The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Chengbo Lian - One of the best experts on this subject based on the ideXlab platform.
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an inland facies controlled eogenetic karst of the carbonate reservoir in the middle permian maokou formation southern sichuan basin sw china
Marine and Petroleum Geology, 2016Co-Authors: Di Xiao, Xiucheng Tan, Hong Liu, Shujiao Shan, Jiwen Xia, Yao Cheng, Chengbo LianAbstract:Abstract Carbonate karst is one of the research highlights in the field of carbonate reservoir geology. Here, we report on a new type of karst formed in the Middle Permian Maokou Formation, southern Sichuan Basin, SW China, i.e., inland facies-controlled eogenetic karst, which is different from the previously defined telogenetic karst. This karst is eogenetic as the formation was buried at shallow depths prior to being subaerially exposed for a period of 7–8 Myr, in the paleo-continental region of the Upper Yangtze Uplift. Subaerial exposure may have been caused by a sea level regression during the Tungwu Orogeny, which gave rise to a depositional hiatus over a broad area. The top of the Maokou Formation is commonly marked by a weathered crust and an unconformable relationship with overlying layers. Below the surface, the Maokou Formation contains sediments deposited by an underground drainage. The geological setting can be inferred from an inland karst far from coastline. The subsurface karst interval consists mainly of coarse-grained limestone and micrite, with the former occurring in shoal facies deposited in a high-energy depositional environment, and the latter in non-shoal facies deposited in a low-energy environment. Both of them were interbedded with in variable thicknesses. The coarse-grained limestone layers with high porosity and permeability acted as inception horizons, more favourable for the development of karst than the micritic layers with low porosity and permeability. Therefore, in places where both coarse-grained limestone and micrite are present, the karst is considered to be facies-controlled. The primary permeability of the coarse-grained limestone, combined with the permeability provided by faults and fractures, provides sufficient channels for karst water. Formation of the karst system was characterized by contemporaneous development at multiple levels, as controlled by the stratigraphic position of coarse-grained shoal facies. The karst reservoir therefore developed in both karst highland and karst transitional zone (area between the karst highland and karst basin). According to this model of karstification, hydrocarbon exploration should focus on karst highlands located on palaeohighs and in synclines located far from fault zones.
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restoration of paleokarst geomorphology of sinian dengying formation in sichuan basin and its significance sw china
Petroleum Exploration and Development, 2015Co-Authors: Xiucheng Tan, Hong Liu, Chengbo Lian, Sicong Luo, L I Ling, Wei Zeng, Bing Luo, Shujiao ShanAbstract:Abstract Based on newly drilled well data in the Gaoshiti area in the central Sichuan Basin, profile data of more than 150 field outcrops of the regional geological survey, and stratigraphic division and correlation of more than 30 wells in the Sichuan Basin and its adjacent areas, combined with regional seismic data, moldic methods are comprehensively used to restore the karst paleogeomorphy of the Dengying Formation, and thus studying the paleogeographic pattern and the significance of oil and gas exploration. The Sichuan Basin was surrounded by paleo-lands/underwater highlands in the late Sininan Dengying period, including Kangdian paleo-land in the west, Songpan paleo-land in the northwest, Hannan paleo-land in the north, Qianjiang-Zheng'an, Zhenba and Wuxi-Jianshi underwater highlands in the southeast and northeast. The Sichuan Basin was adjacent to Jiangnan Basin southeastwards and Qinling paleo-ocean northeastwards respectively. Affected by the separation of NS-striking Zitong-Junlian Aulacogen, NE-striking Langzhong-Tongjiang and Chongqing-Kaixian depressions in this basin, the Sichuan Basin presents the NS-trending framework of “three uplifts (Zhenba, Chuanzhong and Qianjiang-Zheng'an) and two depressions (Langzhong-Tongjiang and Chongqing-Kaixian)”, and is divided into two relatively isolated EW-trending paleo-uplift systems (NS-striking Mianyang-Leshan-Xichang paleo-uplift and nearly NE-striking Chuanzhong paleo-uplift). Controlled by karst paleogeomorphy of the Sinian Dengying Formation, the pattern of karst landscape consists of five secondary geomorphic units, such as karst highland, karst platform, karst slope, karst depression and karst basin, of which the karst platform and karst slope are the favorable zones for the development of karst reservoirs, providing advantages for the formation of large gas fields.
Ligui Xu - One of the best experts on this subject based on the ideXlab platform.
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three dimensional seismic geomorphology and analysis of the ordovician paleokarst drainage system in the central tabei uplift northern tarim basin western china
AAPG Bulletin, 2011Co-Authors: Hongliu Zeng, Guizhong Wang, Xavier Janson, Robert G Loucks, Bingheng Yuan, Ligui XuAbstract:High-quality three-dimensional seismic data acquired in the central Tabei Uplift, Tarim Basin, western China, provide a rare opportunity to characterize in exceptional detail the three-dimensional geomorphology of a deeply buried (5500–6500 m [18,045–21,325 ft]) Ordovician unconformity and the related paleokarst drainage system. An integrated approach was applied that emphasized integration of seismic data with available conventional core, wireline logs, and age-equivalent outcrops. The exceptional quality of the seismic data allowed a seismic detection limit of karstified features of less than 75 75 m (246 246 ft) horizontally and 6 m (20 ft) vertically. Interpreted geomorphologic and depositional elements include fluvial channels and canyons, fluvial valleys, sinkholes, and tower Karsts and hills. The modern tower karst-drainage system in Guilin, China, is very similar to the mapped Ordovician karst-drainage system and is used as a modern analog. The interaction between the surface karst-drainage system and the shallow-subsurface cave-passage system is evidenced by the observation that surface canyons appear to initiate in areas associated with intense sinkhole development. Also, surface river valleys tend to correspond to dip-oriented surface depressions partly related to near-surface cave collapse. During burial into the deeper subsurface, the combination of intrastratal collapse (karstified strata) and suprastratal collapse (postkarst-deposited strata) created large damage zones hundreds of meters thick and kilometers wide. Coalesced-collapsed paleocave systems can be interpreted from the unique circular pattern of faults (observed in map view) that are associated with seismic bright spots.
Johan Michaux - One of the best experts on this subject based on the ideXlab platform.
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diversity and endemism of murinae rodents in thai limestone Karsts
Systematics and Biodiversity, 2013Co-Authors: Alice Latinne, Surachit Waengsothorn, Prateep Rojanadilok, Krairat Eiamampai, Kriangsak Sribuarod, Johan MichauxAbstract:This study aims to investigate the species diversity of rodents living in karst ecosystems of Thailand. A survey has been conducted throughout Thailand, 122 Karsts sampled and 477 Murinae rodents live-trapped. Phylogenetic reconstructions were carried out using two mitochondrial markers (cytb, COI). A sequence-based species delimitation method completed by the analysis of the level of genetic divergence was then applied to define species boundaries within our dataset. The phylogenetic position of Niviventer hinpoon was also investigated and sequences obtained from the holotype specimen of this species were used to reliably identify samples of N. hinpoon. A total of 12 described Murinae species, corresponding to 17 deeply divergent genetic lineages, were encountered in limestone Karsts of Thailand. Our study revealed an important genetic diversity within the traditionally recognized species Maxomys surifer (four highly divergent genetic lineages), Leopoldamys neilli (two highly divergent genetic lineages) ...
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research article diversity and endemism of murinae rodents in thai limestone Karsts
2013Co-Authors: Alice Latinne, Surachit Waengsothorn, Prateep Rojanadilok, Johan Michaux, Surat ThaniAbstract:This study aims to investigate the species diversity of rodents living in karst ecosystems of Thailand. A survey has been conducted throughout Thailand, 122 Karsts sampled and 477 Murinae rodents live-trapped. Phylogenetic reconstructions were carried out using two mitochondrial markers (cytb, COI). A sequence-based species delimitation method completed by the analysis of the level of genetic divergence was then applied to define species boundaries within our dataset. The phylogenetic position of Niviventer hinpoon was also investigated and sequences obtained from the holotype specimen of this species were used to reliably identify samples of N. hinpoon. A total of 12 described Murinae species, corresponding to 17 deeply divergent genetic lineages, were encountered in limestone Karsts of Thailand. Our study revealed an important genetic diversity within the traditionally recognized species Maxomys surifer (four highly divergent genetic lineages), Leopoldamys neilli (two highly divergent genetic lineages) and Berylmys bowersi (two highly divergent genetic lineages). These species could be considered as species complex and require further taxonomic work. This study also provides valuable information on the distribution of the two rodent species endemic to limestone Karsts of Thailand, L. neilli and N. hinpoon. Leopoldamys neilli was the most abundant species encountered in Thai Karsts during our survey. However, L. neilli specimens from western Thailand are genetically highly divergent from the remaining populations of L. neilli and could represent a separate species. Niviventer hinpoon, phylogenetically closely related to N. fulvescens, is much rarer and its distribution limited to central Thailand. Most of the other captured species are typically associated with forest ecosystems. This study suggests that limestone Karsts play a key role in the preservation of the rodent species endemic to such habitat, but they would also provide refuges for the forest-dwelling Murinae rodents in deforested regions.
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thai limestone Karsts an impending biodiversity crisis
1st EnvironmentAsia International Conference on Environmental Supporting in Food and Energy Security: Crisis and Opportunity Bangkok Thaïlande 22-25 M, 2011Co-Authors: Alice Latinne, Surachit Waengsothorn, Vincent Herbreteau, Johan MichauxAbstract:Due to the high level of endemic species that they support and the high threats they are facing, such as unsustainable limestone quarrying, hunting and urbanization, limestone Karsts are recognized as biodiversity hotspots needing urgent protection. The first aim of our study was to investigate the mammal rodent diversity of Thai limestone Karsts. Our second aim was to examine the diversity at a finer scale than the species level (intraspecific biodiversity) using phylogeographic approaches. Therefore, we studied the phylogeographic structure of a threatened rodent, endemic to limestone Karsts of Thailand, the Murinae Leopoldamys neilli. We sampled 76 limestone Karsts in whole Thailand and live-trapped 444 rodents including 115 Leopoldamys neilli. Our study revealed an important rodent diversity in Thai limestone Karsts. Besides endemic rodent species, Karsts also host typical forest species to which they provide forest refugia in deforested regions. At the intraspecific level, our study revealed an unexpected high level of genetic differentiation within the rodent species L. neilli. As each limestone area of Thailand is characterized by a particular genetic lineage of L. neilli, the destruction of these Karsts would lead to the disappearance of unique intraspecific strains not found elsewhere. Our results highlight the importance of protecting limestone habitats to preserve not only their interspecific but also intraspecific rodent diversity that is highly threatened as more than 20% of limestone Karsts in Thailand have already been quarried. Management plans of limestone, a non-renewable resource, should urgently take into account this high biological importance of Karsts. (Resume d'auteur)
Hong Liu - One of the best experts on this subject based on the ideXlab platform.
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restoration of paleokarst landform and its geological significance a case from middle permian maokou formation in northwestern sichuan basin
Petroleum Exploration and Development, 2016Co-Authors: Di Xiao, Dahai Tang, Xiucheng Tan, L I Haiyun, Jirong Xie, Hong Liu, Xun Yang, Benjian ZhangAbstract:Abstract Based on the analysis of deposition and tectonism, “residual thickness method” is used to restore the paleokarst landform of Middle Permian Maokou Formation in northwestern Sichuan Basin. With the feature of plain with karst hilllock, the paleokarst landform in this area can be classified into three secondary geomorphic units: karst platform, karst slope and karst groove, in which the karst hillocks and monadnocks on karst platform and karst slope are the favorable zones for the development of karst reservoirs, and favorable exploration zones in the next step. Furthermore, in the karst grooves, the Maokou Formation are often denuded into Members Mao 3 or Mao 2, and the seismic profiles show the top of Maokou Formation in karst groove is missing due to erosion. Members Mao 4 and Mao 3 are generally preserved in the karst platform. The seismic profiles across the karst platform and karst groove show that the NE and NW striking erosion grooves were the result of differential uplift and erosion caused by basement faulting at the end of Middle Permian, which then successively developed and formed the NW striking Guangyuan-Wangcang and the NE striking Jiangyou-Guangyuan troughs in Changxing Period. It is suggested to pay more attention to the geological research and exploration of the shallow carbonate platform areas adjacent to the syneclise and trough in fairly deep water.
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an inland facies controlled eogenetic karst of the carbonate reservoir in the middle permian maokou formation southern sichuan basin sw china
Marine and Petroleum Geology, 2016Co-Authors: Di Xiao, Xiucheng Tan, Hong Liu, Shujiao Shan, Jiwen Xia, Yao Cheng, Chengbo LianAbstract:Abstract Carbonate karst is one of the research highlights in the field of carbonate reservoir geology. Here, we report on a new type of karst formed in the Middle Permian Maokou Formation, southern Sichuan Basin, SW China, i.e., inland facies-controlled eogenetic karst, which is different from the previously defined telogenetic karst. This karst is eogenetic as the formation was buried at shallow depths prior to being subaerially exposed for a period of 7–8 Myr, in the paleo-continental region of the Upper Yangtze Uplift. Subaerial exposure may have been caused by a sea level regression during the Tungwu Orogeny, which gave rise to a depositional hiatus over a broad area. The top of the Maokou Formation is commonly marked by a weathered crust and an unconformable relationship with overlying layers. Below the surface, the Maokou Formation contains sediments deposited by an underground drainage. The geological setting can be inferred from an inland karst far from coastline. The subsurface karst interval consists mainly of coarse-grained limestone and micrite, with the former occurring in shoal facies deposited in a high-energy depositional environment, and the latter in non-shoal facies deposited in a low-energy environment. Both of them were interbedded with in variable thicknesses. The coarse-grained limestone layers with high porosity and permeability acted as inception horizons, more favourable for the development of karst than the micritic layers with low porosity and permeability. Therefore, in places where both coarse-grained limestone and micrite are present, the karst is considered to be facies-controlled. The primary permeability of the coarse-grained limestone, combined with the permeability provided by faults and fractures, provides sufficient channels for karst water. Formation of the karst system was characterized by contemporaneous development at multiple levels, as controlled by the stratigraphic position of coarse-grained shoal facies. The karst reservoir therefore developed in both karst highland and karst transitional zone (area between the karst highland and karst basin). According to this model of karstification, hydrocarbon exploration should focus on karst highlands located on palaeohighs and in synclines located far from fault zones.
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restoration of paleokarst geomorphology of sinian dengying formation in sichuan basin and its significance sw china
Petroleum Exploration and Development, 2015Co-Authors: Xiucheng Tan, Hong Liu, Chengbo Lian, Sicong Luo, L I Ling, Wei Zeng, Bing Luo, Shujiao ShanAbstract:Abstract Based on newly drilled well data in the Gaoshiti area in the central Sichuan Basin, profile data of more than 150 field outcrops of the regional geological survey, and stratigraphic division and correlation of more than 30 wells in the Sichuan Basin and its adjacent areas, combined with regional seismic data, moldic methods are comprehensively used to restore the karst paleogeomorphy of the Dengying Formation, and thus studying the paleogeographic pattern and the significance of oil and gas exploration. The Sichuan Basin was surrounded by paleo-lands/underwater highlands in the late Sininan Dengying period, including Kangdian paleo-land in the west, Songpan paleo-land in the northwest, Hannan paleo-land in the north, Qianjiang-Zheng'an, Zhenba and Wuxi-Jianshi underwater highlands in the southeast and northeast. The Sichuan Basin was adjacent to Jiangnan Basin southeastwards and Qinling paleo-ocean northeastwards respectively. Affected by the separation of NS-striking Zitong-Junlian Aulacogen, NE-striking Langzhong-Tongjiang and Chongqing-Kaixian depressions in this basin, the Sichuan Basin presents the NS-trending framework of “three uplifts (Zhenba, Chuanzhong and Qianjiang-Zheng'an) and two depressions (Langzhong-Tongjiang and Chongqing-Kaixian)”, and is divided into two relatively isolated EW-trending paleo-uplift systems (NS-striking Mianyang-Leshan-Xichang paleo-uplift and nearly NE-striking Chuanzhong paleo-uplift). Controlled by karst paleogeomorphy of the Sinian Dengying Formation, the pattern of karst landscape consists of five secondary geomorphic units, such as karst highland, karst platform, karst slope, karst depression and karst basin, of which the karst platform and karst slope are the favorable zones for the development of karst reservoirs, providing advantages for the formation of large gas fields.
Di Xiao - One of the best experts on this subject based on the ideXlab platform.
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restoration of paleokarst landform and its geological significance a case from middle permian maokou formation in northwestern sichuan basin
Petroleum Exploration and Development, 2016Co-Authors: Di Xiao, Dahai Tang, Xiucheng Tan, L I Haiyun, Jirong Xie, Hong Liu, Xun Yang, Benjian ZhangAbstract:Abstract Based on the analysis of deposition and tectonism, “residual thickness method” is used to restore the paleokarst landform of Middle Permian Maokou Formation in northwestern Sichuan Basin. With the feature of plain with karst hilllock, the paleokarst landform in this area can be classified into three secondary geomorphic units: karst platform, karst slope and karst groove, in which the karst hillocks and monadnocks on karst platform and karst slope are the favorable zones for the development of karst reservoirs, and favorable exploration zones in the next step. Furthermore, in the karst grooves, the Maokou Formation are often denuded into Members Mao 3 or Mao 2, and the seismic profiles show the top of Maokou Formation in karst groove is missing due to erosion. Members Mao 4 and Mao 3 are generally preserved in the karst platform. The seismic profiles across the karst platform and karst groove show that the NE and NW striking erosion grooves were the result of differential uplift and erosion caused by basement faulting at the end of Middle Permian, which then successively developed and formed the NW striking Guangyuan-Wangcang and the NE striking Jiangyou-Guangyuan troughs in Changxing Period. It is suggested to pay more attention to the geological research and exploration of the shallow carbonate platform areas adjacent to the syneclise and trough in fairly deep water.
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an inland facies controlled eogenetic karst of the carbonate reservoir in the middle permian maokou formation southern sichuan basin sw china
Marine and Petroleum Geology, 2016Co-Authors: Di Xiao, Xiucheng Tan, Hong Liu, Shujiao Shan, Jiwen Xia, Yao Cheng, Chengbo LianAbstract:Abstract Carbonate karst is one of the research highlights in the field of carbonate reservoir geology. Here, we report on a new type of karst formed in the Middle Permian Maokou Formation, southern Sichuan Basin, SW China, i.e., inland facies-controlled eogenetic karst, which is different from the previously defined telogenetic karst. This karst is eogenetic as the formation was buried at shallow depths prior to being subaerially exposed for a period of 7–8 Myr, in the paleo-continental region of the Upper Yangtze Uplift. Subaerial exposure may have been caused by a sea level regression during the Tungwu Orogeny, which gave rise to a depositional hiatus over a broad area. The top of the Maokou Formation is commonly marked by a weathered crust and an unconformable relationship with overlying layers. Below the surface, the Maokou Formation contains sediments deposited by an underground drainage. The geological setting can be inferred from an inland karst far from coastline. The subsurface karst interval consists mainly of coarse-grained limestone and micrite, with the former occurring in shoal facies deposited in a high-energy depositional environment, and the latter in non-shoal facies deposited in a low-energy environment. Both of them were interbedded with in variable thicknesses. The coarse-grained limestone layers with high porosity and permeability acted as inception horizons, more favourable for the development of karst than the micritic layers with low porosity and permeability. Therefore, in places where both coarse-grained limestone and micrite are present, the karst is considered to be facies-controlled. The primary permeability of the coarse-grained limestone, combined with the permeability provided by faults and fractures, provides sufficient channels for karst water. Formation of the karst system was characterized by contemporaneous development at multiple levels, as controlled by the stratigraphic position of coarse-grained shoal facies. The karst reservoir therefore developed in both karst highland and karst transitional zone (area between the karst highland and karst basin). According to this model of karstification, hydrocarbon exploration should focus on karst highlands located on palaeohighs and in synclines located far from fault zones.
