Position Of Wells Research Articles

Geophysical Studies of Wells in the Settlements of Konoplyanka 1 and Konoplyanka 2 (Bronze Age)

In the South Urals, numerous wells have been found inside dwellings in settlements of the Bronze Age. These features are of great interest, not only because of the artifacts found inside the wells, but also as the first hydrotechnical structures within the territory of northern Eurasia. Geophysical studies were carried out over the area of two Bronze Age settlements: the fortified settlement of Konoplyanka and the unfortified settlement of Konoplyanka 2. A gradient magnetic survey was carried out and settlement plans reconstructed, which formed the basis for the selection of sites for the archaeological excavations. Comparison of geophysical and archaeological results showed that, using magnetic maps, it was possible to accurately reconstruct the plans of ancient settlements and localize the positions of wells. At the excavation site of the settlement of Konoplyanka 1, as a result of the magnetic susceptibility survey, it was established that the edges of the wells were reinforced with a special soil that has higher magnetic properties than the subsoils present. At the excavation site at the settlement of Konoplyanka 2, ground penetrating radar (GPR) prospection of the four wells was carried out, the depth and structural features of these wells being determined. Excavations at two of the wells confirmed the results of the geophysical studies.

Characterizing shallow groundwater in hillslope aquifers using isotopic signatures: A case study in the Upper Blue Nile basin, Ethiopia

Study regionRobit-Bata watershed, Upper Blue Nile basin, Ethiopia. Study focusStable isotopes of water (Oxygen-18 and Deuterium) were used as tracers to estimate the contribution of groundwater in shallow hillslope aquifers to streamflow in the Robit-Bata watershed. To assess the spatiotemporal variability of shallow groundwater and develop a hydrograph separation technique, we collected rainfall, shallow groundwater, and streamflow samples and analyzed their δ18O and δ2H isotopic compositions. The local meteoric water line (LMWL) and local evaporative line (LEL) of the study area were determined and compared with the global meteoric water line (GMWL). A standard unweighted two-component isotope-based hydrograph separation model was used to determine the percentage contribution of shallow groundwater to streamflow. New hydrological insights for the regionThe LMWL (δ2H = 8.63·δ18O + 18.2) mostly showed heavy isotopic enrichment relative to GMWL, and the LEL (δ2H = 5.45·δ18O + 6.96) indicated isotopic enrichment compared to Ethiopian lakes. Shallow groundwater responded rapidly to rainfall, with good spatial correlation depending on topographic positions of wells. Pre-event water contributed <50% to peak discharge in July, but >90% when the watershed reached maximum storage. This finding gives insight towards the predominant runoff generation process and has significant implications for sustainable dry season irrigation expansion in the area as the sub-surface flow drains out of the watershed from October onwards reducing water tables in the shallow wells.

A global inventory of concentration measurements of free and dissolved in underground waters molecular hydrogen in the Earth’s crust on land

This paper presents a global inventory of concentration measurements of free and dissolved in underground water molecular hydrogen sampling areas in the Earth’s crust on land. The inventory table indicates their regional belonging, the average hydrogen concentration and standard deviation at each point if concentration exceeds 0.01 %. For information analysis, sampling reservoirs are classified in 5 groups depending on the type of degassing structures. They are ophiolite complexes, geothermal systems, underground waters, ultrabasite massifs, and soils. Samples were taken on 5 continents in 32 countries from 97 reservoirs in 318 sampling areas. The 3481 gas analyzes revealed the presence of hydrogen of different concentrations. The 294 values of R/Ra were presented. All sampling reservoirs are plotted on a world map, which also shows the position of wells in the territory of the former USSR, where hydrogen from underground waters was recorded. In general, most of the reservoirs studied contain hydrogen in small quantities, since on-ly 16 (16.5%) of them have concentration of more than 5 %. The highest concentration of hydrogen (average value of 60.34 %, 7 wells) is in the heads of hydrogeological wells immediately after drilling completion. The concentration of hydrogen in soil near wells is 1070—1600 times less than hydrogen in the wells coming from underground water horizons. Zones of the present-day activation accompanied with intensive geothermal processes generate low concentration hydrogen, whose mean concentration value is 1.6 ± 3.97 % (43 analyses). In soil gases, the hydrogen concentration varies from 0.03 to 0.06% with exception of the Moscow region (0.25 %). The concentration of hydrogen in soil of the zones of active faults varies randomly along the faults depending on the composition of the sedimentary rocks filling them. Only in the zones of active faults during several years of preparation of strong earthquakes in the region hydrogen released to the day surface whose concentration exceeds the background value by 200 times reaching 4 %. The presence of hydrogen in gases with the mantle component was mentioned 14 times in publications mainly due to the values of R/Ra. However, the first integrated study of helium isotopes relationships and seismotomographic data suggests a unique case of occurrence of mantle hydrogen in one of geothermal features of the Yellowstone caldera. The present-day water plays a key role in the formation of hydrogen. Its generation occurs exclusively in the Earth’s crust because of the oxidation of ferrous iron by alkaline water in basic and ultrabasic rocks resulted from various chemical reaction schemes and water vapor always occurrence in magmatic gases where hydrogen is registered 24 times. In rare cases (4), the source of hydrogen in negligible quantities is alkaline water radiolysis or radioactive decay.

Pump-and-treat configurations with vertical and horizontal wells to remediate an aquifer contaminated by hexavalent chromium

Pump-and-treat technology is among the most used technologies for groundwater remediation. While conventional, vertical wells (VRWs) are well-known and used from long time, horizontal wells (HRWs) have been explored for remediation technologies only in last few decades. HRWs have shown to outperform vertical wells in terms of versatility, productivity and clean-up times under certain conditions.In this paper, the efficacy of an innovative pump-and-treat (P&T) configuration for groundwater remediation obtained by adopting either VRWs or HRWs technology is comparatively tested. A 3D transient finite element model of an unconfined aquifer containing a hexavalent chromium (Cr(VI)) contamination plume is considered to compare a single horizontal well configuration vs a range of spatially-optimised arrays containing vertical wells.A sensitivity analysis aimed at finding the best configuration to minimise the remediation time and the related cost is carried out by comparing different well diameters, D, pumping rates, Q, and position of wells. A comparative cost analysis demonstrates that, for the examined case-study, a single HRW achieves the clean-up goals in the same time span as for a greater number of vertical wells, but at higher price due to the excavation costs.

Well Water Site Selection at Local Scale Using Geographical Information System for Flood Victim in Malaysia

Clean water supply is a major problem among flood victims during flood events. This article aims to determine the sites of well water sources that can be utilised during floods in the District of Kuala Krai, Kelantan. Field methods and Geographic Information Systems (GIS) were applied in the process of selecting flood victim evacuation centres and wells. The data used were spatial data obtained primarily, namely the well data, evacuation centre data and flood area data. The well and evacuation centre data were obtained by field methods conducted to determine the position of wells using global positioning system tools, and the same for the location of the evacuation centres. Information related to evacuation centres was obtained secondarily from multiple agencies and gathered into GIS as an evacuation centre attribute. The flood area data was also obtained via secondary data and was digitised using the ArcGIS software. The data processing was divided into two stages, namely the first stage of determining the flood victim evacuation centres to be used in this research in a structural manner based on two main criteria which were the extent to which an evacuation centre was affected by the flood and the highest capacity of victims for each district with the greatest impact to the flood affected population. The second stage was to determine the location of wells based on three criteria, namely i) not affected by flood, ii) the closest distance to the selected flood victim evacuation centre and iii) located at different locations. Among the main GIS analyses used were locational analysis, overlay analysis, and proximity analysis. The results showed that four (4) flood evacuation centres had been chosen and matched the criteria set, namely SMK Sultan Yahya Petra 2, SMK Manek Urai Lama, SMK Laloh and SK Kuala Gris. While six (6) wells had been selected as water sources that could be consumed by the flood victims at 4 evacuation centres in helping to provide clean water supply, namely Kg. Keroh 16 (T1), Kg. Batu Mengkebang 10 (T2), Lepan Meranti (T3), Kg. Budi (T4), Kg. Jelawang Tengah 2 (T5) and Kg. Durian Hijau 1 (T6). With the presence of the well water sources that can be used during flood events, clean water supply can be distributed to flood victims at the evacuation centres. Indirectly, this research can reduce the impact of floods in the future, especially in terms of clean water supply even during the hit of a major flood.

USE OF CONTROL VARIABLES TO IMPROVE THE PERFORMANCE OF WATER AND POLYMER FLOODING STRATEGIES

In oil industry, decisions related to field development take into consideration scenarios that involve many uncertainties and high investments. Thus, a comprehensive decision analysis process is necessary to select the production strategy that maximizes field performance considering these uncertainties. For the selection of a production strategy, two main groups of optimization variables may be considered: design and control variables. The design variables relate to the development of the field, and cannot be altered after the implementation of the strategy (e.g. capacity of the platform, number and position of wells). On the contrary, control variables relate to the management of the field, and can be altered daily by the companies (e.g. production and injection rates). However, even with a robust production strategy selection process, unexpected or undesirable events can occur and decrease the economic efficiency of the project. The objective of this work is to evaluate the use of control variables when undesirable events occur after the implementation of a production strategy, to improve the economic performance of the project. Two production strategies are used: one that uses only water flooding and other one prepared for polymer flooding. The simulation model is based on a heterogeneous heavy oil offshore field. Two approaches (undesirable events) are considered in this work: (1) polymer degradation and (2) a geologic model that is different than the expected one. The results show that the economic performance can be improved greatly by simply adjusting the control variables for the described situations. Moreover, the gain in the polymer flooding case is higher than for water flooding, because of the higher number of optimization variables, such as polymer solution concentration and slug size, giving more flexibility to this kind of project.

Integrated optimization model for location and sizing of offshore platforms and location of oil wells

The oil field development is a hard and critical task that defines the main procedures to be performed during the oil field productive life. Given the complexity of this planning phase, methods to support decision making have been developed to assist in the proper application of high investments. This paper aims to report a 0–1 Linear Programming Model which minimizes the development costs of a given oil field as a whole. The model seeks to define: the number, location and capacities of production platforms; number and positions of wells; points where manifolds must be installed; interconnection between platforms, manifolds and wells; and which sections of each well should be vertical or horizontal. The model was named Multicapacitated Platforms and Wells Location Problem (MPWLP). Two different scenarios were tested and the results were consistent with reality, computationally feasible and presented innovations compared to models found in literature.

Sanitation Mapping of Groundwater Contamination in a Rural Village of India

Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrheal diseases. We examined the spatial information on the groundwater quality and sanitation facilities of a village in southern India using Geographic Information System (GIS) tools. Place of residence, position of wells and latrines were mapped and well water samples were tested for microbial contamination (Total Coliform Counts (TCC), Fecal Coliform Counts (FCC) and Fecal Streptococcal Counts (FSC)). A well structured questionnaire was administered to 50 residents of the selected areas to elicit information on water collection, handling and storage. The location and distances of wells from latrines were determined using the Global Positioning System (GPS) device and a tape rule respectively. Data on 170 cases of various water-borne diseases were collected from primary health centers in the study area. Groundwater in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, design of the wells and improper siting of wells from latrines which were found to be the possible reasons of groundwater contamination. There was a significant difference in TCC between covered and uncovered wells (p p < 0.01). A moderate negative correlation (r = -0.593, r = -0.470) was ensued between the distance from latrine and coliform count. This study accentuates the need to set standards for the siting of wells from latrines and need for treatment.

Growth Rates Made Easy

In the 1960s-1980s, determination of bacterial growth rates was an important tool in microbial genetics, biochemistry, molecular biology, and microbial physiology. The exciting technical developments of the 1990s and the 2000s eclipsed that tool; as a result, many investigators today lack experience with growth rate measurements. Recently, investigators in a number of areas have started to use measurements of bacterial growth rates for a variety of purposes. Those measurements have been greatly facilitated by the availability of microwell plate readers that permit the simultaneous measurements on up to 384 different cultures. Only the exponential (logarithmic) portions of the resulting growth curves are useful for determining growth rates, and manual determination of that portion and calculation of growth rates can be tedious for high-throughput purposes. Here, we introduce the program GrowthRates that uses plate reader output files to automatically determine the exponential portion of the curve and to automatically calculate the growth rate, the maximum culture density, and the duration of the growth lag phase. GrowthRates is freely available for Macintosh, Windows, and Linux. We discuss the effects of culture volume, the classical bacterial growth curve, and the differences between determinations in rich media and minimal (mineral salts) media. This protocol covers calibration of the plate reader, growth of culture inocula for both rich and minimal media, and experimental setup. As a guide to reliability, we report typical day-to-day variation in growth rates and variation within experiments with respect to position of wells within the plates.

Optimal Management of an Overexploited Aquifer under Climate Change: The Lake Karla Case

This paper presents a study for finding the optimal management plan of an overexploited aquifer under global climate change. The study area is the aquifer of the basin of Lake Karla, located in the eastern part of Thessaly in Greece. An optimization method has been used to evaluate the optimum volume of water that can be extracted from the aquifer and the optimum position of the wells with the objective of water table rise to a desirable sustainable level, taking into consideration the climate change forcing. The modelling system consists of a series of interlinked models: a hydrological, a lake-aquifer, a reservoir operation, a groundwater, and an optimization model. The climate change forcing on precipitation and temperature has been evaluated using the outputs of Canadian Centre for Climate Model Analysis General Circulation Model (CGCMa2) and a hybrid downscaling method which combines a multiple regression (MLR) model and a timeseries model for two socioeconomic emissions scenarios. The results of this study show that climate change plays an important role, as it affects the optimum volume of the extracted groundwater and the position of the irrigation wells.

The hydrochemical identification of groundwater flowing to the Bet She’an-Harod multiaquifer system (Lower Jordan Valley) by rare earth elements, yttrium, stable isotopes (H, O) and Tritium

Abstract The Bet She’an and Harod Valleys in Israel are regional recipients and mixing zones for groundwater draining from a multiple aquifer system, which includes carbonate and basalt aquifers and deep-seated pressurized brines. The aquifers drain through two types of outlets, distinct and mixed. The latter type is mainly conditioned by the occurrence of fault-blocks related to the Jordan Rift system, which act as connecting media between the aquifers and facilitate interaquifer flow. Conjoint application of rare earth element distribution and water isotopes enables detection of the local areas replenishment by rainfall infiltration and, in connection with the position of wells or springs, the identification of groundwater flow paths. Once stationary equilibria are established changes of REY composition between REY in groundwater and their surface adsorption, are negligible. In areas with little soil coverage and vegetation even recharge over young Tertiary and diagenetic Cretaceous limestones is distinguishable by their REY distribution patterns. Groundwater recharged over Tertiary limestones show higher REY abundance and more significant Ce anomalies than those derived from the Cretaceous limestones. Weathering of alkali olivine basalts leads to REY patterns in groundwater depleted in the middle REE. The improved knowledge of the hydrological systems is thought to be useful for regional hydrogeological modeling and for designing rational water management schemes.

Optimizing Recovery for Waterflooding Under Dynamic Induced Fracturing Conditions

Summary It is well established within the industry that water injection mostly takes place under induced fracturing conditions. Particularly in low-mobility reservoirs, large fractures may be induced during the field life. This paper presents a new modeling strategy that combines fluid flow and fracture growth (fully coupled) within the framework of an existing "standard" reservoir simulator. We demonstrate the coupled simulator by applications to repeated five-spot pattern flood models, addressing various aspects that often play an important role in waterfloods: shortcut of injector and producer, fracture containment to the reservoir layer, and areal and vertical reservoir sweep. We also demonstrate how induced fracture dimensions (length, height) can be very sensitive to typical reservoir engineering parameters, such as fluid mobility, mobility ratio, 3D saturation distribution (in particular, shockfront position), 3D temperature distribution, positions of wells (producers, injectors), and geological details (e.g., layering and faulting). In particular, it is shown that lower overall (time-dependent) reservoir transmissibility will result in larger induced fractures. Finally, it is demonstrated how induced fractures can be taken into account to determine an optimum life-cycle injection rate strategy. The results presented in this paper are expected to also apply to (part of) enhanced-oil-recovery operations (e.g., polymer flooding).

87Sr/86Sr ratio: a natural tracer to monitor groundwater flow paths during artificial recharge in the Bangkok area, Thailand

The aquifer system in the Thon Buri sedimentary basin below the deltaic flood plain of the Chao Phraya River, central Thailand, has been exploited for public water supply for the capital Bangkok since the early 1920s. Groundwater withdrawal, currently 1.4 million m3/d, has resulted in a maximum decline in hydraulic head of up to 40 m. This has induced land subsidence of as much as 1.7 m (1940–1992) in the eastern suburbs of the metropolis. Artificial injection of purified water within an area-wide network of recharge wells could constitute a remedy to slow the water level depression within the sedimentary basin, and thus the subsidence. This requires a prior shutdown of water withdrawal. The flow paths of the injected water can be traced by changes in the 87Sr/86Sr ratio of the groundwater and injected water mixture within the three main aquifers in the basin that are used for public supply. The ratios, monitored at five monitoring stations within the cone of depression, have been constant over 3 years. Injection of the calculated cone volume of 5.2 × 109 m3 would take at least 10 years, depending on the injection pressure and the number and position of wells.

High-pressure investigation of InGan quantum wells.

ABSTRACTWe have studied the pressure dependence of photoluminescence for various InGaN quantum wells of different Indium compositions. In contrast to classical quantum well systems such as GaAs/AlGaAs, the pressure coefficients of the photoluminescence peak position of wells of similar parameters can vary greatly, depending on conditions of growth. Generally, the pressure coefficient of the emission peak is much lower than the one predicted for a GaN-InN system. We show that this behavior can be related in most cases to the influence of the thick GaN layer compressibility on the strain in the InGaN quantum wells. However, in some cases (Nichia devices), the pressure coefficient of the emission peak seems to be unrelated to the shift of the energy gap of the material, suggesting the involvement of strongly localized electronic states

Field Application of Computer Graphics for Monitoring Borehole Trajectories

Summary A method to present directional wellbore trajectories graphically with microcomputers has been developed. This concept makes use of interactive computer graphics, enabling the user to view computer calculation results immediately. The source code was written in FORTRAN-77 and designed for use with microcomputers. Introduction The vertical and horizontal sections routinely used to evaluate directional wans are simple graphical displays that monitor the spatial position of a wellbore. These graphical profiles are limited in that investigation of multiple wellbores from a common surface point is very difficult. This problem is best resolved with the use of a computer and an interactive graphics computer program, such as the one discussed in this paper. Lutz and Kendle reported on the use of such a computer system, monitoring 1,190 directional wells drilled from marimade islands off California. This system provided speed and precision while eliminating the tedious drafting involved in manual calculations. The design parameters were also optimized to reduce drilling costs while minimizing interference between proposed and existing wells. However, their algorithms and source code were not published. Our work was suggested by techniques available in the computer-aided-drafting type interactive computer graphics systems. These user-friendly interactive systems allow quick recalculation and graphic display. These techniques were applied to a system of multiple wellbores to perform such tasks as translation, rotation, 3D clipping, and zoom onto an area of interest to give the viewer a variety of vantage points. The source code was written in FORTRAN-77. The program was compiled on an IBM PC in DOS and equipped with a graphic adapter, using the Microsoft FORTRAN Optimizing Compiler Version 4.0. It can easily be modified to fit particular user needs in addition to those demonstrated later in the paper. This source code provides a practical, usable program and eliminates the questionable reliability of undisclosed source codes. Theoretical Considerations First, the measured parameters of existing and proposed wells are entered into the computer program as measured depth and inclination and direction angles. These coordinates are immediately converted to an orthogonal system (i.e. north, east, and true vertical depth (TVD) by the minimumcurvature method. Then, the resulting coordinates are transformed to a world coordinate system (i.e., a right-hand Cartesian system where the y axis is vertically upward, the × axis is east, and the z axis is south), whose origin can be chosen by the user (see Fig. 1). Examples of origins are the center of a template for multiple wells or the surface location for a single well. The observer views this fixed coordinate system from a screen coordinate system that is free to move with respect to the world coordinate system. A vector in the world system is mapped to the screen system by applying observation transformations (i.e., scalings, rotations, and translations) and then mapping the screen system to the viewing area (see Fig. 2). Depending on the observation transformations chosen, some portions of the wells may require clipping at the boundaries of the viewing area. This allows the user to view the wellbore paths from a variety of spatial positions, such as from very far away to see all wellbores from surface to bottom or on horizontal planes to view relative positions of wells (see Fig. 3). In effect, the observer is looking through a square window of the world space that contains the information the user wishes to display (see Fig. 4). Then, the viewport is defined as a square portion of the viewing screen onto which the window contents are mapped. The viewport is essentially the 2D orthogonal projection of the contents of the window. Mathematically, the observation transformations, as indicated by primes, can be written as follows. For a translation, x'=x+a, y'=y+b, and z'=z+c, where a, b, and c are the translation parameters. For a rotation about the z axis, x'=x cos() -y sin(), y =x sin() +y cos(), and z'=z JPT December 1989 P. 1254^

Aeromagnetic Detection of Diagenetic Magnetite over Oil Fields: GEOLOGIC NOTES

Aeromagnetic Detection of Diagenetic Magnetite over Oil Fields: GEOLOGIC NOTES

Naive attributors' attributions and predictions: What is informative and when is an effect an effect?

Wells and Harvey (1977) critically evaluated past research that suggested people do not use consensus information when making predictions and causal attributions. Borgida (1978) takes issue with a subset of Wells and Harvey's conclusions. Below, we address the issues raised by Borgida. In particular, it is argued that (a) Borgida incorrectly states the position of Wells and Harvey concerning the issue of ignoring versus underutilizing consensus information; (b) Borgida incompletely summarizes Wells and Harvey's attribution data; (c) Kahneman and Tversky (1973) statistically controlled for target description informativeness, while Nisbett and Borgida (197S) used no control for target description informativeness; (d) Kahneman and Tversky's presentation of data in their lawyerengineer study tended to underrepresen t the majority of their subjects' data; and (e) a replication of Kahneman and Tversky's lawyer-engineer study, using a more appropriate

ASPECTOS GEOQUÍMICOS DAS ÁGUAS SUBTERRÂNEAS DA REGIÃO DE BERTIOGA, ESTADO DE SÃO PAULO, BRASIL

The objective of this work was the characterization of conditions of ground-water wells in the above mentioned area. Methodology included an extensive sampling to obtain fundamental hydrogeological data, technical informations relating to well drilling and the relative position of wells vs cesspool. Geophysical prospecting (by electroresistivity methods) allowed us to determine the quality of the aquifers and the hydrogeological properties of the substratum. Most of the data were obtained by analysis (physicochemical and bacteriological) in situ, with the HACH Water Analysis Kit. Various degrees of potability were found, mainly on account ot the concentration ranges of Fe, NH 4 , NO 2 , and presence of coliform bacteria. The geochemical interpretation showed three types of water. The study of exchangeable bases revealed that there is a relationship between the chemical composition of waters and the lithology, and also the conditions of circulation of these waters within the rocks. Fluctuation of the concentrations of Fe and Cl are controlled by the distance from the beach, on the other hand the TDS, NH 4 and N0 3 , by conditions of circulation.

Aspectos geoquímicos das águas subterrâneas da região de Bertioga, Estado de São Paulo, Brasil

The objective of this work was the characterization of conditions of ground-water wells in the above mentioned area. Methodology included an extensive sampling to obtain fundamental hydrogeological data, technical informations relating to well drilling and the relative position of wells vs cesspool. Geophysical prospecting (by electroresistivity methods) allowed us to determine the quality of the aquifers and the hydrogeological properties of the substratum. Most of the data were obtained by analysis (physicochemical and bacteriological) in situ, with the HACH Water Analysis Kit. Various degrees of potability were found, mainly on account ot the concentration ranges of Fe, NH 4 , NO 2 , and presence of coliform bacteria. The geochemical interpretation showed three types of water. The study of exchangeable bases revealed that there is a relationship between the chemical composition of waters and the lithology, and also the conditions of circulation of these waters within the rocks. Fluctuation of the concentrations of Fe and Cl are controlled by the distance from the beach, on the other hand the TDS, NH 4 and N0 3 , by conditions of circulation.