Oilfield Water Research Articles

The Produced Water Conundrum Grows Across Unconventionals

Shale players have a love-hate relationship with water. It’s an essential ally going into downhole to help proliferate fractures in the subsurface and free up stuck hydrocarbons. It’s a parasite coming out - a briny byproduct that can easily outpace oil production from any given well. Likewise, operators must deal with water management on dual fronts. The first is sourcing the water to be used in the fracturing of the well. Second is finding the right solution for the flowback and formation water coming out of the well. Early on, the answer for the former was freshwater sources. However, once the strain set in from general scarcity, drought, environmental concerns or the like, industry started looking hard at the recycle and reuse of produced water - a solution where the problem becomes the answer. Water recycling rates vary widely between unconventional basins. For the domestic oil industry, data provider IHS Markit forecast in an April 2020 report the vast majority of wastewater leaving an oil field in 2022 will still not be recycled. It will instead be injected into disposal wells, which is currently the most common practice for produced water management. This option is costly and risky, especially for wells that are located some distance from the nearest disposal well. It has also come under increased scrutiny because of the potential effects of disposal well use on the surrounding area’s seismic activity. “Going back to the beginning of unconventional resource production, the focus was understandably on the water needed for drilling and completions,” Paola Perez-Pena, a principal researcher at IHS Markit, commented in an analysis. “Now that there is a considerable, established production, operators are realizing the extent to which produced water is not only a sizable matter, but an ongoing and essentially, perpetual one.” Produced water is a mix of the water pumped down the well to assist with fracturing plus residual drilling fluid and formation water. On average, with every barrel of oil produced in the US, more than 4 bbl of wastewater is produced, though that number varies from basin to basin. “With water, what you find is producers consider a number of different piping configurations, storage, and disposal well options, as well as reuse opportunities,” said John Walsh, principal technologist for Worley Advisian and author of the book, Produced Water. “There’s no one single strategy or approach that’s going to solve the water problem. There is no silver bullet.” According to an industry brief by Raymond James in July 2019, pre-pandemic US oilfield water production was already a whopping 50 million BWPD. For scale, this amount of water could cover more than 8,000 football fields with a foot of water, every day. The investment bank estimated just under half of the total produced water came from horizontal basins, despite making up close to 80% of onshore crude production. The report forecast that the total volume of produced water from major oil basins in the US could grow to more than 60 million BWPD by 2030 (Fig. 1).

Bacterial and Archaeal Community Distribution in Oilfield Water Re-injection Facilities and the Influences from Microorganisms in Injected Water.

Water flooding is widely employed for oil production worldwide. However, there has never been a systematic investigation of the microbial communities occurring in oilfield water re-injection facilities. Here, we investigated the distribution of bacterial and archaeal communities in water re-injection facilities of an oilfield, and illustrated the combined influences of environmental variation and the microorganisms in injected water on the microbial communities. Bacterial communities from the surface injection facilities were dominated by aerobic or facultative anaerobic Betaproteobacteria, Alphaproteobacteria, and Flavobacteria, whereas Clostridia, Deltaproteobacteria, Anaerolineae, and Synergistia predominated in downhole of the injection wells, and Gammaproteobacteria, Betaproteobacteria, and Epsilonproteobacteria predominated in the production wells. Methanosaeta, Methanobacterium, and Methanolinea were dominant archaea in the injection facilities, while Methanosaeta, Methanomethylovorans, and Methanoculleus predominated in the production wells. This study also demonstrated that the microorganisms in injected water could be easily transferred from injection station to wellheads and downhole of injection wells, and environmental variation and diffusion-limited microbial transfer resulted from formation filtration were the main factors determining microbial community assembly in oil-bearing strata. The results provide novel information on the bacterial and archaeal communities and the underlying mechanisms occurring in oilfield water re-injection facilities, and benefit the development of effective microbiologically enhanced oil recovery and microbiologically prevented reservoir souring programs.

Impact of Ionic Liquid on Hydrogen Production from Waste Oilfield Water.

We present a promising method for producing pure hydrogen energy from the dissolution of zinc metal in waste oilfield water (WOW) under various conditions. This process mainly consumes zinc metal and WOW. The results show robust dependence on the temperature and solution pH of the hydrogen gas output. Low pH (2.5) and high temperature (338 K) were discovered to be the better conditions for hydrogen production. The 1-ethyl-3-methylpyridinium ethyl sulfate (EMP-ES) ionic liquid is used to regulate the rate of hydrogen generation for the first time. It has been confirmed that the rate of the dissolution of zinc increased faster and produced more hydrogen per unit of time by an increase in solution temperature and a decrease in solution pH. The adsorption of EMP-ES on the active sites of the Zn surface is unrestrained with mixing physical and chemical orientations. SEM, EDX, and FTIR spectroscopy inspections have been utilized to identify and characterize surface corrosion of zinc in WOW. Furthermore, this process is completely secure and can generate energy on demand.

A Method for Optimising Pump Configuration and Operation in Oilfield Water Injection Network

Some oilfields in China encounter operating problems on water injection pipeline networks. Due to the unreasonable planning of the pipeline, water cannot be transported to the end of the pipeline and injected into the wells. Also, a large amount of water is repeated transported. This paper aims to deal with the above issues by proposing a method of using pipeline pumps to pressurise the water injection pipeline network, which can improve the water supply capacity of the pipeline network, and reduce the energy consumption of water injection. The pipeline pump has the characteristics of convenient installation, compact structure, and wide application range. To effectively utilise the pipeline pump in the water injection network, a pipeline pump boosting optimisation model is developed, taking the lowest cost of the pump and operating energy consumption of the water injection system as the objective function, and considering the constraints of water injection, pipeline network hydraulics and pump operation. An oilfield in China is studied as an example, the results show that the proposed model can optimise the pump installation position and operations. The operating cost was reduced by 184 k CNY, and the total annual cost was saved by 154 k CNY. The maximum water injection increment can reach 4,700 m3/d, which improves the water supply capacity of the water injection pipe network, and the needs of oilfield water injection planning can be satisfied.

Retraction Note to: Amine functionalized magnetic nanoparticles for removal of oil droplets from produced water and accelerated magnetic separation

Magnetic nanoparticles (MNPs) with surface coatings designed for water treatment, in particular for targeted removal of contaminants from produced water in oil fields, have drawn considerable attention due to their environmental merit. The goal of this study was to develop an efficient method of removing very stable, micron-scale oil droplets dispersed in oilfield produced water. We synthesized MNPs in the laboratory with a prescribed surface coating. The MNPs were superparamagnetic magnetite, and the hydrodynamic size of amine functionalized MNPs ranges from 21 to 255 nm with an average size of 66 nm. The initial oil content of 0.25 wt.% was reduced by as much as 99.9% in separated water. The electrostatic attraction between negatively charged oil-in-water emulsions and positively charged MNPs controls, the attachment of MNPs to the droplet surface, and the subsequent aggregation of the electrically neutral oil droplets with attached MNPs (MNPs-oils) play a critical role in accelerated and efficient magnetic separation. The total magnetic separation time was dramatically reduced to as short as 1 s after MNPs, and oil droplets were mixed, in contrast with the case of free, individual MNPs with which separation took about 36∼72 h, depending on the MNP concentrations. Model calculations of magnetic separation velocity, accounting for the MNP magnetization and viscous drag, show that the total magnetic separation time will be approximately 5 min or less, when the size of the MNPs-oils is greater than 360 nm, which can be used as an optimum operating condition.

Ultrafiltration Membrane Technology for Oily Wastewater Treatment

Oil and gas sectors generate large amounts of oily wastewater, which is called produced water. In which, it contains high concentrations of hazardous organic and inorganic pollutants. This paper attempts to evaluate the performance and quality of using a polyethersulfone ultrafiltration membrane (UFM) to treat the produced water of Al-Ahdab oil field (Wassit, Iraq). 8 rectangular flat sheets of polyethersulfone ultrafiltration membrane were used. The area of each is 60 cm2 and pore size about 15 nm used in the experimental work. Prepared UFM is characterized by determining the surface morphology by scanning electron microscopy (SEM). The result showed that the UFM indicated high removal efficiency in all parameters and especially oil and grease and total suspended solid but in general it still less than the requirement of water reuse. The results showed that, a combination of a conventional treatment method and UFM technology have higher efficiency than using UFM only.

Research and practice on optimal design method of the oilfield water injection system pipeline network

The efficiency of oilfield water injection system is generally low and energy consumption is high. With the deepening of oilfield exploitation, the water cut of the oilfield is increasing, the power consumption of the water injection system is increasing year by year, the oilfield exploitation cost is increasing, and energy conservation and consumption reduction are very important. In order to improve oilfield water injection efficiency and reduce water injection energy loss, this paper puts forward the pipe network optimization design method of partial pressure water injection, establishes the mathematical model of partial pressure water injection pipe network and throttling loss calculation model, compiles the calculation software of partial pressure water injection mathematical model, optimizes the partial pressure interval, calculates the partial pressure points, effectively reduces the energy loss of water injection system and improves the efficiency of water injection system.

Lithium sources in oilfield waters from the Qaidam Basin, Tibetan Plateau: Geochemical and Li isotopic evidence

Oilfield waters represent an important source of lithium resources to meet increasing global demand. However, the distribution of Li resources in the western Qaidam Basin is still unclear, and the enrichment mechanism of Li remains to be explained. In this study, we present new hydrochemical data for all the oil-bearing anticlines in the Qaidam Basin. Oilfield waters in the Nanyishan and Dafengshan oilfields are characterized by Li concentrations ranging from 110.1 to 237.5 mg/L, and Mg concentrations ranging from 0.70 to 1.52 g/L. These concentrations are readily recovered and represent a key target for oilfield water exploitation in the future. In oilfield water samples from the Qaidam Basin, δ7Li values show large variation, possibly implying multiple sources of Li, including residual water from ancient lakes, alpine snow water infiltrating along deep faults, springs, and deep hydrothermal fluids. δ7Li values of the oilfield waters from Nanyishan and Dafengshan are lower than those of the river and spring water samples, but close to those of volcanic rocks around the world. These results indicate that the oilfield waters with significant Li-enrichment are associated with local hydrothermal activity. This is the first time that the δ7Li data of oilfield waters in the Qaidam Basin have been reported. It appears that δ7Li is a good tracer for determining the origin and the key controlling factors of Li accumulation processes in oilfield waters.

Experimental Study on High-Performers Quaternary Copolymer Based on Host-Guest Effect.

A quaternary polymer (HGP) was prepared by the free-radical polymerization of acrylamide, acrylic acid, maleic anhydride functionalized β-cyclodextrin (MAH-β-CD), and N-(3-methacrylamidopropyl)-N, N-dimethylnaphthalen-1-aminium chloride (NAP). It was found that host–guest behavior occurred most effectively at a molar rate of NAP and CD with 1:1, which exhibited better solubility than hydrophobically associative polymer. Moreover, the as-prepared polymer has superior salt tolerance, shear resistance, and viscoelasticity due to host–guest strategy. More importantly, the HGP solution simulates the distribution of formation water in the Bohai SZ1-1 oilfield has good rheological properties at 120 °C. All results show that the proposed polymer could be a competitive candidate in oilfield applications such as fracturing fluids, displacement fluids, and drilling fluids.

Assessment of microbiologically influenced corrosion in oilfield water handling systems using molecular microbiology methods

The monitoring, prediction and control of microbiologically influenced corrosion (MIC) are common challenges in the oil industry. This paper aims to optimize monitoring of souring and corrosion threat in oil field water handling systems using latest developments in molecular microbiological methods. Microbial quantification was performed using quantitative polymerase chain reaction (qPCR) method. Microbial population structure fingerprinting was done using next generation sequencing (NGS). The findings were compared with the corrosion rates and most probable number (MPN) values obtained from conventional serial dilution methods. The results show that molecular microbiology methods provide faster and optimum corrosion mitigation strategies.

Low pressure buildup with large disposal volumes of oil field water: A flow model of the Ellenburger Group, Fort Worth Basin, northcentral Texas

Low pressure buildup with large disposal volumes of oil field water: A flow model of the Ellenburger Group, Fort Worth Basin, northcentral Texas

Corrosion behavior of X80 pipeline steel in oilfield injection water in Eastern China

PurposeThis paper aims to under the laboratory environment, the corrosion behavior of X80 pipeline steel in oilfield injection water in eastern China was studied by immersion test.Design/methodology/approachFirst, the corrosion product film was immersed in oilfield injection water and the effect on the corrosion behavior and the corrosion reaction mechanism were constantly observed during this period. The effect was displayed by potentiodynamic polarization curve and electrochemical impedance spectrums (EIS) measurements. Second, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to observe and test the corrosion product film immersed in the oilfield water for 30 days.FindingsThe results indicate that the tendency of metal corrosion becomes weaker at an early stage, but strengthened later, which means the corrosion rate is accelerating. Besides, it is indicated by impedance spectroscopy that with the decreasing of the capacitance arc radius, the reaction resistance is reducing in this progress. Meanwhile, the character of Warburg impedance could be found in EIS, which means that the erosional components are more likely to penetrate the product film to reach the matrix. The corrosion product is mainly composed of the inner Fe3O4 layer and outer shell layer, which contains a large number of calcium carbonate granular deposits. It is this corrosion under fouling that produces severe localized corrosion, forming many etch pits on the metal substrate.Originality/valueThe experiment chose the X80 steel, the highest-grade pipeline steel used in China, to conduct the static immersion test in the injection water coming from an oilfield in eastern China. Accordingly, the corrosion mechanism and the effect of corrosion product film on the corrosion of pipeline steel were analyzed and discussed.

Noble gas signatures constrain oil-field water as the carrier phase of hydrocarbons occurring in shallow aquifers in the San Joaquin Basin, USA

Noble gases record fluid interactions in multiphase subsurface environments through fractionation processes during fluid equilibration. Water in the presence of hydrocarbons at the subsurface acquires a distinct elemental signature due to the difference in solubility between these two fluids. We find the atmospheric noble gas signature in produced water is partially preserved after hydrocarbons production and water disposal to unlined ponds at the surface. This signature is distinct from meteoric water and can be used to trace oil-field water seepage into groundwater aquifers. We analyse groundwater (n = 30) and fluid disposal pond (n = 2) samples from areas overlying or adjacent to the Fruitvale, Lost Hills, and South Belridge Oil Fields in the San Joaquin Basin, California, USA. Methane (2.8 × 10−7 to 3 × 10−2 cm3 STP/cm3) was detected in 27 of 30 groundwater samples. Using atmospheric noble gas signatures, the presence of oil-field water was identified in 3 samples, which had equilibrated with thermogenic hydrocarbons in the reservoir. Two (of the three) samples also had a shallow microbial methane component, acquired when produced water was deposited in a disposal pond at the surface. An additional 6 samples contained benzene and toluene, indicative of interaction with oil-field water; however, the noble gas signatures of these samples are not anomalous. Based on low tritium and 14C contents (≤ 0.3 TU and 0.87–6.9 pcm, respectively), the source of oil-field water is likely deep, which could include both anthropogenic and natural processes. Incorporating noble gas analytical techniques into the groundwater monitoring programme allows us to 1) differentiate between thermogenic and microbial hydrocarbon gas sources in instances when methane isotope data are unavailable, 2) identify the carrier phase of oil-field constituents in the aquifer (gas, oil-field water, or a combination), and 3) differentiate between leakage from a surface source (disposal ponds) and from the hydrocarbon reservoir (either along natural or anthropogenic pathways such as faulty wells).

Отходы нефтегазового комплекса как технологический индикатор геоэкологического состояния регионов России

This publication addresses a issue of heterogeneous waste products oil and gas sphere of society activity leaves behind, first of all about drilling or oil sludge — colloidal system that consists of high-molecular compound of oil, mineral particles of different composition and oilfield water. These large-scale waste products of oil-producing and oil-processing industries significant due to the complexity of chemical composition and are in process of constant transformation. Accumulating of waste products goes with large-scale pollution of the regions and creates ecological risks.

Evaluation of Factors Influencing Energy Consumption in Water Injection System Based on Entropy Weight-Grey Correlation Method

Abstract In order to determine the importance of influencing factors of energy consumption in oilfield water injection systems, the distribution of energy loss in the water injection system was analyzed, the factors affecting the energy consumption of the water injection system were determined, and an evaluation index system for the energy consumption of the water injection system was established. This indicator system covers all links and all energy loss nodes of the energy loss of the water injection system, thereby an evaluation model for influencing factors of energy consumption in water injection system based on entropy weight - grey correlation method was built. Use the entropy weight method to get the ranking of the importance of energy consumption indicators; use the gray correlation method to determine the correlation between each water injection system and energy consumption factors. The application results show that the entropy weight-grey correlation method proposed in this paper can effectively obtain the importance of the energy consumption factors of the oilfield water injection system, and provide scientific guidance for the daily management and targeted optimization of the water injection system.

Identification and Phylogenetic Analyses of Anaerobic Sulfidogenic Bacteria in Two Algerian Oilfield Water Injection Samples

Corrosion of metallic oilfield pipelines by microorganisms is a costly but poorly understood phenomenon. For the first time, sulfidogenic communities in injection waters of two Algerian oilfields, Tin Fuin Tabankort (IT3) and Stah (IS2) were examined using the 16S rRNA gene cloning and sequencing approach. Water samples were inoculated into selective medium for sulfate-reducing bacteria and incubated under anaerobic conditions at 45 °C. The total number of culturable sulfidogenic microorganisms in the samples obtained from the two sampled waters (IT3 and IS2) was 2.4 × 105 cells/mL and 3.9 × 104 cells/mL, respectively. Scanning electron microscopy analyses showed different morphological forms reflecting the diversity of sulfidogenic communities. 16S rRNA gene sequencing and phylogenetic diversity analyses revealed that both water reservoirs harbor large amounts of anaerobic bacteria. However, a majority of all the sequences analyzed (e.g., 34% in the IS2 and 84% in the IT3 samples) were not assigned to any known bacterial group, suggesting that subsurface waters harbor very large sulfidogenic anaerobic microbial communities of as yet undescribed bacterial phyla. Proteobacteria were found to be the most dominant phylum in the IS2 sample (49%); however, no Proteobacteria were detected at the IT3 production well. The Firmicutes phylum (10%) was detected in the two water samples, whereas Bacteroidetes phylum (7%) was retrieved only in IT3. The most abundant related genera were: Desulfotomaculum, Porphyrobacter, Hyphomicrobium, Acidocella, Comamonas, Ramlibacter, Pseudomonas, Enterobacter and Flavitalea. No shared operational taxonomic units were observed among the two samples analyzed, demonstrating the uniqueness of each subsurface water well. This study demonstrates the diversity of the sulfidogenic bacteria that might play a critical role in the souring mediated corrosion of metallic oilfield pipelines. This information could help oilfield companies develop better anticorrosion treatments and strategies.

Relative risk of groundwater-quality degradation near California (USA) oil fields estimated from 3H, 14C, and 4He

Relative risks of groundwater-quality degradation near selected California oil fields are estimated by examining spatial and temporal patterns in chemical and isotopic data in the context of groundwater-age categories defined by tritium and carbon-14. In the Coastal basins, western San Joaquin Valley (SJV), and eastern SJV; 82, 76, and 0% of samples are premodern (pre-1953 recharge), respectively; and 3, 0, and 31% are modern (recharged during or after 1953), respectively. Carbon-14 and helium-4 data indicate most premodern samples are 1000 to 10,000 (33%) or >10,000 (50%) years old. Organic chemicals that could be associated with deeper hydrocarbon reservoirs (e.g. thermogenic gases and benzene) occur most frequently in premodern groundwater, suggesting premodern groundwater has a higher risk of degradation from upward migration of hydrocarbons than modern and mixed-age groundwater. Low sulfate concentrations in some premodern groundwater containing high thermogenic-methane concentrations (>28 mg/L) indicate methane attenuation associated with sulfate reduction can be limited in premodern groundwater. The more common occurrence of manufactured compounds, like tetrachloroethene, in modern and mixed-age groundwater than in premodern groundwater indicates modern and mixed-age groundwater has a higher risk of degradation from land-surface sources than premodern groundwater. Time-series data for chloride in groundwater affected by disposal of oil-field water in unlined ponds indicate some modern and mixed-age groundwater are susceptible to chemical migration within 2–3 km of surface sources. Timescales for diluting chloride concentrations in groundwater with fresh recharge once disposal ponds are decommissioned are shorter in mixed-age groundwater with large fractions of modern water (9–14 years in one example) than in mixed-age groundwater with large fractions of premodern water (no evidence of dilution after 12 years of monitoring in one example). The presence of predominantly premodern groundwater in the Coastal basins and western SJV indicates these areas have relatively high risk from upward migration of hydrocarbons, reduced methane attenuation capacity, and long dilution times, whereas predominantly modern- and mixed-age groundwater in the eastern SJV indicates this area has relatively high risk from chemical migration from land-surface sources and subsequent extensive spreading. Age-based characterizations of relative risk could inform the design of groundwater-monitoring programs near oil fields in terms of the spatial distribution of monitoring points relative to source areas and monitoring frequency and duration.

Biofilm formation and its effects on microbiologically influenced corrosion of carbon steel in oilfield injection water via electrochemical techniques and scanning electron microscopy

In this study, changes in the electrochemical conditions of oil fields caused by biofilms with sulfate-reducing bacteria have been studied as they promote localized pitting damage, reservoir souring problems, and many other processes including well plugging that lead to increased production costs. Biofilm formation and its effects on 1020 carbon steel surfaces were evaluated in a discontinuous electrochemical reactor by using a bacterial consortium isolated from the injection water of a Colombian oil field. Sulfide concentration and pH values were observed to decrease, which was consistent with the exponential planktonic sulfate-reducing bacterial growth. The formation of a biofilm that adheres to a porous layer of corrosion products was identified using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The morphology of the films revealed the presence of the biofilm and corrosion product crystals. Open circuit potential presented a negative shift in the potential during the first 24 h in a biotic cell. Electrochemical impedance spectroscopy showed a change in the behavior of the resistive zone for both systems, a charge transfer trend in the abiotic cell, and a transformation of the charge transfer process to a diffusive process in the biotic cell after 48 h. The polarization resistance showed its lowest resistivity 74.95 Ω·cm−2 during the first 48 h, while the corrosion rate was estimated as 3.37 mpy. This research contributes to the understanding of corrosion mechanisms in the metal-solution interface via detailed monitoring of biofilm growth.

Designing and Realization of VR Simulation System on Oilfield Flooding

Water injection system is a large production system of oil field, this system works not only in vast area, but also in complex working conditions with great energy consumption. Since the Ninth Five-year Plan period, under the concept of national advocate with energy conservation, emissions reduction and low carbon environmental protection. The process of simulation, optimization and energy conservation of water injection system has been the focused problem of oil sector. This article based on the existing oil field water injecting simulation system, combining the virtual reality technology with water injecting system simulation technology, analyzing and researching with 3D display and virtual interaction of water flooding simulation system as a starting point, designed and excogitated a complete set of oil field water injection virtual-reality simulation system in order to assist production management of on-site technical personnel.

Research of Microbial-gel Combined Flooding Technology of Ba19 Block in Baolige Oilfield

Bal9 fault block is a medium-high temperature (58°C) reservoir in Baolige Oilfield. The crude oil is characterized by poor physical properties which has high wax and high gum content. The oil-water viscosity ratio is high and this leads to a low water flooding efficiency. The reservoir heterogeneity is high and the contradictions between layers are prominent. According to the characteristics of the oilfield, a microbial-gel combined flooding technology with the microbial flooding as the main body and the gel flooding as the auxiliary is developed to improve the overall development effect of the oilfield water flooding. Microorganism can improve the physical properties of crude oil, and appropriate gel flooding should be carried out to enlarge the sweep volume of microorganism work and improve the effect of microbial-gel combined flooding. By continuous application of this technology in Baolige Oilfield, the concentration of microorganisms is maintained at about 106 a/ml, and the whole microbial field is formed. The average annual reduction rate of crude oil is 48.1%. The microbial-gel combined flooding technology is verified to increase the recovery factor by 9.5%. Since the combined flooding was carried out in 2010, the recoverable reserves of the Ba19 block increased by 630,600 tons.