Pub Date : 2024-10-05DOI: 10.1016/j.marpetgeo.2024.107146
Mahdi Ali Lathbl , Mohammed Hail Hakimi , Akm Eahsanul Haque , Aref Lashin , Madyan M.A. Yahya , S.M. Talha Qadri , Danis K. Nurgaliev
The Taranaki Basin in New Zealand is an area of active exploration for oil and condensate. This research focuses on integrating geochemical characteristics and 1-D basin modeling to Late Cretaceous to Miocene source rock systems, along with oil and condensate data from fifty-seven wells in the Taranaki Basin. The geochemical study reveals that the oil and condensate samples were generated from clay-rich source rocks, containing mixed organic matter, with large amounts of terrestrial organic matter input. These source rocks were deposited in fluvial to fluvio-deltaic environments under oxic conditions. The presence of oleanane in both oil and condensate samples suggests that the source rocks had a significant terrestrial component and deposited during the Late Cretaceous to Cenozoic. Using various biomarker proxies, oil-source rock correlation along with 1-D basin modeling revealed that the oil and condensate were mainly derived from the Late Cretaceous Rakopi and Paleocene Farewell formations at different maturity stages. The oils were generated within the peak-mature oil window, while the condensates primarily resulted from the secondary cracking of oil taking place in the source rock within the gas generation window. This finding is consistent with the 1-D basin modeling results. The model shows that the Paleocene Farewell source rock has achieved the primary stage of oil generation (0.55–0.95 Easy %Ro), contributing to most of the discovered oils in the Cenozoic reservoir rocks. Meanwhile, the Late Cretaceous Rakopi source rock reached the gas window with a higher vitrinite reflectance of more than 1.30 Easy %Ro, indicating greater gas generation potential.
{"title":"Organic geochemistry and 1D-basin modeling in the Taranaki Basin, New Zealand: Implications for deltaic-source rocks of the cenozoic oil and condensate reservoirs","authors":"Mahdi Ali Lathbl , Mohammed Hail Hakimi , Akm Eahsanul Haque , Aref Lashin , Madyan M.A. Yahya , S.M. Talha Qadri , Danis K. Nurgaliev","doi":"10.1016/j.marpetgeo.2024.107146","DOIUrl":"10.1016/j.marpetgeo.2024.107146","url":null,"abstract":"<div><div>The Taranaki Basin in New Zealand is an area of active exploration for oil and condensate. This research focuses on integrating geochemical characteristics and 1-D basin modeling to Late Cretaceous to Miocene source rock systems, along with oil and condensate data from fifty-seven wells in the Taranaki Basin. The geochemical study reveals that the oil and condensate samples were generated from clay-rich source rocks, containing mixed organic matter, with large amounts of terrestrial organic matter input. These source rocks were deposited in fluvial to fluvio-deltaic environments under oxic conditions. The presence of oleanane in both oil and condensate samples suggests that the source rocks had a significant terrestrial component and deposited during the Late Cretaceous to Cenozoic. Using various biomarker proxies, oil-source rock correlation along with 1-D basin modeling revealed that the oil and condensate were mainly derived from the Late Cretaceous Rakopi and Paleocene Farewell formations at different maturity stages. The oils were generated within the peak-mature oil window, while the condensates primarily resulted from the secondary cracking of oil taking place in the source rock within the gas generation window. This finding is consistent with the 1-D basin modeling results. The model shows that the Paleocene Farewell source rock has achieved the primary stage of oil generation (0.55–0.95 Easy %Ro), contributing to most of the discovered oils in the Cenozoic reservoir rocks. Meanwhile, the Late Cretaceous Rakopi source rock reached the gas window with a higher vitrinite reflectance of more than 1.30 Easy %Ro, indicating greater gas generation potential.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107146"},"PeriodicalIF":3.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Morphometric studies coupled with geophysical investigations from petroliferous basins provide valuable information about tectonics of the regions. We deduce six morphologic parameters from the River Cauvery's designated (sub)watersheds and perform dendrogram clustering analysis. The main channels of the (sub)watersheds showcase steeper gradient and meandering nature with less concavity. On the other hand, the distributaries portray lesser gradient and straight nature with greater concavity. From the offshore region of the Cauvery basin, we perform gravity modeling. The results show variations in gravity values from low to high, −150 to 50 mGal probably because of the basement ridge-depression features. This anomaly orientation indicates the extension of the sub-basin in the region. A strong NE-SW gravity trend possibly suggests a high-density plug at crustal-level. The low gravity values near the Vedaranyam region indicate low-density rocks within the basement. Places of high gravity anomaly show a decrease in bathymetry depth and vice versa. This indicates isostatic compensation of the Moho geometry, possibly due to crustal thinning in the offshore areas. Isostatic regional gravity fields are manifested by Moho relief and can have implications on the lithospheric mechanical strengths. Bathymetric studies indicate multi-directional slopes. Relatively flat areas can indicate depocenters. E-W trending lineaments mapped on the Precambrian basement from a portion of the study area is presumably a manifestation of Cauvery Shear zone, which also persists in the offshore region.
{"title":"Tectonics of cauvery basin (India) in onshore and offshore portions","authors":"Soumyajit Mukherjee , Kutubuddin Ansari , Adrija Raha , Mery Biswas , Subhobroto Mazumder","doi":"10.1016/j.marpetgeo.2024.107142","DOIUrl":"10.1016/j.marpetgeo.2024.107142","url":null,"abstract":"<div><div>Morphometric studies coupled with geophysical investigations from petroliferous basins provide valuable information about tectonics of the regions. We deduce six morphologic parameters from the River Cauvery's designated (sub)watersheds and perform dendrogram clustering analysis. The main channels of the (sub)watersheds showcase steeper gradient and meandering nature with less concavity. On the other hand, the distributaries portray lesser gradient and straight nature with greater concavity. From the offshore region of the Cauvery basin, we perform gravity modeling. The results show variations in gravity values from low to high, −150 to 50 mGal probably because of the basement ridge-depression features. This anomaly orientation indicates the extension of the sub-basin in the region. A strong NE-SW gravity trend possibly suggests a high-density plug at crustal-level. The low gravity values near the Vedaranyam region indicate low-density rocks within the basement. Places of high gravity anomaly show a decrease in bathymetry depth and vice versa. This indicates isostatic compensation of the Moho geometry, possibly due to crustal thinning in the offshore areas. Isostatic regional gravity fields are manifested by Moho relief and can have implications on the lithospheric mechanical strengths. Bathymetric studies indicate multi-directional slopes. Relatively flat areas can indicate depocenters. E-W trending lineaments mapped on the Precambrian basement from a portion of the study area is presumably a manifestation of Cauvery Shear zone, which also persists in the offshore region.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"171 ","pages":"Article 107142"},"PeriodicalIF":3.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-04DOI: 10.1016/j.marpetgeo.2024.107145
Behzad Alaei , Anita Torabi
The complexity of faults and the bias in the gathered fault data from different sources such as outcrops, reflection seismic data and earthquakes causes uncertainty to the understanding of fault plane geometry at the seismic scale, among other fault geometric attributes. Fault plane roughness and irregularities at different scales are important geometric attributes caused by asperities, which are linked to the fault frictional behaviour and mechanics. Asperities are localized areas with higher strength on the fault plane, which resist the applied stress to a certain limit before the fault ruptures. Imaging faults’ real geometry can help us to gain more insight into the fault roughness and asperities, thereby enhancing our understanding of the mechanics of faulting and earthquakes. In this study, for the first time, we map fault asperities and roughness on seismic scale faults using their 3D structures extracted from reflection seismic data. We have studied 21 normal faults ranging in depth from about 0.5 to 3 km with clastic dominated lithology and some carbonates by extracting and characterizing their true fault plane geometry on 3D reflection seismic data using Gaussian filtered coherency attributes and measuring throw over the entire fault plane. The outline of the mapped asperities is the envelope of internal tip-points between the segments on the fault plane 3D structure. Our results show that in most cases, at the boundary of the asperities, the strike of fault internal segments changes and the throw increases. We have introduced two new attributes characterizing fault plane roughness at seismic scale, notably 2D roughness attribute and segment mean roughness. The variations of these two attributes, i.e. higher values near the asperity boundary, have close link to the locations of asperities on the fault planes.
{"title":"Fault asperity and roughness, insight from faults in 3D reflection seismic data","authors":"Behzad Alaei , Anita Torabi","doi":"10.1016/j.marpetgeo.2024.107145","DOIUrl":"10.1016/j.marpetgeo.2024.107145","url":null,"abstract":"<div><div>The complexity of faults and the bias in the gathered fault data from different sources such as outcrops, reflection seismic data and earthquakes causes uncertainty to the understanding of fault plane geometry at the seismic scale, among other fault geometric attributes. Fault plane roughness and irregularities at different scales are important geometric attributes caused by asperities, which are linked to the fault frictional behaviour and mechanics. Asperities are localized areas with higher strength on the fault plane, which resist the applied stress to a certain limit before the fault ruptures. Imaging faults’ real geometry can help us to gain more insight into the fault roughness and asperities, thereby enhancing our understanding of the mechanics of faulting and earthquakes. In this study, for the first time, we map fault asperities and roughness on seismic scale faults using their 3D structures extracted from reflection seismic data. We have studied 21 normal faults ranging in depth from about 0.5 to 3 km with clastic dominated lithology and some carbonates by extracting and characterizing their true fault plane geometry on 3D reflection seismic data using Gaussian filtered coherency attributes and measuring throw over the entire fault plane. The outline of the mapped asperities is the envelope of internal tip-points between the segments on the fault plane 3D structure. Our results show that in most cases, at the boundary of the asperities, the strike of fault internal segments changes and the throw increases. We have introduced two new attributes characterizing fault plane roughness at seismic scale, notably 2D roughness attribute and segment mean roughness. The variations of these two attributes, i.e. higher values near the asperity boundary, have close link to the locations of asperities on the fault planes.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107145"},"PeriodicalIF":3.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.marpetgeo.2024.107143
Haigang Lao , Guang Li , Yixian Shan , Osman Salad Hersi , Cui Mao , Yu Li
Antithetic normal faults play an important role in the tectono–stratigraphic evolution of extensional basins. These faults also control the regional accumulation and distribution of oil and gas, and form an important channel for oil and gas longitudinal migration. However, the evolution of such faults architecture and their hydrocarbon conduction and accumulation are not well constrained. This work examines the evolution of such fault zones and their oil conduction process by employing sand–box simulations based on the actual antithetic normal fault with coring in the Dongying depression. The study reveals that the antithetic normal fault in semi–consolidated strata evolves from initial small faults based on drag folding, the drag in their damage zones effect also makes some fault properties reverse, and the intermittent dilation zone indirectly improves the physical properties of the secondary fault. The fault displacement controls the longitudinal oil–bearing layers and their saturation in the whole fault zone. The number of oil–bearing layers and their oil saturation decrease with decreasing of the total fault displacement. The longitudinal conduction of the fault is controlled by the displacement of the secondary faults in the damage zone. In semi–consolidated strata, the fault further evolves from drag folds, forming extensional fault–related folds overlapped with secondary faults in the damage zone. The secondary faults control the longitudinal conduction of oil and the drag folds become favorable reservoir space. Thus, the mudstone sealing of the main fault and conduction of the entire fault zone are two co–existing but not contradictory geological processes. The results of this study provide a new way to evaluate the transmissibility of the growth fault in extensional basins.
{"title":"Exploring the evolution of antithetic normal fault architecture and its constraints on fault transmissibility: Evidence from sand–box simulation experiments","authors":"Haigang Lao , Guang Li , Yixian Shan , Osman Salad Hersi , Cui Mao , Yu Li","doi":"10.1016/j.marpetgeo.2024.107143","DOIUrl":"10.1016/j.marpetgeo.2024.107143","url":null,"abstract":"<div><div>Antithetic normal faults play an important role in the tectono–stratigraphic evolution of extensional basins. These faults also control the regional accumulation and distribution of oil and gas, and form an important channel for oil and gas longitudinal migration. However, the evolution of such faults architecture and their hydrocarbon conduction and accumulation are not well constrained. This work examines the evolution of such fault zones and their oil conduction process by employing sand–box simulations based on the actual antithetic normal fault with coring in the Dongying depression. The study reveals that the antithetic normal fault in semi–consolidated strata evolves from initial small faults based on drag folding, the drag in their damage zones effect also makes some fault properties reverse, and the intermittent dilation zone indirectly improves the physical properties of the secondary fault. The fault displacement controls the longitudinal oil–bearing layers and their saturation in the whole fault zone. The number of oil–bearing layers and their oil saturation decrease with decreasing of the total fault displacement. The longitudinal conduction of the fault is controlled by the displacement of the secondary faults in the damage zone. In semi–consolidated strata, the fault further evolves from drag folds, forming extensional fault–related folds overlapped with secondary faults in the damage zone. The secondary faults control the longitudinal conduction of oil and the drag folds become favorable reservoir space. Thus, the mudstone sealing of the main fault and conduction of the entire fault zone are two co–existing but not contradictory geological processes. The results of this study provide a new way to evaluate the transmissibility of the growth fault in extensional basins.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107143"},"PeriodicalIF":3.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The linkage between marine incursions and lacustrine petroleum source rock deposition has been studied worldwide. A variety of interpretations have been suggested to explain the influence of marine incursions on the quality of source rocks in the Upper Cretaceous Qingshankou Formation (K2qn), Songliao Basin. In this study, high-resolution of geochemical and sedimentary results of two drilled wells from the K2qn were presented to improve the understanding on this issue. 117 samples from Well GY8HC of the Qijia-Gulong Sag (brief as Gulong Sag) and 251 samples from Well ZY1 of the Sanzhao Sag, the Central Depression of the basin were analyzed to establish the evolution of paleoenvironment and the influence of marine incursions on organic matter enrichment in the two sags. All the evidence suggests that marine incursions have a positive effect on the quality of member 1 of the K2qn source rocks (K2qn1) in the Sanzhao Sag, which was probably due to the rising lake level and increasing salinity of the watermasses. The enhanced salinities could have inhibited lake overturn and oxygenation of bottom water, and thus created a favorable condition for the preservation of organic matter. In contrast, the K2qn1 source rock in the Gulong Sag was less affected by marine incursions, which is likely due to the Daqing placanticline blocking two sags. The lake water in the Gulong Sag was characterized as fresh-brackish with less mixing of seawater. Petrographic observation suggests that organic matter in the Gulong source rocks was mainly derived from lacustrine algal and microsporinite. This research provides novel insights into the linkage between marine incursions and the depositional environment during the formation of K2qn1 in the Songliao Basin.
{"title":"How marine incursions affect the sedimentary environment and the quality of source rocks in the Upper Cretaceous Songliao Basin, NE China","authors":"Ruiqian Chen , Xin Bai , Chengzheng Huang , Xia Wu , Fei Shang","doi":"10.1016/j.marpetgeo.2024.107140","DOIUrl":"10.1016/j.marpetgeo.2024.107140","url":null,"abstract":"<div><div>The linkage between marine incursions and lacustrine petroleum source rock deposition has been studied worldwide. A variety of interpretations have been suggested to explain the influence of marine incursions on the quality of source rocks in the Upper Cretaceous Qingshankou Formation (K<sub>2</sub>qn), Songliao Basin. In this study, high-resolution of geochemical and sedimentary results of two drilled wells from the K<sub>2</sub>qn were presented to improve the understanding on this issue. 117 samples from Well GY8HC of the Qijia-Gulong Sag (brief as Gulong Sag) and 251 samples from Well ZY1 of the Sanzhao Sag, the Central Depression of the basin were analyzed to establish the evolution of paleoenvironment and the influence of marine incursions on organic matter enrichment in the two sags. All the evidence suggests that marine incursions have a positive effect on the quality of member 1 of the K<sub>2</sub>qn source rocks (K<sub>2</sub>qn<sup>1</sup>) in the Sanzhao Sag, which was probably due to the rising lake level and increasing salinity of the watermasses. The enhanced salinities could have inhibited lake overturn and oxygenation of bottom water, and thus created a favorable condition for the preservation of organic matter. In contrast, the K<sub>2</sub>qn<sup>1</sup> source rock in the Gulong Sag was less affected by marine incursions, which is likely due to the Daqing placanticline blocking two sags. The lake water in the Gulong Sag was characterized as fresh-brackish with less mixing of seawater. Petrographic observation suggests that organic matter in the Gulong source rocks was mainly derived from lacustrine algal and microsporinite. This research provides novel insights into the linkage between marine incursions and the depositional environment during the formation of K<sub>2</sub>qn<sup>1</sup> in the Songliao Basin.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107140"},"PeriodicalIF":3.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.marpetgeo.2024.107134
Rodrigo Macedo Penna, Leonardo Costa de Oliveira, Leonardo Souza Rodrigues
The Brazilian pre-salt carbonate province is a scientific frontier that has been subject of extensive research and academic discussion. Santos basin carbonates show that reservoir quality is strongly conditioned by the characteristics of the depositional environment and its associated diagenetic history and alterations. Dolomitization and silicification are two of the most common diagenetic processes in Brazilian carbonates, and the combination of sedimentary and diagenetic complexity leads to a much more heterogeneous reservoir, especially complicated for geoscientists trying to mimic these geological features in terms of static and dynamic modelling. This study proposes a methodology for seismic derived diagenetic properties calculation through seismic quantitative interpretation and classification of inverted P- and S-impedance volumes applied to Brazilian Pre-Salt carbonate reservoirs. Our proposition is to establish relations between petroelastic properties and diagenetic features, first in the well-log domain and, later, in the seismic domain through different quantitative probabilistic techniques. Using the available seismic data and probabilistic approaches through stochastic inversion and Bayesian facies classification, we can interpret the occurrence of diagenetic silica and dolomite in 3D volumes. The volumetric analysis generated through the presented methodology can provide much more insights into the sedimentary history of the field, especially for static and dynamic porosity and permeability modelling.
{"title":"Seismic quantitative interpretation of diagenetic processes: A study in Brazilian pre-salt carbonate reservoirs","authors":"Rodrigo Macedo Penna, Leonardo Costa de Oliveira, Leonardo Souza Rodrigues","doi":"10.1016/j.marpetgeo.2024.107134","DOIUrl":"10.1016/j.marpetgeo.2024.107134","url":null,"abstract":"<div><div>The Brazilian pre-salt carbonate province is a scientific frontier that has been subject of extensive research and academic discussion. Santos basin carbonates show that reservoir quality is strongly conditioned by the characteristics of the depositional environment and its associated diagenetic history and alterations. Dolomitization and silicification are two of the most common diagenetic processes in Brazilian carbonates, and the combination of sedimentary and diagenetic complexity leads to a much more heterogeneous reservoir, especially complicated for geoscientists trying to mimic these geological features in terms of static and dynamic modelling. This study proposes a methodology for seismic derived diagenetic properties calculation through seismic quantitative interpretation and classification of inverted P- and S-impedance volumes applied to Brazilian Pre-Salt carbonate reservoirs. Our proposition is to establish relations between petroelastic properties and diagenetic features, first in the well-log domain and, later, in the seismic domain through different quantitative probabilistic techniques. Using the available seismic data and probabilistic approaches through stochastic inversion and Bayesian facies classification, we can interpret the occurrence of diagenetic silica and dolomite in 3D volumes. The volumetric analysis generated through the presented methodology can provide much more insights into the sedimentary history of the field, especially for static and dynamic porosity and permeability modelling.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107134"},"PeriodicalIF":3.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.marpetgeo.2024.107125
Sicheng Zhu , Panke Sun , Kexin Zhang , Chaoqian Zhang , Qi Zhang , Bin Li , Jiang Wang , Shiyi Jiang , Liyin Bao , Guangbin Jing , Zhangxing Chen , Huaimin Xu
The Oriente Basin is a back-arc basin located east of the Ecuadorian Andes in South America. Evidence suggests that during the Cretaceous period, the basin's margins received a terrigenous shallow marine sedimentation. Due to regional variations in accommodation and depositional controlling factors near a shoreline, the sedimentary environments in the fluvial-marine transitional zones exhibit considerable variability. In this study, we analyzed the sedimentological characteristics of the M1 Sandstone Formation unit (∼83 Ma-72 Ma), which comprises a set of ancient estuarine deposits preserved in the northern part of the basin. We quantified the impact of mixed hydrodynamic processes on the distribution of tidal-dominated estuarine facies and discussed the development conditions and evolutionary processes of an estuarine formation under the background of persistent transgression. Core, well log, and seismic data provide evidence for reconstructing the tidal-dominated estuarine environment. In the core section, we identified 14 lithofacies and 7 major facies association types. The frequent occurrence of sedimentary structures associated with tidal currents indicates that tidal processes extensively reworked the deposits. The spatial distribution trends of facies associations reveal the evolution of mixed hydrodynamic conditions dominated by tidal processes in the estuary and allow us to divide the M1 Sandstone Formation into four depositional periods: the initial development, rapid development, decline, and the post-infilling open coast tidal flat development periods. Furthermore, through a systematic analysis of hydrodynamic conditions and sediment distributions, we identified multiple depositional centers in the tidal-dominated estuary influenced by different hydrodynamic processes. These correspond to the upstream fluvial-dominated tidal point bar depositional region, the middle mixed-energy depositional interaction zone, and the downstream tidal-dominated tidal sand bar depositional region. In these regions, the substantial accumulation of sandy deposits, represented by tidal sand bars, reflects the high accommodation space characteristic of tidal-dominated estuaries. Our findings indicate that the slow subsidence of a broad and gently sloping coastal topography, stable material transport, and sea level change dominated by marine transgression ensured the necessary accommodation for the development of the estuary in the M1 Sandstone Formation. The sedimentological study of the M1 Sandstone Formation provides a case for understanding the sedimentary evolution in fluvial-marine transitional zones.
{"title":"Paleogeographic reconstruction and sedimentary evolution of tidal-dominated estuarine depositional systems: Insights from the campanian M1 sandstone formation, Oriente Basin, Ecuador","authors":"Sicheng Zhu , Panke Sun , Kexin Zhang , Chaoqian Zhang , Qi Zhang , Bin Li , Jiang Wang , Shiyi Jiang , Liyin Bao , Guangbin Jing , Zhangxing Chen , Huaimin Xu","doi":"10.1016/j.marpetgeo.2024.107125","DOIUrl":"10.1016/j.marpetgeo.2024.107125","url":null,"abstract":"<div><div>The Oriente Basin is a back-arc basin located east of the Ecuadorian Andes in South America. Evidence suggests that during the Cretaceous period, the basin's margins received a terrigenous shallow marine sedimentation. Due to regional variations in accommodation and depositional controlling factors near a shoreline, the sedimentary environments in the fluvial-marine transitional zones exhibit considerable variability. In this study, we analyzed the sedimentological characteristics of the M1 Sandstone Formation unit (∼83 Ma-72 Ma), which comprises a set of ancient estuarine deposits preserved in the northern part of the basin. We quantified the impact of mixed hydrodynamic processes on the distribution of tidal-dominated estuarine facies and discussed the development conditions and evolutionary processes of an estuarine formation under the background of persistent transgression. Core, well log, and seismic data provide evidence for reconstructing the tidal-dominated estuarine environment. In the core section, we identified 14 lithofacies and 7 major facies association types. The frequent occurrence of sedimentary structures associated with tidal currents indicates that tidal processes extensively reworked the deposits. The spatial distribution trends of facies associations reveal the evolution of mixed hydrodynamic conditions dominated by tidal processes in the estuary and allow us to divide the M1 Sandstone Formation into four depositional periods: the initial development, rapid development, decline, and the post-infilling open coast tidal flat development periods. Furthermore, through a systematic analysis of hydrodynamic conditions and sediment distributions, we identified multiple depositional centers in the tidal-dominated estuary influenced by different hydrodynamic processes. These correspond to the upstream fluvial-dominated tidal point bar depositional region, the middle mixed-energy depositional interaction zone, and the downstream tidal-dominated tidal sand bar depositional region. In these regions, the substantial accumulation of sandy deposits, represented by tidal sand bars, reflects the high accommodation space characteristic of tidal-dominated estuaries. Our findings indicate that the slow subsidence of a broad and gently sloping coastal topography, stable material transport, and sea level change dominated by marine transgression ensured the necessary accommodation for the development of the estuary in the M1 Sandstone Formation. The sedimentological study of the M1 Sandstone Formation provides a case for understanding the sedimentary evolution in fluvial-marine transitional zones.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107125"},"PeriodicalIF":3.7,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.marpetgeo.2024.107136
Chuan Cai , Nansheng Qiu , Nian Liu , Zhenming Li , Yuanjie Wang , Zhanwen Yu , Yaxian Jiao
Interpreting the hydrocarbon generation, migration, and accumulation process is significant for understanding hydrocarbon evolution and finding exploration targets. The buried hills of Shulu Sag exhibit great potential for hydrocarbon exploration. However, the variations observed in different oil reservoirs highlight the complexity of hydrocarbon migration and accumulation in this region. In this study, 1D basin modeling, fluid inclusion analysis, and quantitative fluorescence techniques were used to investigate the thermal maturation history of the source rock, the timing of hydrocarbon charging, the pathway of hydrocarbon migration, and the oil-water contact. Hydrocarbons in the buried hills in the Western Slope and Paleo-uplift are derived from the source rocks at the edge and center of the sag, respectively, which have different thermal maturation histories. The source rocks in the center of the sag mainly supply hydrocarbons to the Paleo-uplift through faults, while the hydrocarbons generated from the source rocks in the edge of the sag can be rapidly transported to the Western Slope through clast-supported terrigenous carbonate rudstone. Differences in oil sources result in different hydrocarbon charging histories for the Western Slope and Paleo-uplift. The Western Slope experienced a single low-mature oil charging event at 5-0 Ma, while the Paleo-uplift encountered two hydrocarbon charging events, including low-mature oil charging at 35-25 Ma and high-mature oil charging at 5-0 Ma. As a result of secondary changes controlled by the hydrological environment, the oil reservoirs in the Western Slope have undergone varying degrees of adjustment or even destruction, resulting in variations in the oil quality of different buried hills. The results provide a detailed understanding of hydrocarbon migration and accumulation in the study area, which can be used as a reference for hydrocarbon exploration.
解释碳氢化合物的生成、迁移和积累过程对于了解碳氢化合物的演化过程和寻找勘探目标具有重要意义。舒鲁萨格的埋藏丘陵具有巨大的油气勘探潜力。然而，在不同油藏中观察到的变化凸显了该地区油气迁移和积累的复杂性。本研究利用一维盆地建模、流体包裹体分析和定量荧光技术研究了源岩的热成熟历史、油气充注时间、油气迁移路径和油水接触。西坡和古隆起带埋藏山体中的碳氢化合物分别来自下陷边缘和中心的源岩，它们的热成熟历史各不相同。坳陷中心的源岩主要通过断层向古隆起提供碳氢化合物，而坳陷边缘源岩产生的碳氢化合物则可通过碎屑岩支撑的陆相碳酸盐岩快速运往西坡。石油来源的不同导致了西坡和古隆起不同的碳氢化合物充注历史。西坡在 5-0 Ma 时经历了一次低成熟石油充注事件，而古陆隆起则经历了两次碳氢化合物充注事件，包括 35-25 Ma 时的低成熟石油充注和 5-0 Ma 时的高成熟石油充注。由于水文环境控制的次生变化，西坡油藏经历了不同程度的调整甚至破坏，导致不同埋藏山体的油质存在差异。研究结果为详细了解研究区的油气迁移和积累情况提供了依据，可为油气勘探提供参考。
{"title":"Hydrocarbon migration and accumulation in buried hills based on quantitative fluorescence techniques, fluid inclusion, and 1D basin modeling: Shulu sag, Bohai Bay basin, NE China","authors":"Chuan Cai , Nansheng Qiu , Nian Liu , Zhenming Li , Yuanjie Wang , Zhanwen Yu , Yaxian Jiao","doi":"10.1016/j.marpetgeo.2024.107136","DOIUrl":"10.1016/j.marpetgeo.2024.107136","url":null,"abstract":"<div><div>Interpreting the hydrocarbon generation, migration, and accumulation process is significant for understanding hydrocarbon evolution and finding exploration targets. The buried hills of Shulu Sag exhibit great potential for hydrocarbon exploration. However, the variations observed in different oil reservoirs highlight the complexity of hydrocarbon migration and accumulation in this region. In this study, 1D basin modeling, fluid inclusion analysis, and quantitative fluorescence techniques were used to investigate the thermal maturation history of the source rock, the timing of hydrocarbon charging, the pathway of hydrocarbon migration, and the oil-water contact. Hydrocarbons in the buried hills in the Western Slope and Paleo-uplift are derived from the source rocks at the edge and center of the sag, respectively, which have different thermal maturation histories. The source rocks in the center of the sag mainly supply hydrocarbons to the Paleo-uplift through faults, while the hydrocarbons generated from the source rocks in the edge of the sag can be rapidly transported to the Western Slope through clast-supported terrigenous carbonate rudstone. Differences in oil sources result in different hydrocarbon charging histories for the Western Slope and Paleo-uplift. The Western Slope experienced a single low-mature oil charging event at 5-0 Ma, while the Paleo-uplift encountered two hydrocarbon charging events, including low-mature oil charging at 35-25 Ma and high-mature oil charging at 5-0 Ma. As a result of secondary changes controlled by the hydrological environment, the oil reservoirs in the Western Slope have undergone varying degrees of adjustment or even destruction, resulting in variations in the oil quality of different buried hills. The results provide a detailed understanding of hydrocarbon migration and accumulation in the study area, which can be used as a reference for hydrocarbon exploration.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107136"},"PeriodicalIF":3.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.marpetgeo.2024.107138
Tao Luo , Xiaowen Guo , Zhiliang He , Jian-xin Zhao , Ze Tao , Tian Dong , Rui Yang , Junlin Chen
The marine shales in southern China are characterized by high thermal evolution and intensive deformation during multistage burial and uplift. Fracturing and cementation, associated with tectonic activity, diagenesis, hydrocarbon generation and migration processes, are widely and variably distributed in shale reservoirs experiencing different tectonic evolution. In this study, we utilized cross-cutting relationships, fluid inclusion microthermometry, and laser Raman spectroscopy of fluid inclusions, along with U-Pb dating of fracture-filling calcite veins, integrated with burial history modeling, to elucidate the timing and mechanism of fracturing in the Paleozoic Wufeng-Longmaxi shale reservoir, as well as regional variations in the Fuling shale gas field. Bedding-parallel fractures (BFs) in shale reservoirs are filled with calcite and quartz veins. The timing of fracturing, as determined by minimum homogenization temperatures and U-Pb dating, is estimated to have occurred during ca. 191 -122 Ma, during which some short vertical (or high-angle) fractures (VFs) opened around 163.4 Ma and 137 Ma, subsequently sealed by calcite veins, respectively. All calcite and quartz veins within these fractures contain high-density methane inclusions, while shale reservoirs were in a high-over-mature evolutionary stage. This suggests that fracturing was primarily driven by gas generation overpressure during deep burial. In shale reservoirs near fault belt folds, multistage fractures developed, including three stages of intersecting fractures (IFs) and one-stage of long VFs. The timing of fracturing and cementation corresponds to the Yanshanian tectonic uplift (ca. 83 - 69 Ma) with intense tectonic movement likely being the direct cause of fracture opening. The presence of abundant gas inclusions in veins recorded shale gas expulsion during rapid tectonic uplift, reflecting the destruction of shale gas preservation conditions. In contrast, no significant fracturing or cementation processes have been observed in the tectonically gentle zones. The different fracturing and cementation processes indicated that preservation conditions declined with increased fracture openings during uplift, correlating with the gas enrichment.
中国南方海相页岩在多级埋藏和隆起过程中具有高热演化和强烈变形的特点。在经历不同构造演化的页岩储层中，与构造活动、成岩作用、油气生成和迁移过程相关的断裂和胶结分布广泛且差异较大。在这项研究中，我们利用横切关系、流体包裹体微测温、流体包裹体激光拉曼光谱以及裂缝充填方解石脉的铀-铅年代测定，结合埋藏史建模，阐明了古生代五峰-龙马溪页岩储层的压裂时间和机制，以及涪陵页岩气田的区域变化。页岩储层中的层理平行裂缝（BFs）充满了方解石和石英脉。根据最低均化温度和铀-铅年代测定，断裂时间估计发生在大约 191-122 Ma，期间一些短的垂直（或高角度）断裂（VFs）分别在 163.4 Ma 和 137 Ma 左右打开，随后分别被方解石脉封住。这些断裂内的方解石脉和石英脉均含有高密度甲烷包裹体，而页岩储层则处于高度超成熟演化阶段。这表明，在深埋过程中，断裂主要是由气体生成超压驱动的。在断层带褶皱附近的页岩储层中，发育了多级断裂，包括三级相交断裂（IF）和一级长VF。断裂和胶结的时间与燕山构造隆起（约 83 - 69 Ma）相吻合，强烈的构造运动可能是断裂打开的直接原因。岩脉中大量气体包裹体的存在记录了页岩气在快速构造隆升过程中的排出，反映了页岩气保存条件的破坏。与此相反，在构造平缓带没有观察到明显的断裂或胶结过程。不同的断裂和胶结过程表明，在隆起过程中，保存条件随着断裂开口的增加而下降，这与气体富集相关。
{"title":"Contrasting fracturing and cementation timings during shale gas accumulation and preservation: An example from the Wufeng-Longmaxi shales in the Fuling shale gas field, Sichuan Basin, China","authors":"Tao Luo , Xiaowen Guo , Zhiliang He , Jian-xin Zhao , Ze Tao , Tian Dong , Rui Yang , Junlin Chen","doi":"10.1016/j.marpetgeo.2024.107138","DOIUrl":"10.1016/j.marpetgeo.2024.107138","url":null,"abstract":"<div><div>The marine shales in southern China are characterized by high thermal evolution and intensive deformation during multistage burial and uplift. Fracturing and cementation, associated with tectonic activity, diagenesis, hydrocarbon generation and migration processes, are widely and variably distributed in shale reservoirs experiencing different tectonic evolution. In this study, we utilized cross-cutting relationships, fluid inclusion microthermometry, and laser Raman spectroscopy of fluid inclusions, along with U-Pb dating of fracture-filling calcite veins, integrated with burial history modeling, to elucidate the timing and mechanism of fracturing in the Paleozoic Wufeng-Longmaxi shale reservoir, as well as regional variations in the Fuling shale gas field. Bedding-parallel fractures (BFs) in shale reservoirs are filled with calcite and quartz veins. The timing of fracturing, as determined by minimum homogenization temperatures and U-Pb dating, is estimated to have occurred during <em>ca.</em> 191 -122 Ma, during which some short vertical (or high-angle) fractures (VFs) opened around 163.4 Ma and 137 Ma, subsequently sealed by calcite veins, respectively. All calcite and quartz veins within these fractures contain high-density methane inclusions, while shale reservoirs were in a high-over-mature evolutionary stage. This suggests that fracturing was primarily driven by gas generation overpressure during deep burial. In shale reservoirs near fault belt folds, multistage fractures developed, including three stages of intersecting fractures (IFs) and one-stage of long VFs. The timing of fracturing and cementation corresponds to the Yanshanian tectonic uplift (<em>ca.</em> 83 - 69 Ma) with intense tectonic movement likely being the direct cause of fracture opening. The presence of abundant gas inclusions in veins recorded shale gas expulsion during rapid tectonic uplift, reflecting the destruction of shale gas preservation conditions. In contrast, no significant fracturing or cementation processes have been observed in the tectonically gentle zones. The different fracturing and cementation processes indicated that preservation conditions declined with increased fracture openings during uplift, correlating with the gas enrichment.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107138"},"PeriodicalIF":3.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Malaysia-Thailand Joint Development Area (MTJDA) that located in the North Malay Basin has been investigated in this study to resolve few issues concerning to petroleum potential and resources which has been abandon for decades. Despite Malay Basin having been proven to contain prolific oil and gas resources, the MTJDA which located in the Northern area however contains mainly gas with very minor oil. Thus, this study aimed to investigate the main factor that controls the hydrocarbon generation, type and distribution in this basin. The investigation involves biomarker characterization, thermal maturity assessment of source rock, crude oil and condensate, together with oil-oil and oil-source correlation that has never been established before. The geochemical data as indicated by bitumen extraction, GC-MS and Py-GC analyses on 40 cutting samples and 8 liquid samples (six oil samples and two condensate samples) revealed that the cutting samples were moderate in quality with variable richness based on TOC (total organic carbon) and a variable degree of maturity based on the biomarker proxy parameters of isoprenoid, hopanoid and steroid. The organic matter input for the source rock was derived from a mixed marine-terrestrial and terrestrial source and deposited in fluvial-deltaic/estuarine settings having oxic to sub-oxic depositional conditions. Based on biomarker fingerprints and proxy parameters, the oil and condensate samples were essentially of the same group, originating from a similar source rock, with some facies variation due to variations in organic matter input and degree of maturity. The results also indicated that the crude oil samples were originated from the coaly and carbonaceous shales of Group I, with mixed kerogen of type II/III that could produce gas with minor oil. There is also the possibility that these hydrocarbons were generated from a deeper interval of Group E (higher thermal maturity), deposited in a similar setting as Group I.
本研究对位于北马来盆地的马来西亚-泰国联合开发区（MTJDA）进行了调查，以解决与已废弃数十年的石油潜力和资源有关的一些问题。尽管马来盆地已被证实蕴藏着丰富的石油和天然气资源，但位于北部地区的 MTJDA 却主要蕴藏着天然气，只有极少量的石油。因此，本研究旨在调查控制该盆地碳氢化合物生成、类型和分布的主要因素。调查内容包括生物标记表征、源岩、原油和凝析油的热成熟度评估，以及油-油和油-源的相关性，这在以前是从未有过的。对 40 个切割样本和 8 个液体样本（6 个石油样本和 2 个凝析油样本）进行的沥青萃取、气相色谱-质谱（GC-MS）和派-气相色谱（Py-GC）分析所显示的地球化学数据表明，切割样本的质量适中，根据总有机碳（TOC）计算的富集度各不相同，根据异戊烯类、类己酮和类固醇等生物标志物替代参数计算的成熟度也各不相同。源岩的有机质输入来自海洋-陆地和陆地混合源，沉积于具有缺氧至亚缺氧沉积条件的河流-三角洲/河口环境中。根据生物标记指纹和替代参数，石油和凝析油样本基本上属于同一类，来源于相似的源岩，但由于有机质输入和成熟度的不同，面貌存在一些差异。研究结果还表明，原油样本来源于第一组的褐煤页岩和碳质页岩，以及第二/三类混合角质，可产生气体和少量石油。这些碳氢化合物也有可能来自 E 组（热成熟度较高）的较深区段，沉积环境与 I 组类似。
{"title":"Geochemical characteristics of crude oils and source rocks in the Malaysia-Thailand Joint Development Area (MTJDA), North Malay Basin","authors":"Siti Hanisah Sidik , Khairul Azlan Mustapha , Alok Kumar , Supat Napanoparatkaew , Marahizal Malihan","doi":"10.1016/j.marpetgeo.2024.107135","DOIUrl":"10.1016/j.marpetgeo.2024.107135","url":null,"abstract":"<div><div>The Malaysia-Thailand Joint Development Area (MTJDA) that located in the North Malay Basin has been investigated in this study to resolve few issues concerning to petroleum potential and resources which has been abandon for decades. Despite Malay Basin having been proven to contain prolific oil and gas resources, the MTJDA which located in the Northern area however contains mainly gas with very minor oil. Thus, this study aimed to investigate the main factor that controls the hydrocarbon generation, type and distribution in this basin. The investigation involves biomarker characterization, thermal maturity assessment of source rock, crude oil and condensate, together with oil-oil and oil-source correlation that has never been established before. The geochemical data as indicated by bitumen extraction, GC-MS and Py-GC analyses on 40 cutting samples and 8 liquid samples (six oil samples and two condensate samples) revealed that the cutting samples were moderate in quality with variable richness based on TOC (total organic carbon) and a variable degree of maturity based on the biomarker proxy parameters of isoprenoid, hopanoid and steroid. The organic matter input for the source rock was derived from a mixed marine-terrestrial and terrestrial source and deposited in fluvial-deltaic/estuarine settings having oxic to sub-oxic depositional conditions. Based on biomarker fingerprints and proxy parameters, the oil and condensate samples were essentially of the same group, originating from a similar source rock, with some facies variation due to variations in organic matter input and degree of maturity. The results also indicated that the crude oil samples were originated from the coaly and carbonaceous shales of Group I, with mixed kerogen of type II/III that could produce gas with minor oil. There is also the possibility that these hydrocarbons were generated from a deeper interval of Group E (higher thermal maturity), deposited in a similar setting as Group I.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"170 ","pages":"Article 107135"},"PeriodicalIF":3.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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