In view of the problem that a single modeling method cannot predict the distribution of microfacies, a new idea of coupling modeling method to comprehensively predict the distribution of sedimentary microfacies was pr...In view of the problem that a single modeling method cannot predict the distribution of microfacies, a new idea of coupling modeling method to comprehensively predict the distribution of sedimentary microfacies was proposed, breaking the tradition that different sedimentary microfacies used the same modeling method in the past. Because different sedimentary microfacies have different distribution characteristics and geometric shapes, it is more accurate to select different simulation methods for prediction. In this paper, the coupling modeling method was to establish the distribution of sedimentary microfacies with simple geometry through the point indicating process simulation, and then predict the microfacies with complex spatial distribution through the sequential indicator simulation method. Taking the DC block of Bohai basin as an example, a high-precision reservoir sedimentary microfacies model was established by the above coupling modeling method, and the model verification results showed that the sedimentary microfacies model had a high consistency with the underground. The coupling microfacies modeling method had higher accuracy and reliability than the traditional modeling method, which provided a new idea for the prediction of sedimentary microfacies.展开更多
In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron ...In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron microscopy. The main sedimentary microfacies of Chang 2<sub>1</sub><sup>3</sup> is braided river delta sedimentary system in geological history, and there are three main sedimentary microfacies types: swamp microfacies, distributary channel microfacies and natural embankment microfacies on land. The heterogeneity in the study area is as follows: Chang 2<sub>1</sub><sup>2</sup> formation has the strongest heterogeneity, followed by Chang 2<sub>1</sub><sup>1</sup> formation with strong heterogeneity, and finally Chang 2<sub>1</sub><sup>3</sup> formation with medium heterogeneity. The reservoirs of Chang 2 member in the study area are dominated by III<sub>a</sub>, II<sub>b</sub> and III<sub>b</sub>, and the reservoirs are mainly composed of ultra-low porosity and low permeability reservoirs and low porosity and low permeability reservoirs.展开更多
Based on comprehensive analysis of core,cast thin section,logging and seismic data,the sedimentary and reservoir architectures of the MB 1-2 sub-member of Mishrif Formation in Halfaya Oilfield,Iraq,are studied.The MB ...Based on comprehensive analysis of core,cast thin section,logging and seismic data,the sedimentary and reservoir architectures of the MB 1-2 sub-member of Mishrif Formation in Halfaya Oilfield,Iraq,are studied.The MB 1-2 sub-member of Mishrif Formation has three types of microfacies,lagoon,bioclastic shoal,and tidal channel,and facies architecture controlled by sequence stratigraphy.In the 4th-order sequence,the lagoon facies aggradated vertically,and the bioclastic shoals in lenticular shape embed in the background of lagoon,the end of the sequence is incised by the"meandering river"shape tide channel,which represents the depositional discontinuity.Three types of reservoirs including tidal channel grainstone to packstone reservoirs,bioclastic shoal grainstone to packstone reservoirs and dissolved lagoon wackestone reservoirs are developed.The reservoir architectures within tidal channel and bioclastic shoal are strickly controlled by grainy facies,whereas the dissolved lagoon reservoirs controlled by both facies and dissolution are related to the sequence boundary.The reservoir sections occur mainly in the 4 th sequence highstand systems tract(HST)and are separated by barriers formed in the transgressive systems tract(TST).Complicated facies architecture and dissolution modification resulted in strong heterogeneity within the reservoir,which showed the characteristics of"attic type"architecture.The results of this study can guide the development of similar reservoirs in the Middle East.展开更多
Based on the analysis of a large number of core samples, logging results, logging interpretation data and dynamic data in the study area, the characteristics of Chang 6 reservoir in Zhouguan area of Baihe area are stu...Based on the analysis of a large number of core samples, logging results, logging interpretation data and dynamic data in the study area, the characteristics of Chang 6 reservoir in Zhouguan area of Baihe area are studied, and the favorable reservoir areas in the study area are predicted. The results show that the lithology of Chang 6 reservoir is mainly light gray and gray fine-grained to very fine-grained feldspar lithic sandstone. The pore types are mainly residual intergranular pores and feldspar dissolved pores, including debris dissolved pores and microfractures. The porosity and permeability values are low, which belongs to low porosity-low permeability and ultra-low permeability reservoirs. According to the reservoir distribution characteristics and related data, the Chang 6 reservoir in the study area is divided into two types, mainly Class II and Class III reservoirs. The comprehensive evaluation predicts that the spatial distribution of the favorable area of Chang 6 reservoir is not uniform, but the distribution area is large, which has broad exploration and development value, and provides the necessary conditions for the distribution study of the favorable oil-bearing zone in this area and the preparation for the next exploration and development.展开更多
The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and marl...The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and marl.In this study,we conducted an integrated micropaleontological,sedimentological,mineralogical,and geochemical investigation to determine the depositional setting,biochronology,provenance,and paleoclimate of the KF.The study identified six lithofacies and six microfacies,which indicate a variety of environments ranging from floodplains and channels to the margins and shallow marine settings.The nannofossil biostratigraphy places the KF in the Early Eocene,more precisely the NP10 zone(Ypresian),and the fossil zone of benthic foraminifera classifies the study section as the Shallow Benthic Zone SBZ-8(Middle Ilerdian 2).In terms of petrography,the KF sandstone was classified as litharenite and feldspathic litharenite,while the QtFL diagram suggests a recycled orogen.Geochemical proxies indicate an oxidizing environment,a high-to-low regular sedimentation rate,moderate-to-intense chemical weathering in the source region,and a warm-humid to dry climate during the deposition of KF.Overall,the findings suggest that the deposition of KF marks the end of Neo-Tethys due to the Early Eocene Indian–Kohistan collision and that the uplifting of the Himalayas provided the source for the deposition of KF in the foreland basin.The study provides new insights into the depositional environment,biochronology,provenance,and paleoclimate of KF,and highlights the potential for red beds as reliable indicators of oxygenation levels in proximity to mineral deposits.展开更多
The Ma5_(1-4)submembers of Jingbian gas field in Ordos basin of China belongs to epeiric sea evaporative carbonate tidal flat facies.Supratidal zone of gypsum nodule dolostone and upper part of intertidal zone of gyps...The Ma5_(1-4)submembers of Jingbian gas field in Ordos basin of China belongs to epeiric sea evaporative carbonate tidal flat facies.Supratidal zone of gypsum nodule dolostone and upper part of intertidal zone of gypsum crystal dolostone are most favorable reservoir.The carbonate rocks of Ma5_(1-4)had undergone complex diagenesis.Penecontem-poraneous dolomitization and gypsification provided the material foundation of the reservoir.Epidiagenesis selective dissolution of gypseous dolostone constructs the origin shape of pore structure.The dissolution and filling of various minerals in the burial period determine whether the early dissolution pores can be preserved,and the final state of the reservoir.Burial dissolution and filling of various minerals determined the preservation of early dissolved pores and the final condition of the reservoir.The concept of“minus cement porosity”directly reflects that sedimentary facies have great influence on the growth of reservoir in Ma5_(1-4).Combined with sedimentary microfacies and diagenetic facies,a concise numerical symbol is used to express semiquantitatively sed-imentary microfacies and diagenesis facies.This descriptive method has great benefit in reservoir evaluation and prediction.展开更多
The sandstone of the third member of the Funing Formation(E1f3)in the northern slope zone of the Gaoyou Sag has the typical characteristics of high porosity and ultralow permeability,which makes it difficult for oil t...The sandstone of the third member of the Funing Formation(E1f3)in the northern slope zone of the Gaoyou Sag has the typical characteristics of high porosity and ultralow permeability,which makes it difficult for oil to flow.In this study,the lithological characteristics,sedimentary facies,diagenetic characteristics,pore struc-ture,and seepage ability of this sandstone are characterized in detail.Correlation analysis is used to reveal the reason for the sandstone high porosity-low permeability phenom-enon in the study area.The results indicate that this phenomenon is controlled mainly by the following three factors:1)the sedimentary environment is the initial affecting factor,whereby the deposition of a large number of fine-grained materials reduces the primary pores of sandstone.2)The Funing Formation has undergone strong compaction and cementation,which have led to the removal of most of the primary pores and a reduction in size of the throat channels.3)Owing to fluid activity during the later stage of diagenesis,sandstone underwent intense dissolution and a large number of particles(feldspar and lithic debris)formed many dissolution pores(accounting for nearly 60%of the total pore space).Among these factors,dissolution has contributed the most to the development of high porosity-low permeability phenomenon.This is mainly attributed to the inhomogeneous dissolution process,whereby the degree of particle dissolution(e.g.feldspar)exceeds that of cementing minerals(clay and carbonate minerals).The secondary dissolution pores have increased the porosity of sandstone in the study area;however,the pore connectivity(permeability)has not been significantly improved,thus resulting in the special high porosity-low permeability characteristics of this sandstone.展开更多
文摘In view of the problem that a single modeling method cannot predict the distribution of microfacies, a new idea of coupling modeling method to comprehensively predict the distribution of sedimentary microfacies was proposed, breaking the tradition that different sedimentary microfacies used the same modeling method in the past. Because different sedimentary microfacies have different distribution characteristics and geometric shapes, it is more accurate to select different simulation methods for prediction. In this paper, the coupling modeling method was to establish the distribution of sedimentary microfacies with simple geometry through the point indicating process simulation, and then predict the microfacies with complex spatial distribution through the sequential indicator simulation method. Taking the DC block of Bohai basin as an example, a high-precision reservoir sedimentary microfacies model was established by the above coupling modeling method, and the model verification results showed that the sedimentary microfacies model had a high consistency with the underground. The coupling microfacies modeling method had higher accuracy and reliability than the traditional modeling method, which provided a new idea for the prediction of sedimentary microfacies.
文摘In this paper, the Chang 2 reservoir in Zichang Area of Ordos Basin, the second largest sedimentary basin in China, is classified and evaluated by using logging and core data, thin section identification and electron microscopy. The main sedimentary microfacies of Chang 2<sub>1</sub><sup>3</sup> is braided river delta sedimentary system in geological history, and there are three main sedimentary microfacies types: swamp microfacies, distributary channel microfacies and natural embankment microfacies on land. The heterogeneity in the study area is as follows: Chang 2<sub>1</sub><sup>2</sup> formation has the strongest heterogeneity, followed by Chang 2<sub>1</sub><sup>1</sup> formation with strong heterogeneity, and finally Chang 2<sub>1</sub><sup>3</sup> formation with medium heterogeneity. The reservoirs of Chang 2 member in the study area are dominated by III<sub>a</sub>, II<sub>b</sub> and III<sub>b</sub>, and the reservoirs are mainly composed of ultra-low porosity and low permeability reservoirs and low porosity and low permeability reservoirs.
基金Supported by the China National Science and Technology Major Project(2016ZX05004-002)
文摘Based on comprehensive analysis of core,cast thin section,logging and seismic data,the sedimentary and reservoir architectures of the MB 1-2 sub-member of Mishrif Formation in Halfaya Oilfield,Iraq,are studied.The MB 1-2 sub-member of Mishrif Formation has three types of microfacies,lagoon,bioclastic shoal,and tidal channel,and facies architecture controlled by sequence stratigraphy.In the 4th-order sequence,the lagoon facies aggradated vertically,and the bioclastic shoals in lenticular shape embed in the background of lagoon,the end of the sequence is incised by the"meandering river"shape tide channel,which represents the depositional discontinuity.Three types of reservoirs including tidal channel grainstone to packstone reservoirs,bioclastic shoal grainstone to packstone reservoirs and dissolved lagoon wackestone reservoirs are developed.The reservoir architectures within tidal channel and bioclastic shoal are strickly controlled by grainy facies,whereas the dissolved lagoon reservoirs controlled by both facies and dissolution are related to the sequence boundary.The reservoir sections occur mainly in the 4 th sequence highstand systems tract(HST)and are separated by barriers formed in the transgressive systems tract(TST).Complicated facies architecture and dissolution modification resulted in strong heterogeneity within the reservoir,which showed the characteristics of"attic type"architecture.The results of this study can guide the development of similar reservoirs in the Middle East.
文摘Based on the analysis of a large number of core samples, logging results, logging interpretation data and dynamic data in the study area, the characteristics of Chang 6 reservoir in Zhouguan area of Baihe area are studied, and the favorable reservoir areas in the study area are predicted. The results show that the lithology of Chang 6 reservoir is mainly light gray and gray fine-grained to very fine-grained feldspar lithic sandstone. The pore types are mainly residual intergranular pores and feldspar dissolved pores, including debris dissolved pores and microfractures. The porosity and permeability values are low, which belongs to low porosity-low permeability and ultra-low permeability reservoirs. According to the reservoir distribution characteristics and related data, the Chang 6 reservoir in the study area is divided into two types, mainly Class II and Class III reservoirs. The comprehensive evaluation predicts that the spatial distribution of the favorable area of Chang 6 reservoir is not uniform, but the distribution area is large, which has broad exploration and development value, and provides the necessary conditions for the distribution study of the favorable oil-bearing zone in this area and the preparation for the next exploration and development.
文摘The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and marl.In this study,we conducted an integrated micropaleontological,sedimentological,mineralogical,and geochemical investigation to determine the depositional setting,biochronology,provenance,and paleoclimate of the KF.The study identified six lithofacies and six microfacies,which indicate a variety of environments ranging from floodplains and channels to the margins and shallow marine settings.The nannofossil biostratigraphy places the KF in the Early Eocene,more precisely the NP10 zone(Ypresian),and the fossil zone of benthic foraminifera classifies the study section as the Shallow Benthic Zone SBZ-8(Middle Ilerdian 2).In terms of petrography,the KF sandstone was classified as litharenite and feldspathic litharenite,while the QtFL diagram suggests a recycled orogen.Geochemical proxies indicate an oxidizing environment,a high-to-low regular sedimentation rate,moderate-to-intense chemical weathering in the source region,and a warm-humid to dry climate during the deposition of KF.Overall,the findings suggest that the deposition of KF marks the end of Neo-Tethys due to the Early Eocene Indian–Kohistan collision and that the uplifting of the Himalayas provided the source for the deposition of KF in the foreland basin.The study provides new insights into the depositional environment,biochronology,provenance,and paleoclimate of KF,and highlights the potential for red beds as reliable indicators of oxygenation levels in proximity to mineral deposits.
基金This workwas financially supported by the National Natural Science Foundation of China(41772150,41972120).
文摘The Ma5_(1-4)submembers of Jingbian gas field in Ordos basin of China belongs to epeiric sea evaporative carbonate tidal flat facies.Supratidal zone of gypsum nodule dolostone and upper part of intertidal zone of gypsum crystal dolostone are most favorable reservoir.The carbonate rocks of Ma5_(1-4)had undergone complex diagenesis.Penecontem-poraneous dolomitization and gypsification provided the material foundation of the reservoir.Epidiagenesis selective dissolution of gypseous dolostone constructs the origin shape of pore structure.The dissolution and filling of various minerals in the burial period determine whether the early dissolution pores can be preserved,and the final state of the reservoir.Burial dissolution and filling of various minerals determined the preservation of early dissolved pores and the final condition of the reservoir.The concept of“minus cement porosity”directly reflects that sedimentary facies have great influence on the growth of reservoir in Ma5_(1-4).Combined with sedimentary microfacies and diagenetic facies,a concise numerical symbol is used to express semiquantitatively sed-imentary microfacies and diagenesis facies.This descriptive method has great benefit in reservoir evaluation and prediction.
文摘The sandstone of the third member of the Funing Formation(E1f3)in the northern slope zone of the Gaoyou Sag has the typical characteristics of high porosity and ultralow permeability,which makes it difficult for oil to flow.In this study,the lithological characteristics,sedimentary facies,diagenetic characteristics,pore struc-ture,and seepage ability of this sandstone are characterized in detail.Correlation analysis is used to reveal the reason for the sandstone high porosity-low permeability phenom-enon in the study area.The results indicate that this phenomenon is controlled mainly by the following three factors:1)the sedimentary environment is the initial affecting factor,whereby the deposition of a large number of fine-grained materials reduces the primary pores of sandstone.2)The Funing Formation has undergone strong compaction and cementation,which have led to the removal of most of the primary pores and a reduction in size of the throat channels.3)Owing to fluid activity during the later stage of diagenesis,sandstone underwent intense dissolution and a large number of particles(feldspar and lithic debris)formed many dissolution pores(accounting for nearly 60%of the total pore space).Among these factors,dissolution has contributed the most to the development of high porosity-low permeability phenomenon.This is mainly attributed to the inhomogeneous dissolution process,whereby the degree of particle dissolution(e.g.feldspar)exceeds that of cementing minerals(clay and carbonate minerals).The secondary dissolution pores have increased the porosity of sandstone in the study area;however,the pore connectivity(permeability)has not been significantly improved,thus resulting in the special high porosity-low permeability characteristics of this sandstone.
