scholarly journals Some key issues in the design of water wells in unconsolidated and fractured rock aquifers

2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Bruce Misstear
Keyword(s):  
Developing Countries ◽  
Rural Communities ◽  
Fractured Rock ◽  
Small Diameter ◽  
Cost Effective ◽  
Hydraulic Efficiency ◽  
Screen Length ◽  
Well Design ◽  
Well Yield ◽  
Fractured Rock Aquifers

The key well design issues considered in this paper are the length of the intake section; the hydraulic efficiency of the well; the length of grouted upper casing for wells in fractured rock aquifers and the potential trade-off between well yield and security against pollution; and the economics of well design. For wells in thick, relatively uniform unconsolidated aquifers, the well depth and screen length can be estimated using a simple discharge-drawdown relationship. This approach can help avoid constructing unnecessarily deep wells if alternative guidance to screen the bottom third of the aquifer was followed in such situations. Hydraulic efficiency is an important consideration in well design: the paper highlights that whereas screen entrance velocity has been a topic of much discussion in the literature, well upflow velocity has received less attention, but can be an important contributor to well losses in small diameter screens. In fractured hard rock aquifers, there may be a compromise required in well design between maximising well yield by exploiting shallow fracture zones whilst also providing adequate sanitary protection to the well by installing an upper grouted casing. Recent data from Ireland on the distribution of hydraulic conductivity with depth in poorly productive fractured rock aquifers are used to calculate the reduction in well yield that would result from increasing the length of the grouted upper well casing. Economic aspects of well design are especially important where there are a large number of wells to be drilled and/or where wells are required in poor rural communities in developing countries. The principles of cost-effective boreholes for developing countries are summarised, noting the opportunities for small-diameter shallow wells constructed with inexpensive manual or lightweight mechanical drilling rigs.

scholarly journals EXPERIENCE OF OILFIELD DEVELOPMENT IN PERM KRAI USING HORIZONTAL WELLS

2020 ◽  
Vol 20 (2) ◽  
pp. 182-191
Author(s):  
Roman A. Zaitcev ◽  
◽  
Aleksei V. Raspopov ◽  
Keyword(s):  
Horizontal Well ◽  
Small Diameter ◽  
Cost Effective ◽  
Hole Drilling ◽  
Standard Size ◽  
Oil Reserves ◽  
Hydrocarbon Reservoir ◽  
Structural Deterioration ◽  
Well Design ◽  
Perm Krai

Hydrocarbon reservoir engineering has a top priority to achieve the highest possible value of the cost-effective oilrecovery factor. Structural deterioration of residual oil reserves and inevitable development of hard-to-recover reservesrequire new effective technologies and engineering solutions. Today, there is a tendency to replace the standard sizewell drilling technologies (including vertical, directional, horizontal, multilateral wells) and standard size dualcompletion equipment usage by slim-hole drilling technologies. In Perm Krai fields, more than 385 horizontal wellshave been drilled, while 3.4 % of them, i.e. 13 wells, have a small diameter. The conducted well operation analysisshows that the effectiveness of the horizontal well operations in a number of instances is significantly lower than thepotential one. This leads to a deteriorated economic performance of reservoir developments, and, eventually, to assetvalue reductions. Perhaps, the main reason of low effectiveness of the horizontal well operations lies is an insufficientunderstanding of geological and physical conditions of their successful operations. It has become obvious that drillinghorizontal wells in reservoirs with high compartmentalization, low net oil thickness, and decreased hydrodynamicconnectivity to the edge water zone offer a low level of performance. Productivity tends to decrease to average outputvalues of directional wells. Therefore, the problem of choosing a well design and its direction in specific geological andphysical conditions is highly relevant.

Rigorous Design Process for a Groundwater Pump for Low-Yield Water Wells: A Case Study

2010 ◽  
Author(s):  
Peter Anderson ◽  
James Wonson ◽  
W. John Dartnall
Keyword(s):  
Developing Countries ◽  
Water Supply ◽  
Design Process ◽  
High Efficiency ◽  
Low Cost ◽  
Cost Effective ◽  
Production Volume ◽  
Tube Wells ◽  
Well Yield

Ground-water pumping in remote areas, such as Australian farms, was for many years traditionally done by wind pumps in order to satisfy the needs of stock. Since the 1980’s solar pumps of varying designs have become popular for pumping water from farm dams and tube wells. Wind pumps, solar pumps, engine or electric motor driven pumps and even animal/human powered pumps have a future in many remote situations in the world for stock watering, irrigation and for village water supply in developing countries. In these markets there is a wide-spread view that local manufacture of the pumps is preferable, as is well documented in the literature on village water supply in developing countries. Submersible pumps that are either of the multi-stage centrifugal class or that use the progressive cavity principle have increased in popularity in the low well yield environment. However, where well yields are extremely low the efficiency of these pumps also becomes low and oversized pumps of these kinds are often inappropriately applied. Quite often in the low yield situation, tube wells are also oversized in that they are drilled to large diameters and depths so as to provide storage in order to accommodate the water demand requirements of the user. This practice leads to unnecessary deterioration of both pump and well. Designing for low production volume manufacture presents unique challenges for the designer in attempting to design a robust, versatile but cost-effective product. The design challenges include, achievement of: - high efficiency, reliability, longevity, simplicity, versatility with a minimum parts count, and all this at a low cost. A case study is presented in this paper in which the design issues are outlined. A rigorous design process has been applied in this case study.

Hydrogeology of conglomerate fractured-rock aquifers: an example from the Portofino's Promontory (Italy)

2016 ◽  
Vol 41 ◽  
pp. 22-25 ◽  
Author(s):  
Vittorio Bonaria ◽  
Francesco Faccini ◽  
Ilaria Cinzia Galiano ◽  
Alessandro Sacchini
Keyword(s):  
Fractured Rock ◽  
Fractured Rock Aquifers

scholarly journals Advances in Environmental Detection and Clinical Diagnostic Tests for Legionella Species

2021 ◽  
Author(s):  
Rajeshwari Vittal ◽  
Juliet Roshini Mohan Raj ◽  
Ballamoole Krishna Kumar ◽  
Indrani Karunasagar
Keyword(s):  
Developing Countries ◽  
Healthcare System ◽  
Diagnostic Tests ◽  
Clinical Manifestations ◽  
Cost Effective ◽  
Clinical Samples ◽  
Detection Techniques ◽  
Conventional Culture ◽  
Legionella Species ◽  
Mild Fever

Abstract Legionella is a fastidious organism that is difficult to culture in the lab but is widely distributed in environmental, domestic, and hospital settings. The clinical manifestations due to Legionella infections range from mild fever to fatal pneumonia and multiorgan pathologies. Legionella outbreaks though prevalent globally are not reported in developing countries due to difficulties in isolating this organism and the lack of simple diagnostic protocols. Here, we review the literature from across countries to present various methods used to detect Legionella from environmental and clinical samples. We compare the sensitivity and the specificity of the conventional culture-based assays with the recent methods and discuss approaches to develop better detection and diagnostic tests. With better cost-effective detection techniques and regular monitoring of the susceptible sites, which may harbor Legionella colonies, most of the Legionella infections can be prevented. As a result, considerable burden, caused by Legionella infections, on the healthcare system, in especially economically weaker countries, can be mitigated.

scholarly journals Energy Retrofitting Opportunities Using Renewable Materials—Comparative Analysis of the Current Frameworks in Bosnia-Herzegovina and Slovenia

2021 ◽  
Vol 13 (2) ◽  
pp. 603
Author(s):  
Darija Gajić ◽  
Slobodan Peulić ◽  
Tim Mavrič ◽  
Anna Sandak ◽  
Črtomir Tavzes ◽  
...  
Keyword(s):  
Developing Countries ◽  
Residential Buildings ◽  
Cost Effective ◽  
Primary Energy ◽  
Low Carbon ◽  
Resource Exploitation ◽  
Renewable Materials ◽  
Building Stock ◽  
Low Carbon Economy ◽  
Eu Member States

Sustainable approaches for retrofitting buildings for energy efficiency are becoming necessary in a time when the building sector is the largest energy consumer. Retrofitting building stock is effective for reducing global energy consumption and decreasing resource exploitation. Less developed EU member states and neighboring developing countries show reluctance towards healthy and renewable materials. Implementation of sustainable materials for energy retrofitting is slowed down due to gaps in legislation and effective strategic programs, availability of bio-based materials, lack of knowledge regarding use and maintenance of renewable products, and marketing lobbies. Use of bio-based materials in refurbishment is important due to their negative or low global warming potential (GWP), low primary energy (PEI) need for production, cost-effective benefits, and recycling/reuse potential. Role of environmentally friendly solutions and low-carbon economy growth is particularly relevant in developing countries, such as Bosnia-Herzegovina, that cannot afford innovative energy recovery systems, yet possess a significant amount of poorly managed building stock. This research aims to analyze frameworks regarding retrofitting of residential buildings in Bosnia-Herzegovina and Slovenia. The analysis tackles indirect causes, studies the legal background, and examines strategic frameworks; thus, it indicates potential barriers for implementation of recommended retrofitting solutions based on renewable materials.

A cost-effective evaluation of biomass district heating in rural communities

2016 ◽  
Vol 162 ◽  
pp. 561-569 ◽  
Author(s):  
Aaron M. Hendricks ◽  
John E. Wagner ◽  
Timothy A. Volk ◽  
David H. Newman ◽  
Tristan R. Brown
Keyword(s):  
Rural Communities ◽  
District Heating ◽  
Cost Effective ◽  
Effective Evaluation

Direct Push Technology and Application to Vertical Profiling of Hydraulic Conductivity in Unconsolidated Formations

2003 ◽  
Author(s):  
Wesley McCall ◽  
Thomas M. Christy ◽  
James J. Butler
Keyword(s):  
Hydraulic Conductivity ◽  
Test Data ◽  
Small Diameter ◽  
Cost Effective ◽  
Depth Interval ◽  
Contaminant Migration ◽  
Slug Tests ◽  
Monitoring Wells ◽  
Direct Push ◽  
Vertical Profiling

Direct push (DP) methods provide a cost-effective alternative to conventional rotary drilling for investigations in unconsolidated formations. DP methods are commonly used for sampling soil gas, soil and groundwater; installing small-diameter monitoring wells; electrical logging; cone penetration testing; and standard penetration tests. Most recently, DP methods and equipment for vertical profiling of formation hydraulic conductivity (K) have been developed. Knowledge of the vertical and lateral variations in K is integral to understanding contaminant migration and, therefore, essential to designing an adequate and effective remediation system. DP-installed groundwater sampling tools may be used to access discrete intervals of the formation to conduct pneumatic slug tests. A small-diameter (38mm OD) single tube protected screen device allows the investigator to access one depth interval per advancement. Alternatively, a larger diameter (54mm OD) dual-tube groundwater profiling system may be used to access the formation at multiple depths during a single advancement. Once the appropriate tool is installed and developed, a pneumatic manifold is installed on the top of the DP rod string. The manifold includes the valving, regulator, and pressure gauge needed for pneumatic slug testing. A small-diameter pressure transducer is inserted via an airtight fitting in the pneumatic manifold, and a data-acquisition device connected to a laptop computer enables the slug test data to be acquired, displayed, and saved for analysis. Conventional data analysis methods can then be used to calculate the K value from the test data. A simple correction for tube diameter has been developed for slug tests in highly permeable aquifers. The pneumatic slug testing technique combined with DP-installed tools provides a cost-effective method for vertical profiling of K. Field comparison of this method to slug tests in conventional monitoring wells verified that this approach provides accurate K values. Use of this new approach can provide data on three-dimensional variations in hydraulic conductivity at a level of detail that has not previously been available. This will improve understanding of contaminant migration and the efficiency and quality of remedial system design, and ultimately, should lead to significant cost reductions.

Stress-testing groundwater and baseflow drought sensitivity to recharge

2021 ◽  
Author(s):  
Jost Hellwig ◽  
Michael Stoelzle ◽  
Kerstin Stahl
Keyword(s):  
Fractured Rock ◽  
Drought Severity ◽  
Severe Drought ◽  
Stress Tests ◽  
Drought Sensitivity ◽  
The North ◽  
Groundwater Response ◽  
Dry Spells ◽  
Groundwater Drought ◽  
Fractured Rock Aquifers

<p>Groundwater is the main source of freshwater and maintains streamflow during drought. Potential future groundwater and baseflow drought hazards depend on the systems' sensitivity to altered recharge conditions. We performed groundwater model experiments using three different generic stress tests to estimate the groundwater- and baseflow drought sensitivity to changes in recharge. The stress tests stem from a stakeholder co-design process that specifically followed the idea of altering known drought events from the past, i.e. asking whether altered recharge could have made a particular event worse. Here we show that groundwater responses to the stress tests are highly heterogeneous across Germany with groundwater heads in the North more sensitive to long-term recharge and in the Central German Uplands to short-term recharge variations. Baseflow droughts are generally more sensitive to intra-annual dynamics and baseflow responses to the stress tests are smaller compared to the groundwater heads. The groundwater drought recovery time is mainly driven by the hydrogeological conditions with slow (fast) recovery in the porous (fractured rock) aquifers. In general, a seasonal shift of recharge (i.e., less summer recharge and more winter recharge) will therefore have low effects on groundwater and baseflow drought severity. A lengthening of dry spells might cause much stronger responses, especially in regions with slow groundwater response to precipitation. Water management may need to consider the spatially different sensitivities of the groundwater system and the potential for more severe groundwater droughts in the large porous aquifers following prolonged meteorological droughts, particularly in the context of climate change projections indicating stronger seasonality and more severe drought events.</p>

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