Water Flooding Research Articles

Facile fac- to mer-configuration transformation in tricyano Ru(II) complexes: Synthesis, luminescence, and potential application as chemical tracers for water flooding

Two mononuclear tricyanoruthenium(II) compounds fac-(PPh4)[RuII(dpq)(CN)3(PPh3)] (1a), fac-(PPh4)[RuII(Ph2Phen)(CN)3(PPh3)] (2a) have been prepared from the reactions of (PPh4)2[RuII(PPh3)2(CN)4] with pyrazino[2,3-f][1,10]phenanthroline (dpq) and 4,7-diphenyl-1,10-phenanthroline (Ph2Phen) in DMF, respectively. Metathesis of 1a/2a with excess NaPF6 in MeOH afforded fac-Na[RuII(dpq)(CN)3(PPh3)] (1b) and fac-Na[RuII(Ph2Phen)(CN)3(PPh3)] (2b), respectively where the coordination geometries around the Ru(II) centers are retained. However, treatment of 1a with [Zn(cyclam)]Cl2 or [Zn(cyclen)]Cl2 afforded the trinuclear heterobimetallic complexes [Zn(cyclam){mer-RuII(dpq)(CN)3(PPh3)}2] (3) and mer-[RuII(dpq)(CN)3(PPh3)][Zn(cyclen){mer-RuII(dpq)(CN)3(PPh3)}] (4), respectively. The crystal structures of 1a, 1b, 2a, 3, and 4 have been determined by X-ray crystallography. It is clearly shown that the coordination geometries of Ru(II) centers are changed from fac- to mer-configuration upon coordination with Zn2+ complexes. It is noteworthy that in 4 the coordination geometry in the anionic Ru moiety is also changed, although it is not linked to the Zn2+ moiety. The luminescence properties of these compounds have been investigated in detail. Both 1a and 1b exhibit strong solvatochromism as those related complexes. 1b is soluble in H2O and the luminescent detection limit can reach 0.01 mM in H2O. Upon loading 1b onto nano SiO2, the luminescence of 1b@SiO2 is remarkably enhanced and the luminescent detection limit can reach 0.1 µM.

Using ARIMA and ETS models for forecasting water level changes for sustainable environmental management

It is vital to provide useful hydrological forecasts for urban and agricultural water management, hydropower generation, flood protection and management, drought mitigation and alleviation, and river basin planning and management, among other things. This paper introduces a simple and flexible hydrological time series forecasting framework. Predicting water levels is crucial, given the need for sustainable environmental management. The prognosis should be reasonable to persuade individuals to take proper precautions. While many methods have been developed to predict water levels, here the effectiveness of two approaches to predicting river water levels was assessed. For this purpose, nine years of data were used, which were divided into input data (2014–2021) and validation data (2022), on water levels in the Morava e Binçës river for the Vitia station, in the form of monthly time series records, to identify the best model among those used and to identify the information necessary for water resource management and hazard control. Models Autoregressive Integrated Moving Average(ARIMA) and Error Trend and Seasonality, or Exponential Smoothing (ETS), were examined using the R package to determine the most accurate. The results indicate the applicability of both models, as evidenced by the Root Mean Square Error (RMSE) and the Mean Absolute Error (MAE). The predictive analysis based on historical water levels allowed the identification of distinct periods characterized by high and low water levels between 2022 and 2024, which is important for the area in question due to the numerous flood events occurring here.

Study on the properties of oil-water interface after the interaction between ionized water and naphthenic acid

The properties of the oil-water interface have a great influence on improving oil recovery. However, there are few studies on the impact of the interaction between ionized water and polar components of crude oil on the properties of the oil-water interface. In this paper, the influence of ionized water and naphthenic acid on the properties of the oil-water interface was investigated by measuring the oil-water interfacial tension, dilational rheological parameters, and interfacial film thickness, and the displacement mechanism of the ionized water flooding system was discussed. The results show that after the action, the interfacial tension of oil and water continues to decrease, and 1/3 ionized water (salinity diluted to 1/3 of the prepared ionized water, 1253 ppm) decreases to a maximum of 50.89%, while 1/5 ionized water (752 ppm) only decreases 14.40%; the thickness of the oil-water interface film decreases with the salinity of ionized water, but the decrease increases after 1/3 ionized water. In addition, the interfacial shear viscosity, interfacial expansion modulus, and interfacial phase angle tangent values all reach the maximum value within 10–15 days and then decrease. The research results of this article will provide a theoretical basis for the application of ionized water in oilfields.

CFD analysis of pore morphology, gravity, and fluid characteristics influences on water flooding process

In this research, computational fluid dynamics (CFD) was employed to examine the two-phase flow of water and oil in a porous medium. For this purpose, the Navier-Stockes equations, which describe fluid motion, and the Cahn-Hillard phase field, which defines the interface between two phases, are coupled. The numerical discretization system of equations was solved using the finite element method (FEM) with the COMSOL software. To validate the results and the phase-field model (PFM), the Lucas and Washburn equation was used together with the experimental data. Through this study, the effective parameters were evaluated in two parts. In the first part, seven models with different pore morphologies were designed, and the impact of petrophysical parameters of the reservoir, including the shape of pores, connectivity of pores with or without throat lines, porous media heterogeneity, and relative permeability, on oil recovery was investigated. The second part was devoted to performing sensitivity analysis on the effect of fluid properties, including interfacial tension, wettability, viscosity ratio, injected fluid flow, and gravity, upon enhanced oil recovery (EOR) in different morphologies. Owing to the uniform distribution of capillary pressure in the patterns with the throat lines, the sweep efficiency of the injected fluid was found to be better, and thereby oil production increased. The results of the present work proved the significant influence of gravity on EOR, so that by applying gravity to the solution domain, the breakthrough time and oil recovery factor increased by 20 minutes and 28.6 %, respectively. Moreover, the velocity of the injected fluid as a representative of the flow rate had the greatest effect on EOR, with a 35 % increase in production.

Development and Performance Evaluation of a New Conformance Control Agent Gel.

How to effectively plug the multi-scale fractured water channeling has always been the key to achieving efficient water flooding of fractured low-permeability oil reservoirs. In this paper, a new type of supramolecular-polymer composite gel is developed, which is suitable for plugging multi-scale fractured water channeling. The supramolecular-polymer composite gel is composed of a polymer (such as polyacrylamide), cross-linking agent (such as polyethyleneimine), supramolecular gel factor (such as cyclodextrin) and polarity regulator (such as ethyl alcohol). The mass fraction of polyacrylamide, polyethyleneimine, cyclodextrin and ethyl alcohol are 0.15%, 0.2%, 1% and 0.2%, respectively. At the initial state, the viscosity of the composite gelant system is less than 20 mPa·s. It has good injection performance in micro-scale fractures and can enter the deep part of a fractured reservoir. At 40 °C, the composite gelant system can form a gel with a double network structure after gelation. One of the networks is formed by the covalent interaction between polyacrylamide and polyethyleneimine, the other network is formed by the self-assembly of cyclodextrins under the action of the ethyl alcohol. The comprehensive performance of the composite gel is greatly improved. The strength of the composite gel is >5 × 104 mPa·s, and it has good plugging strength in large-scale fractures. The composite gel can be used as a conformance control agent for fractured low-permeability oilfields.

The role of the cryosphere for runoff in a highly glacierised alpine catchment, an approach with a coupled model and in situ data

Abstract Runoff from heavily glacierised catchments, its seasonality and the contribution from different storage units are highly relevant for assessing the seasonal and long-term water supply and flood prediction. Modelling studies on runoff from such basins often use simulated meteorological input (e.g. downscaling products) based on remote observations. We investigate the contribution of snow, firn and ice to runoff in the Vernagtferner basin (Ötztal Alps) from 2020 to 2022, using a physical modelling chain driven by a local observation network. We use the SNOWPACK model to simulate snow/ice development at observation sites and the Alpine3D model to calculate accumulation and melt at the catchment scale. Basin discharge is estimated using a gridded version of the HBV-ETH model. This approach largely reproduces observed glacier mass balances, while modelled and measured basin discharge are in good agreement. Snowmelt dominates discharge in the early melt season, while ice melt becomes increasingly important during summer. This is in strong contrast to the near-equilibrium mass balances in the 1980s, when ice melt played a minor role for annual discharge. The strong reduction of the accumulation area leads to a fundamental change from a snowmelt regime to an ice melt regime, which is especially pronounced in 2022.

Harnessing long-term gridded rainfall data and microtopographic insights to characterise risk from surface water flooding.

Climate projections like UKCP18 predict that the UK will move towards a wetter and warmer climate with a consequent increased risk from surface water flooding (SWF). SWF is typically caused by localized convective rainfall, which is difficult to predict and requires high spatial and temporal resolution observations. The likelihood of SWF is also affected by the microtopographic configuration near buildings and the presence of resilience and resistance measures. To date, most research on SWF has focused on modelling and prediction, but these models have been limited to 2 m resolution for England to avoid excessive computational burdens. The lead time for predicting convective rainfall responsible for SWF can be as little as 30 minutes for a 1 km x 1 km part of the storm. Therefore, it is useful to identify the locations most vulnerable to SWF based on past rainfall data and microtopography to provide better risk management measures for properties. In this study, we present a framework that uses long-term gridded rainfall data to quantify SWF hazard at the 1 km x 1 km pixel level, thereby identifying localized areas vulnerable to SWF. We also use high-resolution photographic (10 cm) and LiDAR (25 cm) DEMs, as well as a property flood resistance and resilience (PFR) database, to quantify SWF exposure at property level. By adopting this methodology, locations and properties vulnerable to SWF can be identified, and appropriate SWF management strategies can be developed, such as installing PFR features for the properties at highest risk from SWF.

Quantifying the Influence of Climatic and Anthropogenic Factors on Multi-Scalar Streamflow Variation of Jialing River, China

Clarifying the impact of driving forces on multi-temporal-scale (annual, quarterly and monthly) runoff changes is of great significance for watershed water resource planning. Based on monthly runoff data and meteorological data of the Jialing River (JLR) during 1982–2020, the Mann–Kendall tendency testing approach was first applied to analyze variation tendencies of multi-timescale runoff. Then, abrupt variation years of runoff were determined using Pettitt and cumulative anomaly mutation testing approaches. The ABCD model was employed for simulating hydrological change processes in the base period and variation period. Finally, influences of climatic and anthropic factors on multi-scalar runoff were computed using the multi-scalar Budyko formula. The following conclusions were drawn in this study: (1) The mutation year of discharge was 1993; (2) the monthly runoff in the JLR presented a “single peak” distribution, and the concentration degree and concentration period in the JLR both showed an insignificant reduction trend; (3) anthropic factors were the dominant factor for spring runoff variations; climatic factors were the dominant factor on annual, summer, fall and winter runoff variations; (4) except for November, climatic factors were the dominant factor causing runoff changes in the other 11 months. This study has important reference value for water resource allocation and flood control decisions in the JLR.

Adaptation and Adversity Acceptance as Resilience to Flooding at World Heritage Sites: A Case Study of Hoi An Ancient Town, Vietnam

ABSTRACT This article investigates long-term adaptation and resilience to floods at World Heritage sites through a case study of Hoi An Ancient Town, Quang Nam, Vietnam. Drawing on fieldwork observation, document review, and unstructured interviews conducted in Hoi An, we examine the enduring processes and experiences of co-living with floods. The article considers residents’ ability to comprehend, acknowledge, and address the challenges of flooding using the conceptual lens of adaptation and adversity acceptance as resilience. Our findings reveal an inseparable bond between residents and their built environment, encompassing invaluable lessons and experiences, local beliefs, resource availability, and adaptive strategies aimed at harmonious cohabitation with flooding described as ‘leaning into nature’. Strikingly, residents have developed their own practices and identities shaped by the town’s inundation by flood waters over a few centuries. Various modern flood prevention measures trace their origins to historical efforts, underscoring the vital role of traditional knowledge and practices in coping with the impacts of climate change. Those efforts are also framed within the local policy context such as Heritage Management Plan, Disaster Risk Management Plan, and Regulation for the Protection of the UNESCO-listed Hoi An Ancient Town.

Experimental study on microscopic production characteristics and influencing factors during dynamic imbibition of shale reservoir with online NMR and fractal theory

Dynamic imbibition and displacement between the matrix and fractures in shale reservoirs can significantly enhance oil recovery (EOR) following initial depletion. However, the microscopic production characteristics and seepage mechanisms at different pore scales during the dynamic imbibition process remain incompletely understood. In this study, we established an online physical simulation experiment method that combines dynamic displacement and imbibition based on nuclear magnetic resonance (NMR) and fractal theory, and a series of online NMR water flooding dynamic imbibition experiments were conducted. Through real-time dynamic monitoring of multiphase flow and migration behavior of crude oil in each stage of dynamic imbibition, the microscopic production characteristics and influencing factors were quantitatively studied from the recovery and residual oil saturation field distribution of different scale pores. Additionally, we developed a novel two-dimensional (2-D) NMR interpretation model to investigate the dynamic development characteristics of shale oil injection-imbibition-soaking-production integration, and the multiphase and multi-scale dynamic imbibition crude oil migration models were discussed. The results show that shale oil occurrence pores can be categorized into two types based on the corresponding production mode (imbibition + displacement). The water flooding dynamic imbibition process in shale reservoirs unfolds in three stages: strong displacement and weak imbibition stage characterized by the rapid production of large pores and fractures under displacement action; weak displacement and strong imbibition stage involving the slow production of small pores under reverse imbibition; and dynamic equilibrium stage characterized by weak displacement and weak imbibition. When viewing the entire water flooding dynamic imbibition process as an organism, it becomes imperative to maximize the recovery of large pores while ensuring the recovery degree of small pores. High permeability contributes to better pore throat connectivity and a greater imbibition and displacement production degree. The contribution of the.two production modes to the recovery of small and large pores increased by 4.67 % and 3.17 %, respectively. A negative correlation was observed between high displacement pressure and imbibition recovery, yet it is conducive to the contribution of displacement to total recovery. Notably, fractures can effectively reduce oil-water seepage resistance, and increase the contribution of displacement to recovery by 21.65 %. Finally.a positive correlation was noted between increased imbibition amount and free oil recovery, while residual oil gradually shifted towards adsorbed and organic matter-dominated forms, leading to decreased recoverability. Effectively utilizing the bridge flow conductivity of fractures, fluid imbibition displacement, and carrying effect is crucial for achieving optimal EOR. The findings provide theoretical support for clarifying the interaction between matrix-fracture imbibition and displacement and for the efficient development of shale oil.

Interactions and oil recovery performance of a prepared extended amphoteric surfactant combining with a nonionic surfactant under high salinity condition

The extended amphoteric surfactant (named C12P3E3NS), characterized by FTIR and 1H NMR, was prepared by amination and sulfonation in order to enhance oil recovery (EOR) for the low-permeability oil reservoirs. The surface and interfacial tensions of its combination systems with nonionic surfactant (APG0810, an Alkyl Polyglycoside), obtained by tension meter, were evaluated to obtain an optimized surfactant system for enhancing oil recovery. The compound system (named C12A) with 40 % mole fractions of C12P3E3NS, exhibiting the strongest interaction behavior and highest expansion modulus, possesses the best abilities of reducing the interfacial tension to ultra-low (10-3 mN/m order of magnitude) at a salinity of 10 wt%, and owns certain abilities of emulsifying crude oil. Meanwhile, the contact angle, measured by the contact angle measuring instrument, can be altered from 108.50°to 55.07°by the compound system C12A, confirming its better wetting alteration ability of transforming the capillary force from resistance to driving force. Eventually, displacement efficiency, obtained from core displacement tests, reveals that the compound surfactant system C12A can decrease the pressure by 15.80 % and its corresponding oil recovery factor is 15.25 % after water flooding, demonstrating its favorable displacement performance and potential application in medium or high salinity reservoirs.

Visualization Experimental Investigation on Flow Regulation and Oil Displacement Characteristics of Gel Foam in Fractured-Vuggy Carbonate Reservoirs.

Fractured-vuggy reservoirs experience severe channeling during water and gas injection operations, and conventional foam shows weak regeneration capabilities in large-scale fracture spaces, thus failing to effectively seal them. Gel foam combines the advantages of both foam and gel, significantly enhancing the foam's stability and showing good suitability in fractured-vuggy reservoirs. In this article, the plugging and flow regulation properties of gel foam in fractures were studied through fracture displacement experiments. The dynamic plugging capability of gel foam was superior to that of ordinary foam, and its plugging effect was significantly influenced by the fracture opening. Gel foam had strong retention capacity in fractures, and after plugging large-opening fractures, the diversion rate of small-opening fractures was increased by at least 83.3 times during subsequent parallel water flooding, making the flow regulation effect remarkable. Through the oil displacement experiments in typical fractured-vuggy models, the profile control law and enhanced oil recovery performance of gel foam under different fractured-vuggy structures were studied. In the regular fractured-vuggy network, gel foam adhered to occupy the fractured-vuggy space for plugging and controlled the top gas migration direction to synergistically drive the recovery of remaining oil, ultimately achieving a recovery of 95%. In the combination of fractures and irregular vugs, due to the density, gel foam continuously pushed down and right along the fractures to the vugs, pushing the crude oil and formation water in the vugs to migrate to the production well. The recovery of the gel foam flooding stage was as high as 48%, and the final recovery reached 93.5; only a small amount of shielded remaining oil was difficult to drive. The research results are of great significance to the application of gel foam in enhancing oil recovery in fractured-vuggy reservoirs.

Influence of Polymer Concentration on the Viscous and (Linear and Non-Linear) Viscoelastic Properties of Hydrolyzed Polyacrylamide Systems in Bulk Shear Field and Porous Media.

Enhanced oil recovery (EOR) methods are generally employed in depleted reservoirs to increase the recovery factor beyond that of water flooding. Polymer flooding is one of the major EOR methods. EOR polymer solutions (especially the synthetic ones characterized by flexible chains) that flow through porous media are not only subjected to shearing forces but also extensional deformation, and therefore, they exhibit not only Newtonian and shear thinning behavior but also shear thickening behavior at a certain porous media shear rate/velocity. Shear rheometry has been widely used to characterize the rheological properties of EOR polymer systems. This paper aims to investigate the effect of the polymers' concentrations, ranging from 25 ppm to 2500 ppm, on the viscous, linear, and non-linear viscoelastic properties of hydrolyzed polyacrylamide (HPAM) in shear field and porous media. The results observed indicate that viscous properties such as Newtonian viscosity increase monotonically with the increase in concentration in both fields. However, linear viscoelastic properties, such as shear characteristic time, were absent for concentrations not critical in both shear rheometry and porous media. Beyond the critical association concentration (CAC), the modified shear thinning index decreases in terms of concentration in both fields, signifying their intensified thinning. At those concentrations higher than CAC, the viscoelastic onset rate remains constant in both fields. In both fields, the shear thickening index, a strict non-linear viscoelastic property, initially increases with concentration and then decreases with concentration, signifying that the polymer chains do not stretch significantly at higher concentrations. Also, another general observation is that the rheological properties of the polymer solutions in both porous media and shear rheometry only follow a similar trend if the concentration is higher than the CAC. At concentrations less than the CAC, the shear and porous media onset rates follow different trends, possibly due to the higher inertial effect in the rheometer.

REVIEW AND COMPARATIVE STUDY OF HYDROLOGICAL MODELS FOR RAINFALL-RUNOFF MODELLING

Water is considered as an important resources for human existence on the earth. In order to simulate or optimized hydrological data for various water resources management, several hydrological models are very useful to attain this aim for water resources management and as a decision support tools. A rainfall-runoff model is a quantitative prototype explaining the rainfall-runoff interactions at basin scale. The hydrological models have peculiarities in terms of capabilities for various water resources management. This paper tends to reviewed over fifty (50) papers that are peculiar to hydrological models as applicable to rainfall-runoff modeling. It involved evaluating and comparing different hydrological models used in simulating rainfall process converting into surface runoff for water use efficiency. Several runoff models such as Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS), Soil and Water Assessment Tool (SWAT), Precipitation-Runoff Modeling System (PRMS), Variable Infiltration Capacity model (VIC), LISt-based Erosion Model (LISEM), MIKE Surface Water - Groundwater Hydrology (MIKE SHE) and Runoff Prophet were critically assessed. Rainfall-runoff models are globally utilized for different applications to enhance water use efficiency across different sectors. However, types of hydrological models by examining various hydrological models, model accuracy by evaluating the accuracy and reliability of each model in predicting runoff from rainfall data, scope of applications by determining the adequacy of the models for numerous geographical regions and climatic circumstances, complexity and usability by assessing the complexity of the models, their data requirements, ease of use and computational efficiency, also the models advantages and limitations in capturing the dynamics of the rainfall-runoff process were critically assessed. This was to aid modeling objectives. It was inferred that HEC-HMS is widely applied for modelling precipitation-runoff processes in watersheds of various sizes, aiding in flood forecasting, reservoir operation, and water management for agricultural and urban water use efficiency. SWAT is used for assessing the impact of land management practices (e.g., crop rotation, irrigation, land use changes) on water resources, including runoff generation and water quality, thus optimizing water use efficiency in agriculture. PRMS is applied to model the transport of water via complex hydrological systems, aiding in watershed management and water use efficiency assessments. In conclusion, this comparative review seeks to guide water scientists, the users of hydrological models and hydrological engineers in selecting the most suitable models for their specific modelling needs for sustainable water resources management.

Mechanisms of surfactant improving water injection huff and puff efficiency in tight reservoir

Water injection huff and puff is an economical and effective method to enhance the recovery of tight oil reservoir, in which the addition of suitable surfactants is critical, but its mechanism needs to be further studied. In this paper, the huff and puff process is divided into replenishment, imbibition and water flooding stages. This study compared and analyzed the effects of various surfactants on interfacial tension, wettability, flow resistance, and oil washing efficiency, using mineralized water as the control group. The relationships between different surfactants and imbibition recovery efficiency, water flooding recovery efficiency, and flooding pressure were investigated. The mechanisms by which surfactants influence the imbibition and flooding processes were also explored. The results show that, the effect of permeability on imbibition and water flooding recovery efficiency in natural cores can be ignored. During the imbibition stage, the maximum recovery efficiency with mineralized water is 18.33 %, while with surfactants it is 21.40 %. In the water flooding stage, the maximum recovery efficiency with mineralized water is 3.89 %. The addition of surfactants significantly increases the water flooding recovery efficiency to 19.82 %. Furthermore, surfactants can reduce the water flooding pressure by approximately 7.00 MPa and increase the total recovery rate by about 5.00 %. The primary mechanisms by which surfactants improve the water injection huff and puff effect include reducing interfacial tension, altering wettability, facilitating crude oil detachment from rock surfaces, and enhancing oil washing efficiency. Reduction of flow resistance, leading to a decrease in the pressure required for flooding. The research results provide a theoretical basis for the practical application of surfactants in water injection huff and puff in tight reservoirs.

Rainfall in California: Special Reference to 2023 Rains That Caused Floods

After years of crippling drought, California experienced a barrage of intense atmospheric river storms starting from late 2022 and continuing into early 2023 after so many years of extensive drought. This resulted in extensive flooding across the northern and central parts of the state. Major urban centers like San Francisco and Sacramento saw their wettest January on record, with damage to infrastructure and thousands evacuated in flooded areas. Southern California also saw higher than average rainfall. The extensive rainfall provided much-needed relief from the recent drought, helping to replenish reservoirs and groundwater basins, but also causing lot of catastrophic events due to California’s insufficient flood control infrastructure. Decades of underfunding and lack of coordination have left dams, levees, and urban flood control channels unable to handle increased precipitation, putting communities at risk. Historically, California has experienced periodic droughts, where precipitation falls well below average for multiple seasons or years. Significant droughts were observed in the past century such as in the years 1976–1977, 1987–1992, and 2012–2016. The most recent drought from 2012–2022 ranked as one of the most severe and most prolonged droughts on record in California. Although the 2023 storms helped in recovery from drought conditions, California must bolster its flood control systems and water storage capabilities. The state must prepare for a future where climate change drives intense precipitation alongside more intense droughts. Sustainable infrastructure and coordinated management will be vital for withstanding increased hydrological extremes. This article examines the rainfall extremes of 2023 within the context of California’s drought history and makes recommendations for long-term water security to overcome increased climate variability.

NATURAL HAZARD ELIMINATION USING ELECTROCHEMICAL PROPERTIES – WATER FLOOD

A combination of science is a way to accommodate various effective phenomena that could influence the entire life cycle. Recently, emphasis has been placed on the electrochemical polymerization mechanism that is involved in numerous technological applications, including sensors and detectors. Accordingly, daily promises were raised to eliminate life disasters and alleviate the challenges such as water floods as a part of weather changes, which could cause severe damage to life health explicitly, infrastructure, economic productivity, and much more. The proposal considers the matter via compromising the water overflow as well as eliminating the disaster that would come in no warning time and tackling the climate emergency flooding with the potential of water reclamation and offers scholarly suggestions by the requirements of the scientific approach. The investigation clarified the electromagnetic absorber beside the electrochemical polymerization through engagement in the flooded water track stations and the calculation result shows that 19.73% could be absorbed when using 300 grams of polymer gel capacity in 240 grams of water. Generally, the paper explores the electromagnetic flood disaster and how to address it to build a more secure forthcoming.

Study on Microscopic Oil Displacement Mechanism of Alkaline-Surfactant-Polymer Ternary Flooding.

Alkali-surfactant-polymer (ASP) flooding is one of the most effective and promising ways to enhance oil recovery (EOR). The synergistic effect between alkali, surfactant, and polymer can respectively promote emulsification performance, reduce interfacial tension, and improve bulk phase viscosity, thus effectively improving flooding efficiency. However, the displacement mechanism of ASP flooding and the contribution of different components to the oil displacement effect still need further discussion. In this study, five groups of chemical slugs were injected into the fracture model after water flooding to characterize the displacement effect of weak alkali, surfactant, polymer, and their binary/ternary combinations on residual oil. Additionally, the dominant mechanism of the ASP flooding system to improve the recovery was studied. The results showed that EOR can be improved through interfacial reaction, low oil/water interfacial tension (IFT), and increased viscosity. In particular, the synergistic effect of ASP includes sweep and oil washing. As for sweep, the swept volume is expanded by the interfacial reaction between the alkali and the acidic components in Daqing crude oil, and the polymer increases the viscosity of the system. As for oil washing, the surfactant generated by the alkali cooperates with surfactants to reduce the IFT to an ultra-low level, which promotes the formation and migration of oil-in-water emulsions and increases the efficiency of oil washing. Overall, ASP can not only activate discontinuous oil ganglia in the pores within the water flooding range, but also emulsify, decompose, and migrate the continuous residual oil in the expanded range outside the water flooding. The EOR of ASP is 38.0% higher than that of water flooding. Therefore, the ASP system is a new ternary composite flooding technology with low cost, technical feasibility, and broad application prospects.

PEMANFAATAN DATA HUJAN BERBASIS SATELIT CHIRPS UNTUK PEMETAAN HUJAN RANCANGAN DI KABUPATEN LOMBOK UTARA

The design rainfall value is a critical parameter in flood analysis and water structure design. In general, the design rainfall calculation uses measured rainfall data. However, sometimes it is difficult to find complete rainfall data from evenly distributed rainfall stations and in an extended measurement range. This study aims to test the use of CHIRPS satellite-based rainfall data as an alternative solution for providing data in areas with difficulty with rainfall data. The analysis includes data accuracy and calibration evaluation, followed by design rainfall analysis with frequency analysis and mapping using spatial data processing software. The accuracy test results obtained an average deviation value of the original CHIRPS that did not meet the average NSE value of 0.346. Furthermore, the data was calibrated using the regression method, and corrected data was obtained with an NSE of 0.446 with an interpretation of the meeting. A rainfall analysis was conducted for corrected CHIRPS with ARR (Automatic Rainfall Recorder) measurement as a control. The results obtained the average percentage deviation for design rainfall with a return period of 2, 5, 10, 25, 50, and 100 years using corrected CHIRPS ranging from 18 - 28% lower than design rainfall using ARR. The design rainfall isohyet map using spatial data processing software for the North Lombok Region shows that high design rainfall occurs in the eastern part of North Lombok, namely around the Santong and Sambik Bangkol stations, while design rainfall with low values is in the western part of North Lombok, namely around the Tanjung and Gunungsari stations.

Study on the pathways of thermochemical sulfate reduction between sulfates and alkanes at low temperatures

To reduce the energy consumption of heavy oil thermal recovery, low-temperature hot water flooding is becoming popular. The occurrence of thermochemical sulfate reduction (TSR) reactions during the hot water flooding process generates H2S, which can corrode equipment and jeopardize personnel safety. Preventing and managing H2S requires studying TSR reactions. The study investigated the reactivity of SO42-, HSO4-, and [MgSO4]CIP in the TSR reaction during heavy oil low-temperature hot water flooding. The results indicated that during low-temperature hot water flooding, no significant thermal cracking of heavy oil occurs, only a minor aquathermolysis takes place, while the TSR reaction proceeds vigorously. The TSR reaction leads to increased yields of H2S, CH4, and CO2, as well as a higher S content in the heavy oil. Based on experimental results, numerical simulations of the reaction process between SO42- and CH4 were conducted using density functional theory and transition state theory. The results indicated that the reduction of SO42- to produce SO32- is the rate-limiting step in the entire reaction pathway between SO42- and CH4. Further analysis of the reaction barriers and chemical reaction rates of the three sulfates (SO42-, HSO4-, and [MgSO4]CIP) and C1-C5 alkanes was conducted based on the limiting step. Through macro and micro analysis, this study not only confirmed previous findings regarding the order of alkanes participating in TSR reactions from the perspective of microscopic molecular but also clarified the oxidation order of sulfate species under heavy oil low-temperature thermal water flooding conditions, with the sequence being HSO4- > [MgSO4]CIP>SO42-. This study provides a foundational understanding of TSR reactions during heavy oil low-temperature hot water flooding and is of significance for the prediction and management of H2S.