• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 57
  • 14
  • 9
  • 4
  • 3
  • 2
  • 1
  • Tagged with
  • 115
  • 22
  • 20
  • 15
  • 13
  • 12
  • 11
  • 11
  • 10
  • 10
  • 9
  • 9
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Fluid dynamics and thermodynamics of sea ice

Feltham, Daniel Lee January 1997 (has links)
No description available.
2

The effects of brine on the invertebrate faunas of some inland waters

Buckley, B. R. January 1977 (has links)
No description available.
3

Remediation of brine-contaminated soil using calcium nitrate, gypsum, and straw

Nielsen, Jennifer I. 23 April 2013 (has links)
Salt-affected soils from point source brine contamination are common in the active oil field in SE Saskatchewan. A remediation process that included dewatering by sub-surface tile drains, application of surface amendments (calcium nitrate and straw), and growing forages has been successful but not previously examined. In a field study of two remediation sites, the changes in vegetation, soil salinity, and groundwater were assessed using geo-referenced electromagnetic (EM) maps (EM38h, EM38v, and EM31v), piezometers, and soil sampling. A laboratory soil core leaching experiment studied the effect of gypsum, calcium nitrate, and straw at various rates on the remediation of a brine-contaminated soil. All treatments including the control reduced the electrical conductivity (EC) to non-saline values (<4 dS m-1). The sodium adsorption ratio (SAR) was reduced to <13 with the high rates of gypsum and calcium nitrate. The fastest and most effective treatments were comprised of all rates of gypsum and the highest rate of calcium nitrate.
4

Remediation of brine-contaminated soil using calcium nitrate, gypsum, and straw

Nielsen, Jennifer I. 23 April 2013 (has links)
Salt-affected soils from point source brine contamination are common in the active oil field in SE Saskatchewan. A remediation process that included dewatering by sub-surface tile drains, application of surface amendments (calcium nitrate and straw), and growing forages has been successful but not previously examined. In a field study of two remediation sites, the changes in vegetation, soil salinity, and groundwater were assessed using geo-referenced electromagnetic (EM) maps (EM38h, EM38v, and EM31v), piezometers, and soil sampling. A laboratory soil core leaching experiment studied the effect of gypsum, calcium nitrate, and straw at various rates on the remediation of a brine-contaminated soil. All treatments including the control reduced the electrical conductivity (EC) to non-saline values (<4 dS m-1). The sodium adsorption ratio (SAR) was reduced to <13 with the high rates of gypsum and calcium nitrate. The fastest and most effective treatments were comprised of all rates of gypsum and the highest rate of calcium nitrate.
5

Surfactant phase behaviour in relation to oil recovery

Ashayer-Soltani, Roya January 1999 (has links)
No description available.
6

Deep-Basinal Lithium-Rich Brines

Palmer, Timothy 04 May 2018 (has links)
The hydrocarbon producing rocks of the Upper Jurassic in the northern Gulf of Mexico are known to contain lithium-rich brines. However, the genesis of the lithium-rich water is not very well understood. Analysis of hydrogeochemical data indicates that the brines are enriched in bromide, Calcium, Lithium, and sodium, and depleted in potassium, magnesium, and sulfate. Considering this, hydrogeochemical, petrographic, and X-ray Powder Diffraction (XRD) data shows that the brines have been significantly altered relative to the original composition of the water, by salt dissolution, freshwater mixing, and dolomitization. Based on the results of this study, the ore-grade lithium brine is being enhanced by the same stratigraphic and geochemical controls that is depositing dolomite in the Upper Jurassic reservoirs of the northern Gulf of Mexico.
7

Sustainable Carbon Sequestration: Increasing CO2-Storage Efficiency through a CO2-Brine Displacement Approach

Akinnikawe, Oyewande 2012 August 1900 (has links)
CO2 sequestration is one of the proposed methods for reducing anthropogenic CO2 emissions to the atmosphere and therefore mitigating global climate change. Few studies on storing CO2 in an aquifer have been conducted on a regional scale. This study offers a conceptual approach to increasing the storage efficiency of CO2 injection in saline formations and investigates what an actual CO2 storage project might entail using field data for the Woodbine aquifer in East Texas. The study considers three aquifer management strategies for injecting CO2 emissions from nearby coal-fired power plants into the Woodbine aquifer. The aquifer management strategies studied are bulk CO2 injection, and two CO2-brine displacement strategies. A conceptual model performed with homogeneous and average reservoir properties reveals that bulk injection of CO2 pressurizes the aquifer, has a storage efficiency of 0.46% and can only last for 20 years without risk of fracturing the CO2 injection wells. The CO2-brine displacement strategy can continue injecting CO2 for as many as 240 years until CO2 begins to break through in the production wells. This offers 12 times greater CO2 storage efficiency than the bulk injection strategy. A full field simulation with a geological model based on existing aquifer data validates the storage capacity claims made by the conceptual model. A key feature in the geological model is the Mexia-Talco fault system that serves as a likely boundary between the saline aquifer region suitable for CO2 storage and an updip fresh water region. Simulation results show that CO2 does not leak into the fresh water region of the iv aquifer after 1000 years of monitoring if the faults have zero transmissibility, but a negligible volume of brine eventually gets through the mostly sealing fault system as pressure across the faults slowly equilibrates during the monitoring period. However, for fault transmissibilities of 0.1 and 1, both brine and CO2 leak into the fresh water aquifer in increasing amounts for both bulk injection and CO2-brine displacement strategies. In addition, brine production wells draw some fresh water into the saline aquifer if the Mexia-Talco fault system is not sealing. A CO2 storage project in the Woodbine aquifer would impact as many as 15 counties with high-pressure CO2 pipelines stretching as long as 875 km from the CO2 source to the injection site. The required percentage of power plant energy capacity was 7.43% for bulk injection, 7.9% for the external brine disposal case, and 10.2% for the internal saturated brine injection case. The estimated total cost was $0.00132–$0.00146/kWh for the bulk injection, $0.00191–$0.00211/kWh for the external brine disposal case, and $0.0019–$0.00209/kWh for the internal saturated brine injection case.
8

Characteristics and removal of filter cake formed by formate-based drilling mud

Alotaibi, Mohammed Badri 15 May 2009 (has links)
Formate-based mud has been used to drill deep gas wells in Saudi Arabia since 2004. This mud typically contains XC-polymer, starch, polyanionic cellulose, and a relatively small amount of calcium carbonate particles, and is used to drill a deep sandstone reservoir (310°F). Calcium carbonate particles are frequently used as weighting material to maintain the pressure that is required for well control and minimize the leak-off. Such solids become consolidated and trapped in the polymeric material and this makes the filter cake a strong permeability barrier. Various cleaning fluids were proposed to remove drilling mud filter cake; including: solid-free formate brine and formate brine doped with organic acids (acetic, formic, and citric acids), esters, and enzymes. The main objective of this research is to assess the effectiveness of these cleaning fluids in removing drilling mud filter cake. A dynamic high-pressure/high-temperature (HPHT) cell was used to determine characteristics of the drilling mud filter cake. Drilling mud and completion fluids were obtained from the field. Compatibility tests between potassium formate brine, cleaning fluids, and formation brine were performed at 300ºF and 200 psi using HPHT visual cells. Surface tensions of various cleaning fluids were also measured at high temperatures. The conventional method for cleaning the filter cake is by circulating solid-free formate brines at a high flow rate. This mechanical technique removes only the external drilling fluid damage. Citric acid at 10 wt%, formic acid, and lactic acid were found to be incompatible with formate brine at room temperature. However, these acids were compatible with formate brine at temperatures greater than 122°F. Only acetic acid was compatible with formate brine. A formula was developed that is compatible at room and reservoir temperature. This formula was effective in removing filter cake. A corrosion inhibitor was added to protect downhole tubulars. In general detail, this research will discuss the development of this formula and all tests that led to its development.
9

Oil-Field Brine Impacts on Seed Germination and a Contemporary Remediation Technique for Contaminated Soils

Green, Aaron Wesley January 2019 (has links)
The growth of fossil fuel production in North Dakota has resulted in numerous releases of brine. Brine releases cause vegetation mortality as well as the deterioration of soil structural and edaphic properties. Little research to date has been dedicated to the germination response of plant species grown in North Dakota to brine-induced salinity. Through the exposure of plant seeds to increasing levels of brine and NaCl-induced salinity, it was determined that the graminoid species Elymus hoffmannii (AC Saltlander) and Pascopyrum smithii (Western Wheatgrass) exhibited the greatest germination at high salinities. Current remediation technologies for brine-impacted lands often produce mixed results, requiring further research and testing. In two laboratory experiments, the ability of materials to wick salts from brine-contaminated soils was tested. The results of these studies show that some materials reduced Na concentrations in sandy loam, loam, and silty clay soils by upwards of 88, 89.5, 38.4% respectively.
10

The Use of Land Management Practices to Reclaim Brine-Affected Cropland Soils and Restore Shrub Invaded Rangeland

Bartels, Dylan John January 2021 (has links)
Land management techniques can enhance altered ecosystems on a variety of landscapes. In the Williston Basin of North Dakota, brine ponds created 50 years ago still cause problems today. We applied six treatments to reclaim the A-horizon of brine-affected soil on six legacy brine ponds and monitored soil nutrients until 23 months after treatment. We found that from 0-15 cm, all treatments were significantly better at reducing electrical conductivity than the control. In addition, sodium adsorption ratio was reduced at all depths over time. In Southcentral North Dakota, we monitored the effects of fire and grazing on colonies of western snowberry (Symphoricarpos occidentalis), an invasive woody shrub. Prescribed burning had a significant effect on western snowberry by reducing the number of mature plants and increasing the number of new shoots/m2. By incorporating drone aerial imagery, we helped develop an increasingly useful tool in vegetation monitoring.

Page generated in 0.0438 seconds