Reservoir Basin Research Articles

Sistem Distribusi Dan Pemenuhan Kebutuhan Air Bersih Di Desa Lonthoir, Kecamatan Banda Kabupaten Maluku Tengah

Distribution System and Fulfillment of Clean Water Needs in Lonthoir Village, Banda Sub-district, Central Maluku Regency, with a pipeline network only in a few houses, so there are still many residents who do not have a clean water network. In addition, the quality of the existing water network is unknown. This study aims to determine the distribution system and fulfillment of clean water needs in Lonthoir Village, Central Maluku District. The type of research used is descriptive analytic using Cross Sectional design, with 2 research samples, namely water samples (reservoir basins and community basins) and community samples (consisting of 10 respondents). The results showed that in Lonthoir Village one of the things that made the water distribution system less fulfilled: the reservoir tub was only 5x6, the pipe used to be estimated from the broncaptering to the reservoir tub was still using a 5 inch pipe and from the reservoir tub to the community the pipe used was the same. Fulfillment of clean water needs is less fulfilled if water is distributed from the reservoir. The flowed water still uses gravity to slow down the distribution of water to the community while the water demand for the community itself is >200 L / day. In addition, the results of the lab test for the two existing water samples contained 1 indicator of the chemical parameters that did not meet the maximum quality standards that did not meet the requirements of PERMENKES No. 32 of 2017, namely the Ph indicator element.

Evolution processes and diagenetic response of paleo-pore fluids in continental rift basin: A case study of Bonan Sag

Evolution and transport processes of pore fluids are accompanying with the burial process of sedimentary basins. Those processes lead to redistribution of materials and energies, and control the distribution of favorable reservoirs in sedimentary basins too. For petroliferous basins, confirming the evolution processes of pore fluids is useful for favorable reservoirs prediction. In this study, formation waters chemistry characteristics, skeleton particle compositions, and diagenetic products of sandstones were all take into consideration. It is to invert the evolution processes of pore fluids in continental rift basin. This study shows the changes of formation waters, diagenetic products and skeleton particle compositions are regularly with depth. The evolution processes of pore fluids are mainly controlled by basin sinking and uplifting, fluids concentration, mudstones compaction, organic matter evolution, diagenesis. The evolution of pore fluids in Bonan Sag have experienced seven stage: firstly, primary lake water; and then alkaline fluids from mudstone, which is caused by compaction; and then acidic fluids with organic acids; and then the alkaline fluids, which is caused by basin uplifting and water-rock interactions; and then acidic fluids with CO2, which is from cracking of organic matters; and then acidic fluids with CO2/H2S which caused by TSR; at last, alkaline fluids caused by deep buried and water-rock interactions. Changes of pore fluids (physical or chemical) lead parts of minerals in sandstones be unstable, and then dissolved by pore fluids. At the same time, part of dissolved particles in pore fluids reacted with each other, and then precipitated as diagenetic products.

Inter-basin water transfers under changing climate and land use: Assessing water security and hydropower in the Paraíba do Sul River basin, Brazil

The intensification of climate extremes and land uses poses a major challenge for water managers, especially in heavily populated basins with large reservoirs, multiple uses, and inter-basin transfers. In this study, we analyzed water security in the Paraíba do Sul River basin, responsible for supplying a significant fraction of the needs of Brazil's two largest metropolitan areas through water transfer. Unless existent studies emphasize aspects of water scarcity disregarding other competitive water use, we considered the impacts on hydropower generation in a fully integrated modeling framework, which includes reservoir operation rules. To achieve this, we integrated future projections of land uses, global climate change (RCP 4.5 and RCP 8.5), and water demand for the period 2016–2055. Most of the climate change scenarios suggested a reduction in the frequency of both high and low flows, by nearly 25%, which resulted in an increase in flow regularization in the main basin's reservoirs. An undesirable consequence of those trends was the reduction of hydropower generation. Regarding water supply to the metropolis outside the basin, results indicated a possibility of a more contentious water governance scenario. The long-term sustainability of the basin's water resources will require implementing policies to enhance water use efficiency and reuse, in combination with other renewable energy sources.

Fluid evolution and gas enrichment in the Wufeng-Longmaxi shale reservoirs of the eastern Sichuan Basin, SW China

Abundant calcite and quartz veins have been developed in the Wufeng-Longmaxi (O3w-S1l) shale reservoirs, which are direct records of fluid flow events in the southern Jiaoshiba area, Sichuan Basin. To investigate their origin and timing, multiple in-situ analytical approaches were conducted on selected calcite and quartz veins. Three stages of calcite veins and two stages of quartz veins are identified in the studied region as: stage 1 calcite veins (Cal-1 veins), stage 2 quartz veins (Qtz-1 veins), stage 3 calcite veins (Cal-2 veins), stage 4 quartz veins (Qtz-2 veins), and stage 5 calcite veins (Cal-3). The Cal-1, Qtz-1, Cal-2, Qtz-2, and Cal-3 veins were formed at 177–166 Ma, 167–145 Ma, 156–145 Ma, 84–83 Ma, and 65 Ma, respectively, as indicated by combining with fluid inclusions data in both the calcite and quartz veins and burial-thermal history reconstruction. Intra-layer diagenetic fluid in the O3w-S1l shale was responsible for the formation of Cal-1, Qtz-1, Cal-2, and Qtz-2 veins. The Cal-3 veins were only identified in the O3w-S1l shale reservoirs of the Zilichang zone, and the vein-forming fluid was derived from extraneous fluids under an oxidative environment. In addition, methane inclusions in the calcite and quartz veins show three episodes of natural gas expulsion in the southern Jiaoshiba area. Due to the effective sealing capabilities of shale, the three episodes of gas expulsion were transported for a short distance within the O3w-S1l shale reservoirs in the Piangqiao zone. The last episode of gas expulsion occurred in the Zilichang zone during the Late Yanshanian uplift was corresponded to the formation of Cal-3 veins. Extraneous fluid can infiltrate the reservoir through the local fault-fracture systems in the Zilichang zone, indicating the destruction of sealing capability. Our methane inclusion data analysis indicates the loss of shale gas in the Zilichang zone, which was potentially associated with the fluid flow responsible for the formation of Cal-3 vein in the O3w-S1l shale reservoirs. Fluid evolution in different gas-bearing shale reservoirs reveals preservation conditions during the process and has an implication for the differential enrichment of shale gas.

Catch dynamics of freshwater bram Abramis brama in the Ob river basin as a reflection of the success of its acclimatization

The native range of the freshwater bream Abramis brama includes the basins of the North, Baltic, White, Azov, Black, Caspian and Aral seas. This species is not a popular object of aquaculture, but it is cultivated in some countries of Eastern Europe and Central Asia. In the water bodies of Italy, Spain, Portugal, England and China, it is a naturalized alien species that does not have a large number. At first freshwater bream was introduced into the Ob basin in 1862, in the reservoirs of the eastern slope Urals. By the end of the 19th century, bream became common in this region, but spread slowly downstream: in the Lower Irtysh it was noted only in the mid-1920s, and entered the commercial statistics in 1936. It became known in the Middle Irtysh in the 1930s, but it became an object of fishing only in 1963. In the lakes of the Ob-Irtysh interfluve, at first bream was introduced in 1928. In the largest of them, it became naturalized. In the Ubinskoye lake the bream formed a stable self-reproducing population, which served as a source of juvenile bream for resettlement in water bodies of Siberia and Kazakhstan in the middle of the twentieth century. Currently, the bream in the Ubinskoye lake does not inhabit due to the shall owing of the lake. Bream was introduced into the Novosibirsk reservoir in 1957–1960. It quickly became numerous and began to spread up and down the river Ob. It has been known in the Upper Ob in the Altai Region since the early 1960s, and in the Middle Ob in the Tomsk Region since the end of the same decade. Currently, the catch of bream in the Ob basin are maximum in the Bukhtarma reservoir, relatively large in the Novosibirsk reservoir and in the water bodies of the Khanty- Mansiysk Autonomous Region. At the same time, the share of this species in the total volume of fish catch in large reservoirs of the Ob basin is about 80% of the fishing, in the Middle Ob and Middle Irtysh — about 20%, and in the north of Western Siberia — less than 0.5%. The decrease in the share of bream in the fishery from south to north reflects not only a decrease in the abundance of this species in the latitudinal direction, but also an increase in the stocks of native fish species.

Shale Gas Reservoir Pore Pressure Prediction: A Case Study of the Wufeng–Longmaxi Formations in Sichuan Basin, Southwest China

Pore pressure prediction is critical for shale gas reservoir characterization and simulation. The Wufeng–Longmaxi shale, in the southeastern margin of the Sichuan Basin, is identified as a complex reservoir affected by overpressure generation mechanisms and variability in lithification. Thus, standard methods need to be adapted to consistently evaluate pore pressure in this basin. Based on wireline logs, formation pressure tests, and geological data, this study applied the Eaton–Yale approach, which extends the theoretical basis of Eaton and Bowers methods to reservoir geological conditions and basin history. The method was developed by integrating petrophysical properties, rock physics interpretations, and geology information. The essential steps include (1) a multi-mineral analysis to determine mineral and fluid volumes; (2) a determination of the normal pressure trend line and extending it to overpressured sections; (3) predicting pore pressure using the basic Eaton approach and identifying overpressured zones; (4) correcting compressional velocity using lithology logs and a rock physics model; (5) determining the Biot Alpha coefficient and vertical-effective stress and estimating the new pore pressure values using the Eaton–Yale method. Overpressure zones were corrected, and reservoir pore pressure varied between 30.354 and 34.959 MPa in the wells. These research results can provide a basis for building reservoir simulation models, identifying reservoir boundaries, and predicting relative permeability.

Influence of Grain on Green Patterns and Their Underlying Surface Characteristics on Water Conservation: A Case Study in a Semiarid Area

Water-conservation enhancement is a crucial objective of regional ecological restoration projects in arid and semiarid areas, and it is significantly influenced by land use/cover change (LUCC). The Grain for Green Project (GFGP) is a common strategy for ecological restoration. However, insufficient attention has been paid to the impact of reforestation patterns and the underlying surface characteristics on the effectiveness of GFGP in enhancing water conservation. In this study, a Soil and Water Assessment Tool (SWAT) scenario-based simulation was conducted to assess changes in water-conservation depth (WCD) in the Zhangjiakou section of the Guanting Reservoir basin. Redundancy analysis (RDA) and a mixed linear model were employed to determine the effects of different reforestation patterns and their underlying slope gradient and soil-type characteristics on WCD variation. The results showed that there were differences in the effect characteristics of reforestation patterns and different vegetation types on WCD changes; the effectiveness of increased water conservation is associated with the adaptation of reforestation plants to underlying characteristics. Returning farmland to evergreen forests was the most effective approach, leading to a relative increase in WCD that was 2.6 times greater than the relative increase in total WCD. WCD decreased with the slope gradient, with WCD decreasing by 0.2 mm for every 1° increase in slope. Converting grassland to evergreen forests on slopes greater than 16.19° and converting deciduous forests to grassland on slopes less than 16.19° would further increase WCD, promoting the synergistic development of ecosystem services. This study provides insights into the development of more efficient reforestation strategies to enhance water conservation in a complex terrain area.

Ecological, epizootic, sanitary and hygienic problems of echinococcosis in domestic goats and dogs in the North Caucasus

Echinococcal invasion, included by the World Health Organization in the list of especially socially dangerous parasitic zoonoses, is an unresolved epidemic, epizootic and sanitary-hygienic problem for the population and animals in more than 250 countries of the world. The purpose of the research was to study the epizootic and sanitary-hygienic problems of echinococcosis of domestic goats in the North Caucasus region. In 2019-2022, the research was carried out in 3 climatic zones of Kabardino-Balkaria. The objects were liver and lungs of 120 slaughter goats. The intestines were dissected from 15 dog corpses slaughtered in accordance with the International Rules for the Humane Treatment of Animals (2012). Monitoring of echinococcosis in dogs and goats was performed by the method of autopsy of organs and tissues according to K.I. Scriabin (1928). The number of eggs of taeniid type in faeces of dogs and in 520 samples of water from natural reservoirs of the Terek river basin was determined according to the guidelines of Russian Research Institute of Parasitology (1986). In plain climatic zone, index of occurrence of cystic Echinococcus granulosus invasion in liver and lungs of goats was 18 %, in foothill zone - 24 %, in mountain zone - 28 % (on average, 25 %). Extracted from liver and lungs of sheep, transparent cysts of echinococcus contained protoscolexes in 100 % of the samples, which indicates the likelihood of foci involving dogs and wild predators in the region. Natural reservoirs of Kabardino-Balkaria are also large biotopes of teniosis. Contamination of river water samples with taeniid eggs is 11.037.0 %. The region belongs to the group of subjects with high rates of zoonosis in animals due to violation of the terms of deworming for priotary dogs, lack of sanitary and preventive work with the population. According to the epizootic situation for animal echinococcosis, the Kabardino-Balkarian Republic can be attributed to disadvantaged regions of the Russian Federation, as there is an increase in the number of dogs with echinococcosis and goats infected with fertile cysts. Sanitary and hygienic pollution of the Terek river and its tributaries, Malka, Baksan, Cherek and Chegem, with eggs of cestodes is a threat to the spread of echinococcosis among animals and humans.

Segmentation and lateral growth of intracratonic strike-slip faults in the northern Tarim Basin, NW China: influences on Ordovician fault-controlled carbonate reservoirs

Intracratonic strike-slip faults have been recognized as a major factor controlling the formation of fracture-cave carbonate reservoirs in deep buried basins, yet which properties and how the strike-slip faults influence reservoir distribution and their connectivity are still ambiguous. This uncertainty significantly restricts hydrocarbon exploration and development, such as in the Fuman oilfield, northern Tarim Basin, NW China. Using a high-resolution 3D seismic reflection survey and borehole data, we investigated the geometry and kinematic evolution of the FI17 fault zone in the Fuman oilfield. This fault zone is characterized by a single fault zone, pop-up or pull-apart structures, right-stepping en echelon normal faults, and much smaller displacement (<30 m) normal fault arrays from bottom to top. The FI17 fault zone consists of four genetic segments, including the extensional strike-slip duplex, Riedel left-lateral shear, right-stepping horsetail splay, and horizontal slip segments in map view. In particular, the formation of the ∼18 km Riedel shear zone is characterized by the growth and linkage of segmented shear faults (synthetic and secondary synthetic shears). We observed that the large-scale fault-controlled fracture-cave reservoirs are distributed in positions with wider fault zones, which are characterized by overlapping of neighboring secondary shear faults. Furthermore, the reservoir width examined in this study is natural logarithmic correlated (positively) to the fault zone width. The reservoirs linked by the same shear faults show better internal connectivity. The spatial coherence between fault geometry and reservoir features indicates that segmentation and lateral growth of intracratonic strike-slip faults controls the occurrence of fracture-cave reservoirs, which may provide support for reservoir prediction in the Fuman oilfield and other deeply buried fault-controlled carbonate reservoirs in general.

Characterization of organic phosphorus in soils and sediments of a typical temperate forest reservoir basin: Implications for source and degradation

Reservoirs can intercept upstream inputs and greatly alter their migration and transformation processes at a basin scale. Taking a typical reservoir basin in the Xiaoxing'an Mountains of Northeast China as an example, the organic phosphorus (Po) and organic matter (OM) compositions in the upstream soil, river and reservoir sediments were characterized by 31P NMR, stable carbon (δ13C) and nitrogen isotopes (δ15N), and the migration and transformation processes of Po from soil to reservoir sediments were explored. The compositional data indicated that both the OM and Po in the reservoir were mainly imported by C3 plants from the upper reaches. Higher monoester phosphorus (P) components in the upstream soils than in the reservoir sediments, which indicated the migration and degradation process of Po from the upstream soils to the river and then to the reservoir sediments. The degradation rate of monoester P was higher, approximately 30.6% and the phosphonate fraction had the lowest degradation rate, about 0.4%. Specifically, the degradation of monoester P including inositol P was higher than that of organic carbon. Thus, at the basin scale, more forest-derived organic carbon was likely intercepted by reservoirs and precipitated to sediments, while Po might degrade to a greater extent. Aggregative results showed that reservoirs may play an important role in the differentiated migration and transformation process of forest-derived OM and Po. And then, the highly degradable Po including inositol P poses a greater risk of eutrophication in the typical temperate forest reservoirs and their downstream, even the ocean, and is accompanied by possible algal blooms in the future. Information derived from this study provides a more scientific basis for the assessment of the ecological and environmental effects of reservoir and dam construction projects.

The consequences of neglecting reservoir storage in national‐scale hydrologic models: An appraisal of key streamflow statistics

AbstractA better understanding of modeled streamflow errors related to basin reservoir storage is needed for large regions, which normally have many ungaged basins with reservoirs. We quantified the difference between modeled and observed streamflows for one process‐based and three statistical‐transfer hydrologic models, none of which explicitly accounted for reservoir storage. Streamflow statistics representing low to high flows, seasonality, annual variability, and daily autocorrelation were examined at 1082 study basins across the conterminous USA. All models increasingly overpredict (or decreasingly underpredict) observed annual maximum flows with increasing storage. Correlations between absolute values of errors for low‐flow statistics and storage are often larger in magnitude than those for signed errors—additional storage is associated with increases in model errors in both directions even when its overall effect in one direction is weak. The rate of increase in absolute values of model errors was nonlinear for most statistics. For low flows, model errors had a change point to larger errors at 48 days of reservoir storage (relative to long‐term mean daily flow); mean and high flows had change points at 147 to 176 days. We present predicted‐to‐observed errors for nine streamflow statistics over a large range of reservoir storage to help modelers and users of modeled streamflow understand the amount of storage for which explicit reservoir modeling is needed.

Methodology for the study of the traceability of runoff water feeding reservoirs

Abstract Water reservoirs are essential to ensure water supply to both the population and agriculture, especially in the Mediterranean basin. In some cases, analyses of water intended for human consumption have detected high levels of agrochemicals. Knowing the possible origin of these products is complex because there may be many agricultural plots within the reservoir basin. In this paper, we introduce a methodology to obtain the set of agricultural plots whose rainwater reaches the reservoir and in what proportion they affect the points where chemical analyses are performed. The method implements an extension of the D8 algorithm for the calculation of the drainage network, in which additional information about the land-use type of the area, as well as rainfall maps, are also considered. In order to facilitate the user's analysis of the data, a plugin has been implemented in QGIS. This allows usability and easy interaction with the visual information. The Rumblar reservoir basin, located in Andalusia (Spain) has been studied as a use case, surrounded by olive orchards. The result is a replicable methodology for any other water reservoir and for carrying out an individualized study of agricultural plots.

Numerical simulation of optimization of volume fracturing parameters for horizontal wells in tight oil

ABSTRACT A comprehensive workflow for optimizing the fracturing parameters of horizontal wells in tight oil reservoirs is demonstrated. A numerical simulation model with geologic characterization data from Cangdong Sag Basin reservoirs was constructed. Geometrical parameters of the fractures were calculated through a volumetric model of the fracture network. The fracture lengths, heights, and network radius were optimized using dynamic local grid refinement. The equivalent stimulated reservoir volume considering fracture propagation was then simulated. Based on the simulation results of the mechanism model, after considering factors such as interfracture interference, fracturing operation duration, cost, and construction safety, the following optimal ranges of fracturing parameters are recommended: number of fracturing fractures = 8–11 levels, half-length of fracturing fractures = 130–160 m, and conductivity of fracturing fractures = 14–20 D∙cm. Based on the actual situation of the work area, it is recommended that the number of fracturing fractures be 9, the half-length of the fracture be 150 m, and the fracture conductivity be 18 D∙cm to achieve higher horizontal well production and provide a certain data reference for the efficient development of similar dense oil reservoirs.

Predictive simulation and optimal allocation of surface water resources in reservoir basins under climate change

Predicting and allocating surface water resources are becoming increasingly important tasks for addressing the risk of water shortages and challenges of climate change, especially in reservoir basins. However, surface water resource management includes many systematic uncertainties and complexities that are difficult to address. Thus, advanced models must be developed to support predictive simulations and optimal allocations of surface water resources, which are urgently required to ensure regional water supply security and sustainable socioeconomic development. In this study, a soil and water assessment tool-based interval linear multi-objective programming (SWAT-ILMP) model was developed and integrated with climate change scenarios, SWAT, interval parameter programming, and multi-objective programming. The developed model was applied to the Xinfengjiang Reservoir basin in South China and was able to identify optimal allocation schemes for water resources under different climate change scenarios. In the forecast year 2025, the optimal water quantity for power generation would be the highest and account for ∼60% of all water resources, the optimal water quantity for water supply would account for ∼35%, while the optimal surplus water released from the reservoir would be the lowest at ≤5%. In addition, climate change and reservoir initial storage would greatly affect the surplus water quantity but not the power generation or water supply quantity. In general, the SWAT-ILMP model is applicable and effective for water resource prediction and management systems. The results from different scenarios can provide multiple alternatives to support rational water resource allocation in the study area.

Study on the migration law of biogenic substances under different scheduling schemes of reservoirs

In order to study the migration process of biogenic substances in river basins under reservoir regulation and quantify the migration characteristics of nitrogen and phosphorus pollution in the middle and lower reaches of the Lancang River cascade reservoir basin. This article constructs a simulation model for the migration of biogenic substances in the Lancang River Basin based on the SWAT model, and preliminarily simulates the migration process of nitrogen and phosphorus in the basin. The results indicate that the model has good applicability in the Lancang River basin, with the NSE coefficient of 0.76 and the R2 coefficient of 0.78. Moreover, there is a roughly positive correlation between nitrogen and phosphorus production and rainfall distribution in the basin, but rainfall is not the only factor determining the distribution of nitrogen and phosphorus pollution load. By inputting different reservoir regulation schemes into the reservoir regulation module, the migration processes of nitrogen and phosphorus in various sections of the watershed under natural conditions, conventional regulation, power generation regulation, and ecological regulation schemes are calculated. The results indicate that the conventional and power generation scheduling schemes have a significant impact on the migration of total nitrogen and phosphorus in the watershed, leading to a certain retention and accumulation effect of nitrogen and phosphorus in the reservoir. However, the ecological scheduling scheme to some extent reduces the impact of reservoir scheduling on the migration of biogenic substances.

“Tri-in-One” Accumulation Model of Lithologic Reservoirs in Continental Downfaulted Basins: A Case Study of the Lithologic Reservoir of Nantun Formation in Tanan Sag, Mongolia

This article analyzes the key controlling factors and hydrocarbon distribution rules of lithologic reservoirs in a continental downfaulted basin according to the structural features, sedimentary evolution, types of sedimentary facies, source rock features, diagenesis evolution, reservoir features, hydrocarbon formation mechanisms, exploration status, and hydrocarbon resource potential. The results show that three major controlling factors (sandbody types, effective source rocks, and effective reservoirs) and one coupled factor (fractures that act as a tie) influence hydrocarbon accumulation in the lithologic traps in the Nantun Formation in Tanan Sag. With the increase in depth, sufficient hydrocarbon is generated in the source rock with thermal evolution. When the depth threshold is reached and critical conditions of hydrocarbon supply are met, hydrocarbon generation and expulsion are more intensive. Traps that are surrounded or contacted by source rock or connected by faults are able to form reservoirs. As the buried depth increases, the intensity of hydrocarbon generation–expulsion grows, and the trap is more petroliferous. Hydrocarbon accumulation and reservoir formation are also controlled by sandbody accumulation conditions. When the critical conditions for hydrocarbon generation are met and concrete oil and gas are charged in, the better physical properties of the sandbody will always indicate more hydrocarbon accumulation in the trap. The allocation of sand type, effective source rock, and an effective reservoir is optimized under the effect of fractures and the coupled hydrocarbon reservoir with these three elements.

Fracture Characterization Explores Potential of Phra Wihan Formation, Thailand

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 22845, “Fracture Characterization and Basement Reservoir Potential of Phra Wihan Formation in Southern Part of Uttaradit Province, Northern Thailand,” by Watcharapong Piewmoh, SPE, PTTEP, and Pitsanupong Kanjanapayont, Chulalongkorn University. The paper has not been peer reviewed. Copyright 2023 International Petroleum Technology Conference. Reproduced by permission. _ The complete paper describes the characterization of fractures in the Mesozoic sandstones of the Phra Wihan Formation in northern Thailand. Fracture characterization of outcrop analogs is important to determine the potential of subsurface reservoirs. The methodology used field study and petrography analysis to determine the relationship of fractures and other structures such as bedding planes and fold geometry. In addition, microstructure analysis can assist in the evaluation of a reservoir’s potential. Introduction Basement reservoir sandstones are one of the main targets in a mature onshore oil field in Thailand. But most basement reservoirs of the onshore Tertiary basin are pre-Tertiary and are associated with low quality. Prediction of reservoir quality in low-porosity and -permeability conditions requires an understanding of fractures in the subsurface. Outcrop analogs are key in characterizing fractured reservoirs. Geological Setting The tectonic evolution of Thailand is detailed in the complete paper. The country’s primary geological provinces are subdivided into the following five components, from west to east: - Sibumasu terrane - Inthanon zone - Sukhothai terrane - Nan and Sra Keao sutures - Indochina terrane The Sibumasu and Indochina terranes are major continental masses that collided during the Devonian-Triassic. Two subparallel suture zones exist along the convergence between the Sibumasu and Indochina terranes; one is an accretionary complex defined by the Inthanon zone. Another is a closed back-arc basin defined by the Nan and Sra Keao sutures. The Sukhothai terrane is an island-arc system formed along the margin of the Indochina terrane.

Subaqueous volcanic eruptive facies, facies model and its reservoir significance in a continental lacustrine basin: A case from the Cretaceous in Chaganhua area of southern Songliao Basin, NE China

The conventional lithofacies and facies model of subaerial and marine pyroclastic rocks cannot reflect the characteristics of subaqueous volcanic edifice in lacustrine basins. In order to solve this problem, the lithofacies of subaqueous eruptive pyroclastic rocks is discussed and the facies model is established by taking the tuff cone of Cretaceous Huoshiling Formation in the Chaganhua area of the Changling fault depression, Songliao Basin as the research object. The results indicate that the subaqueous eruptive pyroclastic rocks in the Songliao Basin can be divided into two facies and four subfacies. The two facies are the subaqueous explosive facies and the volcanic sedimentary facies that is formed during the eruption interval. The subaqueous explosive facies can be further divided into three subfacies: gas-supported hot pyroclastic flow subfacies, water-laid density current subfacies and subaqueous fallout subfacies. The volcanic sedimentary facies consists of pyroclastic sedimentary rocks containing terrigenous clast subfacies. A typical facies model of the tuff cone that is formed by subaqueous eruptions in the Songliao Basin was established. The tuff cone is generally composed of multiple subaqueous eruption depositional units and can be divided into two facies associations: near-source facies association and far-source facies association. The complete vertical succession of one depositional unit of the near-source facies association is composed of pyroclastic sedimentary rocks containing terrigenous clast subfacies, gas-supported hot pyroclastic flow subfacies, water-laid density current subfacies and subaqueous fallout subfacies from bottom to top. The depositional unit of the far-source facies association is dominated by the subaqueous fallout subfacies and contains several thin interlayered deposits of the water-laid density current subfacies. The gas-supported hot pyroclastic flow subfacies and the pyroclastic sedimentary rocks containing terrigenous clast subfacies are favorable subaqueous eruptive facies for reservoirs in continental lacustrine basins.

Development and application of a multi-centre cloud platform architecture for water environment management

To promote the intelligent and accurate management of river basins, especially large basins which involve many catchments, it is highly required to develop a useful platform to effectively coordinate arithmetic resources and data, and simultaneously help to make decisions based on the real-time calculation. In this study, a multi-centre cloud platform architecture called 3L4C was constructed, which includes a Cloud-edge-terminal Layer (3L), data centre, model centre, control centre, and customer-service centre (4C). Data fusion technology and an air-land-water coupled model were constructed. Based on HTML5, JavaScript, and Java, an integrated water environment management platform was created and applied to the Three Gorges Reservoir Basin, China. The platform was tested and successfully used for automatic water quality prediction, water environment pollution analysis and control, early warning of abnormal water quality, and emergency water pollution incident evaluation. This platform quickly and accurately forecasts and perfectly displays past, present and future state of the water environment, and offers beneficial support for management decisions in various water environment departments.

Tracking multiple paleo oil charges in the Precambrian dolomite reservoirs of the central Sichuan Basin, China

In the Precambrian dolomites in the central Sichuan Basin, a substantial paleo-oil system previously existed, which has since evolved into a dry gas system that is currently in place. The genesis of this paleo-oil system remained poorly understood, leaving uncertainties regarding the timing of oil charging and associated source rocks. Integration of Re–Os geochronometry with basin modeling allows temporal-spatial constraints on the ancient petroleum system to be established.Two texturally distinct generations of reservoir bitumen were identified. Late-generation bitumen yielded a geologically meaningful Re–Os age of 189 ± 20 Ma (MSWD = 10.4, 2σ), distinct from the previously documented Re–Os ages such as the 414 ± 44 Ma reported by Shi et al. (2020). This new age, along with the ∼414 Ma, aligns within uncertainties with the two relative timings derived from our independent basin model (ca. 450–390 Ma and 260–180 Ma), revealing two temporally distinct oil generation-migration events. The date of ∼189 Ma also lends support to the previous oil charge timing inferred from fluid inclusions. We evaluated the imprecisions of these two Re–Os ages and considered them to result from a narrow spread in 187Re/188Os, and variations in initial Os isotopic compositions (Osi) due to the giant size of the petroleum system and a long duration of oil generation from source kitchen over a large geographical area in this play. Effects of asphaltene precipitation, due to uplift-induced decompression of the migrating oils, may also have contributed to the scatter. Separating the samples based on Osi produced a higher precision age (184.1 ± 5.7 Ma, Model 1) with an MSWD of 0.97.The first oil charge is relatively weak as shown by the basin model and observed bitumen volumes, and it had not been well preserved due to significant reservoir exhumation by Caledonian tectonism. Consequently, the younger oil charge is considered to be the principal precursor to the current dry gas accumulations. Os isotope histories for four potential source units were constructed using publicly available Re–Os data. Comparisons between bitumen and rock Os compositions tend to support the lower Cambrian Qiongzhusi Formation as the predominant source unit for the two major paleo-oil charges. However, contributions from the Duoshantuo, Dengying, and Maidiping source rocks can not be precluded. Overall, these new observations allow temporal-spatial constraints to be placed on the complex evolution, from paleo-oil generation to destruction and dry gas generation.