The Benin and Western Nigeria Offshore Basins, which are parts of an extensive basin called the Dahomey (Benin) Embayment, were formed during the Early Cretaceous under similar tectonic conditions and continental sedi...The Benin and Western Nigeria Offshore Basins, which are parts of an extensive basin called the Dahomey (Benin) Embayment, were formed during the Early Cretaceous under similar tectonic conditions and continental sedimentary environments. Based mainly on available lithological, biostratigraphic and paleoenvironmental data, this paper summarizes the stratigraphic succession of theses basins and attempts a comparison of these stratigraphic nomenclatures. The bulk of data shows that sedimentation begins with terrestrial at the base, passes through shallow marine, deep marine (with restrictive bottom circulation) and ends with open deep marine conditions. The stratigraphy of the Offshore Benin Basin was established later and considering lithological and paleontological similarities with formations of various southern Nigeria basins, the stratigraphic chart adopted for this basin was a mixed variant of various Southern Nigerian basins nomenclatures. For the first time, a correlation of stratigraphic charts of each basins and a schematic cross section showing their lithostratigraphic units, especially the Cretaceous-Paleocene interval which is petroliferous, are proposed. The study shows that the nomenclature adopted in Benin Republic must be revised by using type section/locality names for some particular Formations and widely accepted Formations names of Nigeria for the others. This will permit to avoid confusions as it is presently the case for the name “Afowo Formation” representing a Cretaceous sequence in Nigeria and which is use in Benin Republic to distinguish some sediments of Miocene age. Moreover, a High Resolution Biostratigraphy summary (including micropaleontology, nannopaleontology and palynology distributions) relating to each offshore basin is needed for sequences correlations and entire harmonization of the stratigraphic nomenclature of these offshore basins.展开更多
Sea area is an important area of oil and gas exploration in China.It has been found that China's sea area mainly consists of coal type oil and gas,and the exploration of coal-bearing series source rocks has become...Sea area is an important area of oil and gas exploration in China.It has been found that China's sea area mainly consists of coal type oil and gas,and the exploration of coal-bearing series source rocks has become an important part of oil and gas exploration there.Through years of comprehensive geological research in China's sea area,it has been revealed that it has undergone multiple occurrences of tectonic opening and closing movements in varying degrees in the Paleogene,forming 26 Cenozoic sedimentary basins of various types,such as active continental margin,passive continental margin,transitional continental margin and drift rift basins.In the present study,it is observed for the first time that coal type source rocks are mainly developed in 14 continental margin basins in China's sea area,revealing that a very large C-shaped coal-bearing basin group developed there in the Cenozoic.Next,based on the coupling analysis of paleoclimate,paleobotany,paleogeography and paleostructure,it is observed that there are five coal-forming periods in China's sea area,namely the Paleocene,Eocene,early Oligocene,late Oligocene and Miocene-Pliocene,and the coal-forming age is gradually new from north to south.It is also found that the coal seams in the sea area are mainly developed in three coal-forming environments in Cenozoic,namely delta,fan delta and tidal flat-lagoon.The coal seams developed in different environments are characterized by thin thickness,many layers and poor stability.However,the coal-bearing series source rocks in China's sea area have a wide distribution range,very high thickness and large amount,thus forming a material basis for the formation of rich coal type oil and gas.展开更多
In this study, we apply geochemical and statistical analyses to evaluate the source rocks and kerogen type of Cretaceous sediments from the Cote d’Ivoire sedimentary basin. The geochemical analysis includes pyrolysis...In this study, we apply geochemical and statistical analyses to evaluate the source rocks and kerogen type of Cretaceous sediments from the Cote d’Ivoire sedimentary basin. The geochemical analysis includes pyrolysis data such as total organic carbon (TOC%), generation source potential (S2) and hydrogen index (HI). The results of the cluster analysis separated the source rocks in the study area into two main groups. 1) Source rocks characterized by HI > 300 (mg/g), TOC from 1.76% to 3.19% by weight, and S2 from 6.55 to 14.46 (mg/g), indicating good to excellent source rocks with type II kerogen and are capable of generating oil. 2) Source rocks characterized by HI between 200 and 300 (mg/g), TOC from 1.6 to 2.02 wt%, and S2 from 3.45 to 5.36 (mg/g) indicating medium to good source rocks with type II-III kerogen and capable of generating a mixture of oil and gas.展开更多
The tests performed with two hundred and thirty-nine (239) samples from the A-X and B-X drillings help to know their sedimentological and chemostratigraphic characters. In sedimentological term formations are composed...The tests performed with two hundred and thirty-nine (239) samples from the A-X and B-X drillings help to know their sedimentological and chemostratigraphic characters. In sedimentological term formations are composed of sand, sandstone, limestone, siltstone and argillite that alternate along the drill. In chemostratigraphic term two megasequences (MS1 and MS2) have been identified. A correlation of chemostratigraphic data completed by the lithology results allowed a subdivision of oil wells that shows two main types of deposits environments. First, a proximal marine environment to continental and to Albian marked by a detrital flow deducted from the concentrations evolution of indicator elements of terrigenous material that are K, Mg, and Rb. On the other hand, a deep to shallow marine environment of Cenomanian to Paleocene marked by the presence of predominantly clay sediments and abundant glauconite in the lower Senonian. Nevertheless, there is a transition or intermediate environment that is characterized by the presence of glauconite and detrital flows.展开更多
Based on the study of natural gas resource, low buried hill trap formation mechanism, high quality reservoir control factors and natural gas preservation conditions, the formation conditions and reservoir accumulation...Based on the study of natural gas resource, low buried hill trap formation mechanism, high quality reservoir control factors and natural gas preservation conditions, the formation conditions and reservoir accumulation characteristics of Bozhong 19-6 large condensate gas field were summarized. Large gas generation potential of multiple sets of thick humic-sapropelic source rocks in high maturity stage in Bozhong depression was the basis of large gas field formation. The multi-stage tectonic evolution since Indosinian period formed large-scale buried hill traps. The Tanlu fault activity formed multi-type reservoirs, and buried hill metamorphic rock of Archean and sand-conglomerate of Kongdian Formation were high-quality reservoirs. Thick overpressure lacustrine mudstone and weak neotectonic movement provided good preservation conditions. Bozhong 19-6 gas reservoir was a condensate gas reservoir with very high condensate oil content, and the gas origin was humic-sapropelic and kerogen-cracking gas, and the gas field had large gas thickness, high gas column characteristics and the accumulation process was first oil and then gas. The buried hill reservoir was a massive reservoir and the Kongdian reservoir was a stratified reservoir. The gas field had multi-channel hydrocarbon intense charge from overpressure source rocks, atmospheric-weak overpressure reservoir favorable for accumulation, thick overpressure mudstone caprock favorable for preservation, and natural gas ultra-late rapid accumulation model.展开更多
Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seis...Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.展开更多
Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity ...Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity level tools and the empirical parameters pose challenges due to the strong nonlinear coupling effects of FOWTs.A novel method,named SADA,was proposed by Chen and Hu(2021)for optimizing the design and dynamic performance prediction of FOWTs in combination with AI technology.In the SADA method,the concept of Key Disciplinary Parameters(KDPs)is also proposed,and it is of crucial importance in the SADA method.The purpose of this paper is to make an in-depth investigation of the characters of KDPs and the internal correlations between different KDPs in the dynamic performance prediction of FOWTs.Firstly,a brief description of SADA is given,and the basin experimental data are used to conduct the training process of SADA.Secondly,categories and boundary conditions of KDPs are introduced.Three types of KDPs are given,and different boundary conditions are used to analyze KDPs.The results show that the wind and current in Environmental KDPs are strongly correlated with the percentage difference of dynamic response rather than that by wave parameters.In general,the optimization results of SADA consider the specific basin environment and the coupling results between different KDPs help the designers further understand the factors that have a more significant impact on the FOWTs system in a specific domain.展开更多
The current status of the China's software industry is introduced, including the great potential opportunities and many problems across the path to success. The main measures are discussed to keep abreast of the...The current status of the China's software industry is introduced, including the great potential opportunities and many problems across the path to success. The main measures are discussed to keep abreast of the time needs and fuse with the whole family of global IT industry.展开更多
Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in re...Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in relation to structural styles, sedimentation and hydrocarbon potential evolved in Block 5. Results show that during Early to Late Jurassic, Block 5 was affected by the break-up of Gondwana and the drifting of Madagascar as evidenced by patterns of sediments and structural features. The chaotic and discontinuous reflectors are characteristics features on the sediments pattern indicating a possible transitional setting following the breakup of Gondwana. From the Late Cretaceous, Block 5 sits in more stable subsiding sag as the consequence of the high thermal subsidence. The period displayed continuous parallel reflectors with few markable faults. This was followed by the late post rift sedimentation that occurred after Middle Eocene Unconformity characterized by high wavy and sub parallel reflectors. The evolution of Block 5 through major tectonic events reveals a more complete petroleum system towards the south. Thus, Block 5 responded in both space and time to a complex interplay between tectonics and sedimentation. This indicates that structural styles and associated features are potential control for hydrocarbon generation and migration.展开更多
The anticline is large in size and gentle.an individual structure covers an area up to 100-300.km*.At top of mudcone little tensional faults are often associated.The mudcones themselves are either possible source rock...The anticline is large in size and gentle.an individual structure covers an area up to 100-300.km*.At top of mudcone little tensional faults are often associated.The mudcones themselves are either possible source rock bodies or hydrocarbon-draining.pressure-releasing paths.Natural gas migrated upwards along mudcone diapir zone and faults.and accumulated in the upper structural.traps.The already drilled Dongfang 1-1 and Ledong 15-1 Structures are identified to bre gas-bearing structures.Some structures similar to them.such as Cangjiang 29-1.Ledong 8-3 and Ledong 16-1 Structures.are today's exploration targets.Most of this type of traps contain gas.But three aspects still need to be studied in future:firstly.overpressure and high-temperature result in difficulties of drilling engineering:secondly,reservoirs do not develop very well or are not high-quality:thirdly.there is non-hydrocarbon gas such as CO2 to be.associated with.so the fluid properties are more complicated.展开更多
文摘The Benin and Western Nigeria Offshore Basins, which are parts of an extensive basin called the Dahomey (Benin) Embayment, were formed during the Early Cretaceous under similar tectonic conditions and continental sedimentary environments. Based mainly on available lithological, biostratigraphic and paleoenvironmental data, this paper summarizes the stratigraphic succession of theses basins and attempts a comparison of these stratigraphic nomenclatures. The bulk of data shows that sedimentation begins with terrestrial at the base, passes through shallow marine, deep marine (with restrictive bottom circulation) and ends with open deep marine conditions. The stratigraphy of the Offshore Benin Basin was established later and considering lithological and paleontological similarities with formations of various southern Nigeria basins, the stratigraphic chart adopted for this basin was a mixed variant of various Southern Nigerian basins nomenclatures. For the first time, a correlation of stratigraphic charts of each basins and a schematic cross section showing their lithostratigraphic units, especially the Cretaceous-Paleocene interval which is petroliferous, are proposed. The study shows that the nomenclature adopted in Benin Republic must be revised by using type section/locality names for some particular Formations and widely accepted Formations names of Nigeria for the others. This will permit to avoid confusions as it is presently the case for the name “Afowo Formation” representing a Cretaceous sequence in Nigeria and which is use in Benin Republic to distinguish some sediments of Miocene age. Moreover, a High Resolution Biostratigraphy summary (including micropaleontology, nannopaleontology and palynology distributions) relating to each offshore basin is needed for sequences correlations and entire harmonization of the stratigraphic nomenclature of these offshore basins.
基金The Ministry of Land and Resources Project of Oil and Gas Resource Investigation and Evaluation under contract Nos XQ-2004-05 and XQ-2007-05the National Key Basic Research Program of China(973 Program)under contract No.2009CB219400+3 种基金the National Science and Technology Major Project under contract Nos 2008ZX05025,2011ZX05025 and2016ZX05026the National Natural Science Foundation under contract Nos 41872172 and 42072188the Research and Innovation Team Support Program of Shandong University of Science and Technology under contract No.2018TDJH101Hebei Provincial Resources Survey and Research Laboratory Open Foundation。
文摘Sea area is an important area of oil and gas exploration in China.It has been found that China's sea area mainly consists of coal type oil and gas,and the exploration of coal-bearing series source rocks has become an important part of oil and gas exploration there.Through years of comprehensive geological research in China's sea area,it has been revealed that it has undergone multiple occurrences of tectonic opening and closing movements in varying degrees in the Paleogene,forming 26 Cenozoic sedimentary basins of various types,such as active continental margin,passive continental margin,transitional continental margin and drift rift basins.In the present study,it is observed for the first time that coal type source rocks are mainly developed in 14 continental margin basins in China's sea area,revealing that a very large C-shaped coal-bearing basin group developed there in the Cenozoic.Next,based on the coupling analysis of paleoclimate,paleobotany,paleogeography and paleostructure,it is observed that there are five coal-forming periods in China's sea area,namely the Paleocene,Eocene,early Oligocene,late Oligocene and Miocene-Pliocene,and the coal-forming age is gradually new from north to south.It is also found that the coal seams in the sea area are mainly developed in three coal-forming environments in Cenozoic,namely delta,fan delta and tidal flat-lagoon.The coal seams developed in different environments are characterized by thin thickness,many layers and poor stability.However,the coal-bearing series source rocks in China's sea area have a wide distribution range,very high thickness and large amount,thus forming a material basis for the formation of rich coal type oil and gas.
文摘In this study, we apply geochemical and statistical analyses to evaluate the source rocks and kerogen type of Cretaceous sediments from the Cote d’Ivoire sedimentary basin. The geochemical analysis includes pyrolysis data such as total organic carbon (TOC%), generation source potential (S2) and hydrogen index (HI). The results of the cluster analysis separated the source rocks in the study area into two main groups. 1) Source rocks characterized by HI > 300 (mg/g), TOC from 1.76% to 3.19% by weight, and S2 from 6.55 to 14.46 (mg/g), indicating good to excellent source rocks with type II kerogen and are capable of generating oil. 2) Source rocks characterized by HI between 200 and 300 (mg/g), TOC from 1.6 to 2.02 wt%, and S2 from 3.45 to 5.36 (mg/g) indicating medium to good source rocks with type II-III kerogen and capable of generating a mixture of oil and gas.
文摘The tests performed with two hundred and thirty-nine (239) samples from the A-X and B-X drillings help to know their sedimentological and chemostratigraphic characters. In sedimentological term formations are composed of sand, sandstone, limestone, siltstone and argillite that alternate along the drill. In chemostratigraphic term two megasequences (MS1 and MS2) have been identified. A correlation of chemostratigraphic data completed by the lithology results allowed a subdivision of oil wells that shows two main types of deposits environments. First, a proximal marine environment to continental and to Albian marked by a detrital flow deducted from the concentrations evolution of indicator elements of terrigenous material that are K, Mg, and Rb. On the other hand, a deep to shallow marine environment of Cenomanian to Paleocene marked by the presence of predominantly clay sediments and abundant glauconite in the lower Senonian. Nevertheless, there is a transition or intermediate environment that is characterized by the presence of glauconite and detrital flows.
基金Supported by the China National Science and Technology Major Project(2016ZX05024-003-001)
文摘Based on the study of natural gas resource, low buried hill trap formation mechanism, high quality reservoir control factors and natural gas preservation conditions, the formation conditions and reservoir accumulation characteristics of Bozhong 19-6 large condensate gas field were summarized. Large gas generation potential of multiple sets of thick humic-sapropelic source rocks in high maturity stage in Bozhong depression was the basis of large gas field formation. The multi-stage tectonic evolution since Indosinian period formed large-scale buried hill traps. The Tanlu fault activity formed multi-type reservoirs, and buried hill metamorphic rock of Archean and sand-conglomerate of Kongdian Formation were high-quality reservoirs. Thick overpressure lacustrine mudstone and weak neotectonic movement provided good preservation conditions. Bozhong 19-6 gas reservoir was a condensate gas reservoir with very high condensate oil content, and the gas origin was humic-sapropelic and kerogen-cracking gas, and the gas field had large gas thickness, high gas column characteristics and the accumulation process was first oil and then gas. The buried hill reservoir was a massive reservoir and the Kongdian reservoir was a stratified reservoir. The gas field had multi-channel hydrocarbon intense charge from overpressure source rocks, atmospheric-weak overpressure reservoir favorable for accumulation, thick overpressure mudstone caprock favorable for preservation, and natural gas ultra-late rapid accumulation model.
基金This work was financially supported by National Natural Science Foundation of China(91858208,41406080,42076069)China Geological Survey(DD20190581).
文摘Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.
文摘Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity level tools and the empirical parameters pose challenges due to the strong nonlinear coupling effects of FOWTs.A novel method,named SADA,was proposed by Chen and Hu(2021)for optimizing the design and dynamic performance prediction of FOWTs in combination with AI technology.In the SADA method,the concept of Key Disciplinary Parameters(KDPs)is also proposed,and it is of crucial importance in the SADA method.The purpose of this paper is to make an in-depth investigation of the characters of KDPs and the internal correlations between different KDPs in the dynamic performance prediction of FOWTs.Firstly,a brief description of SADA is given,and the basin experimental data are used to conduct the training process of SADA.Secondly,categories and boundary conditions of KDPs are introduced.Three types of KDPs are given,and different boundary conditions are used to analyze KDPs.The results show that the wind and current in Environmental KDPs are strongly correlated with the percentage difference of dynamic response rather than that by wave parameters.In general,the optimization results of SADA consider the specific basin environment and the coupling results between different KDPs help the designers further understand the factors that have a more significant impact on the FOWTs system in a specific domain.
文摘The current status of the China's software industry is introduced, including the great potential opportunities and many problems across the path to success. The main measures are discussed to keep abreast of the time needs and fuse with the whole family of global IT industry.
文摘Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in relation to structural styles, sedimentation and hydrocarbon potential evolved in Block 5. Results show that during Early to Late Jurassic, Block 5 was affected by the break-up of Gondwana and the drifting of Madagascar as evidenced by patterns of sediments and structural features. The chaotic and discontinuous reflectors are characteristics features on the sediments pattern indicating a possible transitional setting following the breakup of Gondwana. From the Late Cretaceous, Block 5 sits in more stable subsiding sag as the consequence of the high thermal subsidence. The period displayed continuous parallel reflectors with few markable faults. This was followed by the late post rift sedimentation that occurred after Middle Eocene Unconformity characterized by high wavy and sub parallel reflectors. The evolution of Block 5 through major tectonic events reveals a more complete petroleum system towards the south. Thus, Block 5 responded in both space and time to a complex interplay between tectonics and sedimentation. This indicates that structural styles and associated features are potential control for hydrocarbon generation and migration.
文摘The anticline is large in size and gentle.an individual structure covers an area up to 100-300.km*.At top of mudcone little tensional faults are often associated.The mudcones themselves are either possible source rock bodies or hydrocarbon-draining.pressure-releasing paths.Natural gas migrated upwards along mudcone diapir zone and faults.and accumulated in the upper structural.traps.The already drilled Dongfang 1-1 and Ledong 15-1 Structures are identified to bre gas-bearing structures.Some structures similar to them.such as Cangjiang 29-1.Ledong 8-3 and Ledong 16-1 Structures.are today's exploration targets.Most of this type of traps contain gas.But three aspects still need to be studied in future:firstly.overpressure and high-temperature result in difficulties of drilling engineering:secondly,reservoirs do not develop very well or are not high-quality:thirdly.there is non-hydrocarbon gas such as CO2 to be.associated with.so the fluid properties are more complicated.