Repository logo

Browsing by Author "Carlson, Kenneth H., advisor"

Now showing 1 - 12 of 12
  • Thumbnail Image
    ItemOpen Access
    Development of a GIS based tool to analyze produced water from oil and gas wells and prediction of equilibrium concentrations using CalcAQ
    (Colorado State University. Libraries, 2013) Dhanasekar, Ashwin, author; Carlson, Kenneth H., advisor; Arabi, Mazdak, committee member; Sutton, Sally, committee member
    New extraction techniques based on hydraulic fracturing and horizontal drilling have significantly increased the available oil and gas in the United States. Producing oil and gas from shale formations is the main source of these unconventional resources. When shale formations are hydraulically fractured to increase the permeability, up to 5 million gallons of water can be used for each well. The significant use of water has caused concerns by several stakeholders, particularly in regions that are constantly facing water shortages such as Texas or Colorado. After the well is fractured, large amounts of water return as frac flowback and then after the well is put into production, water that is coproduced with oil and gas must be collected for the life of the well. The produced water has hazardous characteristics since it has been in contact with oil and gas for millions of years and disposal or reuse is an important part of an oil and gas operation. Current water management for produced water includes underground injection and surface disposal or reuse. Owing to a large amount of total dissolved solids (TDS), metals and hydrocarbons (e.g. BTEX) in the produced water, the brine needs to be treated to achieve acceptable water quality for subsequent disposal or reuse. Reusing and recycling of produced water for drilling and fracturing after appropriate treatment has multiple advantages including less truck traffic and lower fresh water demands. The objective of the research in this thesis was to integrate the OLI chemical equilibrium model into the OWM (Optimized Water Management) tool framework to allow chemical equilibrium calculations to be made for each well and in the aggregate throughout the Wattenberg oil and gas field of northern Colorado. The calculations from this model can then be used as design criteria for treatment train definition based on the desired water disposal outcome. OLI Systems software was developed for the chemical and oil and gas industry and is well suited as a module for calculating chemical equilibrium values for produced water and frac flowback water. The research described in this thesis includes predictions of equilibrium chemistry, solids precipitation and scale forming index, based on water quality data collected in the field. The model can also predict requirements for combining and treating produced water streams to achieve process objectives. At the same time, water quality will be analyzed after detailed sampling from various parts of the field. Finally, water quality after precipitation, settling and filtration has been used to estimate the osmotic pressure and design reverse osmosis processes for different levels of TDS rejection. This will be integrated with a customized ArcGIS tool that will help in predicting treatment specifics on a spatial scale.
  • Thumbnail Image
    ItemOpen Access
    Development of graphical user interface tools for optimal fluid management in shale oil and gas operations
    (Colorado State University. Libraries, 2015) Shoaei, Farnaz, author; Catton, Kimberly B., advisor; Carlson, Kenneth H., advisor; Bradley, Thomas H., committee member
    Oil and gas extraction is increasing in many parts of the country due to the use of hydraulic fracturing. Hydraulic fracturing is a technique to extract oil and gas from shale rock formations that is characterized by the input of large quantities of pressurized water into horizontal wells. The high pressure fluid generates cracks in the shale formation that release the gas, oil, and other constituents into the fluid. The fluid that returns to the surface is characterized as flowback or produced water. Flowback is defined as the water that returns to the surface prior to the initiation of oil or gas production and produced water refers to the post-production return water. There is widespread public and government agency interest in assessing the quantity and quality of water used in hydraulic fracturing to ensure environmental protection and public health. Optimal water management in hydraulic fracturing has the potential to (1) reduce freshwater use, (2) increase produced water recycle, (3) reduce energy expenditures from water transport, and (4) enhance safety and environmental protection in the development of natural gas and other petroleum resources. Improved management of water can enhance safety and environmental protection by minimizing impacts such as road damage, truck traffic, noise, air pollution, water pollution and landscape disturbance. Interactive management tools allow operators to increase water reuse and minimize the environmental risks of hydraulic fracturing. This research entails developing graphical user tools to optimize water management in shale oil and gas operations. The tools that were developed include (1) a Water Production Modeling Tool, (2) a Water Use Calculator, and (3) a Water Quality Tool. The tools are MATLAB executable files that can run without a MATLAB license. The output of these tools will provide information for users to predict wastewater production, water demand needed for treatment, and analyze water quality components such as contaminant concentrations.
  • Thumbnail Image
    ItemOpen Access
    Development, testing and application of a real-time sensing network for monitoring chemical contamination events in a drinking water distribution system
    (Colorado State University. Libraries, 2007) Cho, Seongho, author; Carlson, Kenneth H., advisor
    Routine on-line monitoring which detects the change of water quality by both chemicals and biofilm of drinking water distribution systems offers potential in eliminating the danger of purposeful contamination events.
  • Thumbnail Image
    ItemOpen Access
    Enhancing natural treatment systems by utilizing water treatment residuals
    (Colorado State University. Libraries, 2008) Yarkin, Mustafa, author; Carlson, Kenneth H., advisor
    The current project envisions the application of riverbank filtration (RBF) and aquifer recharge and recovery (ARR) in series as preliminary treatment steps of a multi-barrier treatment approach for the City of Aurora's Prairie Waters Project. The primary focus of the project is the removal of phosphorus, nitrogen, and carbon from the source water resulting in biologically stable water that can be stored in a terminal reservoir. In addition to nutrients, perchlorate and three commonly used pesticides, atrazine, alachlor, and metolachlor have been studied in terms of removal with the RBF and ARR systems. Aluminum based water treatment residual (WTR) was considered along with other sorbents for enhanced phosphorus removal. The experimental studies include the monitoring of an RBF field site and pilot columns that simulate RBF and ARR systems. Possible benefits of WTR as an amendment were tested by amending a column with 30% WTR under RBF and ARR conditions. Also an application scenario of RBF followed by a WTR amended ARR infiltration basin and ARR was simulated by a column study. Results of the studies indicated that the RBF and ARR systems are insufficient to provide sustainable phosphorus removal. Phosphorus removal mechanism is limited by the sorption capacity of the alluvial sand and minor biological activity. Use of the WTR amendment reduced phosphorus levels to less than the method detection limit of 0.03 mg/L with a high adsorption capacity. The ARR system in sequential RBF-ARR application suffers from the lack of labile organic carbon and therefore microbially mediated treatment processes are limited. Amending the infiltration of the ARR system with organic carbon rich WTR can promote biological activity, thus allowing further biodegradation of contaminants. Results of the study indicated that the RBF system is a sustainable barrier for nitrate removal while labile carbon limited ARR cannot achieve significant nitrate removal. To use the ARR system as a secondary barrier for nitrate, a labile carbon source should be introduced to the system. WTR was used as a supply of organic carbon to the ARR system and the experimental studies indicated that, once optimized, WTR can promote biological denitrification through the ARR system. The field and column studies also showed that both RBF and ARR can achieve perchlorate removal as long as sufficient electron donating compounds (e.g. organic carbon) are present in the environment. It has also been observed that the ability of RBF and ARR systems to remove alachlor and metolachlor is limited by the biodegradation through the alluvial sand while they achieve sustainable atrazine removal. WTR was tested as an amendment alternative the ARR infiltration basin. Concentrations of selected pesticides were reduced to the method detection limit of 0.3 μg/L during 1-foot 30% WTR amended column treatment with the residence time of 1.25 days under both abiotic and biotic conditions. The overall study suggested that once the source and type of the WTR was selected, the optimum amount of WTR can be obtained by adjusting the application ratio and the media depth for the efficient removal of all contaminants of concern.
  • Thumbnail Image
    ItemOpen Access
    Environmental impacts of oil and gas activities in northern Colorado
    (Colorado State University. Libraries, 2018) Li, Huishu, author; Carlson, Kenneth H., advisor; Sharvelle, Sybil, committee member; Omur-Ozbek, Pinar, committee member; Liu, Jiangguo, committee member
    The surge of shale oil and gas exploration and production in the United States is driven by the application of horizontal drilling and hydraulic fracturing which require and generate massive amount of water during the production of crude oil and natural gas. Since 2010, shale oil and gas production from northern Colorado (Wattenberg field) has increased rapidly due to the rich deposit of oil and natural gas in the shale formation, which also raises a lot of concerns over its potential environmental impacts on groundwater and air. To understand the contaminant transport mechanisms, identify the sources of contamination caused by oil and gas operations, and detect the contamination associated with drilling and fracturing activities will help improve the environmental and economic sustainability of shale-gas extraction. Therefore, our research focuses on the following topics: 1, determine the contaminants due to horizontal drilling and hydraulic fracturing; 2, study on the subsurface transport and distribution of contaminants related to oil and gas activities in groundwater; 3, design and evaluate a regional groundwater monitoring network to detect the contamination events.
  • Thumbnail Image
    ItemOpen Access
    Exploration of Anammox-based deammonification and phosphorus recovery systems using biomolecular tools
    (Colorado State University. Libraries, 2018) Turpin, DeeAnn-Rose G., author; Carlson, Kenneth H., advisor; De Long, Susan K., committee member; Catton, Kimberly B., committee member; Kipper, Matthew J., committee member
    To view the abstract, please see the full text of the document.
  • Thumbnail Image
    ItemOpen Access
    Flowback quality characterization for horizontal wells in Wattenberg field
    (Colorado State University. Libraries, 2013) Jiang, Xi, author; Carlson, Kenneth H., advisor; Omur-Ozbek, Pinar, committee member; Bradley, Thomas H., committee member
    The development of hydraulic fracturing has driven both the need for more fresh water, and also has increased the amount of flowback being produced. Faced with a shortage of usable water, transportation issues, strict environmental regulation and environmental concerns, flowback management is an important topic for oil and gas companies. Recycle and reuse flowback waste is a promising method, since it can simultaneously reduce the need of more fresh water for fracking and decrease the potential environmental issues. Understanding the quality characteristics of flowback is significant for implementing the required treatment of flowback water. Flowback flows back to the surface during and after hydraulic fracturing and often flows for over a period of 3-4 weeks, though most wells finish in seven to 10 days. The fluid contains high total dissolved solids (TDS) and high salinity, and also contains some of the same chemicals that are pumped into wells. The volume of flowback can range from 10%-50% of initial injected fracturing fluid. In our study, sampling time was from March to April 2013 and all the samples were taken separately from Wells Ranch State PC USX #AA16-69-1HNL and Wells Ranch State USX #AA16-68-1HNL. The results in this report used well #68 and well #69. Well #68 was injected with PermStim fracture fluid (injected pH 5.0) and well #69 was injected with SliverStim fracture fluid (injected pH 10.2). Wellhead pressure, temperature, pH, dissolved carbon dioxide (CO2), bicarbonate (HCO3) and dissolved hydrogen sulfide (H2S) were tested in the field once samples were collected. TDS, chloride, sulfate, bicarbonate, aluminum, barium, boron, calcium, iron, magnesium, potassium, silicon, strontium and zirconium were tested by E-Analytics Laboratory. The objective of this paper is to analyze flowback water quality from two horizontal wells, located in the same place, which were injected with two different fracturing fluids. Based on the results of the temporal quality trend, this paper also intends to analyze the impact of different pH on water quality and the possible chemical reactions that occur during drilling and fracturing phases.
  • Thumbnail Image
    ItemOpen Access
    Frac flowback water blending and treatment requirements based on spatial and temporal water quality analysis
    (Colorado State University. Libraries, 2015) Li, Wanze, author; Carlson, Kenneth H., advisor; Omur-Ozbek, Pinar, committee member; Stednick, John D., committee member
    Because of the large amount of wastewater generated with oil and gas production and the complex components of produced water, associates in the human health and environmental disciplines consider the treatment and reuse of produced water as a central issue for the petroleum industry. At present, produced water recycling is one of the best ways to reduce fresh water consumption in the hydraulic fracturing process and lessen environmental impact. This study focuses on the analysis of produced water quality and the optimization of the produced water recycling. Samples of produced water from more than two hundred horizontal wells in seven Integrated Development Plans in the Wattenberg Field were analyzed for temporal and spatial levels of total dissolved solids (TDS), sodium, chloride, calcium, and iron. Concentration of total dissolved solids, sodium, chloride and calcium were modeled to accommodate the different temporal functions in each Integrated Development Plan; the temporal logarithmic functions of each model allow prediction of produced water quality data for existing wells or new wells in certain regions. Iron concentration, however, closely correlates with geological formation, so the iron concentration of produced water must be determined spatially as an average value and maximum value in each Integrated Development Plan. A framework for optimizing produced water reuse is presented as part of this study. Typically, some volume of fracturing fluid is retained in wells; further, portions of flowback fluids might be injected into disposal wells. Produced water must be treated to meet recycled water quality requirements. In this study, coagulation/filtration, softening/clarification, and reverse osmosis (RO) were applied to treat samples effectively for suspended solids, total dissolved solids, sodium, chloride and calcium. Following treatment, the proper amount of fresh water needed to blend with the produced water must be determined. With sources of fresh water limited, the amount of water used to optimize the recycling of produced water is one of the most significant issues in the management of produced water. Calculating the quantity of fresh water necessary can be based on the quality of the fresh water, fracturing fluids and the targeted quality of the recycled water; in some cases, it might be based on the quantity of fracturing fluids and recycled water targeted. If the result based on quality is not less than the quantity based result, additional treatment will be required. Frac fluids modification could also be used in some conditions in this program, however, the cost of additives can be high, and additional treatment may be the better option. Most of recycle produced water quality with our treatment reaches requirements of fracturing fluids after blending with certain amount of fresh water. Produced water quality analysis of the horizontal wells in the Wattenberg Field and the established produced water recycling system program are supporting produced water management and the viability of produced water reuse. The Matlab produced water recycling program incorporates both internally sourced quality analysis data and external data uploaded from users. As a tool simulating produced water recycling, it can help users make good decisions to use in water management.
  • Thumbnail Image
    ItemOpen Access
    Nutrient load inputs to the Cache la Poudre River watersheds
    (Colorado State University. Libraries, 2013) Son, Ji-Hee, author; Carlson, Kenneth H., advisor; Watson, Chester, committee member; Bond, Craig, committee member; Sharvelle, Sybil, committee member
    Nutrient (phosphorus and nitrogen) has been ranked as a leading source of water quality impairment of surface waters in the United States for the past two decades. Based on strong encouragement for developing in-stream nutrient numeric criteria by the Environmental Protection Agency of the U.S., the Colorado Department of Public Health and Environment proposed the in-stream numeric total phosphorus (TP) and total nitrogen (TN) criteria as 2 mg TN L-1 and 0.16 mg TP L-1 for warm surface waters and 0.40 mg TN L-1 and 0.11 mg TP L-1 for cold surface waters. As a consequence, nutrient limits for point sources, the municipal wastewater treatment plants, have been proposed as annual averages of 0.7 mg TP L-1 and 5.7 mg total inorganic nitrogen (TIN) L-1 and quarterly averages of 1.0 mg TP L-1 and 9.0 mg TIN L-1 to achieve the in-stream standards. Rivers and streams, however, receive nutrient loads from point sources and nonpoint sources in a mixed land-use area and therefore nutrient reduction only at point sources is unlikely to result in improvements to the environment without nonpoint source controls. The objectives of this study were to monitor TP (Chapter 4.1) and TN (Chapter 4.2) concentrations and estimate loads along the Cache La Poudre River as it flows from the pristine upstream area through a mixture of agricultural and urban land uses, and compare the loads between point sources and nonpoint sources under various hydrologic conditions. Twelve and seven sampling events were completed between April 2010 and August 2011 for TP and TN, respectively. Point sources, wastewater treatment plants (WWTPs) in the study area, were the major sources of TP and TN during midrange and dry flow conditions, but nonpoint sources were more substantial under high flow conditions. Loading exceedance of TP from the proposed in-stream TP limit was observed for all hydrologic conditions, but the significance of the exceedance was drastically increased during high flow conditions (p<0.05). Contrary to expectations, significant loading exceedance of TN was observed only for lower flow conditions, and other sources dominated during events when exceedance of TN was observed. Nutrient loads increased in areas of greater anthropogenic influence (p < 0.05) and nonpoint source loads became significant in the areas with more agricultural activity (p < 0.05). We attempted to simulate TP and TN loads in the CLP River to determine whether the loads under different effluent conditions in the WWTPs would comply with the proposed in-stream limits (Chapter 4.3). The study shows that reducing nutrient load only at WWTPs will merely reduce nutrient load in the river and that the in-stream limits cannot be achieved without substantial reduction of nonpoint source loads (e.g., stormwater and agricultural runoff) and therefore other sources need to be considered in establishing the in-stream standard limits. An intense wildfire occurred in a forested area of Colorado in June 2012 while a study of the role of riverbed sediment in terms of phosphorus source under various hydrologic conditions was being conducted. River water and sediment samples were collected after the fire, and water quality and sediment properties of the post-fire samples were spatially and temporally compared with the pre-fire samples collected prior to the fire event (Chapter 4.4). Disturbance of water quality and soil properties by the fire were observed, but the magnitude of significance was relatively small without precipitation; however, in-stream TN and TP concentrations significantly increased in the upstream section after precipitation event. Large amounts of particulate P were introduced to the upstream section and impacts downstream were apparent. After precipitation event, soluble reactive phosphorus (SRP) dominated dissolved P in the river replacing dissolved organic phosphorus (DOP), which was the main dissolved species before the fire event. In the riverbank, TP mass concentration increased significantly after fire with silt-clay and organic matter (OM) concentrations after precipitation. Riverbed TP mass concentrations decreased due to a reduced sorption capacity leading to a considerable P release from the sediments. The results indicate that fire-released P species will impact the downstream area of the watershed for a considerable time period as the bank erosion-sorption-desorption cycles in the watershed adjust to the fire-related loading.
  • Thumbnail Image
    ItemOpen Access
    Occurrence and biodegradation of antibiotic compounds in the aquatic environment
    (Colorado State University. Libraries, 2007) Cha, Jongmun, author; Carlson, Kenneth H., advisor
    The occurrence and fate of antibiotics in the aquatic environment are an emerging area of interest due to the potential impact of these compounds on the environment. This study applied rapid, sensitive and reliable analytical methods for the determination of β-lactam and polyether ionophore antibiotics in surface water, wastewater, sediment, lagoon water, and animal manure. The method incorporated solid-phase extraction and liquid chromatography-ion trap tandem mass spectrometry (LC-MS-MS) with selected reaction monitoring. Specifically, the method was applied to evaluate the occurrence of these compounds in a small watershed in northern Colorado. The study also investigates the potential for on-farm removal of these compounds by measuring the biodegradation kinetics of oxytetracycline, sulfamethoxazole, tylosin, and monensin in bioreactors setup to simulate a dairy wastewater lagoon.
  • Thumbnail Image
    ItemOpen Access
    Produced water quality characterization and prediction for Wattenberg field
    (Colorado State University. Libraries, 2013) Li, Huishu, author; Carlson, Kenneth H., advisor; Sharvelle, Sybil, committee member; Stednick, John, committee member
    Produced water is the major Exploration & Production waste in oil and gas production operations on most onshore and offshore platforms. There are some concerns about the environmental impacts of produced water, because of the potential danger of large volume of water disposal by shale plays. It is a complex mixture of dissolved and particulate inorganic and organic matters ranging from near freshwater quality to concentrated saline brine. The most abundant inorganic chemicals are calcium, magnesium, sodium and chloride. Other inorganic components, such as barium, strontium, boron, sulfate, carbonate and bicarbonate are also present in the produced water but at high concentrations. The dominant organic chemicals in most produced water are soluble low molecular weight organic acids and some aromatic hydrocarbons. Constituents of produced water vary a lot depending on a number of factors, including geographic locations, characteristics of formations (i.e. the depth of formation, porosity and permeability of formation rocks/sands, water content) and injected fracturing fluid. Since water is becoming a big issue in some arid areas and as regulations become more restrictive for disposal and reinjection, produced water reuse/recycle will be a solution to reduce the wastewater production and alleviate environmental effects. The main objective of this study was to statistically evaluate the produced water quality and to provide an assessment on the spatial distribution of specific groundwater quality parameters. Produced water samples were collected at 80 sample points (producing oil and gas wells) from May to August in 2012. pH, conductivity, alkalinity, turbidity, total organic carbon, total nitrogen, and barium were tested at Colorado State University's Environmental Engineering lab; total dissolved solids (TDS), calcium, magnesium, sodium, potassium, strontium, boron, chloride and sulfate were measured in ACZ Laboratories Inc., Colorado. All the produced water samples were acidic with pH ranging from 5.1-6.8. TDS, cations, anions and organic carbons tested in our study varied a lot. Maps showing the spatial distributions of these parameters were made using ArcGIS. Linear correlations between chloride, conductivity/TDS, and cations (log) were shown, which made it possible to estimate unknown parameters. Spatial and temporal trends of pH, TDS and total organics together with inner relationships of ion concentrations could allow us to make predictions of produced water qualities. This project was the first phase of the development of a GIS application that will provide a tool that can benefit industry when making decisions regarding produced water recycling.
  • Thumbnail Image
    ItemOpen Access
    Utilizing river bank stabilization and reactive stream stabilization as best management practices for achieving total maximum daily load regulations
    (Colorado State University. Libraries, 2010) Son, JiHee, author; Carlson, Kenneth H., advisor; Sharvelle, Sybil, committee member; Borch, Thomas, committee member
    Phosphorus is recognized as a limiting factor for growth of aquatic organisms in surface water bodies. When excess amounts of this nutrient are discharged into a stream, biomass of phytoplankton starts to increase and eutrophication can result. A Reactive Stream Stabilization (RS2) structure has been developed to stabilize the stream bank and minimize release of some agricultural nonpoint source pollutants through erosion from farms, waste sites, and animal feed lots to the stream. The RS2 system was studied for its nutrient (nitrogen and phosphorus) removal efficiency from 2003 to 2006 at the Colorado State University. Based on this study at CSU, a RS2 structure was designed and installed along the bank of the Little Bogue Creek near Grenada, Mississippi in November 2008. The scope of the research for this Master's thesis research was to assist in design and installation of a field scale RS2 structure and to conduct assessment of the initial nutrient removal performance of the system. The reactive barrier of the installed RS2 has shown high concentrations of Al and organic matter, design criteria intended to promote adsorption of phosphorus (P) and facilitate nitrogen (N) removal through denitrification. The performance of the RS2 structure was examined from the soils, monitoring wells and the stream waters that were sampled in May and July, 2009. The mean concentration of aluminum from the reactive barrier was 2.1 mg/g soil and organic matter from the monitoring wells in the bank was 4.68 mg/L which were significantly greater than the surrounding area (p<0.05). Soil Mehlich-3 P and total P (TP) were decreased by 55 % and 30 %, and 40 % of TN and 51 % of nitrate in the ground water were removed through the RS2. The RS2 is expected retain P efficiently although accumulation of P has not yet been observed. From this research, the design objectives of the RS2 structure have been satisfied and the initial sampling data shows promise. Future research will be conducted to verify the effectiveness of RS2 structures for achieving TMDL regulations.