Water Flooding Research Articles

The Effects of Wetland Degradation on Ecological Species

Wetlands are vital ecosystems that provide numerous ecological services, including flood control, water filtration, carbon sequestration, and habitat for diverse flora and fauna. However, human activities such as urbanization, agriculture, and infrastructure development have led to widespread wetland degradation worldwide. Wetland ecosystems diminished by 21-35% between 1700 and 2020 as a result of human interference, with at least 1.3 million square miles of wetlands lost globally—an area about the size of Alaska, Texas, California, Montana, New Mexico, and Arizona combined. This research used a documented methodology for extracting information from different books, conversations, conferences, and international organizations to understand the effects of wetland degradation on the decline of species and strategies for wetland conservation and restoration. This paper aims to elucidate the multifaceted effects of wetland degradation on ecological species. The results indicate that wetland degradation declines water quality, leading to alterations in water flow patterns, decreased groundwater recharge, and increased flooding downstream. This can result in the loss of biodiversity, as many species depend on specific water levels and habitats within wetlands. Moreover, the loss of wetlands diminishes their volume to store carbon, contributing to greenhouse gas emissions and exacerbating climate change. Furthermore, wetland degradation compromises water quality by reducing the natural filtration and purification functions of wetlands. Contaminants from agricultural runoff, industrial discharge, and urban pollution accumulate in degraded wetlands, posing risks to human health and aquatic ecosystems. Additionally, the loss of wetlands exacerbates erosion and sedimentation, leading to habitat destruction and loss of coastal resilience against storms and sealevel rise. Addressing wetland degradation requires a multifaceted approach, including policy interventions, restoration efforts, and public awareness campaigns. Effective wetland conservation strategies involve the preservation of existing wetlands, restoration of degraded ones, and sustainable management practices to mitigate further degradation. Collaborative efforts between governments, NGOs, local communities, and stakeholders are essential to safeguarding these critical ecosystems and the invaluable services they provide to the environment and society.

Impacts of climate change and land cover factor on runoff in the Coastal Chinese Mainland region

The increasingly frequent storms pose significant threats to the sustainable development of coastal regions, particularly in densely populated and economically vibrant areas. Comprehending the dynamics and intricate mechanisms underlying runoff generation is crucial in the context of climate change and anthropogenic interference. Based on hydro-meteorological and land-use data from 1980 to 2018, this study investigates the runoff variation and its driving factors in the Coastal Chinese Mainland (CCM). The aims of this study are to reveal the temporal and spatial trends of runoff yield, to clarify the sensitivity of runoff in coastal cities to the integrated and individual parameters of climate change and anthropogenic interference, including precipitation (P), potential evapotranspiration (E0), and land cover factor (n), and to support the establishment of spatially tailored adaptation strategies. The results show that: (1) runoff has generally increased over the study period, particularly in regions such as the Yangtze River Delta, Shandong, and Guangxi, while it has decreased in western Liaoning and eastern Guangdong; (2) in the northern CCM with larger aridity index, the land cover factor plays a dominant role in runoff production, while in the wetter southern CCM, precipitation is more influential, and potential evapotranspiration mainly hinders runoff generation all over CCM; (3) urban expansion tends to negatively impact n, while the loss of grasslands and shrinkage of croplands tend to undermine the value of n. To facilitate the achievement of sustainable development goals in the CCM, it is imperative to introduce a more comprehensive and theoretical framework that encompasses the natural, technical, and social dimensions of human-water systems into traditional flood regulation and water resource management. This framework should promote interdisciplinary collaboration from an integrated perspective, to bridge the administrative and watershed boundaries, to effectively address the complex challenges posed by climate change and anthropogenic activities on runoff and water resources in coastal regions, and to enhance the realization of local sustainable development goals (UN SDGs).

Effect of Polymer and Crosslinker Concentration on Static and Dynamic Gelation Behavior of Phenolic Resin Hydrogel.

The application results of profile control and water plugging technology are highly related to the gelation time and strength of phenolic resin hydrogel. In this work, a hydrogel solution was prepared by fully mixing the prepared polymer solution with a crosslinker. The static gelation process of PFR hydrogel in ampoule bottles and porous media was analyzed by changes in the viscosity and residual resistance coefficient. Then, the dynamic gelation of the PFR hydrogel in porous media was tested using a circulating flow device, and the changes in viscosity and injection pressure were analyzed during the dynamic gelation process. Finally, the effects of the polymer concentration and crosslinker concentration on dynamic gelation were analyzed. The initial gelation time and final gelation time in porous media were 1-1.5 times and 1.5-2 times those in ampoule bottles under static conditions, respectively. The initial dynamic gelation time in porous media was 2-2.5 times and 1.5-2 times the initial static gelation times in ampoule bottles and porous media, respectively. The final dynamic gelation time was four times and two times the initial static gelation times in ampoule bottles and porous media, respectively. The production after dynamic gelation in porous media comprised hydrogel aggregates and water fluid, leading to a high injection pressure and low viscosity of the produced liquid. As the concentration of polymer and crosslinker increased, the dynamic gelation time was shortened and the gel strength was increased. In the dynamic gelation process in porous media, the phenol resin hydrogel could migrate deeply, but it was limited by the concentrations of the polymer and crosslinker. The results of subsequent water flooding showed that the polymer hydrogel had a good plugging ability after dynamic gelation. The deep reservoir could only be blocked off in the subsequent water flooding process when the migration of hydrogel happened in the dynamic gelation process.

The influence of the Black Sea rim current and the coastal quasi-stationary anticyclonic Eddie on the distribution of ichthyoplankton and jellyfish

This article describes the Black Sea quasi-stationary coastal anticyclonic eddy (CAE), with large accumulations of zooplankton and ichthyoplankton, which were registered in August 2021 off the northeastern Black Sea during the period of a tropical-type atmospheric mesocyclone. Intense rains (60–80 millimeters of precipitation) caused flooding and large volumes of terrestrial water entered the sea. Water flows came from rivers into the coastal area and flowed into the CAEs. As a result, there were favorable conditions for the growth of plankton, fish eggs and, larvae. Thus, in the Sochi CAE, against the background of a high concentration of chlorophyll a, and the abundance of small-sized fractions of the fodder zooplankton, there was an almost 30-fold increase in the number of fish larvae (947 ind.·m−2 in the CAE and 33.5 ind.·m−2 in the surrounding waters) and the accumulation of jellyfish Aurelia aurita (Linnaeus, 1758), which is their food competitor, with an abundance of up to 44 ind.·m−2. The data obtained indicates that the Black Sea coastal quasi-stationary anticyclones arise between the cyclonic rim current (Main Black Sea current) and the coast, which can be of great importance in the formation of fish abundance.

Density gradient effect on circulation patterns and mixing processes: Observations at the convergence front of a salt wedge, microtidal estuary

The convergence front in estuaries is a crucial area influenced by dynamic mixing processes which vary from one tidal cycle to another, with density gradients playing a key role in shaping circulation patterns. This significance is particularly pronounced in salt wedge estuaries, where discharge holds greater influence than tides. Despite this, there is a limited amount of research based on high-resolution in-situ data to analyze circulation and mixing processes affected by density gradients in the convergence front of a salt wedge estuary. In this study, continuous measurements of current velocities and CTD profiles were conducted over three tidal cycles to analyze the intratidal variability of circulation patterns (u, v, w) and mixing parameters in the convergence front. Stratification parameter (ηs) and Richardson numbers (RL and Ri) were calculated to analyze the mixing/stratification variability within a tidal cycle. The observations revealed a persistent Subsurface Velocity Maximum (SVM) in the longitudinal component, coinciding with density gradient increases > 4 kg m−3 along the water column. Similarly, lateral circulation patterns were influenced by those increases in density gradient, resulting in eastward-directed currents and the formation of two circulations cells. As expected in a salt wedge estuary, stratification occurs during flood and High Water (HW), when the density gradient increases due to intrusion of the salt wedge. Notably, in the Magdalena River estuary, when the discharge is below 3800 m3 s−1, the salt wedge remains consistently present irrespective of the tidal phase, resulting in a permanently stratified water column with ηs values between 1.60 – 1.95. It is expected that the steady presence of stratified conditions during periods of low discharge leads to an increased accumulation of sediments. These findings provide valuable quantitative insights into the complex interplay of density gradients, circulation patterns, and stratification dynamics in salt wedge estuaries.

Enhancing root physiology for increased yield in water-saving and drought-resistance rice with optimal irrigation and nitrogen.

Water-saving and drought-resistance rice (WDR) plays a vital role in the sustainable development of agriculture. Nevertheless, the impacts and processes of water and nitrogen on grain yield in WDR remain unclear. In this study, Hanyou 73 (WDR) and Hyou 518 (rice) were used as materials. Three kinds of nitrogen fertilizer application rate (NFAR) were set in the pot experiment, including no NFAR (nitrogen as urea applied at 0 g/pot), medium NFAR (nitrogen as urea applied at 15.6 g/pot), and high NFAR (nitrogen as urea applied at 31.2 g/pot). Two irrigation regimes, continuous flooding cultivation and water stress, were set under each NFAR. The relationships between root and shoot morphophysiology and grain yield in WDR were explored. The results demonstrated the following: 1) under the same irrigation regime, the grain yield of two varieties increased with the increase of NFAR. Under the same NFAR, the reduction of irrigation amount significantly reduced the grain yield in Hyou 518 (7.1%-15.1%) but had no substantial influence on the grain yield in Hanyou 73. 2) Under the same irrigation regime, increasing the NFAR could improve the root morphophysiology (root dry weight, root oxidation activity, root bleeding rate, root total absorbing surface area, root active absorbing surface area, and zeatin + zeatin riboside contents in roots) and aboveground physiological indexes (leaf photosynthetic rate, non-structural carbohydrate accumulation in stems, and nitrate reductase activity in leaves) in two varieties. Under the same NFAR, increasing the irrigation amount could significantly increase the above indexes in Hyou 518 (except root dry weight) but has little effect on Hanyou 73. 3) Analysis of correlations revealed that the grain yield of Hyou 518 and Hanyou 73 was basically positively correlated with aboveground physiology and root morphophysiology, respectively. The grain yield could be maintained by water stress under medium NFAR in WDR. The improvement of root morphophysiology is a major factor for high yield under the irrigation regime and NFAR treatments in WDR.

A review of scale inhibitor methods during modified smart water injection

AbstractEnhancing oil recovery (EOR) through water flooding methods, including smart water injection, low salinity water injection, polymer injection, and surfactant injection has become a pivotal strategy for enhancing productivity. Despite their promising outcomes, these methods often encounter challenges such as scaling formation and deposition, impacting reservoir permeability and production rates. A comprehensive understanding of scaling formation is crucial for effective implementation of these methods. This article explores various scaling types prevalent in the field, examining key parameters (temperature, pressure, and pH) that influence scaling formation. Additionally, it presents a diverse range of inhibitors employing both chemical and mechanical methods to mitigate and prevent scaling, thus safeguarding reservoir performance. The efficiency of inhibitors is scrutinized concerning chemical composition and performance maintenance under different temperature and pressure conditions. This study serves as a valuable resource for researchers, engineers, and industry experts involved in the oil industry and reservoir management. By elucidating scaling mechanisms, delineating consequences, and offering extensive solutions, it enhances comprehension and provides a foundation for improving oil recovery strategies. The findings of this study contribute to a better understanding of scaling mechanisms, providing insights that can be applied to optimize oil recovery processes, mitigate reservoir challenges, and improve overall reservoir management strategies.

Modelled effectiveness of NbS in reducing disaster risk: Evidence from the OPERANDUM project

The use of nature-based solutions (NbS) to address the risks posed by hydro-meteorological hazards have not yet become part of the mainstream policy response, and one of the main reasons cited for this, is the lack of evidence that they can effectively reduce disaster risk. This paper addresses this issue, by providing model-based evidence from five European case studies which demonstrate the effectiveness of five different NbS in reducing the magnitude of the hazard and thus risk, in present-day and possible future climates. In OAL-Austria, the hazard is a deep-seated landslide, and the NbS analysed is afforestation. Modelling results show that in today's climate and a landcover scenario of mature forest, a reduction in landslide velocity of 27.6 % could be achieved. In OAL-Germany, the hazard is river flooding and the NbS analysed is managed grazing with removal of woody vegetation. Modelling results show that the NbS could potentially reduce maximum flood water depth in the near-future (2031–2060) and far-future (2070–2099), by 0.036 m and 0.155 m, respectively. In OAL-Greece, the hazard is river flooding, and the NbS is upscaled natural storage reservoirs. Modelling results show that in a possible future climate the upscaled NbS show most potential in reducing the total flooded area by up to 1.26 km2. In OAL-Ireland, the hazard is surface and river flooding, and the NbS is green roofs. Results from a modelled upscaling analysis under two different climate scenarios show that both maximum flood water depth, and total flooded area were able to be reduced. In OAL-UK, the hazard is shallow landslides, and the NbS is high-density planting of two different tree species. Modelling results under two different climate scenarios show that both tree species were able to improve slope stability, and that this increased over time as the NbS matured. The significance of these results is discussed within the context of the performance of the NbS over time, to different magnitude events, impact with stakeholders in engendering wider support for the adoption of the NbS in the OALs, and the uncertainty in the modelling analyses.

Synergizing Solar Power with Enhanced Oil Recovery: Integrating Solar-Assisted Methods into Existing EOR Techniques

This study investigates the utilization of solar energy to enhance the efficiency of oil recovery processes, known as Solar Assist-Enhanced Oil Recovery (SA-EOR). The project objectives involve assessing the feasibility and effectiveness of integrating solar technologies with traditional oil recovery methods, such as steam injection or water flooding, to improve oil production rates and reduce operational costs. Methods employed include computational modeling, laboratory experiments, and field trials to evaluate various solar-assisted techniques and their impact on oil recovery. Key findings suggest that solar integration can enhance oil recovery by optimizing thermal processes, improving fluid mobility, and reducing environmental footprint. Additionally, the study underscores the economic viability and sustainability of SA-EOR solutions in the context of evolving energy landscapes. Overall, this research contributes valuable insights into the potential of solar technologies to revolutionize conventional oil recovery practices and advance towards more efficient and environmentally friendly energy production methods. Methods, termed Solar Assist-Enhanced Oil Recovery (SA-EOR). The objective is to investigate the efficacy of utilizing solar power to optimize thermal processes in oil extraction, such as steam injection or water flooding. Through computational modeling, laboratory experiments, and field trials, various SA-EOR techniques are evaluated for their potential to enhance oil recovery rates and reduce environmental impact. Findings indicate promising opportunities for leveraging solar energy to improve fluid mobility, optimize reservoir conditions, and ultimately increase oil production efficiency. This research underscores the significance of SA-EOR methods in advancing sustainable energy practices within the oil industry while addressing pressing environmental concerns.

Advanced Uncertainty Quantification for Flood Inundation Modelling

Flood hazards present a significant risk to the UK, with homes, businesses and critical infrastructure exposed to a mixture of fluvial, surface water and coastal flooding. Climate change is expected to influence river flows, changing the frequency and magnitude of future flood events. Flood hazard assessments are used by decision-makers to implement policies and engineering interventions to reduce the impacts of these flood events. Probabilistic flood modelling can explore input and parameter uncertainties in flood models to fully quantify inundation uncertainty. However, probabilistic methods require large computational costs—limiting their application. This paper investigates a range of advanced uncertainty quantification methods (traditional Monte Carlo (FMC), Kriging and multi-fidelity Monte Carlo (MFMC)) to reduce the dichotomy between accuracy and costs. Results suggest that Kriging can reduce computational costs by 99.9% over FMC. The significantly increased efficiency has the potential to improve future policy and engineering decisions, reducing the impacts of future flood events.

Two-phase flow in the gas diffusion layer with different perforation of proton exchange membrane fuel cell

ABSTRACT Gas diffusion layer (GDL) is an important pathway for water transport in the proton exchange membrane fuel cell. The presence of excessive liquid water in the cathode GDL will cause “water flooding” and block the reactant transport path to catalyst sites. Therefore, it’s critical to understand water transfer mechanism in GDL and propose novel strategy to improve water management. In this study, the effect of GDL with different perforation holes on liquid water transport behavior are investigated by volume of fluid method. The simulation model is validated by comparing with the reported data. The results show that the GDL with perforation holes will accelerate the liquid water breakthrough. Specially, the GDL with cylindrical perforation achieves the lowest breakthrough pressure, and most excellent water drainage capacity under various pressure drops. The gradient hydrophobic distribution in GDL will improve the water breakthrough path and drainage capacity. However, gradient hydrophobic treatment in GDL with conical perforations will result more water leakage along the though-plane direction. The simulation results will provide significant guidance for designing high performance GDL and improving the water management in proton exchange membrane fuel cell.

Mechanism analysis of injection technique of water composition modification for enhanced oil recovery

ABSTRACT By adjusting the composition of injection water, including ionic type and strength, the goal of enhance oil recovery rate can be achieved. However, there is no clear understanding of which factor, ionic type or strength, has a greater impact. In this paper, based on the formation water of the offshore G oilfield, various brines with different ionic strengths and types were prepared. By measuring the zeta potential of rock powder and oil droplets, three-phase contact angle, interfacial tension between oil and water, emulsification properties of brines, and film strength of oil-water interface, the variation rules of the core wettability and emulsification performance of brine were systematically analyzed when the ionic strength and ionic type were changed. The experimental results showed that ionic strength has a greater impact than that of ionic type. For the oil-water-solid (rock) system of the G oilfield, an ionic strength of 82 mM/kg is the threshold for low salinity effect. Reducing ionic strength resulted in an increase in the hydrophilicity of rock and the ability of water flooding to emulsify oil droplets, which contribute to the improvement of oil displacement efficiency. Theoretically, water flooding to enhance oil recovery can be achieved by only reducing the ionic strength. This understanding was verified by dual polarization interferometry (DPI) experiments and low-field nuclear magnetic resonance experiments, which showed that reducing the salinity of the injection water from 42,000 mg/L (ionic strength of 820 mM/kg) to 4200 mg/L (ionic strength of 82 mM/kg) enhanced the oil recovery by 7.9%.

Characterization of pore structures after ASP flooding for post-EOR

With the global assistance of oil fields entering the stage of improving oil recovery, diversified composite flooding technology has become one of the key research targets. This article takes composite flooding to improve oil recovery as the research object, explores the differential mechanism of crude oil displacement efficiency under water flooding and composite flooding conditions, and elucidates the dynamic evolution characteristics of pore structure before and after composite flooding. Results show that: (a) The permeability and porosity of Daqing oilfield cores have a good correlation. The porosity of cores after water driving and ternary composite driving mainly ranged from 23.6 % to 27.4 % and 22.8 %–26.8 %. The water-driving permeability mainly ranged from 168 × 10−3 μm2 to 2162 × 10−3 μm2. Ternary composite driving permeability mainly ranges from 302 × 10−3 μm2 to 2307 × 10−3 μm2. (b) Compared with water driving, quartz and clay minerals are corroded by alkali during ternary composite driving. (c) Under the condition of similar permeability, the average pore size of the core after ternary composite driving is smaller than the average pore size after water driving.

Application of BIM+GIS Integration Technology in the Construction of Urban Intelligent Water Informatization

Urban intelligent water informatization is the process of managing and operating urban water systems with the use of contemporary information and communication technology in order to increase productivity, security, and sustainability. Establishing the appropriate infrastructure is the initial stage in building an intelligent water system so that management can choose wisely how to manage and operate the water system. Building information modeling (BIM) is a digital depiction of a building's or infrastructure's structural and functional details. In most metropolitan regions, a fast development phase is predicted to cause several water issues, including water resource shortages, floods, poor drainage, and water resource contamination. As a result, a practical approach is required for urban intelligent water information technology with the help of artificial intelligence techniques. Intelligent water systems may be built using Building Information Modeling (BIM) software to increase the system's effectiveness, stability, and durability. By offering a potent tool for storing and analyzing geographical data connected to the water distribution system, a geographic information system (GIS) can play a crucial role in the development of urban intelligent water informatization using ArcGIS mapping Software. The Internet of Things (IoT) system is used to implement intelligent water informatization, hardware implementation using ESP32, and software development using MQTT Broker and Node-Red. As a result, we recommended utilizing BIM+GIS integration technology for building urban intelligent water informatization. The suggested system is evaluated using management efficiency, urban flood control, innovative Construction, intensive management, and computation cost. In this research, the main objective is to identify where there are water leaks broken pipes and early warning system and monitoring system for flash flood disasters in urban areas. The result findings show that the integration of BIM and GIS provides a comprehensive platform for managing complex water informatization infrastructure projects and maximizes efficiency and sustainability.

Optimization of oil recovery using heated low salinity water (HLSW) in the horizontal sand pack column during water flooding: radiotracer intervention

Water-flooding is a prevalent technique for secondary oil recovery that is capable to increase oil recovery by up to 45%. Due to its accessibility, affordability, and simplicity, water flooding is the most frequently used secondary oil recovery technique. However, the efficiency of conventional water flooding is limited by capillary forces which holds the residual crude oil in pore structures. Moreover, during water flooding operation, the injected fluid does not penetrate sufficiently due to low permeability or presence of channelling inside the sandstone reservoir. Therefore, in this study, thermal recovery was introduced to 100ppm (0.1g/L) low salinity water (LSW) in order to investigate the percentage of oil recovery during water flooding. A horizontal sand pack column was used for water flooding experiment and temperature and injections rate are the parameters to be optimised with respect to percentage of oil recovery. The column was initially packed with 125micrometer sieved sand to ensure constant homogeneity is achieved. Initially, formation water which comprised with NaCl, CaCl2 and MgSO4 was introduced inside the column together with light oil and was aged overnight. TAPIS oil with viscosity of 0.001382 Pa.s (1.382cP) was used as light-oil in this study. The injection rate was set to 1 mL/min, 2 mL/min, and 3 mL/min respectively whereas, the temperature of the LSW was heated at 50 °C, 70 °C, and 90 °C subsequently. Heated water was supplied continuously throughout the sand pack which was heated using water blanket to retain heat at 70°C (reservoir temperature). In conclusion, 3 mL/min and 70°C were identified as optimum parameters and the oil recovery experiment was proceeded with liquid radiotracer using Technecium-99m (Tc-99m) intervention and resulted with 73% of yield. Nevertheless, the radiotracer intervention only provides the Residence Time Distribution (RTD) model which describe the behaviour of the sand pack during water flooding process.

Risk prediction for hydrogen sulfide emission based on sulfate-reducing bacteria in the water flooding oilfield

The water quality of the injection–production systems deteriorates as the water flooding oilfields are developed more deeply, and the content of sulfate-reducing bacteria (SRB) increases. Accordingly, hydrogen sulfide (H2S) emission related to SRB is intensified, which will arise safety and health problems. In order to investigate the effect of SRB on H2S emission in the water flooding oilfield, the contents of SRB and sulfide of the different nodes of a typical injection–production system of Daqing Oilfield were measured first, and then, H2S emission from water was simulated under different conditions. Consequently, a H2S emission prediction model was established based on Henry coefficient and the correlation between sulfide content and SRB content in the water. The measured sulfide contents were ranging from 0.25 to 6.34 mg/l, and the SRB contents were from 2.5 to 25 000 pcs/ml, and the highest SRB and sulfide contents were found in the settling tank. The correlation between sulfide content and SRB content was much remarkable, and the R2 value of the correlation analysis was 0.94. Henry coefficient of H2S emission was obtained from the simulated experiments under varied conditions such as sulfate content, oil content, and temperature. The established H2S emission prediction model was much reliable for predicting H2S emission for water flooding injection–production system, and the accuracy of the predicted H2S emission of four nodes of the injection–production system was larger than 95% compared to the measured results. This study provides theoretical guidance for predicting H2S emission risks in water flooding injection–production systems.

Flood Analysis on Lake Tempe, South Sulawesi

Tempe Lake is one of the largest lakes in Wajo, Sopen, and Siddenreng Rappang in southern Sulawesi. Lake Tempe is the reservoir of his five major rivers: Bilokka, Lidaratangu, Masaka, Siddenreng, Bira and Walane. The lake offers many benefits to the community such as securing water resources, flood control, agriculture, fishing, and tourism. However, approximately 20–40 cm of silt is produced annually. This can cause flooding in the surrounding areas. Therefore, the restoration of Lake Tempe is necessary to mitigate flooding caused by continuous sedimentation. The Department of Public Works and Housing has developed a phased dredging plan to improve the capacity of Lake Tempe. Later, as no disposal sites were available, dredged materials were used to build several artificial islands along the perimeter of the lake. After the reconstruction project was completed, two major floods occurred, overtopping embankments. Therefore, the design analysis of embankments is required. Analysis indicates that two flood events occur, with a 20-year return period flood and a 50-year return period flood at elevations of 8.36 m and 9.2 m. From hydraulic analysis it is found that flood embankment height of 10 m is overtopped by water level of total 9.56 m and 10.4 m respectively because of wave run up. For a 20-year return period, there is an indication that slope stability and settlement problems affect flood events. It can be concluded that flood problems occur because of extreme events and the failure of flood embankments due to overtopping.

Wave Loads On Hydraulic Structures

Hydraulic structures are essential for flood protection, water management and navigation in coastal, delta and lake regions. Their importance will continue to grow in the coming years and decades, because of two main factors. Firstly, because of the consequences of climate change and sea level rise. Secondly, because of the continuous development and urbanization of coastal, delta and lake regions, with an increase in the value of the assets and activities in those locations combined with more strict safety requirements. Those factors will lead to the construction of a series of new hydraulic structures and the renovation of several existing structures around the world. Wave loads acting on such hydraulic structures are crucial for their design and safety assessment. This study addresses two different types of wave loads acting on hydraulic structures: confined wave impact loads and bimodal wave loads. To this end, a series of laboratory experimental test campaigns were carried out in a wave flume.

Study on a Strong Polymer Gel by the Addition of Micron Graphite Oxide Powder and Its Plugging of Fracture.

It is difficult to plug the fracture water channeling of a fractured low-permeability reservoir during water flooding by using the conventional acrylamide polymer gel due to its weak mechanical properties. For this problem, micron graphite powder is added to enhance the comprehensive properties of the acrylamide polymer gel, which can improve the plugging effect of fracture water channeling. The chemical principle of this process is that the hydroxyl and carboxyl groups of the layered micron graphite powder can undergo physicochemical interactions with the amide groups of the polyacrylamide molecule chain. As a rigid structure, the graphite powder can support the flexible skeleton of the original polyacrylamide molecule chain. Through the synergy of the rigid and flexible structures, the viscoelasticity, thermal stability, tensile performance, and plugging ability of the new-type gel can be significantly enhanced. Compared with a single acrylamide gel, after adding 3000 mg/L of micrometer-sized graphite powder, the elastic modulus, the viscous modulus, the phase transition temperature, the breakthrough pressure gradient, the elongation at break, and the tensile stress of the acrylamide gel are all greatly improved. After adding the graphite powder to the polyacrylamide gel, the fracture water channeling can be effectively plugged. The characteristics of the networked water flow channel are obvious during the injected water break through the gel in the fracture. The breakthrough pressure of water flooding is high. The experimental results are an attempt to develop a new gel material for the water plugging of a fractured low-permeability reservoir.

Low-Salinity Waterflooding for EOR in Field A of Western Offshore Basin: A Pilot Study Analysis with Laboratory and Simulation Studies—Early Observations

Carbonate reservoirs hold vast oil reserves, but their complex properties make traditional enhanced oil recovery (EOR) methods challenging. This study explores the application of low-salinity water flooding (LSWF) as a novel EOR method for India’s largest offshore carbonate oil field. Conventional EOR techniques were deemed unsuitable due to reservoir heterogeneity, pressure decline, high temperature, and the offshore location. Favorable factors for LSWF included successful seawater flooding history, medium-weight crude oil, and existing infrastructure. Following core flooding experiments demonstrating a 6–16% increase in oil recovery, a multi-pronged evaluation process was implemented. Single-well chemical tracer tests (SWCTT) and reservoir simulations confirmed the potential of LSWF. A specific target area was chosen based on reservoir characteristics, production data, and available facilities. Simulations predicted a 1.5% incremental oil recovery using diluted seawater (25% salinity) at 30% pore volume injection. After a positive techno-economic analysis, the first offshore LSWF project in India was completed within 3 years. Initial monitoring results are encouraging. This study highlights the successful journey of LSWF from concept to field deployment in a challenging carbonate reservoir, showcasing its potential for revitalizing such fields. Furthermore, this work provides valuable data relevant to Indian offshore environments, where factors like salinity, mineralogy, and crude oil composition pose unique challenges compared to other LSWF applications. These detailed data fill a critical gap in the existing literature.