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Potential for Beneficial Use of Oil and Gas Produced Water
Abstract
Technology advancements and the increasing need for fresh water resources have created the potential for desalination of oil field brine to be a cost-effective fresh water resource for the citizens of Texas. In our state and in other mature oil and gas production areas, the majority of wells produce brine water along with gas and oil. Many of these wells produce less than 10 barrels of oil a day (bbl/day) along with substantial amounts of water. Transporting water from these stripper wells is expensive, so much so that in many cases the produced water can be treated on site, including desalination, for less cost than hauling it away. One key that makes desalination affordable is that the contaminants removed from the brine can be injected back into the oil and gas producing formation without having to have an EPA Class I hazardous injection permit. The salts removed from the brine originally came from the formation into which it is being re-injected and environmental regulations permit a Class II well to contain the salt "concentrate". This chapter discusses key issues driving this new technology. Primary are the costs (economic and environmental) of current produced water management and the potential for desalination in Texas. In addition the cost effectiveness of new water treatment technology and the changes in environmental and institutional conditions are encouraging innovative new technology to address potential future water shortages in Texas.
... In certain conditions, PW can be reused for beneficial purposes such as agricultural irrigation, but, the volume of PW currently reused this way represents only a small proportion of the total PW generated. Nonetheless, beneficial reuse of PW is growing (Burnett, 2004;Clark and Veil, 2015) and could provide a substantial volume of irrigation water to crops located near O&G facilities in drylands (Guerra et al., 2011). ...
... PW quality also differs Table 1 Estimates of water-to-oil ratios (WOR = m 3 of produced water/m 3 of oil produced), water-to-gas ratios (WGR = m 3 of produced water/1000 m 3 of gas produced), and total volumes of produced water (PW) by type of production and country or region located in drylands. (Burnett, 2004); 9 (Clark and Veil, 2015); 10 (Digital H2O, 2015); 11 (Sharr, 2014); 12 (Waterfind, 2016); 13 (Jacobs Consultancy, 2010); 14 (Commonwealth of Australia, 2014); 15 (IESC, 2014); 16 (Blackam, 2017); 17 (Robles, 2016); 18 (Waldron, 2005); 19 (Al-Haddabi et al., 2015); 20 (Keesom et al., 2009); 21 (Sorkhabi, 2010); 22 (Kuraimid, 2013); 23 (Breuer, 2011); 24 (Al-Mahrooqi et al., 2007); 25 (Alanezi, 2016); 26 (Ahan, 2014); 27 (Gulf Intelligence, 2016); 28 (Rice and Nuccio, 2000); 29 (NSW Government, 2013); 30 (Scanlon et al., 2014); 31 (Gordon, 2015); 32 (Kurz et al., 2016); 33 (Terrel, 2015); 34 (Vaz and Di Falco, 2011); 35 (Williams and Simmons et al., 2013); 36 (Miller, 2010). ...
Water scarcity severely affects drylands threatening their food security, whereas, the oil and gas industry produces significant and increasing volumes of produced water that could be partly reused for agricultural irrigation in these regions. In this review, we summarise recent research and provide a broad overview of the potential for oil and gas produced water to irrigate food crops in drylands. The quality of produced water is often a limiting factor for the reuse in irrigation as it can lead to soil salinisation and sodification. Although the inappropriate use of produced water in irrigation could be damaging for the soil, the agricultural sector in dry areas is often prone to challenges in soil salinity. There is a lack of knowledge about the main environmental and economic conditions that could encourage or limit the development of irrigation with oil and gas effluents at the scale of drylands in the world. Cheaper treatment technologies in combination with farm-based salinity management techniques could make the reuse of produced water relevant to irrigate high value-crops in hyper-arid areas. This review paper approaches an aspect of the energy-water-food nexus: the opportunities and challenges behind the reuse of abundant oil and gas effluents for irrigation in hydrocarbon-rich but water-scarce and food-unsecured drylands.
... From an economical point of view, management of produced water can become a key factor in controlling the production volume. Moreover, the treatment of produced water provides interesting opportunities to reuse it for exploration activities, irrigation, washing and miscellaneous other local needs [4]. ...
Proper management and treatment of produced water has emerged as a big challenge for oil and gas industry. Increasingly stringent environmental regulations and economic constraints are compelling the use of more ad- vanced treatment methods. Membrane operations are gaining significant interest for this application due to their broad range of separation capabilities, high efficiency and low operational cost. Commercially less-adopted membrane operations, such as membrane distillation (MD) and membrane crystallization (MCr) are gaining significant interest for produced water treatment due to their almost concentration-independent performance and less fouling potential. The current study analyzes the performance of an integrated microfiltration (MF) and direct contact membrane distillation (DCMD)/membrane crystallization (MCr) system for freshwater and mi- nerals recovery from produced water. Based on the experimental data, thermodynamic/exergetic/quantitative analyses have been performed. Performance of the integrated processes has been compared with the conven- tional multi-stage flash (MSF) in terms of process intensification metrics.
... The membrane based operations tested so far include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). Moreover, the combination of membrane based processes has been investigated as a successful tool to treat the produced water in order to meet the quality standards of potable and irrigation water [8,13,14]. However, the performance of the membrane based methods tested so far is limited either at high solute concentration (RO) or due to their inability to remove hydrocarbons and all the suspended and dissolved solids (MF,UF). ...
... Combined membrane pretreatment and RO technology are effective methods for produced water treatment [108]. Xu et al. [109] investigated a two-stage laboratory-scale membrane to treat gas field produced water generated from sandstone aquifers as shown in Fig. 5. ...
... Combined membrane pretreatment and RO technology are effective methods for produced water treatment [108]. Xu et al. [109] investigated a two-stage laboratory-scale membrane to treat gas field produced water generated from sandstone aquifers as shown in Fig. 5. ...
... The re-injection of produced water has been routinely used in the petroleum industry for oily produced water management [44][45][46]. The technical and regulatory framework as well as economic feasibility of conventional deep well disposal of oily produced water has been established. ...
Oil and gas are significant sources of energy worldwide, and their importance increases due to the ever increasing global demand for energy. The production of conventional oil, atural gas, and unconventional gas, for example, of coal seam gas (CSG) or coal bed methane, is usually accompanied with contaminated water. This article reviews the similarities and differences between the water produced during exploitation of conventional hydrocarbon and unconventional CSG resources in terms of quantity, characteristics, current treatment and a promising alternative treatment that can be used. The volume of produced water from conventional oil and gas exploitation increases during the operating life of a well. In contrast, in CSG exploitation, produced water is generated from an early stage in large volumes. Characteristics of oily and CSG produced water differ considerably from each other in terms of organic content (e.g. the occurrence of oil and grease and specific petroleum organic contaminants such as benzene, toluene, ethylbenzene, and xylene or BTEX), ionic composition and total dissolved solids. In general, methods for treating and disposing oily produced water are more established but somewhat less stringent given the long history of conventional oil and gas extraction. On the other hand, the treatment of CSG produced water requires a more comprehensive and stringent treatment train and almost always involves reverse osmosis filtration, particularly if the treated water is for beneficial reuse. Membrane filtration technologies have played and will continue to play a major role in the treatment of produced water. Several new membrane processes, particularly forward osmosis, have also emerged as notable candidate technologies for sustainable management of produced water from the oil and gas industry.
... External reuse applications, other than for reinjection, require much higher water quality. Microfiltration (MF) and ultrafiltration (UF) standalone processes or their hybrid integration have been efficiently used to separate suspended particles, macromolecules and oil as a pretreatment step while the combination of ultra-low-pressure nanofiltration (NF) and reverse osmosis (RO) has been applied to treat produced water for higher water quality standards which are potable and for irrigation [17][18][19][20][21][22][23][24][25][26][27][28][29]. However, in this review, we focus more on advanced membrane technologies for high-salinity produced water sources, such as produced water from shale gas wells [30,31], where the concentration of total dissolved solids (TDS) varies from 8,000 to 360,000 mg/L [32]. ...
Water and energy have always been crucial for the world’s social and economic growth. Their supply and use must be sustainable. This review discusses opportunities for membrane technologies in water and energy sustainbility by analyzing their potential applications and current status; providing emerging technologies and scrutinizing research and development challenges for membrane materials in this field.
... Furthermore, RO process and incorporated membrane pretreatment such as ultrafiltration (UF), and nanofiltration (NF) processes are nowadays seen to be the significate techniques for the treatment produced water application [5,6]. Moreover, Xu and co-authors [7] studied the treating of produced water created from sandstone aquifers by using nanofiltration (NF) and reverse osmosis (RO) membranes operated at very low transmembrane pressure. ...
The application of ultrafiltration (UF) and nanofiltration (NF) processes in the handling of raw produced water have
been investigated in the present study. Experiments of both ultrafiltration and nanofiltration processes are performed in
a laboratory unit, which is operated in a cross-flow pattern. Various types of hollow fiber membranes were utilized in
this study such as poly vinyl chloride (PVC) UF membrane, two different polyether sulfone (PES) NF membranes, and
poly phenyl sulfone PPSU NF membrane. It was found that the turbidity of the treated water is higher than 95 % by
using UF and NF membranes. The chemical oxygen demand COD (160 mg/l) and Oil content (26.8 mg/l) were found
after treatment according to the allowable limits set by means of world health organization WHO water quality
standards. The final composition of SO4
-2 (110 mg/l) and NO3 (48.4 mg/l) components within the produced water after
treatment were agreed with the permissible limits of WHO, whereas Cl-1 (8900 mg/l) component is not in the allowable
limits. Finally by the use of PVC, PES and PPSU hollow fiber membranes; this method is seen to be not sufficient to
remove the salinity of the produced water.
... Macedonio et al. concluded that MD has an overall salt and carbon rejection of over 99% and 90% respectively, for treatment of oilfield produced water and estimated that the total water cost varies from $0.72/m 3 to $1.28/m 3 depending on feed water temperature and MD recovery factor [26]. Previous research has also proposed a combination of membrane based techniques for enhancing the performance and economics of water treatment process [26,[56][57][58][59]. For example, Macedonio et al. have evaluated the economics of seven different configurations of integrated membrane systems including microfiltration, nanofiltration, RO, MD, and membrane crystallization and concluded that adoption of integrated membrane systems provides an opportunity for increasing plant recovery factor, reducing the brine disposal problem, and environmental impacts [60]. ...
Membrane distillation (MD) is a promising desalination technology for treatment of high salinity shale gas produced water. Techno-economic assessment (TEA) is necessary for evaluating the economic feasibility of MD for produced water treatment as compared to other shale gas produced water management strategies. A detailed TEA for a hypothetical 0.5 million gallons per day (MGD) direct contact MD (DCMD) that concentrates produced water from 10% (100,000 mg/L) Total Dissolved Solids (TDS) to 30% salinity is presented in this study. The model is developed based on a combination of experimental results, ASPEN Plus process model, best available engineering knowledge, and cost estimates. Analysis reveals that thermal energy cost for MD operation contributes the most to total cost of treating produced water in an MD plant. Additionally, the results of sensitivity analysis reveal that feed TDS level and thermal energy price have a significant impact on total cost of treating produced water. We also explore the implications of utilizing waste heat on the economics of the MD technology for produced water treatment. The results reveal that the total cost of treating produced water using MD is $5.70/m³feed which decreases significantly to $0.74/m³feed when MD is integrated with a source of waste heat.
... Combined membrane pretreatment and RO technology are effective methods for produced water treatment [108]. Xu et al. [109] investigated a two-stage laboratory-scale membrane to treat gas field produced water generated from sandstone aquifers as shown in Fig. 5. ...
Produced water is the largest waste stream generated in oil and gas industries. It is a mixture of different organic and inorganic compounds. Due to the increasing volume of waste all over the world in the current decade, the outcome and effect of discharging produced water on the environment has lately become a significant issue of environmental concern. Produced water is conventionally treated through different physical, chemical, and biological methods. In offshore platforms because of space constraints, compact physical and chemical systems are used. However, current technologies cannot remove small-suspended oil particles and dissolved elements. Besides, many chemical treatments, whose initial and/or running cost are high and produce hazardous sludge. In onshore facilities, biological pretreatment of oily wastewater can be a cost-effective and environmental friendly method. As high salt concentration and variations of influent characteristics have direct influence on the turbidity of the effluent, it is appropriate to incorporate a physical treatment, e.g., membrane to refine the final effluent. For these reasons, major research efforts in the future could focus on the optimization of current technologies and use of combined physico-chemical and/or biological treatment of produced water in order to comply with reuse and discharge limits.
... Furthermore, RO process and incorporated membrane pretreatment such as ultrafiltration (UF), and nanofiltration (NF) processes are nowadays seen to be the significate techniques for the treatment produced water application [5,6]. Moreover, Xu and co-authors [7] studied the treating of produced water created from sandstone aquifers by using nanofiltration (NF) and reverse osmosis (RO) membranes operated at very low transmembrane pressure. ...
The application of ultrafiltration (UF) and nanofiltration (NF) processes in the handling of raw produced water have
been investigated in the present study. Experimentsof both ultrafiltration and nanofiltration processes are performed in
a laboratory unit, which is operated in a cross-flow pattern. Various types of hollow fiber membranes were utilized in
this study such as poly vinyl chloride (PVC) UF membrane, two different polyether sulfone (PES) NF membranes, and
poly phenyl sulfone PPSU NF membrane. It was found that the turbidity of the treated water is higher than 95 % by
using UF and NF membranes. The chemical oxygen demand COD (160 mg/l) and Oil content (26.8 mg/l) were found
after treatment according to the allowable limits set by means of world health organization WHO water quality
standards. The final composition of SO4
-2
(110 mg/l) and NO3
(48.4 mg/l) components within the produced water after
treatment were agreed with the permissible limits of WHO, whereas Cl
-1
(8900 mg/l) component is not in the allowable
limits. Finally by the use of PVC, PES and PPSU hollow fiber membranes; this method is seen to be not sufficient to
remove the salinity of the produced water.
... TDS is usually removed using membranes where the treatment cost is generally dependent on the level of TDS in the influent stream. Since water salinity directly affects the desalination cost, it was established that membrane treatment is best suited for produced water having less than 10,000 TDS (Burnett 2010). The high TDS found in the produced water will instigate membrane scale leading to shorter membrane's lifetime. ...
... TDS is usually removed using membranes where the treatment cost is generally dependent on the level of TDS in the influent stream. Since water salinity directly affects the desalination cost, it was established that membrane treatment is best suited for produced water having less than 10,000 TDS (Burnett 2010). The high TDS found in the produced water will instigate membrane scale leading to shorter membrane's lifetime. ...
The large volume and high salinity of produced water (PW) could pose severe environmental impacts. This paper presents the laboratory results on PW from G oil field, located in North Africa, and on groundwater samples from nearby freshwater wells, in order to best comprehend the chemical composition of PW and to evaluate their potential impact on the surrounding environment of this oil field. Such a sizeable data set can make it difficult to integrate, interpret and represent the results. Thus, multivariate statistical techniques were used in the usefulness evaluation of geochemical groundwater control process classification and identification. Principal component analysis of produced water identified three components: the first being a salinization factor that accounted for 53.6% of the overall variance; the second accounted for 24.3% of overall variance and was mostly dictated by scale forming potential; and the third component (12.3% of total variance) representing the quality of the water formed by the rock water interaction. The aforementioned components demonstrated that the quality of discharged produced water didn’t meet national or international standards. For the groundwater analysis, two principal components/clusters were identified. The first one (69.6% of total variance) represented the hardness and salinity of the water, and the second one (18.4% of total variance) can be regarded as the overall effect of weathering and interactions between water and rock on the groundwater quality factor in general. The analysis did not show any contamination in groundwater at the G oil field and in the nearby farms water wells.
... In terms of the reduction in TDS, Table 7 confirms that the method proposed in the current research has better performance than the methods used by Doran et al. (Doran et al., 1998(Doran et al., , 1997 and Boysen et al. (Boysen et al., 1999). Furthermore, the performance of the proposed method in reducing TDS is closely similar to that of the methods used by Burnett et al. (Barrufet et al., 2005;Burnett, 2004;Sarker et al., 2006), Riley et al. (Riley et al., 2018), and Piemonte et al. (Piemonte et al., 2015). It should also be noted that the amount of TDS in the feeds treated in the current study is much higher compared to the other works, and the applying membrane methods to treating such produced water faces fouling. ...
The current work investigates the performance of a single-stage, bench-scale system using a spray dryer to treat produced water. The produced water is generated in three large reservoirs of Ahvaz, Maroon, and Mansouri fields, which have different compositions but the same high total dissolved solids (TDS) and total organic carbon (TOC). The results of this study indicate that the newly developed bench scale rig is able to reduce the amount of TDS in the water produced in Ahvaz, Maroon, and Mansouri reservoirs to 98.78, 98.65, and 98.90, and TOC decreases the three types of the produced water to zero. Investigating the effect of independent parameters on the performance of this system using response surface methodology shows that the most effective parameters affecting the efficiency of the produced water treatment system are the entering carrier gas temperature (TGIT), the flow rate of the produced water (QL), the carrier gas flow rate entering the spray dryer (QG), and the atomizer pore size (d). Additionally, the optimal conditions are obtained as follows: TGIT = 113.7 °C, QL = 20.8 cc/min, QG = 59.9 m3/hr., and d = 0.03 mm.
... According to some sources, for every barrel of crude oil extracted from conventional oil reservoirs, about 3 to 9.5 barrels of water are produced on average. [1][2][3] This amount is usually lower for gas reservoirs. 3 Produced water can be injected into wells for enhanced oil recovery. ...
Uniform CO2 corrosion of carbon steel facilities is often a major problem when handling produced water in the oil and gas fields. High amounts of dissolved salts are often present in produced water. A limited number of research studies has been conducted on the effect of salt concentration on uniform CO2 corrosion. In this study, the effect of NaCl concentration on uniform CO2 corrosion of X65 carbon steel was investigated in CO2 saturated aqueous solutions using a rotating cylinder system at 30oC, autogenous pH, and 1 bar total pressure in an NaCl concentration range of 0‒4.27 molality (m) (0‒20 wt.%). With increasing NaCl concentration, the corrosion rate increased sharply and reached its maximum value at ~ 0.17 m (1 wt.%) NaCl and then decreased with further increase in NaCl concentration. The observed trend in the corrosion rate with increasing NaCl concentration was primarily a consequence of the change in the cathodic limiting current density, which was the main factor controlling the rate of the overall corrosion process. The additional factor was the change in the rate of the anodic reaction with salt concentration.
... Typically, there are three (3) barrels of oil produced for every one (1) barrel of oil produced in a four (4) barrel production stock. Produced water represents by far the largest byproduct of crude oil production (Burnett, 2004, Farajzadeh, 2004. ...
Produced water reinjection (PWRI) is one of the methods employed by oilfield operators to optimize production while conforming to increasingly stringent produced water disposal policies. Different produced water species from different facilities also have different salinities as a result of entrainment of treatment fluids, precipitation of salts at surface conditions, etc. During re-injection operations, the salinity of the injection fluid has to be accounted for as it affects the production. Previous studies have focused on laboratory analysis by core flooding. While this approach is indeed reasonable and offers a first-hand impression of the reservoir conditions, it presents a problem of cost and the age-old opinion that the core sample may not be representative of the entire reservoir. Therefore, I have employed a computer modeling approach using a commercial simulator to analyze the influence of salinity on production during produced water re-injection. It was found that the salinity truly affects production. Re-injection of produced water with salinity equal to the reservoir salinity of 1000 ppm was compared to three cases of re-injection of produced water from extraneous sources having salinities of 100 ppm, 500 ppm and 10000 ppm. It was found that salinity of 10000 ppm gave the best oil production performance for the reservoir model; a daily rate of 40 STB/DAY and an oil cumulative production of 40,000 STB. Incremental salinity of injected produced water led to incremental oil recovery. The mechanism resulting in incremental recovery was attributed to the increase in viscosity and decrease in mobility as the salinity increases.
... Since desalination costs are a function of water salinity, produced water with less than 10,000 TDS (total dissolved solids) will be the best candidate for membrane treatment. 62 High TDS will cause membrane scale and shorten the lifetime of the membranes. ...
The large thermal potentials with geothermal gradient of abandoned wells provide the possibility and opportunity for carbon-neutrality transition of district heating systems, whereas energy harvesting from abandoned geothermal wells is full of challenges, due to the considerable initial investment in economic cost, system performance degradation, and so on. In this chapter, a systematic and comprehensive review on the application techniques of abandoned wells is presented, in terms of advanced thermal/power conversions, renewable integrations for district heating, and strategies for performance enhancement. Discussions on real applications have been conducted and future prospects presented, from perspectives of lifetime system performance, techno-economic feasibility analysis, and potential assessment of abandoned wells for carbon-neutrality transition. The results of this chapter can provide preliminary knowledge and cutting-edge technologies on renewable integrations with abandoned wells, so as to demonstrate techno-economic-environmental potentials of abandoned wells and contributions toward carbon-neutrality transition.
Produced water quantities in Sudan oil fields increased largely in recent years as the oil production increased and the old fields matured. Approximately 1.5 million bb/day of water are produced in central region fields. The W/O ratio tends to be 4:1 in most Field Processing Facilities (FPFs). Produced water samples were collected from oil fields and analysed for chemical and physical properties (BOD, TDS, pH, COD… etc) and the crude oil content of untreated water was analysed by Gas Chromatograph. Current treatment practices were studied and evaluated carefully. Chemical and physical composition of samples showed normal environmental values of many parameters (BOD, TDS, pH, COD) but the Sodium Content is high. Chromatographic analysis of samples showed that crude oil content is of high value (250-300 mg/l) in untreated produced water. Samples of biologically treated water were also examined for the same parameters and evaluation of the current treatment technology insures the need for improvement of biodegradation rates of hydrocarbons.
As oil production in the Permian Basin surges, the impact of shale production on groundwater resources has become a growing concern. Most existing studies focus on the impact of shale production on shallow freshwater aquifers. There is little understanding of the shale development's impact on other groundwater resources (e.g., deep carbonate aquifers and deep basin meteoric aquifers). The possible natural hydraulic connections between shallow aquifers and formation water suggest such an impact can be consequential. This study explores the relationship between shale production and groundwater using produced water (PW) samples from active unconventional oil wells. Focusing on the most productive portion of the Permian Basin-the four-county region in Southeast New Mexico between 2007 and 2016, a large produced water dataset allows us to analyze the conditional correlations between shale oil production and PW constituents. The results suggest that (1) expanding from primarily conventional wells to unconventional wells during the recent shale boom has led to dramatic increases of the TDS, chloride, sodium, and calcium levels in groundwater (i.e., producing formation). (2) Nearby oil well density positively correlates with the TDS, chloride, and sodium levels in the PW samples.
Geothermal energy (GE), as an ideal renewable resource for building cooling/heating with stability and abundance in energy supply, has been widely exploited in developing countries. The common utilization forms of GE mainly include the ground source heat pump (GSHP), underground duct system (UDS), and abandoned wells energy (AWE) system. However, there is still a lack of comprehensive overview of the current developmental status of the GSHP, UDS, and AWE systems for building cooling/heating in developing countries. This chapter will be conducted from the following aspects: (1) The literature review and categories of GE utilization in the developing countries, mainly including the latest literature review on GE development and categories of utilization for building cooling/heating. (2) The common utilization of the GSHP system and its current application and development in the developing countries, mainly including the ground-coupled heat pump (GCHP) system and groundwater heat pump (GWHP) system. (3) The common utilization of the UDS system and its current application and development in the developing countries, mainly including the horizontal UDS system, vertical UDS system, and the corresponding coupled system with phase change energy storage and other advanced technologies. (4) The common utilization of the AWE system and its current application and development in the developing countries, mainly including the abandoned oil and gas wells. (5) The existing issues and in-depth analysis on the practical application of GE for building cooling/heating in the developing countries. This chapter can provide some effective guidelines on the various GE utilization forms for building cooling/heating in developing countries.
In the oil and gas fields, there are many deep wells that have produced hydrocarbons for decades. Some of these wells have been abandoned by new explorations or economic problems. Before developing an oil or gas field, it is necessary to explore and drill some wells to complete geology and geophysics studies to find a reservoir that contains a large amount of hydrocarbons. However, due to the uncertainties of the previous studies, the exploration wells do not always reach a feasible reservoir. Thus the operating company, because of the environmental considerations, abandons the well abandoned. In addition to the exploration reasons, from the economic viewpoint, the large volumes of coproduced water is another issue in matured fields, which forced the company to terminate the hydrocarbon production.
Regarding the geothermal gradient of the region, deep oil and gas wells have significant heat and temperature. This extracted heat can be used in geothermal energy applications. Therefore, reusing the abandoned wells and repurposing the old active wells that produce water uneconomically have attracted researchers’ and the operating companies’ attention in recent decades. Besides the novel studies for geothermal energy extraction from these wells, some case studies have also investigated the produced geothermal energy for direct utilization in space heating, greenhouses, the oil industry, and for power generation purposes. Some studies have also compared the direct utilization of the abandoned oil wells with conversion of the producing oil and gas wells to the borehole heat exchangers.
The extraction of geothermal energy from oil and gas fields is divided into two branches: first, matured active wells that produce large amounts of high-temperature water in an uneconomical manner (before the well is abandoned), and second, the abandoned wells. There are many case studies in which geothermal energy has been extracted from oil wells for some applications, including greenhouse heating, space heating or cooling, heat tracing, etc. Research showed that the extracted geothermal energy could be combined with solar energy for enhancing oil recovery goals. This study aims to investigate the case studies in geothermal energy extraction from abandoned oil wells.
When reverse osmosis (RO) is used to desalinate brackish water feed streams, a small but significant amount of the brine is discharged as a "reject" stream from the RO unit. This brine contains concentrated dissolved salts and other materials. Disposing of this brine concentrate for traditional RO processes can represent a significant fraction of the cost of operating the unit to recover fresh water. Coincidently, in the oil and gas industry, high salinity brines are routinely injected into formations for pressure maintenance and secondary recovery by water flooding. If water from desalination operations could be injected into these oil- and gas-containing formations, the estimated cost savings could be as much as 30% of the cost of operating the desalination unit. This represents a significant cost savings for RO technology that would make fresh water available to communities in need of this valuable resource.
To provide a comprehensive assessment of the perceived benefits compared to the possible hazards of this practice, we use risk analysis theory to define this process in more detail. The potential for formation damage, reduced injectivity, produced water scaling, and environmental impact is evaluated through comparison with traditional waterflood compatibility studies. We also provide an analysis of how state and federal Underground Injection Control (UIC) rules may be used to regulate injection of RO reject brines. The risk analysis study goes beyond classical decision analysis theory to address the "triple bottom line" economic, environmental, and societal benefits afforded by the process and provides a roadmap to gather quantifiable information for regulators, businesses, and community leaders who might consider this technology.
Introduction
Environmentalists, regulators, industry personnel, and concerned citizens have a basic interest in how to set or negotiate environmental priorities given limited and possibly changing resources. When a new technology or process is being introduced into society, setting these priorities is a problem, especially if the technology has the potential to impact a significant part of the local community. Desalination of brackish ground water, oil field produced brine, or even seawater is one of those technologies. Those who study history have seen that water resources dictate the development of civilizations.1,2
Historically, one of the major impacts of the desalination process to create fresh water resources has been the problem of the disposal of the salts (RO "concentrate") and other materials removed from the source water. Assessing the impact of RO concentrate disposal requires knowledge of the physical, biological, or social conditions associated with various risks. Placing this relatively new process among a host of other environmental priorities of our society requires not only ranking risks but also finding solutions to risk problems. Priority-setting entails trade-offs among competing values when resources are inadequate to do everything; resource consumption demands prudence; or additional resources require negotiation.
Our Texas A&M group is working in fresh water resources research.3 One of the processes the group has been testing is the desalination of oil field produced brine to make it available for beneficial use. The technology is based on waterflood process designs routinely used by the industry for decades (Figure 1). We need to answer the following questions: Is this process viable? Can fresh water resources be recovered from oil field brine? What is the impact of this new technology?
Engineers are accustomed to evaluating technical options when considering the development of a new project.4 Assessing the uncertainty and comparative economic risk of a drilling prospect is also common. What is not common, however, is an effort to quantify the qualitative aspects of a project. It is uncommon for a proposed engineering program to address public and other stakeholder issues that might be important in considering the impact of the project on society and the environment.
Conventional opinion has often viewed produced water as a byproduct from oil production. Disposal of this water is an expense every treatment facility must contend with as long as their wells continue to produce. This issue can become a serious logistical or environmental problem for fields with limited disposal capacity or that generate produced water with poor water quality.
Instead of discarding the water as waste, advances in membrane water treatment technology can allow economical treatment of water for potable consumption. Placing this water to productive use may not completely eliminate daily wastewater disposal. However, it will drastically reduce the disposal volume, possibly freeing up other resources. This concept shifts the paradigm for produced water, transforming its image from what seemingly is a costly waste to possibly a valued commodity.
This paper will present a conceptual design for a 50,000 BPD integrated membrane filtration plant capable of handling typical oilfield produced water. Included will be an evaluation of capital and operating & maintenance costs. A discussion on the marketing potential for this water as a new potable or irrigation water source will also be presented by comparing its economics against conventional surface water or seawater desalination treatment.
1.0 Introduction
Treatment of oilfield produced-water typically involves the removal of hydrocarbons, ammonia, hydrogen sulfide, and perhaps silica before injection into wastewater disposal wells. Should limited disposal capacity require disposal into nearby waterways or watersheds, the produced water must be further treated to remove salinity, boron, dissolved organics, and certain heavy metals.
This report describes how current chemical precipitation and advance membrane technologies can enhance conventional oilfield water treatment plants to provide an economical answer for removing all of the above constituents. The goal of the proposed plant is to produce high quality water that can meet drinking water standards. The produced water can then be sold for irrigation or potable consumption or safely discharged into local rivers and streams for disposal.
2.0 Design Overview
The conceptual design focuses on the removal of hydrocarbon, ammonia, hydrogen sulfide, hardness, silica, boron, and salinity from the produced water. The design basis assumes that most free oil in the produced water has been removed by conventional processes, such as wash tanks, dissolved gas floatation, and walnut shell filtration.
The following is a list of conceptual treatment processes and the constituent(s), which these processes will remove:Warm Lime Softening (WLS) - Carbonate Hardness and SilicaMembrane Bioreactor (MBR) - Emulsified Oil & Grease, Ammonia, Soluble Organics, Settleable / Suspended solidsReverse Osmosis (RO) - Salinity and Boron
A block flow diagram of the above processes is presented in Figure 2.1.
Management and disposal of produced water is one of the most important problems associated with oil and gas (O&G) production. O&G production operations generate large volumes of brine water along with the petroleum resource. Currently, produced water is treated as a waste and is not available for any beneficial purposes for the communities where oil and gas is produced. Produced water contains different contaminants that must be removed before it can be used for any beneficial surface applications. Arid areas like west Texas produce large amount of oil, but, at the same time, have a shortage of potable water. A multidisciplinary team headed by researchers from Texas A&M University has spent more than six years is developing advanced membrane filtration processes for treating oil field produced brines The government-industry cooperative joint venture has been managed by the Global Petroleum Research Institute (GPRI). The goal of the project has been to demonstrate that treatment of oil field waste water for re-use will reduce water handling costs by 50% or greater. Our work has included (1) integrating advanced materials into existing prototype units and (2) operating short and long-term field testing with full size process trains. Testing at A&M has allowed us to upgrade our existing units with improved pre-treatment oil removal techniques and new oil tolerant RO membranes. We have also been able to perform extended testing in 'field laboratories' to gather much needed extended run time data on filter salt rejection efficiency and plugging characteristics of the process train. The Program Report describes work to evaluate the technical and economical feasibility of treating produced water with a combination of different separation processes to obtain water of agricultural water quality standards. Experiments were done for the pretreatment of produced water using a new liquid-liquid centrifuge, organoclay and microfiltration and ultrafiltration membranes for the removal of hydrocarbons from produced water. The results of these experiments show that hydrocarbons from produced water can be reduced from 200 ppm to below 29 ppm level. Experiments were also done to remove the dissolved solids (salts) from the pretreated produced water using desalination membranes. Produced water with up to 45,000 ppm total dissolved solids (TDS) can be treated to agricultural water quality water standards having less than 500 ppm TDS. The Report also discusses the results of field testing of various process trains to measure performance of the desalination process. Economic analysis based on field testing, including capital and operational costs, was done to predict the water treatment costs. Cost of treating produced water containing 15,000 ppm total dissolved solids and 200 ppm hydrocarbons to obtain agricultural water quality with less than 200 ppm TDS and 2 ppm hydrocarbons range between $0.5-1.5 /bbl. The contribution of fresh water resource from produced water will contribute enormously to the sustainable development of the communities where oil and gas is produced and fresh water is a scarce resource. This water can be used for many beneficial purposes such as agriculture, horticulture, rangeland and ecological restorations, and other environmental and industrial application.
Keynote Address at the 35th annual Offshore Technology Conference (OTC)
- Andrew Gould
Gould, Andrew, "Technology and Production, A View for the Future," Keynote Address at
the 35th annual Offshore Technology Conference (OTC), May 4, 2004, Houston. TX.
Produced Water from the Production of Crude Oil, Natural Gas and Coal Bed Methane
- J A Veil
- M G Pruder
- D Elcock
- R J Redweik
Veil, J. A., Pruder, M. G., Elcock, D., and Redweik, R. J. Jr., "Produced Water from the
Production of Crude Oil, Natural Gas and Coal Bed Methane, " U.S. DOE NETL Report
W-31-109-Eng 38 January 2004.
Ranchers, Indians Sue BLM over Wells in Otero Mesa
- Tania Soussan
Soussan, Tania, "Ranchers, Indians Sue BLM over Wells in Otero Mesa, New Mexico," The
Albuquerque Journal, Feb. 5, 2005.
Yates Field Steam Pilot Applies Latest Seismic and Logging Monitoring Techniques" paper SPE 56791 presented at the 1999 SPE Annual Technical Conference and Exhibition
- Philip H Winterfeld
Winterfeld, Philip H. "Yates Field Steam Pilot Applies Latest Seismic and Logging
Monitoring Techniques" paper SPE 56791 presented at the 1999 SPE Annual Technical
Conference and Exhibition held in Houston, Texas, 3-6 October 1999.
Recovery of Fresh Water Resources from Desalination of Brine Produced during Oil and Gas Production Operations
- D B Burnett
- T A Pankratz
Burnett, D. B. and Pankratz, T. A. "Recovery of Fresh Water Resources from Desalination of
Brine Produced during Oil and Gas Production Operations", Report to the Texas Water
Development Board, September 2004.
Evaluation of Field Trial of Pre-Treatment of Mobile Desalination Unit, Brayton Water Treatment Plant
- D B Burnett
Burnett, D. B. "Evaluation of Field Trial of Pre-Treatment of Mobile Desalination Unit,
Brayton Water Treatment Plant," GPRI non-Confidential Briefing August 18,2004.
Brine Disposal in Deep Aquifer Reservoirs: Evaluation and Operation Experiences
- Michael Borgmeier
- Agnes Gilch
- Rohleder
- Ranier
- Jochen Zemke
Borgmeier, Michael, Gilch, Agnes, Rohleder, Ranier, Zemke, Jochen, "Brine Disposal in
Deep Aquifer Reservoirs: Evaluation and Operation Experiences," Solution Mining
Research Institute, Fall 2001 Meeting 7 -10 September 2001 Albuquerque, New Mexico,
USA