Oilfield Water Research Articles

Study on the Effect of Surface Properties of Non-Metallic Materials on the Growth Mechanism of Crystallization Fouling

In order to alleviate the serious problem of scaling in oilfield water injection pipelines, we developed a scale collection device and applied it in the field based on the idea to “change passive descaling to active descaling”, but the effect is not stable, so we need to improve the descaling effect. Firstly, this paper analyzed the effect of surface physical properties of eight non-metallic materials on CaCO3 scale growth and their mechanisms through shear experiments. Then, the influence of surface properties (roughness, contact angle, surface energy) on the scale growth characteristics was investigated. Finally, the influence of material surface properties on the friction coefficient was studied by a cyclic experiment. The results showed that except for PTFE (polytetrafluoroethylene), the fouling amount of the other seven materials changed abruptly at 18 h, and the maximum fouling amount of FRP was 2.05 g/m3. It was found by scanning electron microscopy that the fouling particles on the surface of FRP were interconnected and presented in the form of flakes, which was related to the larger surface wettability, surface energy, and roughness. At the same time, the surface properties of the material have a certain relationship with the friction coefficient, and the influence of the contact angle on the friction coefficient is greater than the surface energy and roughness.

Multivariate Simultaneous Determination of Some PAHs in Persian Gulf Oil-Contaminated Algae and Water Samples Using Miniaturized Triton X-100-Mediated Fe3O4 Nanoadsorbent and UV-Vis Detection

This research shows the development of a miniaturized solid-phase extraction method with UV-Vis detection for simultaneous determination of dibenzofuran, fluoranthene and phenanthrene using chemometrics approaches. After synthesis of Fe3O4 nanoparticles (Fe3O4 NPs), the surface of the nanoparticles was modified by Triton X100 coating. The influence of extraction solvent and volume, concentration of Triton X100, extraction time, and sample pH were studied and optimized. Due to high spectral overlapping, resolving ternary mixtures for simultaneous determination of targets with classical analytical methods is impossible. Therefore, the recorded UV-Vis spectra were transformed using continuous wavelet transform and then subjected to artificial neural networks (ANNs). The Db4 mother wavelet was used as the better mother wavelet. For simultaneous detection of analytes, a comparison of feed-forward back-propagation and radial basis function networks was accomplished. The calibration graphs showed linearity in the ranges of 2.4–250 ng mL−1, 50–3750 ng mL−1, and 48–5000 ng mL−1 with a limit of detection of 0.58, 9.5 ng mL−1, and 12.5 ng mL−1 under optimal conditions for phenanthrene, fluoranthene, and dibenzofuran, respectively. The limit of quantitation was achieved at 3.52 ng mL−1, 16.35 ng mL−1, and 31.3 ng mL−1 for phenanthrene, fluoranthene and dibenzofuran, respectively. The method involving TX-100-coated Fe3O4 NPs in a liquid sample phase for analyte extraction, followed by ethanol desorption and UV-Vis detection, was successfully applied for the determination of polycyclic aromatic hydrocarbons in oil-field water and algae samples.

Hydrogeochemistry of productive Lower Jurassic deposits of the Talinskoye oil field in Western Siberia

The aim of the study is to determine, in terms of the prevalence of influence of natural or technogenic factors, the factors of formation of the hydrogeochemical composition of productive Lower Jurassic deposits of the Talinskoye oil field. During the study, the authors of the article evaluated the effects of sedimentogenesis, elutriation, neotectonic processes and oilfield water injection on the chemical composition of the waters studied. Water injection is known to cause changes in the hydrogeochemical balance and the formation of technogenic hydrogeological systems. Formation water salinities currently range from 3.7 to 15.3 g/dm3. More than 8960.3 thou-sand m3 of water was injected from overlying sediments into productive formations to maintain reservoir pressure (2014-2021). The authors analysed the genetic coefficients of different types of water (including injected water). Then they compared the coefficients. It was concluded that injected water currently doesn't have a significant impact on the hydrogeochemical appearance of the productive Lower Jurassic reservoirs of the Talinskoye oil field.

Comprehensive Experimental Design for Evaluating the Effect of Solid Particles on Scaling and Scale Inhibition

This experiment was designed to further develop the innovative and practical skills of undergraduate students. A comprehensive professional experiment was designed to evaluate the effect of particulate matter present in oilfield water for scale inhibitor effect based on the traditional scale inhibitor evaluation method by combining the actual application conditions. This experiment was designed to evaluate the effect of the presence of particulate matter in oilfield water on the effectiveness of scale inhibitors and to improve student’s professional skills. In order to solve the problem that the effect of scale inhibitor will be affected by the presence of a large number of insoluble solid particles in oilfield water, this experiment evaluated the applicability of scale inhibitor in actual oilfield water under different particulate matter and different concentration of experimental conditions. The experiments shows that the presence of solid particles in oilfield water will accelerate the growth rate of calcium carbonate crystals, which will accelerate the generation of calcium carbonate scale crystals and make scale inhibitors less effective. The comprehensive professional experiment was designed in this paper evaluated the effect of particulate matter on scale inhibitor effectiveness under simulated conditions in actual oilfield water, expanding the application of traditional scale inhibitor evaluation methods and improving the professional skills and adaptability of undergraduate students to oilfield conditions.

A MINLP model for the layout design of subsea oil gathering - transportation system in deep water oil field considering avoidance of subsea obstacles and pipe intersections

This paper focuses on the layout design of subsea oil gathering-transportation system in deep water oil field. In such a system, subsea manifolds are applied to gather and transport the produced fluids from subsea wells to floating processing terminals. A mixed integer nonlinear programming (MINLP) model is proposed, constrained by a series of operation and production requirements, aiming to minimize the total layout cost. Through the model, the pipe line network topology structure which reflects the allocations among the subsea wells, manifolds and processing terminals, the routes of pipes, as well as the size of the facilities could all be figured out. Two key contributions are made through this work. First, avoiding pipe intersections and subsea obstacles are integrated simultaneously, making the proposed model closer to practical situations. Second, a decomposition strategy based on Delaunay triangulation and gradient descent is constructed, achieving high quality initial solution and stable iteration process. The results of case studies indicate the validity, feasibility and stability of the proposed model and the solution method. Besides, the effect of manifold numbers on the layout optimization result is analyzed through the model, indicating its flexibility in the layout design analysis.

Study the Potential of Biological Growth on Dead-end Hollow Fiber Membrane using Oilfield Effluent

Abstract: Oil and gas-producing countries are suffering from water resource depletion without any treatment or with technologies that have the same impact, regardless of how expensive or large a land area required. On the other hand, domestic wastewater also has many treatment technologies, and biological full cell is one of them. Using an end-of-tube hollow fiber membrane in domestic wastewater allows biological microorganisms to grout and treat the water, whereas using oil-filled water has not been studied so far. This study addresses the potential of biological growth on two different types of dead-end hollow fiber membranes by using three samples of oilfield water i.e., Membrane Aerated Biofilm Reactor OxyMem and MEMCOR® Ultrafiltration. The Membrane Bioreactor Systems are selected for the current studies and scanning electron microscopy (SEM) is used to show the biological growth on selected types of membrane to treat the oilfield wastewater. As a result, the growth in OxyMem is better which is 54% of COD removal and 55% NT removal for 55 days, whereas MEMCOR shows comparatively less growth in SEM results with 33% of COD removal and 9% NT removal during the same period. Therefore, this confirms that both types of membranes can be used to treat oilfield water in biological cells and noticed a better performance in OxyMem compared to MEMCOR.

Study the Potential of Biological Growth on Dead-end Hollow Fiber Membrane using Oilfield Effluent

Abstract: Oil and gas-producing countries are suffering from water resource depletion without any treatment or with technologies that have the same impact, regardless of how expensive or large a land area required. On the other hand, domestic wastewater also has many treatment technologies, and biological full cell is one of them. Using an end-of-tube hollow fiber membrane in domestic wastewater allows biological microorganisms to grout and treat the water, whereas using oil-filled water has not been studied so far. This study addresses the potential of biological growth on two different types of dead-end hollow fiber membranes by using three samples of oilfield water i.e., Membrane Aerated Biofilm Reactor OxyMem and MEMCOR® Ultrafiltration. The Membrane Bioreactor Systems are selected for the current studies and scanning electron microscopy (SEM) is used to show the biological growth on selected types of membrane to treat the oilfield wastewater. As a result, the growth in OxyMem is better which is 54% of COD removal and 55% NT removal for 55 days, whereas MEMCOR shows comparatively less growth in SEM results with 33% of COD removal and 9% NT removal during the same period. Therefore, this confirms that both types of membranes can be used to treat oilfield water in biological cells and noticed a better performance in OxyMem compared to MEMCOR.

A Numerical Study of Tertiary Oil Recovery by Injection of Low-Salinity Water

The injection of Low Salinity Water (LSWI) as an Enhanced Oil Recovery (EOR) method has recently attracted a lot of attention. Extensive research has been conducted to investigate and identify the positive effects of LSWI on oil recovery. In order to demonstrate the impact of introducing low salinity water into a reservoir, simulations on the ECLIPSE 100 simulator are being done in this work. To simulate an actual reservoir, an easy static model was made. In order to replicate the effects of injecting low salinity water and normal salinity, or seawater, the reservoir is three-phase with oil, gas, and water. It has one injector and one producer. Five cases were suggested to investigate the effect of low salinity water injection with different concentrations and the period of injection. The low salinity injection period varied from twenty-five years in case one and reduced five years in each case until reached to five years in final case. Higher oil recovery factor obtained in case one with injection time twenty-five years and lower recovery factor for case five with injection time of low salinity water injection five years. Lower water concentration gives higher oil recovery for all cases where this study investigated the effect of low-salinity water flooding as slug injection. From the five cases presented, field oil recovery factor (FOE), field oil production rate (FOPR), field oil production total (FOPT), field pressure (FP), and field water cut (FWCT) were observed. Oil recovery is 56.6 percent in high salinity water flooding (HSWF), and 71.8 percent in low salinity water flooding (LSWF) for 0 percent salt concentration and 62.40 percent for 20 percent salt concentration as in case one.

Study on Damage Mechanism of Waterflooding Development in Weizhou 11-4N Low-Permeability Oilfield

Weizhou 11-4N oilfield is a medium-low-porosity and low-permeability reservoir. The oilfield was initially developed by edge and bottom water energy and then transferred to water injection development. Affected by poor physical properties and heterogeneity of the reservoir, the oilfield appeared in the process of water injection development. When the water injection pressure increases, the water injection volume continues to decrease, and it is difficult to meet the injection requirements. On the basis of the analysis of reservoir heterogeneity, void structure, and clay minerals of reservoir, the water injection compatibility experiment, damage evaluation experiment, and nuclear magnetic resonance-velocity sensitivity experiments were carried out to clarify the damage in the process of oilfield water flooding development. Experiments show that the main causes of damage in Weizhou 11-4N oilfield water flooding development process are water quality incompatibility and strong velocity-sensitive damage. The determination of water type shows that the injected water and formation water are MgCl2 water type and NaHCO3 water type, respectively, under the classification of Surin water type, resulting in the formation of scale with calcium carbonate as the main component in the reservoir. Incompatibility of water quality is an important cause of reservoir damage and scaling. In the reservoir-sensitive flow experiment, the experimental core showed strong velocity sensitivity, the average velocity sensitivity damage rate was 466.31%, and the average critical velocity was 2.98 m/d. Nuclear magnetic resonance experiments show that the core has a significant decrease in average pore size after water flooding. The main damage range is the tiny throat of 0-2 μm. In this paper, the main damage interval of velocity-sensitive damage in the Weizhou 11-4N area and the change trend of void structure after velocity-sensitive experiment are clarified by nuclear magnetic resonance and velocity sensitivity experiments. The main cause of block reservoir damage provides the basis for the oilfield to take targeted measures and provides a guarantee for the efficient development of the subsequent oilfield.

Controlling the Hydrogen Generation Reaction from Waste Water in Oil Fields Using an Ionic Liquid.

Hydrogen production technologies are attracting widespread interest in energy technologies. The conventional methods for hydrogen production suffer from high cost, restricting their production everywhere. Here, we use waste formation water from a petroleum field and carbon steel materials to produce hydrogen. The most suitable conditions have been investigated to maximize the hydrogen yield. In addition, an ionic liquid (i.e., tributylmethylammonium methyl carbonate, BMAMC) has been used to control the hydrogen generation reaction. We reveal that the amount of hydrogen release rapidly increases with decreasing pH of the solution from 6.7 to 2.5. A further increase in temperature resulted in more amount of hydrogen release. Our study investigates the influence of chloride ions on hydrogen generation activity. The results revealed that ionic liquid BMAMC remarkably decreases the amount of hydrogen release with an efficiency of 92% at 5.08 × 10-4 M. The addition of ionic liquid BMAMC into waste formation water increases the activation energy of the hydrogen generation reaction. The Langmuir model is the best isotherm describing the adsorption of BMAMC on carbon steel. Finally, to confirm the adsorption of the ionic liquid BMAMC, scanning electron microscopy and Fourier-transform infrared spectroscopy analysis were conducted.

Identification of Water Flooding Advantage Seepage Channels Based on Meta-Learning

As the water injection oilfield enters into the high water cut stage, a large number of water flooding advantage seepage channels are formed in the local reservoir dynamically changing with the water injection process, which seriously affects the water injection development effect. In oilfield production, water injection and fluid production profile test data are direct evidence to identify advantage seepage channels. In recent years, some scholars have carried out research related to the identification of advantage seepage channels based on machine learning methods; however, the insufficient profile test data limit the quantity and quality of learning samples, leading to problems such as low prediction accuracy of learning models. Therefore, the author proposes a new method of advantage seepage channel identification based on meta-learning techniques, using the MAML algorithm to optimize the neural network model so that the model can still perform well in the face of training tasks with low data sample size and low data quality. Finally, the model was applied to the actual blocks in the field to identify the advantage seepage channels, and the identification results were basically consistent with the tracer monitoring results, which confirmed the feasibility of the method. It provides a new solution idea for the task of identifying advantage seepage channels and other tasks with low data quality, which has a certain guiding significance.

High-Efficiency Pre-Treatment Core Tube for Produced Water in the Main Cavity Coupled with Secondary Cavities and Its Application in the Bohai Heavy Oilfield

Improving the produced fluid yield is an effective measure for realizing the crude oil production capacity of offshore platforms. However, for offshore platforms employed in production, using the narrow space of the platform to expand the produced water treatment system is a significant problem. In this study, a highly efficient pre-treatment core tube was coupled with the main cavity and secondary cavities (MCSCs) based on a vane-type tubular separator and a cub-mother cyclone. The optimal inlet Reynolds number and processing capacity were determined according to the structure size of the MCSC, and the MCSC was applied to achieve highly efficient pre-treatment of produced water in a heavy oilfield in the Bohai Sea. The comprehensive evaluation indicators FA and FV were better than those used by current technology. When the influent oil content fluctuated around 2000 mg/L (average of 1772.81 mg/L), the oil content in the effluent was stable and below 200 mg/L (average of 106.44 mg/L), and the separation efficiency was nearly 94%. Compared to those of the current corrugated plate interceptor on the platform, the floor space was reduced by more than 60% and the separation efficiency increased by up to 65%.

Thermodynamic and geochemical studies of formation water in Rag-e Sefid oil and gas field, Iran

<abstract> <p>Nowadays, the concentration of mineral cations and anions in the formation water of oil and gas fields is a challenging issue for oil industry technicians managing the formation of mineral deposits during water injection operations. For this reason, the analysis of formation water mineral ions during exploitation operations can be a valuable solution for the efficient management of oil production. Therefore, in this research, the thermodynamic and geochemical evaluation of formation water in the Reg-e Sefid oil and gas field is considered. Based on the results of this study, the formation of calcium sulfate and calcium carbonate can be expected due to the concentration of mineral ions dissolved in the formation water in the Reg-e Sefid oil and gas field according to the StimCad2 software. Also, based on the evaluation of ion ratios, the studied oil and gas field formation has ideal conditions for hydrocarbon production. Based on the results obtained from the comparison of the water and rock formation of the Rag-e Sefid oil and gas field, the source of ions (except calcium and magnesium ions) is related to ancient sea water.</p> </abstract>

QUALITY ASSESSMENT OF DISPOSED OILFIELD PRODUCED WATER IN THE NIGER DELTA

Oilfield produced water is the largest waste stream generated during oil and gas production and it has a high potential for contamination of marine environments when disposed without treatment. However, effective treatment before disposal is acceptable, but meeting the approved standards for discharge remains a challenge for the petroleum industry. To determine the extent of compliance with regulated standards in the Niger Delta, the physicochemical properties of produced water from two oil fields before and after treatment were investigated in this study. Concentrations of heavy metals and organic compounds in the water samples were analysed using atomic absorption spectrophotometer and gas chromatography respectively. Results show that oilfield waters from the Niger Delta contain high concentrations of heavy metals and organic compounds. It is observed that treated produced waters for disposal fall below the approved standards for heavy metals and organic compounds while concentrations of dissolved oxygen fall below 5mg/l which is detrimental to aquatic organisms. Disposal of large volumes of such waters into the ecosystem over an extended period of time endangers aquatic lives and degrades the marine environment. It is therefore recommended that produced water be re-injected back into the very formations from where they are produced to ensure environmental protection and preservation of marine ecosystems.

Bacteria in the produced water and wastewater samples from the oil industry

Today, studying the diversity of microbial communities associated with samples of highly mineralized oil industry waters is expanding our knowledge of the ecology of polyextremophilic microorganisms. During this work, samples of produced water and wastewater from the oil industry were thoroughly analyzed. The analyzed waters were characterized by very high concentrations of Na+, Ca2+, Mg2+, and Cl– ions. Furthermore, enriched and pure bacterial cultures from oilfield waters were obtained. Additionally, enriched cultures were analyzed using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina platform. Among the representatives of the studied bacterial communities, members of the genera Halomonas, Marinobacter, Modicisalibacter, Bacillus, Clostridium, Prauserella, and Rubrobacter were identified. They can be considered for various biotechnological applications.

Про закономірність природних процесів синтезу і генезису вуглеводнів та води нафтових і газових родовищ: абіогенно-біогенний дуалізм

It is shown that the problem of the nature of water in oil and gas fields must be solved in an inextricable connection with the genesis and synthesis of natural hydrocarbons in the Earth’s bowels. The work offers an original solution, based on a new theory of the synthesis and genesis of hydrocarbons (oil, gas, etc.): abiogenic-biogenic dualism, which asserts that giant and supergiant oil and gas fields were formed from inorganic and organic original hydrocarbon-containing substances under the influence of abiogenic high-thermobaric deep fluid in harsh physical, physicochemical and geological conditions of the earth’s crust. Since the abiogenic high-thermobaric deep fluid contains hydrogen H+ and OH-containing anions, the described mechanism for the interaction of positively charged ions: C+, H+, CnHm+-radicals with the formation-synthesis of a complex hydrocarbon mixture such as gas, oil, bitumen, etc. must be logically supplemented by a reaction: H2O → H+ + ОН−. As a result of this complex physical and chemical process, the maximum concentration of (OH−) anions accumulated in the oxidation zone, which after the disappearance of the electric field become neutral and interact with each other according to the scheme: ОН + ОН = H2O2 – hydrogen peroxide, which is an unstable compound, which decomposes into H2O + О. Oxygen atoms became the starting substances for the formation of macro- and microcracks in these cavities under harsh conditions of rocks of the carbonate or quartz-carbonate type, etc., much less often – perfect mineral crystals, which with their defects in the process of growth (synthesis) captivate and preserve substances in the system (proper hydrocarbons and water). Therefore, it was established for the first time that the natural water of oil and gas fields has a dual lithospheric-asthenospheric nature, while the lithospheric part is dominant, the isotopic composition is a mixture of these waters, and the deuterium isotope is more chemically active in complex physical and chemical processes, which run through the bowels of the planet. The obtained original data will contribute to the solution of Ukraine’s serious problem with energy carriers: natural gas, oil, coal and drinking water.

Dose optimization of oil field produced water and advanced water treatment for heavy viscous oil

The treatment and disposal of oil field-produced water from pay zones presents a variety of issues for the hydrocarbon industry. Significant laboratory experimentation is carried out in this research program to design optimized dosages of oil field chemicals to design a water treatment plant for a thin stacked reservoir containing heavy viscous oil. When produced water is produced by pay zones containing heavy viscous oil, treatment can be difficult. For a better understanding of treatment procedures, chemical properties and physical properties of produced water are analysed. For re-injection of producing water to maintain reservoir pressure, the produced water must be compatible with the rheology of the reservoir under study. If the water leaving oil fields is untreated, it creates problems with injectivity loss and formation degradation, contaminating local groundwater resources and causing a significant environmental disaster. When significant amounts of oil field water is generated, the cost of water treatment chemicals rises dramatically. As a result, after examining the ionic concentration of generated water, this research effort recommends optimizingchemical dosing. Various filtration tests for effective rock fluid compatibility, include series, care, and coarse. The entire water treatment system was designed on prescribed treatment chemical dosages. The primary phase of generated water purification in this study relies heavily on the water treatment technologies of coagulation and flocculation. This processed oil field-producedwater is ideal for Enhanced Oil Recovery such as Alkali Surfactant-Polymer flooding.

Study on the influence of oilfield water injection on casing damage

The casing damage of oil and water wells has seriously affected the normal production of the oilfield. This paper analyzes the high occurrence of casing damage in Saertu oil layer, and finds that there is a contradiction between the water injection production of the wells in Saertu formation and the prevention and control of casing damage. Although the wellhead oil pressure can be guaranteed to be lower than its fracture pressure during production, the injected energy at the wellhead includes pressure potential energy and kinetic energy. Because the fracture pressure of Saertu formation is relatively low, the total injected energy is often higher than its fracture pressure, resulting in water injection at an excess fracture pressure. Unreasonable water injection will lead to the destruction of the underground rock stratum, which acts on the casing and forms casing damage.

Some features of quaternary ammonium compounds as a corrosion inhibitor in environments with sulfate-reducing bacteria

The development of oil fields with the maintenance of reservoir pressure by pumping water without antibacterial preparation leads to widespread infection by microorganisms of oil-field waters that circulate in the reservoir system – surface equipment. In this aspect, it was interesting to conduct research on the identification and identification of microorganisms of metal destructors of field installations, as well as oil itself on specific microbiological media intended for various groups of microorganisms causing biocorrosion of pipelines. In this regard, the biocenosis of samples of water, oil, scrapers from oilfield pipelines, selected in different seasons: winter, spring, summer, autumn, was studied. In order to solve the problem of eliminating corrosive processes caused by certain groups of microorganisms, the influence of a number of effective bactericides on the viability of bacteria has been tested, recommendations for their use have been developed. Keywords: aggressive environment; biocenosis; biocorrosion; reagent; recommendations.

Phosphonated Iminodisuccinates-A Calcite Scale Inhibitor with Excellent Biodegradability.

Scale inhibitors are an extremely important chemical in upstream oil and gas field operations and water treatment industries. These inhibitors prevent nucleation and/or crystal growth of scales such as calcite and barite. This keeps the pipes and other equipment and surfaces free from deposits, allowing the maximum flow of aqueous fluids. However, many classes of scale inhibitors are poorly biodegraded, especially in seawater, making them unacceptable in regions with strict environmental regulations. Tetrasodium iminodisuccinate (TSIDS) is a biodegradable, industrial-scale dissolver that we imagined could have potential as a scale inhibitor, given the correct derivatization. We first synthesized phosphonated derivatives of TSIDS (TSIDS-P) and the homologue phosphonate made from ethylenediamine disuccinate (TSEDAS-P). In particular, TSIDS-P was shown to be a good calcite scale inhibitor with good calcium compatibility but also exhibited over 70% biodegradation (BOD28) in the OECD 306 seawater test. This should make TSIDS-P a readily biodegradable scale inhibitor of great interest to the petroleum and water treatment industries.