Significance of Silica Analysis in Groundwater Studies of Domestic Shallow Wells in Parts of Jeli District, Kelantan, Malaysia

2017 ◽  
pp. 103-114
Author(s):  
Mohammad Muqtada Ali Khan ◽  
Fatin Wahida Fadzil ◽  
Hafzan Eva Mansor ◽  
Dony Adriansyah Nazaruddin ◽  
Zameer Ahmad Shah
Keyword(s):  
Shallow Wells

scholarly journals Occurrence of carcinogenic illudane glycosides in drinking water wells

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Natasa Skrbic ◽  
Vaidotas Kisielius ◽  
Ann-Katrin Pedersen ◽  
Sarah C. B. Christensen ◽  
Mathilde J. Hedegaard ◽  
...  
Keyword(s):  
Drinking Water ◽  
Health Concern ◽  
Liquid Chromatography Mass Spectrometry ◽  
Deep Groundwater ◽  
Hydrolysis Products ◽  
First Finding ◽  
Water Wells ◽  
Shallow Wells ◽  
Great Health ◽  
Groundwater Wells

Abstract Background Ptaquiloside (PTA), caudatoside (CAU) and ptesculentoside (PTE) are carcinogenic illudane glycosides found in bracken ferns (Pteridium spp.) world-wide. The environmentally mobile PTA entails both acute and chronic toxicity. A comparable risk might be associated with the structurally similar CAU and PTE. It is of great health concern if these compounds are present in drinking water, however, it is currently unknown if these compounds can detected in wells in bracken-dominated regions. This study investigates the presence of PTA, CAU, PTE, and their corresponding hydrolysis products pterosins B (PtB), A (PtA) and G (PtG) in water wells in Denmark, Sweden and Spain. Water samples from a total of 77 deep groundwater wells (40–100 m) and shallow water wells (8–40 m) were collected and preserved in the field, pre-concentrated in the laboratory and analysed by liquid chromatography–mass spectrometry (LC–MS). Results Deep groundwater wells contained neither illudane glycosides nor their pterosins. However, seven private shallow wells contained at least one of the illudane glycosides and/or pterosins at concentrations up to 0.27 µg L−1 (PTA), 0.75 µg L−1 (CAU), 0.05 µg L−1 (PtB), 0.03 µg L−1 (PtA) and 0.28 µg L−1 (PtG). This is the first finding of illudane glycosides and pterosins in drinking water wells. Conclusions Detected concentrations of illudane glycosides in some of investigated wells exceeded the suggested maximum tolerable concentrations of PTA, although they were used for drinking water purpose. Contaminated wells were shallow with neutral pH and lower electric conductivity compared to deep groundwater wells with no illudane glycosides nor pterosins.

scholarly journals Hydrochemistry and environmental isotopes (18O, 2H, 3H, 3He/4He) of groundwater and floodwater in the great area of Hurghada, Eastern Desert of Egypt

2021 ◽  
Vol 80 (11) ◽  
Author(s):  
M. Wannous ◽  
C. Jahnke ◽  
U. Troeger ◽  
M. Falk ◽  
F. Bauer
Keyword(s):  
Environmental Isotopes ◽  
Eastern Desert ◽  
Hydrochemical Parameters ◽  
Deep Wells ◽  
Fractured Aquifers ◽  
He Isotopes ◽  
Shallow Wells ◽  
The Common ◽  
Faulted Zone

AbstractPorous and fractured aquifers exist in the area of Hurghada, Eastern Desert of Egypt, whose recharge processes through the common flash floods are not identified. Hydrochemical parameters, stable isotopes 18O, 2H and tritium in floodwater and groundwater were applied in the area subject to study. Additionally, He isotopes were investigated in the deep wells in the faulted zone at the Abu Shaar Plateau. 3H activity in all sampled points lies below the detection limit excluding a recent recharge component in groundwater. However, the hydrochemical ratios and the stable isotope signature confirm that the shallow wells and springs (Red Sea Hills group) are being recharged from modern precipitation. The hydrochemical parameters of the deep wells at the Abu Shaar Plateau (coastal plain group) confirm another origin for the ions rather than the modern precipitation. Together with the 18O and 2H values, the Br/Cl ratio of this group confirms the absence of seawater intrusion component and the role of the fault as a hydraulic barrier. These 18O and 2H values deviate from the GMWL confirming an evaporation effect and colder infiltration conditions and reveal strongly a possible mixing with the Nubian Sandstone in the region. The 3He/4He ratio confirms a mantle contribution of 2% from the total He components.

Conditions In Shallow Wells In The South Coast Region Of Kenya

1989 ◽  
Vol 14 (3) ◽  
pp. 112-121 ◽  
Author(s):  
G. K. Thambu ◽  
I. C. Goulter
Keyword(s):  
South Coast ◽  
The South ◽  
Shallow Wells ◽  
Coast Region

Case Study for Reducing Tubing Failures in Suriname's Tambaredjo Field

2014 ◽  
Author(s):  
D.. Nurmohamed ◽  
H. Chin Lien ◽  
S.. Kisoensingh
Keyword(s):  
Best Practices ◽  
Rotational Motion ◽  
Direct Contact ◽  
Visual Inspection ◽  
Pilot Program ◽  
Pilot Test ◽  
Sucker Rod ◽  
Tubing String ◽  
Shallow Wells

Abstract In Staatsolie, as of December 2013, there were 1549 shallow wells from its 3 oilfields. One thousand one hundred and thirty (1130) of these were in the Tambaredjo field (TAM field). In the 3 decades of its operations, the prime mechanism for lifting the 15.6oAPI crude to surface has been with progressive cavity pumps (PCP). The down hole pumps are surface driven and installed at an average true vertical depth (TVD) of 1000 ft. Oilfield best practices are employed in the design, installation and operation of the production strings and pumps. In the period 2008-2012 an average 580 down hole failures occurred annually of which 54% was caused by tubing leaks, with a repetitive frequency of up to 6 faillures per year on individual wells. Visual inspection of internal tubing's have shown that the principal failure mechanism stems from rod tubing wear (abrasion caused by the rotational motion) exacerbated by the corrosiveness of the produced fluids. Most of the tubing wear occurs at the tubing body in direct contact with the rod couplings. It is found that most tubing leakages (up to 70%) occur on the lower part of the tubing string above the pump. Previous installation of shorter rods above the pump, which is causing a high eccentrically movement of the rod string, also increased the occurrences of these failures directly above the pump. In an effort to reduce these tubing failures, an eight-well pilot program was commenced to install rod guides in wells with the highest failure rate and to install a sucker rod of 25 feet right above the pump. These eight wells were selected based on their high tubing failure rates. Although the program is still being conducted, preliminary results thus far have been quite promising in these wells. In four (4) wells, the work-over frequency was reduced from average 5 to 3 jobs per annum resulting in 40% reduction. The remaining 4 wells are still producing after an average 5-month period without any tubing failures. This paper presents the approach and strategy used to minimize rod-tubing wear in shallow vertical well applications based on the outcome of the pilot test.

Buoyancy Force on a Plain or Perforated Portion of a Pipe

2021 ◽  
Author(s):  
Eric Cayeux ◽  
Sigmund Stokka
Keyword(s):  
Buoyancy Force ◽  
Construction Operations ◽  
Drilling Operation ◽  
Drill Stem ◽  
Shallow Wells ◽  
Plain Tube ◽  
End Caps ◽  
Drag Models ◽  
The One ◽  
Perforated Tube

Abstract Torque and drag models have been used for many decades to calculate tensions and torques along drill-strings, casing strings and liner strings. However, when applied to sand-screens, it is important to check that all the initial hypotheses used for torque and drag calculations are still valid. In particular, it should be checked whether the buoyancy force on a perforated tube may differ from the one applied to a plain tube. The buoyancy force applied on a pipe, contributes to the sum of efforts at the contact between the pipe and the borehole and therefore influences torque and drag calculations. This contact force is local and should account for localized effects as well as the material internal forces, torques and moments on each side of the contact. As the buoyancy force is the result of the gravitational component of the pressure gradient on the surface of the pipe that is in contact with the fluid, the presence of holes in the pipe also influences the buoyancy force. When applied to a portion of a pipe, buoyancy does not have contributions at the end caps of that portion of the drill-stem since these end caps are not in contact with the fluid, except at positions with a change of diameter. Therefore, one shall be cautious when calculating the local buoyancy force either on a plain or a perforated tube. The paper describes how to calculate the local buoyancy force on a portion of a drill-stem by application of the Gauss theorem accounting for the necessary corrections arising from the end caps not being exposed to the fluid. An experimental setup has been built to verify that the tension inside a pipe subject to buoyancy does follow the derived mathematical calculations. With complex well construction operations, for instance during extended reach drilling or when drilling very shallow wells with high kick-off rates, the slightest error in torques and drag calculations may end up in jeopardizing the chance of success of the drilling operation. It is therefore important to check that all initial calculation hypotheses are still valid in those contexts and that for instance, sand-screens may be run in hole safely after a successful drilling operation.

scholarly journals Hydrogeological Conceptual Model in the Middle of Randublatung Groundwater Basin

2021 ◽  
Vol 926 (1) ◽  
pp. 012078
Author(s):  
D L Setyaningsih ◽  
K D Setyawan ◽  
D P E Putra ◽  
Salahuddin
Keyword(s):  
Groundwater Flow ◽  
Conceptual Model ◽  
Unconfined Aquifer ◽  
Primary Data ◽  
Essential Information ◽  
Aquifer System ◽  
The North ◽  
Shallow Wells ◽  
Groundwater Basin ◽  
Constant Head

Abstract Randublatung groundwater basin is one of the groundwaters basins with massive utilization of groundwater pumping. However, the knowledge of the comprehensive hydrogeological system in this groundwater basin is limited, so this research aims to determine a comprehensive hydrogeological conceptual model of the Randublatung groundwater basin. The methodology was conducted by collecting secondary and primary data of deep and shallow wells to evaluate boundaries of pattern and direction of groundwater flow and develop the aquifer system’s geometry. The result shows that the groundwater flow boundaries are Grogol River in the west, Wado River in the East, Bengawan Solo river in the South as a river boundary, and Rembang Mountains in the North as a constant head boundary. Therefore, groundwater flows from the hills area to the Bengawan Solo River and the north as the river’s flow. Based on the log bor evaluation, the aquifer system of the study area consist of an unconfined aquifer with a maximum thickness of 20 m and three layers of confined aquifers with thickness vary between 8 to 60 m. the hydraulic conductivity of the aquifers depends on the aquifer’s lithology range from sand, gravel, limestone, and sandstone. This hydrogeological conceptual model provides essential information for numerical groundwater models in the middle of the Randublatung groundwater basin.

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