.0-11.0%,average at 7.9%,The permeability mainly distributed in 0.04-0.18×10^(-3)μm^(2),average at 0.12×10^(-3)μm^(2),The pore diameters of the tight oil reservoir distributed in 2-8μm.The high-quality Chang 7_(3)source rocks and the micropsammite of Chang 7_(2)subaqueous distributary channel were widely distributed in the study area.The lenticular or banded sand bodies are distributed among mudstone or hydrocarbon source rocks and have the advantage of migration distance for hydrocarbon accumulation.The reservoir space is composed of micro-nanometer pores and throat,that is formed in the process of increasing pressure during hydrocarbon generation and hydrocarbon accumulation.The Chang 7 tight oil was generated in the early Cretaceous and injected into the sand of the subaqueous distributary channel driven by continuous hydrocarbon generation supercharging.The formation and accumulation of tight oil reservoirs are mainly controlled by source rocks,sedimentary microfacies and reservoirs of good quality.展开更多
The major steps of oilfield development are given in this paper. The optimal model of oilfield development is built and the methods of optimum decision analysis are studied. The solution and analysis of the optimal ta...The major steps of oilfield development are given in this paper. The optimal model of oilfield development is built and the methods of optimum decision analysis are studied. The solution and analysis of the optimal tactics have been set up according to the data collected in the oilfield.展开更多
China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of
Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield che...Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield chemicals.The target screening was initially carried out on 8 suspected organic chlorides by evaluating the capability of the enhanced separation and reliable identification at a trace concentration. GC×GC-TOFMS allowed for the fast and automated analysis of organic chlorides at a level of 200 μg/L. This method was subsequently applied for non-target screening of organic chlorides in different oilfield chemicals at various locations across China. 22 organic chlorides were identified and verified by comparison with pure standards in the mixed sample. Finally, this method was used to determine the content of the organic chlorides in individual samples. The result showed that the organic chloride levels in 19 of the 39 tested oilfield chemicals were above the threshold limit of 1.0 mg/L.展开更多
Petroleum migration process of Bamianhe oilfield of Dongying depression, East China is evaluatedon the basis of our detailed work on geochemistry of the crude oil and the source. Molecular tracers, especially nitrogen...Petroleum migration process of Bamianhe oilfield of Dongying depression, East China is evaluatedon the basis of our detailed work on geochemistry of the crude oil and the source. Molecular tracers, especially nitrogen compounds, are employed in assessing style of oil migration and accumulation. Additionally, absolute quantitative results of heteroaromatics including dibenzofuran, dibenzothiophene and fluorene with similar basic frames to pyrrolic nitrogenic compounds are also used to evaluate the quantity of petroleum migration. According to apparent migration effects of the pyrrolic nitrogen compounds, it is indicated that most of Bamianhe oil was derived from potential source kitchen-Niu-zhuang sag, migrated and accumulated at Bamianhe fault belt through selective paths according to a main filling point displayed. Generally, upward migration trend from the main point along the south slope is noted. There are observable migration effects from Guangli subsag to the north Bamianhe and Yangjiaogou oilfields showing Guangli subsag was a secondary kitchen accounting for the oils in the north portion. Significant vertical migration effects shown in several cross sections demonstrate that faults well developed in the area play an important role in oil migration and accumulation. Unformality, sandstone reservoirs distributed locally also suggest important fairways in connecting sources with traps. The tectonic and a combination of tectonic and lithological mechanism are identified as the critical mechanisms in entrapping hydrocarbons. Migration trend suggested by nitrogenic compounds agrees well with analysis of lateral compositional variety and thermal maturity gradient. This study also confirms well with our previous studies. It is the location of source rocks, tectonic and stratigraphic characteristics that have a comprehensive control on the model of hydrocarbon migration and accumulation in Bamianhe oilfield. Results also show that the oils are mostly derived from the deep parts of the Niuzhuang and Guangli sags within normal oil window.展开更多
Owing to porous structure,stable chemical properties,low cost and available raw material,biomass carbon aerogel is a promising adsorbent framework material.Herein,a pomelo peel-based carbon aerogel was prepared by hyd...Owing to porous structure,stable chemical properties,low cost and available raw material,biomass carbon aerogel is a promising adsorbent framework material.Herein,a pomelo peel-based carbon aerogel was prepared by hydrothermal-freeze drying-high temperature carbonization method and modified with Tri-n-ocylamine(N235)and γ-Glycidyloxypropyltrimethoxysilane(KH560)via impregnation process.The as-prepared adsorbents exhibit superior adsorption performance for iodide in simulated and oilfield brines,and the highest adsorption amount of iodide in oilfield brine can reach 0.58 mmol/g.It is also demonstrated by adsorption kinetics and isotherms that iodide is adsorbed through chemical adsorption.Protonation of tertiary amide group in N235 and epoxy group in KH560 may be the main reason for the highly selective adsorption of iodide.展开更多
Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,C...Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,China.Using 16S rRNA Illumina high-throughput sequencing technology and several statistical methods,the bacterial diversity of the soil was studied.Subsequently,the environmental parameters were measured to analyze its relationship with the community variation.Nonmetric multidimensional scaling and analysis of similarities indicated a significant difference in the structure of the bacterial community between the nonpetroleum-contaminated surface and subsurface soils,but no differences were observed in different depths of petroleum-contaminated soil.Meanwhile,many significant correlations were obtained between diversity in soil bacterial community and physicochemical properties.Total petroleum hydrocarbon,total organic carbon,and total nitrogen were the three important factors that had the greatest impacts on the bacterial community distribution in the long-term petroleum-contaminated soils.Our research has provided references for the bacterial community distribution along a petroleum gradient in both surface and subsurface petroleum-contaminated soils of oilfield areas.展开更多
With the development of mobile technology, especially the development of 3G and mobile IP, the computational capacity of handsets is becoming more and more powerful, which provides a new method to solve the difficulti...With the development of mobile technology, especially the development of 3G and mobile IP, the computational capacity of handsets is becoming more and more powerful, which provides a new method to solve the difficulties encountered in real time GIS accessing caused by the characteristics of mobility and remoteness of fieldwork in oilfield. On the basis of studying in-depth on the technologies of J2ME platform, Mobile SVG and mobile data transfer, etc., and in accordance with the actual situation of oilfield, the design framework of oilfield mobile GIS service is put forward and the schemes of key technologies are given in this paper, which establishes the technical foundation for the construction of “Digital Oilfield”.展开更多
Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfac...Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.展开更多
1 Introduction Yanchang Formation in Upper Triassic,Ordos basin contains the most abundant hydrocarbon resources in North China(Wang et al.,2014).The sandstones are the most important oil-bearing reservoirs in
基金Supported by the National Natural Science Foundation of China (72088101)。
文摘The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle model. With the new model, the statistical correspondence between the production decline stage and the reserve-production imbalance is clarified,and the correlation of water cut with the recovery percent of recoverable reserves is discussed, providing quantitative basis of reservoir engineering for dividing development stages of oilfield and defining mature oilfields. According to the statistics of oilfields in eastern China, the time point corresponding to the reserve-production balance coefficient dropping to less than 1dramatically is well correlated the beginning point of production decline, thus the time when the reserve-production balance coefficient drops dramatically can be taken as the initiation point of production decline stage. The research results show that the water cut and the recovery percent of recoverable reserves have a good statistical match in the high water cut stage, and it is more rational to take both the start point of production decline stage and the water cut of 90%(or the recovery percent of recoverable reserves of 80%) as the critical criteria for defining a mature oilfield. Five production evolution patterns can be summarized as follows: growth–peak plateau–stepped decline, growth–stepped stabilizing–stepped decline, growth–stepped stabilizing–rapid decline, growth–peak plateau–rapid decline, and growth–continuous decline.
基金Supported by the PetroChina Science and Technology Major Project(2021DJ1806,2023ZZ15).
文摘The reservoirs in the seventh member of the Triassic Yanchang Formation (Chang 7 Member) in the Qingcheng Oilfield of the Ordos Basin are characterized by thin sandbody, tight rocks, high heterogeneity, low formation pressure coefficient, and complex geomorphology. Through the efforts in the stages of exploration, appraisal, pilot testing and development, a series of key technologies have been formed, including “sweet spot” optimization, differentiated three-dimensional well deployment, fast drilling and completion of large-cluster horizontal well, intensively-staged volume fracturing in long horizontal well, and optimization of rational production system. Furthermore, a production organization mode represented by factory-like operations on loess platform has been implemented. Application of these technologies has enabled to significantly improve the single-well production of the Qingcheng Oilfield, reduce the investment cost, and realize a large-scale and beneficial development at a full cost below $55 per barrel. In 2022, the annual production of Chang 7 shale oil in the Ordos Basin reached 221×10^(4) t, accounting for 70% of the annual shale oil production of China. The practice of development technologies in the Qingcheng Oilfield provides valuable references for efficient development of continental shale oil.
基金Supported by the National Natural Science Foundation of China(42230816)PetroChina Science and Technology Project(2021DJ1501)Tarim Oilfield Technology Project(T202112).
文摘To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, China, the main strike-slip faults in and around well FD1 in the basin were analyzed in terms of sedimentary facies, sequence stratigraphy, intraplatform shoal reservoir property, and oil and gas origins, based on drilling data. The Yingshan Formation intraplatform shoal between the main strike-slip faults is superimposed with low-order faults to form a new type of hydrocarbon play. Firstly, hydrocarbons generated from the Lower Cambrian Yuertusi Formation source rocks vertically migrated into the second member of Yingshan Formation through the main strike-slip faults, and then migrated laterally until they were accumulated. A small amount of oil from Well FD1 came from the Yuertusi Formation source rocks in the mature stage, and a large amount of gas originated from oil cracking in the ultra-deep reservoirs. Therefore, the secondary gas condensate reservoir in Well FD1 is characterized by high gas to oil ratio, dry gas (dryness coefficient being 0.970) and hybrid origin. This new type of hydrocarbon play characterized by intraplatform shoal and low-order fault suggests a prospect of continuous hydrocarbon-bearing area in Fuman Oilfield, which will expand the ultrap-deep oil and gas exploration in the oilfield.
基金supported by the Jiangsu Natural Science Foundation project(SBK2021045820)the Chongqing Natural Science Foundation general Project(cstc2021jcyj-msxmX0624)+1 种基金the Graduate Innovation Program of China University of Mining and Technology(2022WLKXJ002)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_2600).
文摘The Ordos Basin is the largest continental multi-energy mineral basin in China,which is rich in coal,oil and gas,and uranium resources.The exploitation of mineral resources is closely related to reservoir water.The chemical properties of reservoir water are very important for reservoir evaluation and are significant indicators of the sealing of reservoir oil and gas resources.Therefore,the caprock of the Chang 6 reservoir in the Yanchang Formation was evaluated.The authors tested and analyzed the chemical characteristics of water samples selected from 30 wells in the Chang 6 reservoir of Ansai Oilfield in the Ordos Basin.The results show that the Chang 6 reservoir water in Ansai Oilfield is dominated by calcium-chloride water type with a sodium chloride coefficient of generally less than 0.5.The chloride magnesium coefficients are between 33.7 and 925.5,most of which are greater than 200.The desulfurization coefficients range from 0.21 to 13.4,with an average of 2.227.The carbonate balance coefficients are mainly concentrated below 0.01,with an average of 0.008.The calcium and magnesium coefficients are between 0.08 and 0.003,with an average of 0.01.Combined with the characteristics of the four-corner layout of the reservoir water,the above results show that the graphics are basically consistent.The study indicates that the Chang 6 reservoir in Ansai Oilfield in the Ordos Basin is a favorable block for oil and gas storage with good sealing properties,great preservation conditions of oil and gas,and high pore connectivity.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA14010204).
文摘The Ordovician reservoirs in the Tahe oilfield are dominated by fractured-vuggy carbonate reservoirs, of which fault-karst reservoirs are a hot topic in recent years. Fault-karst reservoirs feature high production, large burial depth, and strong heterogeneity under the control of faulting and karstification. Based on geological, logging, and seismic data, this study classified the Ordovician fault-karst reservoirs in the Yuejin block of the Tahe oilfield into three types, namely karst-cave, dissolved-vug, and fractured types, and established the integrated identification criteria of the three types of reservoirs. This study characterized karst caves, dissolved vugs, and multi-scale faults through seismic wave impedance inversion and frequency-domain detection of multi-scale faults. 3D geological models of different types of reservoirs were built using the combined deterministic and stochastic methods and characterized the spatial distribution of multi-scale faults, karst caves, dissolved vugs, and physical property parameters of reservoir. This study established the method for the geological modeling of fault-karst reservoirs, achieved the quantitative characterization and revealed the heterogeneity of fault-karst reservoirs. The karst-cave and dissolved-vug types are high in porosity and act as reservoirs, while the fractured type is high in permeability and act as flow pathway. This study lays the foundation for the development index prediction, well emplacement, and efficient development of the fault-karst carbonate reservoirs.
文摘About 88. 1% of the proven reserves in the Tahe Oilfield in the Tarim Basin of Northwest China are trapped in Ordovician carbonate reservoirs. These reservoirs are formed by unconnected and interconnected networks of karstic porosity forming a heterogeneous and complex reservoir system. Oil, water and gas characteristics vary significantly in different portions of the Ordovician reservoir. There is no uniform oil/water contact in the field, adding to its complexity.An acid fracture treatment is beneficial in 76% of the wells, stimulating nonproductive wells and enhancing production in other wells by fracturing into unconnected reservoirs and enhancing flow pathways with acid. Acid fracture treatments should be a standard procedure for developing this and similar oil fields.
基金National Iranian Oil Company-Exploration Directorate(NIOC-EXP)the Petroleum Geology and Geochemistry Research Center(PGGRC)of Shahid Chamran University of Ahvaz.
文摘A collection of data obtained from analytical methods in geochemistry along with the reservoir engineering and geologic data were used to investigate the reservoir continuity in the Cretaceous Fahliyan, Gadavan, Kazhdumi and Sarvak reservoirs of the super-giant Azadegan oilfield, SW Iran. The geochemical data indicate that the oil samples, with medium to high level of thermal maturity, have been generated from the anoxic marine marl/carbonate source rock(s). The Sargelu(Jurassic) and Garau(Cretaceous) formations are introduced as the main source rocks for the studied oils. The dendrogram obtained from the cluster analysis of high-resolution gas chromatography data introduces two main oil groups including Fahliyan reservoir, and Kazhdumi along with Sarvak/Gadvan reservoirs. This is confirmed by C7 Halpern star diagram, indicating that, the light oil fraction from Fahliyan reservoir is distinct from the others. Also, different pressure gradient of the Fahliyan Formation(over-pressured) relative to other reservoirs(normally-pressured) show the presence of compartments. The relation between toluene/n-heptane and n-heptane/methylcyclohexane represents the compartmentalization due to maturation/evaporative fractionation for Fahliyan and water washing for other studied reservoirs. Also, the impermeable upper part of the Fahliyan Formation and thin interbedded shaly layers in the Kazhdumi, Sarvak and Gadvan formations have controlled reservoir compartmentalization.
基金financially supported by the Exploration Directorate of the National Iranian Oil Company
文摘Located in Iranian sector of the Persian Gulf, Foroozan Oilfield has been producing hydrocarbons via seven different reservoirs since the 1970 s. However, understanding fluid interactions and horizontal continuity within each reservoir has proved complicated in this field. This study aims to determine the degree of intra-reservoir compartmentalization using gas geochemistry, light hydrocarbon components, and petroleum bulk properties, comparing the results with those obtained from reservoir engineering indicators. For this purpose, a total of 11 samples of oil and associated gas taken from different producing wells in from the Yammama Reservoir were selected. Clear distinctions, in terms of gas isotopic signature and composition, between the wells located in northern and southern parts of the reservoir(i.e. lighter δ13 C1, lower methane concentration, and negative sulfur isotope in the southern part) and light hydrocarbon ratios(e.g. nC 7/toluene, 2,6-dmC7/1,1,3-tmcyC5 and m-xylene/4-mC8) in different oil samples indicated two separate compartments. Gradual variations in a number of petroleum bulk properties(API gravity, V/Ni ratios and asphaltene concentration) provided additional evidence on the reservoir-filling direction, signifying that a horizontal equilibrium between reservoir fluids across the Yammama Reservoir is yet to be achieved. Finally, differences in water-oil contacts and reservoir types further confirmed the compartmentalization of the reservoir into two separate compartments.
文摘The geochemical characteristics of crude oils from Zao\|Ⅴ oil measures in the Shenjiapu oilfield are systematically described in terms of the fractional composition of crude oils, GC characteristics of saturated hydrocarbon fraction of crude oils and the characteristics of their biomarkers. The depositional environment, type and evolution of the biological source are also discussed. All pieces of evidence such as low saturated hydrocarbon fraction, high resin and asphalt, high isoprenoid alkane, weak odd\|carbon number predominance (CPI ranging from \{1.23\} to \{1.29\}, OEP ranging from \{1.14\} to \{1.16\}) and low sterane and terpane maturity parameters show these crude oils are immature oils. Low Pr/Ph ratios (\{0.66\}-\{0.88\}) and high gammacerance/C\-\{31\} hopane ratios (\{0.59\}-\{0.86\}) indicate the source rocks were formed in a slightly saline to brackish reducing lake depositional environment. Gas chromatographic characteristics of the saturated hydrocarbon fraction and the predominance of C\-\{30\} hopane in terpane series and C\-\{29\} sterane in sterane series indicate the biological source of the crude oils is composed mainly of bacterial and algal organic matter, and some algae are perhaps the main contributor of organic matter to the source rocks.
基金financially supported by the Chinese National Special Plan Project"Formation conditions,enrichment regularity and resource potential of tight oil”(No.2016ZX05046-001)。
文摘Xin’anbian Oilfield of the Ordos Basin is the large tight oilfield to be first exploration discovery in china.The production of tight oil increased significantly in recent years.It shows great exploration potential of Chang 7 tight oil.But the physical property and hydrocarbon enrichment characteristics of Chang 7 tight oil reservoirs were rarely studied,The forming conditions of tight oil reservoirs are systematically summarized and analyzed through the study of hydrocarbon generation,sedimentary reservoirs and hydrocarbon migration and accumulation based on production and core experimental data.The result shows that,The porosity of the Chang 7_(2)reservoir mainly distributed in 5.0-11.0%,average at 7.9%,The permeability mainly distributed in 0.04-0.18×10^(-3)μm^(2),average at 0.12×10^(-3)μm^(2),The pore diameters of the tight oil reservoir distributed in 2-8μm.The high-quality Chang 7_(3)source rocks and the micropsammite of Chang 7_(2)subaqueous distributary channel were widely distributed in the study area.The lenticular or banded sand bodies are distributed among mudstone or hydrocarbon source rocks and have the advantage of migration distance for hydrocarbon accumulation.The reservoir space is composed of micro-nanometer pores and throat,that is formed in the process of increasing pressure during hydrocarbon generation and hydrocarbon accumulation.The Chang 7 tight oil was generated in the early Cretaceous and injected into the sand of the subaqueous distributary channel driven by continuous hydrocarbon generation supercharging.The formation and accumulation of tight oil reservoirs are mainly controlled by source rocks,sedimentary microfacies and reservoirs of good quality.
文摘The major steps of oilfield development are given in this paper. The optimal model of oilfield development is built and the methods of optimum decision analysis are studied. The solution and analysis of the optimal tactics have been set up according to the data collected in the oilfield.
基金supported by Geological survey project (Project Number: 12120113078500)
文摘China is lack of bromine and potassium seriously.Oilfield brines is the headline goal of bromine and potassium resources exploration.Applicants grab 24oilfield brines samples from various wells of
基金supported by grants from the contract of China Petrochemical Corporation (3020001914-ZC0607-0013)the National Natural Science Foundation of China (20107073)+1 种基金the Guangdong Science and Technology Project (2014B030301030)the Innovative Research Team in University (No.IRT13078)
文摘Advanced analytical methodology based on comprehensive two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOFMS) is proposed for investigation of organic chlorides in different oilfield chemicals.The target screening was initially carried out on 8 suspected organic chlorides by evaluating the capability of the enhanced separation and reliable identification at a trace concentration. GC×GC-TOFMS allowed for the fast and automated analysis of organic chlorides at a level of 200 μg/L. This method was subsequently applied for non-target screening of organic chlorides in different oilfield chemicals at various locations across China. 22 organic chlorides were identified and verified by comparison with pure standards in the mixed sample. Finally, this method was used to determine the content of the organic chlorides in individual samples. The result showed that the organic chloride levels in 19 of the 39 tested oilfield chemicals were above the threshold limit of 1.0 mg/L.
基金hispaperissupportedbytheNaturalScienceResearchCouncilofChi na (underChina 973NationalKeyResearchandDevelopmentProgram #G1 999 4331 0 ) .
文摘Petroleum migration process of Bamianhe oilfield of Dongying depression, East China is evaluatedon the basis of our detailed work on geochemistry of the crude oil and the source. Molecular tracers, especially nitrogen compounds, are employed in assessing style of oil migration and accumulation. Additionally, absolute quantitative results of heteroaromatics including dibenzofuran, dibenzothiophene and fluorene with similar basic frames to pyrrolic nitrogenic compounds are also used to evaluate the quantity of petroleum migration. According to apparent migration effects of the pyrrolic nitrogen compounds, it is indicated that most of Bamianhe oil was derived from potential source kitchen-Niu-zhuang sag, migrated and accumulated at Bamianhe fault belt through selective paths according to a main filling point displayed. Generally, upward migration trend from the main point along the south slope is noted. There are observable migration effects from Guangli subsag to the north Bamianhe and Yangjiaogou oilfields showing Guangli subsag was a secondary kitchen accounting for the oils in the north portion. Significant vertical migration effects shown in several cross sections demonstrate that faults well developed in the area play an important role in oil migration and accumulation. Unformality, sandstone reservoirs distributed locally also suggest important fairways in connecting sources with traps. The tectonic and a combination of tectonic and lithological mechanism are identified as the critical mechanisms in entrapping hydrocarbons. Migration trend suggested by nitrogenic compounds agrees well with analysis of lateral compositional variety and thermal maturity gradient. This study also confirms well with our previous studies. It is the location of source rocks, tectonic and stratigraphic characteristics that have a comprehensive control on the model of hydrocarbon migration and accumulation in Bamianhe oilfield. Results also show that the oils are mostly derived from the deep parts of the Niuzhuang and Guangli sags within normal oil window.
基金Funded by the Joint Funds of the National Natural Science Foundation of China(U20A20150)the Foundation of Qinghai Provincial Science and Technology Project,China(2019-ZJ-901)the Thousand Talents Plan of Qinghai Province and the Youth Innovative Talents Project of Department of Education of Guangdong Province(2021KQNCX026)。
文摘Owing to porous structure,stable chemical properties,low cost and available raw material,biomass carbon aerogel is a promising adsorbent framework material.Herein,a pomelo peel-based carbon aerogel was prepared by hydrothermal-freeze drying-high temperature carbonization method and modified with Tri-n-ocylamine(N235)and γ-Glycidyloxypropyltrimethoxysilane(KH560)via impregnation process.The as-prepared adsorbents exhibit superior adsorption performance for iodide in simulated and oilfield brines,and the highest adsorption amount of iodide in oilfield brine can reach 0.58 mmol/g.It is also demonstrated by adsorption kinetics and isotherms that iodide is adsorbed through chemical adsorption.Protonation of tertiary amide group in N235 and epoxy group in KH560 may be the main reason for the highly selective adsorption of iodide.
基金supported by the Major Research Plan of Tianjin (No.16YFXTSF00460)the National Natural Science Foundation of China (No.21878220)
文摘Diversity in bacterial communities was investigated along a petroleum hydrocarbon content gradient(0-0.4043 g/g)in surface(5-10 cm)and subsurface(35-40 cm)petroleum-contaminated soil samples from the Dagang Oilfield,China.Using 16S rRNA Illumina high-throughput sequencing technology and several statistical methods,the bacterial diversity of the soil was studied.Subsequently,the environmental parameters were measured to analyze its relationship with the community variation.Nonmetric multidimensional scaling and analysis of similarities indicated a significant difference in the structure of the bacterial community between the nonpetroleum-contaminated surface and subsurface soils,but no differences were observed in different depths of petroleum-contaminated soil.Meanwhile,many significant correlations were obtained between diversity in soil bacterial community and physicochemical properties.Total petroleum hydrocarbon,total organic carbon,and total nitrogen were the three important factors that had the greatest impacts on the bacterial community distribution in the long-term petroleum-contaminated soils.Our research has provided references for the bacterial community distribution along a petroleum gradient in both surface and subsurface petroleum-contaminated soils of oilfield areas.
文摘With the development of mobile technology, especially the development of 3G and mobile IP, the computational capacity of handsets is becoming more and more powerful, which provides a new method to solve the difficulties encountered in real time GIS accessing caused by the characteristics of mobility and remoteness of fieldwork in oilfield. On the basis of studying in-depth on the technologies of J2ME platform, Mobile SVG and mobile data transfer, etc., and in accordance with the actual situation of oilfield, the design framework of oilfield mobile GIS service is put forward and the schemes of key technologies are given in this paper, which establishes the technical foundation for the construction of “Digital Oilfield”.
基金Supported by the National Natural Science Foundation of China(41772101)China National Science and Technology Major Project(2017ZX05009001-002)
文摘Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.
基金financially supported by the National Natural Science Foundation of China (grant No. 41272115)
文摘1 Introduction Yanchang Formation in Upper Triassic,Ordos basin contains the most abundant hydrocarbon resources in North China(Wang et al.,2014).The sandstones are the most important oil-bearing reservoirs in
