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This study addresses this issue by exploring the effectiveness of abrasive water jet drilling (AWJD) as an unconventional machining approach for UHMWPE. The research employs a full factorial analysis to examine various hole characteristics, including machining time (MT), surface roughness (Ra), taper angle (TA), material removal rate (MRR), and taper ratio (TR). The study aims to understand the effect of the process features, namely abrasive water jet pressures (p), traverse rates (v), and abrasive mass flow rates (ma), on the geometry and position of the drilled holes. The results show that (v) and (p) affect the drilled hole characteristics of surface morphology, roughness, MT, MRR, TA, and TR. The microstructural characteristics of the drilled-hole surfaces are analyzed by scanning electron microscopy (SEM). It revealed that the smooth surface is attained at the lower v of 150 mm/min and ma of 250 g/min. [ABSTRACT FROM AUTHOR]

Arizona has a long history of groundwater use, and there is concern about long term groundwater sustainability across the state. We explore groundwater trends across Arizona and how they vary with respect to: (1) whether groundwater pumping is regulated, and (2) relative access to local or imported surface water. Well observations from the Arizona Department of Water Resources are used to quantify water table depth trends and groundwater drilling patterns. There are more than 85,000 groundwater wells in Arizona, and new wells are routinely being drilled. The number of new shallow wells (<200 ft) has decreased over time in all parts of the state. But midrange (200–500 ft) to deep (>500 ft) wells have increased in the past 10 years in regulated and groundwater dominated areas. Most wells are small with low pumping capacities that fall below the regulatory limit; however, there are still large wells being drilled in unregulated areas. Results show statewide decreasing water storage and groundwater levels. Groundwater declines are less severe in the parts of the state that have groundwater regulation. However, looking closer at this trend, groundwater recovery is strongest in areas receiving imported Colorado River water which also implement managed groundwater recharge with the imported water. Our findings indicate that groundwater recovery is very localized and driven more by managed recharge from surface water as opposed to decreased groundwater pumping. [ABSTRACT FROM AUTHOR]

Copyright of Afyon Kocatepe University Journal of Science & Engineering / Afyon Kocatepe Üniversitesi Fen Ve Mühendislik Bilimleri Dergisi is the property of Afyon Kocatepe University, Faculty of Science & Literature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of subglacial lakes requires clean access and sampling technologies. One of the most promising alternatives is the newly developed hot-point RECoverable Autonomous Sonde (RECAS), which allows downward and upward ice drilling and subglacial water sampling while the subglacial lake remains isolated from the surface. The original sonde descends downward under the force of gravity, and the borehole trajectory cannot be controlled. However, in certain cases, the sonde would preferably be able to drill at specific angles and directions, enabling it to follow a desired trajectory (e.g., maintaining verticality within the desired range) or bypass obstacles in the ice (e.g., stones and other inclusions). The general principle for the steering RECAS is to adjust the voltage for the electric thermal head heaters, which provides an opportunity to control the heat distribution on the drill head surface, thereby altering borehole trajectory during drilling. In this paper, the general principles of steering RECAS are described, and experimental results on deviational ice drilling with a controllable electric thermal head are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Madinah City in Saudi Arabia is rapidly growing with high population growth, water demand, sewage generation, and agricultural activities. The hydrogeological layering sequence in Madinah City reveals that there are three main layers that extend within the areas between wadi systems. The shallow water table rise (SWTR) problem has risen in several areas of the city, and the fluctuations in the piezometric water observed from the shallow aquifer systems. The research aims to investigate the changes in shallow groundwater levels within the Madinah City. Sources of water table rise and fluctuations are investigated through an extensive field hydro-geological survey comprising wells drilling and water level monitoring, which indicated the following results between 1977 and 2010 including those of newly drilled wells: (i) water flow is partially blocked along wadi Alaqiq and this has caused an increased regional flow moving from west along wadi Alaqiq towards the central area; (ii) groundwater levels have changed in the agricultural areas as indicated by 15–26 m rise along wadi Alaqiq; (iii) groundwater level fluctuations as indicated by 590 m amsl (1977) against less than 575 m amsl (2010) in the east and southeast of the study area as a result of increased heavy pumping since past 37 years. The overall flow phenomenon is reflected in the groundwater gradients on an increasing trend with orientation from the western region along the wadi Alaqiq towards the central area and southeast which has invariably resulted in the overall declining of water levels throughout the affected area. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultra-high molecular-weight polyethylene (UHMWPE) is one of the most extensively utilized supporting materials inside total knee replacement (TKR) because of its combination of outstanding mechanical qualities and wear resistance. The integrity of the hole is an essential component for fastening the femur and tibia elements in knee replacements. Due to its viscoelasticity behavior, it often causes difficulties such as rapid tool wear, burr formation, and poor finish in conventional machining operations, which causes poor hole features. Since unconventional methods are currently being investigated for drilling UHMWPE. Abrasive water jet drilling (AWJD) is particularly promising for handling hard-to-machine materials, and AWJ drilling of UHMWPE materials demands focus on it. The focus of this research is to determine the importance of AWJD variables for UHMWPE. In this experiment, 64 holes, each with a diameter of 10mm, were drilled into the sample material using a complete factorial approach to evaluation. Abrasive water jet pressure (AWJP) (210, 260, 310, and 360MPa), abrasive mass flow rate (AMFR) (250, 300, 350, and 400g/min.), and traverse rate (TR) (150, 300, 450, and 600mm/min.) were all taken into account. Furthermore, the geometrical properties of the hole, such as hole diameter (entry and exit), circularity, perpendicularity, and cylindricity, were investigated. The outcomes identified that both AWJP and TR played significant roles in determining the geometric features of the hole. During the drilling operation, the material removal mechanism and the hole defects were observed and identified using scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

Mechanical water detection is recognized as the most reliable and safe production technology for coal mines, mainly for the detection of water hazards in pre-mining operations. Intelligent water detectors are currently the main research direction in mechanical water detection, and the automatic installation of drilling bars is the key to achieving intelligent water detection. Improving the connection accuracy in the process of installing drilling bars is an important research topic for the improvement of control links. To improve the connection accuracy of the drilling bars at the time of supplying material, we used the modified Denavit–Hartenberg method to analyze the motion gestures of the supplied material device and the Lagrange equation to establish a dynamic analysis model. We aimed at better control precision by improving the sliding mode control algorithm and at increasing the convergence rate of tracking errors with a sliding controller based on an exponential approximation law and using saturated functions instead of the symbol functions in the reaching law to weaken the vibration in the control process. We then used particle swarm optimization (PSO) to find the optimum combination parameters of the sliding mode controllers and test the performance of the sliding mode controllers before and after PSO with MATLAB/Simulink. The results showed that the optimized controller has a strong resistance to parameter fluctuations, and the system responds quickly, achieves a good performance, and improves the convergence rate of tracking errors. [ABSTRACT FROM AUTHOR]

In the weighting drilling fluid, barite will adsorb the free water and additives in the drilling fluid, which often worsens the performance of the drilling fluid. In order to optimize the performance of drilling fluid, a method for measuring the specific surface area of powder in liquid phase based on low field nuclear magnetic resonance (NMR) relaxation was established to study the occurrence state of barite in drilling fluid. The variation of specific surface area of barite in suspension with different concentrations were measured by particle size calculation and low field NMR, and the experimental results show that the specific surface area obtained by low field NMR can reflect the aggregation state of barite in liquid phase. Through organic carbon adsorption and rheological test, the adsorption law of barite to different drilling fluid additives was obtained. This study can solve the problem of additive addition in drilling fluid and optimize the performance of drilling fluid. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Subglacial lakes and hydrological systems play crucial roles in Antarctic subglacial hydrology, water balance, subglacial geomorphology, and ice dynamics. Satellite altimetry has revealed that some recurrent water exchange occurs in subglacial lakes. They are referred to as 'active lakes', which prominently influence a majority of subglacial hydrological processes. Our analysis indicates that active subglacial lakes are more likely to be situated in regions with higher surface ice flow velocities. Nevertheless, the origin of subglacial lakes still remains enigmatic and uncertain. They could have potential associations with geothermal heat, ice sheets melting, and ice flow dynamics. Subglacial lake drilling and water sampling have the potential to provide valuable insights into the origin of subglacial lakes and subglacial hydrological processes. Moreover, they could also offer unique opportunities for the exploration of subglacial microbiology, evolution of the Antarctic ice sheets, and various fundamental scientific inquiries. To date, successful drilling and sampling has been accomplished in Lake Vostok, Lake Mercer, and Lake Whillans. However, the use of drilling fluids caused the water sample contamination in Lake Vostok, and the drilling attempt at Lake Ellsworth failed due to technical issues. To explore more of the conditions of the Antarctic subglacial lakes, the Lake Centro de Estudios Científicos (Lake CECs) and Lake Snow Eagle (LSE) drilling projects are upcoming and in preparation. In this study, we aim to address the following: (1) introduce various aspects of Antarctic subglacial lakes, subglacial hydrological elements, subglacial hydrology, and the interactions between ice sheets and the ocean; and (2) provide an overview and outlook of subglacial lakes drilling projects. [ABSTRACT FROM AUTHOR]

Shale hydration dispersion and swelling are primary causes of wellbore instability in oil and gas reservoir exploration. In this study, inulin, a fructo-oligosaccharide extracted from Jerusalem artichoke roots, was modified by acylation with three acyl chlorides, and the products (C10-, C12-, and C14-inulin) were investigated for their use as novel shale hydration inhibitors. The inhibition properties were evaluated through the shale cuttings hot-rolling dispersion test, the sodium-based bentonite hydration test, and capillary suction. The three acylated inulins exhibited superb hydration-inhibiting performance at low concentrations, compared to the commonly used inhibitors of KCl and poly (ester amine). An inhibition mechanism was proposed based on surface tension measurements, contact angle measurements, Fourier-transform infrared analysis, and scanning electron microscopy. The acylated inulin reduced the water surface tension significantly, thus, retarding the invasion of water into the shale formation. Then, the acylated inulin was adsorbed onto the shale surface by hydrogen bonding to form a compact, sealed, hydrophobic membrane. Furthermore, the acylated inulins are non-toxic and biodegradable, which meet the increasingly stringent environmental regulations in this field. This method might provide a new avenue for developing high-performance and ecofriendly shale hydration inhibitors. [ABSTRACT FROM AUTHOR]

In this article, microbiological studies of waters from Municipalities in the Burgas region are considered. Microbiological analyses were made on 112 borehole water samples. In 56% of the analyses carried out, it can be seen that there is no bacterial contamination in the examined drilling waters, in 44% of the examined samples bacterial growth is observed, of which 21% have the presence of E. coli and coliforms, and 23% with the presence of intestinal enterococci. The present study examines the importance and impact of water safety on human health. [ABSTRACT FROM AUTHOR]

Stick-slip in drilling happens when the drill bit and assembly repeatedly stop and slide due to factors like friction and torque. Using better lubricants in the drilling mud can help reduce friction, lessening stick-slip issues. Nanotechnology has improved drilling mud, making it more resistant to heat and enhancing its viscosity and friction properties. This research extensively investigates the use of nanofluids in drilling processes through thorough lab tests. It examines the impact of introducing NanoSiO2 into two types of drilling mud—freshwater bentonite (FWB) and polymer-based mud—at concentrations of 0.04%, 0.08%, 0.15%, and 0.31% under higher temperatures. The study also explores two methods of dispersing NPs using ultrasonic and solvent techniques. The results show that SiO2 nanoparticles notably improve the flow and filtering abilities of FWB mud but have negative effects on polymer-based mud. A 0.05% addition of NanoSiO2 significantly reduces friction by 52% in FWB mud. In FWB mud, all NanoSiO2 concentrations lead to a 25% decrease in mud cake thickness. Furthermore, adding NanoSiO2 to FWB mud decreases torque, with the most substantial reduction of 40% observed at 0.09% concentration (0.35 gm). On the contrary, incorporating NanoSiO2 into polymer-based mud increases fluid loss volume for all concentrations, reaching up to 36% compared to the base mud. Additionally, filter cake thickness increases eightfold, while lubricity factor doubles. This study offers insights into the advantages of using SiO2 nanoparticles in drilling mud and their impact on the fluid properties during drilling. [ABSTRACT FROM AUTHOR]

Copyright of Exacta is the property of Exacta - Engenharia de Producao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new kind of modified emulsified bitumen used to plug a microcrack was studied. The sizes of high-temperature emulsified bitumen were fit for the sizes of the microcrack, which were approved by the scanning electron microscope and laser particle size analyzer. Some tests have been designed to demonstrate that the polymer could be used to promote the softening point of modified asphalt, and the high-temperature emulsified bitumen has also shown an excellent performance in terms of static filtration, the viscous coefficient, and extreme pressure lubrication, as well as to inhibit ting shale expansion. The permeability recovery could reach 88.26%, which meets the specification requirements. The mud cake, which was formed by high-temperature emulsified bitumen as an additive, was thin, tough, and dense, which was proved by the scanning electron microscope. The process used to obtain this additive was simple, and the performance of the plugging microfracture was excellent, so this kind of plugging agent could have a better application future. [ABSTRACT FROM AUTHOR]

In this study, neat glass (NG) fiber and hybrid GF/Al-wire mesh composites with two different aluminum configurations (AG: with Al in the outer surface, and GA [Glass fiber/Al-mesh]: with Al in the core) were fabricated using hand-layup technique and then drilled via an abrasive water jet (AWJ) machine. The impact of the drilling parameters on the hole qualities; delamination Fd, kerf angle (Ka), and circularity error (Ce) of the holes were studied. Using Taguchi L9 orthogonal array, drilling operations were conducted. The following AWJ drilling parameters were chosen; water pressure (P), stand-off distance (S), and traverse speed (V) with three levels each. A single-objective optimization using Taguchi method was performed to minimize the drilling responses for the least outcome. In addition, gray relational analysis (GRA) was used as a multi-decision technique. Analysis of variance (ANOVA) was carried out to identify the impacts of AWJ drilling parameters. The results indicated that for AG specimen, Fd was reduced by 5.3%-10.96% and its Ce by 10.4%-29.65%. GA had the lowest kerf angle. The most effective parameters on delamination for NG, AG, and GA were P, followed by S and V. Validation tests showed small variations between experimental and predicted values. Highlights • A new GF/Al Wire Mesh Reinforced Epoxy Hybrid Composites were manufactured. • AWJ drilling of the manufactured Composites was conducted. • Hole quality was improved by adding Al to the outer layers (AG specimen). • AWJ parameters were Controlled and optimized to reduce Fd, Ce, and Ka. • Process optimization was performed by single and multi-objective optimization. [ABSTRACT FROM AUTHOR]

Produced water is the main waste stream in the oil and gas sector, with significantly greater concentrations of hydrocarbons, heavy metals, and other contaminants. Several works and technologies were developed to reuse the produced water in many applications including drilling and completion fluids. However, in general, a pretreatment is required. According to our knowledge, the reuse of produced water in non-aqueous drilling is still not reported. Therefore, this work proposed the formulation of olefin-based drilling fluids containing between 20-40% of untreated produced water. Through factorial experimental design, the influence of produced water, emulsifier, and viscosifier on the properties of the formulated emulsions was investigated. Our results show that produced water without treatment can be used as an aqueous phase for olefin-based drilling fluids, with the best formulation being the test that has RO/A = 60/40, emulsifier concentration of 14.26 kg/m³ and viscosifier concentration of 2.85 kg/m³. The well-cleaning properties of the proposed formulation were evaluated through numerical simulation in a well with high inclination. The results showed that the hole cleaning was not affected by using untreated produced water in the fluid formulation. The results presented here open a new possibility to reuse produced water in drilling operations without performance loss. [ABSTRACT FROM AUTHOR]

Methane hydrates are widely distributed along continental margins, representing a potential source of methane to the ocean and atmosphere, possibly influencing Earth's climate. Yet, little is known about the response of methane hydrates to global climate change, especially at the timescale of glacial-interglacial cycles. Here we present a chronology of methane seepage from seep carbonates derived from a series of tens to hundreds of meters long hydrate-bearing sediment records from the South China Sea, drilled at water depths of 664-871 m. We find that six out of seven episodes of intense methane seepage during the last 440,000 years were related to hydrate dissociation, all coinciding with major interglacials, the so-called Marine Isotope Stages 1, 5e, 7c, 9c, and 11c. Using numerical modeling, we show that these events of methane hydrate instability were possibly triggered by the rapid warming of intermediate waters by ~2.5-3.5 °C in the South China Sea. This finding provides direct evidence for the sensitivity of the deep marine methane hydrate reservoir to glacial-interglacial climatic and oceanographic cyclicity. [ABSTRACT FROM AUTHOR]

During deepwater drilling, testing, production, or hydrate mining, the circulating medium in the wellbore may contain solid particles, such as rock chips and sand, in addition to drilling fluids, gas, and water. In the high-pressure, low-temperature conditions of deep water, gas intrusion can easily combine with free water in the drilling fluid to form hydrates, increasing the drilling risk. Therefore, understanding the formation patterns of hydrates in drilling fluids is of significant importance for the prevention and control of hydrates. This study utilized a small-scale high-pressure reactor to investigate the impact of the stirring rate, NaCl, and methanol additives, as well as the sand content on the hydrate formation process and gas consumption. The results indicate that the hydrate formation process can be divided into an induction stage, a rapid formation stage, and a slow formation stage. The induction stage and rapid formation stage durations are significantly reduced under stirring conditions. In NaCl and methanol solutions, hydrate formation is inhibited, with the induction stage duration increasing with higher concentrations of NaCl and methanol. There was no apparent rapid formation stage observed. The final gas consumption decreases substantially with increasing concentrations of NaCl and methanol, reaching no significant hydrate formation at a 20% concentration. The sand content has a significant impact on the slow formation stage, with the final gas consumption increasing within a certain range (in this work, at a sand content of 20%), and being notably higher than in the pure water system under the same conditions. [ABSTRACT FROM AUTHOR]

Owing to its outstanding properties such as corrosion resistance, low density, relatively low cost, and stiffness, Al2024-T3 aluminium alloy has been widely applied in aircraft manufacturing. To perfectly assemble an aircraft, numerous high-quality holes are drilled into its structures employing conventional drilling processes. Conventional drilling poses some challenges such as thermal distortions, burr formations, and tool wear. Alternatively, abrasive water jet drilling (AWJD) is a thermal-free machining process that can be employed as an alternative to conventional drilling of aeronautical structures. Hence, in this work, the effect of abrasive water jet parameters, namely stand-off distance, water jet pressure, and abrasive mass flow rate, on hole-quality parameters was evaluated at traverse speed = 10 mm/min. Three parameters were stand-off distance = 1, 2, and 3 mm, abrasive mass flow rate = 200, 250, and 300 g/min, and water jet pressure = 1800, 2100, and 2600 bar. Using a 6 mm circular-movement diameter of the nozzle tip, optimal stand-off distance, water jet pressure, and abrasive mass flow rate obtained by multi-objective optimization were 2 mm, 250 g/min, and 2600 bar, respectively. The corresponding hole-quality parameters were Diameter = 6.232 mm, Kerf angle = 0.018°, Cylindricity = 0.051 mm, Perpendicularity = 0.033 mm, Circularity = 0.0041 mm and Surface roughness Ra = 2.909 µm. The results showed that water jet pressure had the greatest influence on Perpendicularity, Circularity; stand-off distance had the highest effect on Kerf angle; and abrasive mass flow rate has the largest influence on Hole diameter, Cylindricity and Surface roughness Ra, and Rz at the given value of traverse speed. The adopted optimization process for abrasive water jet of Al2024-T3 aluminium alloy was successfully verified through confirmation runs, clearly illustrating its benefits. [ABSTRACT FROM AUTHOR]

The present work is part of a series of works that deal with the manufacture by 3D printing of some specimens for mechanical tensile and bending tests. The samples are made by 3D printing from three types of materials such as ABS+, PETG and PLA+. The printing positions are A-horizontal position, B-vertical position and C-lateral position. In order for the mechanical tests of the samples to be conclusive, 5 samples of each material and from each printing position must be made by 3D printing. The purpose of the mechanical tests is to investigate the mechanical characteristics of the filaments from which the 3D printed samples are manufactured, with the aim of replacing some classically manufactured components within water well drilling installations. The present work deals only with the manufacture by 3D printing in vertical position B, of a number of 5 specimens for bending. [ABSTRACT FROM AUTHOR]

The quality of drinking water is a challenge for consumers and scientists in our century. The bacterial diseases and deaths recorded in recent years, as a result of the consumption of fecal-contaminated water, are reasons for concern and microbiological evaluation of water in all populated areas on Earth. In this paper, microbiological and chemical analyses were performed for ten samples of water from wells drilled in households in the perimeter of Timis County, Romania. The analyses included the range of microbial groups and species considered indicators of water quality. Their isolation and identification were carried out on specific nutrient media and were completed with determinations of nitrates, phosphates and pH. According to the analysis reports, faecaligenous enterococci were not identified, instead clostridia were observed in most of the samples and a contamination with Escherichia coli. The microbial load is high in the majority of samples. The chemical analyses indicated the presence of phosphates and nitrates in most of the evaluated samples. The nitrates in the analyzed water samples did not exceed the value of 50 mgL-1stipulated in the standard. The obtained results suggest the presence of some sources of faecal contamination and require taking measures to treat the waters in question. [ABSTRACT FROM AUTHOR]

Infill drilling is the first choice to increase the recovery factor, but the mission of selecting the best well location is considered a major challenge with the huge area of the reservoir and the time consumption to conducting the simulation runs that may reach hundreds to thousands. This paper adopted the design of an experiment plus a proxy optimization technique to solve this problem. Where the Latin Hypercube represents the DoE while the radial basis function network represents the artificial intelligence proxy model. The proxy model mimics the reservoir model to reduce the computation time and speed up the well-placement optimization process. The Latin Hypercube approach is used to generate data to train the proxy model to construct a reliable artificial intelligence model to predict the best wells locations. The results are very optimistic and encouraging to rely on using the art-of-state to construct a proxy model to conduct the infill wells drilling optimization. Where the increase in cumulative oil production for the optimized case is more than the un-optimized case by 6.45% and the decrease in the field cumulative water production for the optimized case is less than the un-optimized case by 16.11% from 2020 to 2040. [ABSTRACT FROM AUTHOR]

Drillships are used for exploratory drilling operations in a water depth above 3000 m. Design variants in the new-generation drillships include flexible internal storage and payload capacity. While their operations are quite satisfactory in moderate weather conditions, response under metocean hurricane conditions to preserve operation versatility poses challenges. The design and operation of drillships, which are intricate and domain-specialized vessels, need attention. This study examines the motion characteristics of a drillship for different sea states and environmental conditions. Their stability across critical sea states is also assessed. Based on the numerical studies, it is seen that they experience a modest degree of instability due to excessive roll and pitch under extreme environmental loads. While preliminary checks under mild heave motion showed that the coupled heave–pitch motion dominates the design shear and longitudinal bending, they are critically influenced by the pitch motion. The forces of second-order steady drift in the far field and the near field are compared in the frequency domain. This study identifies parameters that influence its strength and stability, and the results are useful for improving the operational safety and reliability of drillships under challenging offshore conditions. [ABSTRACT FROM AUTHOR]

The Essaouira Basin, located in central western Morocco, faces a significant threat of water shortage due to both the substantially reduced rainfall caused by climate change and the continuously increasing demand for this essential resource. Groundwater resources are being increasingly exploited to meet the needs of the population, whether for agricultural or domestic purposes. Therefore, it has become necessary to intensify investigations across the entire basin, particularly through indirect methods such as geophysical techniques, to accurately delineate the productive zones. In this context, the present study was undertaken to investigate the deep structure of this basin with the aim of comprehending the functioning of its aquifer system. This study is based on the interpretation of gravity data covering the Essaouira Basin. In addition to their qualitative analysis, these data underwent a methodological approach involving transformations to extract meaningful insights. The observed anomalies were interpreted in terms of (i) thickness variations within the slightly folded sedimentary series of the basin; (ii) Paleozoic basement topography; and (iii) the presence of salt deposits. In fact, among the negative anomalies, some coincide with evaporitic deposits that are known either from the geological outcrops or the seismic surveys carried out in the Essaouira Basin within the framework of petroleum exploration programs, while others coincide with areas of increased thickness of sedimentary sequences. The latter include synclines and basement depressions, where the accumulation of groundwater tends to occur; as a result, they constitute suitable zones for the drilling of water extraction wells. Groundwater flows observed in some existing wells are consistent with this hypothesis. The results of the contact analysis approach implemented within the framework of the study reveals the Essaouira Basin is affected by a fault network whose main direction is parallel to the Atlantic margin (i.e., NNE–SSW). This implies that the extensional tectonic phase responsible for initiating the rifting of the Central Atlantic in the Triassic era has primarily impacted the structural configuration of this basin. This study demonstrates the strong potential of the gravity method as a tool to delineate the deep structure of sedimentary basins and to identify potentially productive groundwater zones. The final results will provide important support to decision makers in sustainable groundwater management, especially in vulnerable areas. [ABSTRACT FROM AUTHOR]

Objective The aim is to evaluate the environmental risk and explore the feasibility of clear water drilling cuttings soilization. Methods The structural and chemical properties, microbial composition and pollution characteristics of clear water drilling cuttings were analyzed systematically and the soilization experiment of clear water drilling cuttings was also carried out. Results The main components of clear water drilling cuttings are similar to those of surface soil. The particle size distribution of cuttings is wide and the particle size distribution of cuttings from different sources varies greatly. The water retention rate is very poor and the fertility is low. Compared with the surface soil, the diversity of bacteria in the cuttings was similar: However, the diversity of fungi was significantly lower. The oil content, biological toxicity and heavy metal content of clear water drilling cuttings were all lower than relevant standards. The results of soilization experiment showed that in some treatments, the contents of Cr. Hg and Pb in plants exceeded the relevant standards. After mixing with soil in different proportions, the concentration of heavy metals in plants decreased significantly, which could meet the food safety standards. Conclusions Clear water drilling cuttings exhibit low environmental risk, high soilization security, but low fertility, thus it is not suitable to be used as planting soil directly. The risk of heavy metal bioaccumulation can be controlled by mixing with soil in different proportions, selecting different plants or planting non- edible plants, etc., so as to realize the safe and effective soilization of clear water drilling cuttings. [ABSTRACT FROM AUTHOR]

This paper presents the use of resistivity method to quantify the thickness of the freshwater aquifer for supply in a coastal region, where saltwater intrusion is constant. The results obtained have unusual clarity and quality in the literature, being a historical case. vertical electrical sounding (VES) technique was used to determine water table and saltwater intrusion depths. Sandy sediments thicker than 120 m and smooth topography are constant, where an area of approximately 2.7 × 2.2 km with 15 well-distributed VES was studied. The area is located between Lagoa dos Patos (brackish water) and the Atlantic Ocean. The only possibility of obtaining fresh water is the exploitation of the water table with the drilling of shallow wells in places, where the freshwater layer is thicker. The VES results quantified the water level depths between 3.5 and 6.0 m and the saltwater intrusion between 12.5 and 21.0 m, obtaining the thickness of the freshwater stratum. This work also approaches considerations about the depth of investigation of the VES, showing that this depth does not depend only on the openings between the current electrodes, but also on the distribution of the geoelectric strata. [ABSTRACT FROM AUTHOR]

This work aims to analyse the mechanisms and factors contributing to shallow soil landslides in river valleys entrenched in lowlands on the example of the Central Radunia Valley. The combination of susceptibility analysis using geographic-information-system-based statistical models, field surveys, analysis of archival materials, and numerical modelling for the analysis of slope stability and hydrogeological processes allows for comprehensive landslide reconstruction, mass movement mechanism description, and an explanation of the role of triggering and causal factors. The results emphasise the need for cross-disciplinary studies of shallow soil landslides. The identification and prioritisation of the causal factors indicate that geomorphological conditions play a particularly important role. The current study shows that the greatest influence on landslide formation in the Central Radunia Valley is slope angle, as determined using a high-resolution digital elevation model. The slope angle factor is sufficient to produce a reliable susceptibility map (the areas under the curve of the success rate and prediction rate curves are 87.84% and 85.34%, respectively). However, numerical modelling of slope failure also clearly indicated that there was a significant influence of anthropogenic impacts on the landslide process. We determined that the main triggering factor causing the January 2019 Rutki landslide was related to the drilling of a borehole on 10 January 2019. The water used for drilling hydrated the soil and thus weakened the stability conditions. [ABSTRACT FROM AUTHOR]

• New surface active Tetracationic AImILs highly adsorbed 2.8 mol of CO 2 /mol. • Amphiphilic thermal stable porous spheres of CaCO 3 NPs prepared from CO 2. • Highly dispersed CaCO 3 NPs in seawater used as additive for WBD fluids. • CaCO 3 @ HDAP-ImA and CaCO 3 @DDAP-ImA particles employed as a viscosifier and/or filtrate control agent in bentonite- based WBMs. Conversion and capture of carbon pollutants based on carbon dioxide to valuable green oil-field chemicals are target all over the world for controlling the global warming. The present article used new room temperature amphiphilic imidazolium ionic liquids with superior surface activity in the aqueous solutions to convert carbon dioxide gas to superior amphiphilic calcium carbonate nanoparticles. In this respect, tetra-cationic ionic liquids 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate and 2-(4-hexyldimethylamino) phenyl)-1,3-bis(3-hexcyldimethylammnonio) propyl) bromide-1 H-imidazol-3-ium acetate were prepared. Their chemical structures, thermal as well as their carbon dioxide absorption/ desorption characteristics were evaluated. They were used as solvent and capping agent to synthesize calcium carbonate nanoparticles with controlled crystalline lattice, sizes, thermal properties and spherical surface morphologies. The prepared calcium carbonate nanoparticles were used as additives for the commercial water based drilling mud to improve their filter lose and rheology. The data confirm that the lower concentrations of 2-(4-dodecyldimethylamino) phenyl)-1,3-bis (3-dodecyldimethylammnonio) propyl) bromide-1-H-imidazol-3-ium acetate achieved lower seawater filter lose and improved viscosities. [ABSTRACT FROM AUTHOR]

Groundwater Week 2023, held in Las Vegas, Nevada, was the largest event in the history of the National Ground Water Association (NGWA), with 6,642 attendees from 40 countries and all 50 states. The event featured educational sessions, exhibits, and workshops on topics such as workforce development and passing knowledge to the next generation. NGWA also elected new board members and discussed goals for 2024, including the establishment of NGWA University and the launch of NGWA Business PRO. The association will continue to work on initiatives related to groundwater protection, rural water systems, and private wells in the coming year. NGWA also provided resources on PFAS contamination and hosted a conference on groundwater in the PFAS era. The association's geothermal retrofit project at its headquarters in Ohio was discussed at the event, highlighting the benefits of retrofit applications. NGWA also announced the passing of two past presidents, Peter Thein and Wayne Westberg, as well as the former director of sales and marketing for Johnson Screens, Mike Mehmert. The association submitted comments to the Federal Emergency Management Agency regarding floodplain regulations and recognized the importance of managed aquifer recharge structures for groundwater recharge. [Extracted from the article]

The accurate prediction of wellbore temperature and pressure is important for safe drilling. However, annulus temperature and pressure changes are more complicated due to phase transition. To study this problem, a prediction model of temperature and pressure in deep water riserless drilling is established by considering hydrate cuttings decomposition, interphase mass transfer, and phase transition heat. Based on this model, the effects of hydrate cuttings decomposition on the temperature and pressure of drilling in a hydrate reservoir are explored. The results show that the influence of hydrate cuttings decomposition increases significantly with an increase in the inlet temperature. The influence of hydrate cuttings decomposition on temperature and pressure decreases with an increase in displacement. A small range in the variation of density and penetration rates has little impact on the annulus pressure but mainly affects the temperature. The influence of hydrate cuttings decomposition increases with an increase in the penetration rate. In normal drilling conditions, hydrate cuttings decomposition has little impact on annulus temperature and pressure, but under the conditions of a high inlet temperature, high hydrate saturation, low displacement, and high penetration rate, it is necessary to consider the impact of hydrate cuttings decomposition. This study can provide reference for the prediction of temperature and pressure in deep water hydrate reservoir riserless drilling. [ABSTRACT FROM AUTHOR]

Well (2020) is an installation by Israeli artists Noga Or Yam and Faina Feigin. It investigates the story of an underground passage in Tel Aviv designed by a British Mandate-era Jewish architect. Starting from this building, the artists' archival research leads them to the story of a water source which does not figure in the architect's plan. While the story of the well is unearthed, so is one about the tense relations between the Jewish architect and the Palestinian orange merchant who inhabited the site before 1948. By restaging a hypothetical archive, Well reminds us of the problems inherent in narrative formation and erasure in the context of the Palestinian–Israeli conflict. Noga Or Yam also examined space and water in an earlier work, Black Soldier, White Soldier (2018): with the background sound of water drilling in southern Israel, urban photographic landscapes of Palestinian rooftops covered with water tanks are projected onto the walls. Water, either concealed or lacking, emerges in both works as a vehicle for unearthing a historical narrative that counters the official one. This research article reflects on contemporary art's engagement with the formation of history, and how such engagement shapes the identity of present-day art in postcolonial realities. [ABSTRACT FROM AUTHOR]

A water based mud was formulated with lignite resin and bentonite in laboratory in accordance with the standard SY/T 5679—2017. After agitating the mud with high-speed mixer, the mud was treated with ultrasonic wave to investigate the effects of ultrasonic vibration on the colloidal properties of the mud. The purpose of this test is to find a new way of preparing mud with which the performance of the existing mud additives can be improved. The test results show that ultrasonic vibration can remarkably reduce the filtration rate of the water based mud formulated. In the test the filtration rate of the mud is continuously reduced at increased power of the ultrasonic wave and in the length of time the ultrasonic wave is working. Furthermore, the apparent viscosity of the mud is slightly reduced by the action of the ultrasonic wave. With an ultrasonic wave of 20 kHz/850 W acting on the mud for 14 min, the API and HTHP filtration rates of the water based mud are reduced by 26.7% and 27.6% (both maximum reductions) respectively. The thickness of the mud cakes is also reduced by 30%-35% after the action of the ultrasonic wave on the mud. Filtration test on a brine mud shows that the API and HTHP filtration rates are reduced by 29.5% and 32.7% (both maximum reductions) respectively after the action of the ultrasonic wave. Particle size distribution analysis, adsorption experiment and SEM observation show that ultrasonic wave is able to reduce the average size of the bentonite particles and increase the adsorptive capacity of the lignite resin on the particles of bentonite, thereby helping form a denser thin mud cake under the action of pressure differential of the mud. Laboratory studies show that mixing new mud with ultrasonic wave is beneficial to improving the filtration property of lignite resin water based drilling fluids. This performance of ultrasonic wave is the so-called “acoustic cavitation mechanisms”. [ABSTRACT FROM AUTHOR]

Fast plugging of microfractures and micropores in the hard brittle shales and deep buried sandstone/mudstone interbeds is one of the challenges that needs to be dealt with in solving borehole wall collapse in drilling the shale formation and reservoir damage. Graphene materials, because of their excellent properties such as nanometer sizes and layered membrane structures, can be used to solve these downhole problems at low concentrations and with high efficiency. A graphene slurry with good stability is prepared in laboratory with graphite using rolling lift-off technique. Evaluation of the performance of the graphene slurry shows that the D50 of the graphene particles is ±5 μm. The graphene slurry has good filtration control property and shale swelling inhibitive capacity. PPA test results show that the graphene slurry is able to effectively seal off the micropores on the sand plate. The application of the graphene slurry on two wells shows that it has good compatibility with the water based drilling fluids used and improves the plugging efficiency of the drilling fluids. Using this graphene slurry, the borehole wall collapse problem previously encountered is successfully solved. [ABSTRACT FROM AUTHOR]

During the development of the carbonate reservoir of the Tahe oilfield, the conventional polysulfonate drilling fluid damages reservoir duo to non-acid-soluble solid phase after loss, and sulfonalized agent does not conform to the concept of green development. The oilfield water is introduced to formulate a solid free drilling fluid to avoid damage reservoir from solid, and the key treatment agents such as anti-high temperature anti-calcium viscosifier, flow pattern modifiers, high-temperature anti-calcium polymer filtrate reducer. The dual-protective oilfield water drilling fluids system without solid was developed. Indoor evaluation datas show that the drilling fluid was heat resistant to 150 ℃，the ratio between yield point and plastic viscosity is as high as 0.68～0.76 Pa/mPa·s, the EC50 value of biological toxicity indicators is as high as 28,600 mg/L, and the bio-degradation index BOD5 /CODCr is as high as 21.35%. The dynamic permeability recovery value is as high as 91.8%, which has good formation damage control performance. The developed dual-protective oilfield water drilling fluids without solid were successfully used in more than ten sidetrack wells,and the application effect was significant. [ABSTRACT FROM AUTHOR]

In view of the problem that high concentration of dust is easily generated during rock tunnel drilling and blasting construction, explosive water mist to reduce dust is given in this paper. Water bag is set up on tunnel face and explosive water mist is used to reduce blasting dust concentration. With the help of numerical simulation software FLUENT and combined with theoretical analysis, The key parameters of explosion fog and dust reduction technology are obtained: water bag spacing, blasting time difference, water bag layout position, etc., which provides a theoretical basis for practical application of the technology. At the same time, combined with the field test of Huangtai tunnel blasting, the dust concentration with and without water mist was measured, respectively. The results show that the maximum dust removal rate of the tunnel section under the dust removal measures with water mist can reach 80.85%, the average dust removal rate can reach 65.16%. So, the dust removal effect is remarkable. [ABSTRACT FROM AUTHOR]

In this study, a drilling fluid prediction method based on an online sequential extreme learning machine (OS-ELM) is proposed, which is prepared for water well drilling on the muddy clay formation of Tarim Basin, Qinghai Province. First, we investigated the mechanism linking mix ratio to fluid performance, allowing us to employ an OS-ELM algorithm derived from the extreme learning machine. Particularly, the proposed prediction method is bidirectional to identify an appropriate slurry formulation. The forward prediction model is established to predict the fluid performance, where the mud additive contents are inputs, and the drilling fluid properties parameters are outputs. Correspondingly, the backward prediction model is established to modify the slurry formula, where differences in the drilling fluid properties are inputs and percentages of slurry additives amount are output. The simulation results show that the two-direction OS-ELM prediction model can better predict the drilling fluid properties in water well drilling. [ABSTRACT FROM AUTHOR]

The paper represents the problem of expanding wells in hard and especially hard rocks. The general direction of solving this problem, the previous methods of solving it and their shortcomings are shown. A new method of drilling and blasting expansion of wells in strong and especially hard rocks is presented, using the energy of a directed explosion of low power to create a three-dimensional network of cracks in the rock mass around the well. The drawings of the tool for drilling and blasting expansion of wells in strong and especially hard rocks at the level of a draft design are given, and the calculation of the explosion energy of a single charge of explosives is carried out, and their mass necessary for such an explosion is determined. [ABSTRACT FROM AUTHOR]

The objective of this investigation is to find out the effect of the woven glass fiber reinforced polymer (GFRP) laminates with different glass fiber densities, such as 610 GSM and 210 GSM, and manufactured by the hand layup technique, supported by compression molding on mechanical properties and abrasive water jet (AWJ) drilling responses. During the investigation, the woven GFRP with a fiber density of 610 GSM has been found to display greater flexural strength, interlaminar strength (ILSS), and tensile strength as compared to the woven GFRP with a fiber density of 210 GSM. The woven GFRP with a fiber density of 610 GSM has also displayed reduced drilling damage in the surface region and less delamination compared to the woven GFRP with a fiber density of 210 GSM. The results of both types of composites prove that the TR and JP considerably impact the delamination extent (DE) and surface roughness (SR). A decrease in the TR and an increase in the JP are primarily responsible for optimizing the desired machining performances. Finally, a FESEM analysis has been done to examine the machined surfaces' morphology. [ABSTRACT FROM AUTHOR]

Radial drilling-fracturing is an innovative fracturing technology that achieves superior stimulation effects. In order to study the permeability-increasing effect and main influencing factors of radial water jet drilling in the low physical section, this paper uses a fracking electrical simulation experiment, based on the principle of hydropower similarity, to simulate the reservoir conditions and well pattern in the low physical section and, at the same time, establishes the radial fracturing model of the low physical section reservoir, simulates the saturation field, pressure field, and production-change law under different drilling parameters, and studies different influencing factors. The experimental results show that when the number of drilling holes exceeds two, the effect of increasing production gradually becomes less significant as the number of drilling holes increases; Within the range of the angle between the two boreholes, the forward distance of the oil–water displacement front is the farthest and the sweep is relatively uniform. On both sides of the included angle, the forward distance of the oil–water displacement front edge is smaller than the forward distance of the displacement within the included angle range and it is clearly inclined towards the radial drilling with uneven spread. Radial drilling has an impact on the seepage field, causing changes in its streamline. The pressure inside the borehole is lower than the surrounding formation pressure and most of the flow lines change direction near the borehole location, causing deflection. As the borehole length increases, the oil-well production also increases. The optimal effect is for the borehole length to be 100 m. This study provides a reference for the on-site application of radial fracturing in low physical properties sections. [ABSTRACT FROM AUTHOR]

Swirling impeller abrasive water jet (SAWJ) is a viable alternative for larger-diameter drilling of mining and oil and gas extraction. Abrasive material plays an important role in eco-efficient drilling of SAWJ. Here, we investigate performances of six types of abrasive materials during SAWJ drilling of hard granite. Rock breaking performances and abrasive particles characteristics before and after impact were studied. Besides, reusability, efficiency and economy of different abrasive materials were discussed. The results indicated that SAWJ would create a large-diameter (63–71 mm) hole with a conical bulge on the bottom regardless of the abrasive material used in it. Abrasive particles size distribution and shape factor before and after impacting with granite had slight changes. Moreover, median diameter of the particles and shape factor were used for estimating the reusability of the abrasive particles after impacting with granite, and the results indicated that all the abrasive materials had excellent reusability. Besides, the efficiency and economy analyses showed that the garnet abrasive had the best rock breaking performance. Therefore, we recommend garnet as the abrasive during swirling impeller abrasive water jet drilling of granite. Highlights: Performances of six types of abrasive materials during SAWJ drilling of granite. Particle size and shape factor are used to estimate the abrasive materials reusability. Garnet abrasive is recommended as the abrasive during SAWJ drilling of granite. [ABSTRACT FROM AUTHOR]