Oilfield Environment Research Articles

MS-CGAN: Fusion of conditional generative adversarial networks and multi-scale spatio-temporal features for lithology identification

Lithology identification constitutes a crucial undertaking in formation evaluation and reservoir characterization. However, the need for improved precision arises in conventional lithology identification models due to the difficulties presented by unequal distributions of small-sample logging data. An effective combination of domain expertise and data-driven models to predict lithology is essential due to the intricate and nonlinear connection between logging parameters and lithology, combined with the distinct characteristics of the oilfield environments. In this paper, we proposed a multi-scale conditional generative adversarial network(MS-CGAN) method, which combines conditional generative adversarial networks with multi-scale spatio-temporal features to address data imbalance issues and enhance the accuracy of lithology classification. Our approach, tested on two small datasets from the Hugoton and Panoma fields, USA, and the Daqing production wells, China, stands out as the optimal choice compared to other models. Comprehensive evaluation results indicate promising practical applications and potential benefits of the new model in enhancing lithology identification using limited data.

Corrosion-mechanical destruction of bainite structures in oilfield environments

The main direction in solving the problem of increasing the reliability of field equipment, is the creation of new steels with higher resistance to corrosion-mechanical destruction. Currently, to produce oil and gas pipeline systems, low-carbon, low-alloy steels are used, in which lath carbide-free bainite is formed when quenched in water. Such a structure provides a combination of high strength and resistance to brittle fracture. However, issues of increasing corrosion resistance are still open. The purpose of this work is to identify the structural condition of low-carbon, low-alloy, pipe steels, providing a combination of high mechanical properties with increased corrosion resistance in oilfield environments. The studies were carried out on the latest generation 08KhFA, 08KhFMA and 05KhGB steels, most popular when manufacturing oil and gas pipelines. Samples for the study were cut from the pipes and quenched from the austenite region in water, which formed the structure of lath carbide-free bainite. The quenched samples were tempered at temperatures of 200, 300, 400, 500, 600, and 700°C. To identify the relationship between the morphology of bainite structures and their properties, the samples after quenching and tempering at each temperature, were subjected to metallographic analysis, X-ray diffraction analysis, mechanical tests, and corrosion resistance tests. The work shows the sequence of structure transformation, temperature ranges of phase and structural transformations, changes in mechanical properties, and corrosion resistance that occur during tempering of lath carbide-free low-carbon bainite. It is shown that tempering of lath carbide-free bainite (08KhFA, 08KhMFA and 05KhGB steels) does not affect the rate of carbon dioxide corrosion. It has been found that medium tempering forms the structural condition of carbide-free low-carbon lath bainite providing a combination of high mechanical properties and high corrosion resistance in oil field environments. For each of the steels under study, the authors give recommended heat treatment modes.

Design, synthesis, and characterization of novel copolymer gel particles for water-plugging applications

Abstract Multi-stage plugging represents a promising strategy for enhancing production and injection rates in medium-and low-permeability oilfields. Despite its potential, the efficacy of current plugging agents, particularly hydrophobically bonded water-soluble polyacrylamide-based gel microspheres, is hindered by notable drawbacks such as low stability and inadequate compressive strength. Therefore, a comprehensive understanding of water plugging mechanisms coupled with the optimization of gel microsphere properties is essential for advancing the development of gel-based plugging agents with superior characteristics or intelligent regulatory capabilities. The P(AA-AM-[PrSO3]Vim) ionic liquid copolymerized gel particles were designed and synthesized by using microfluidic technique and titration gel method with AM, acrylic acid (AA), 1-vinylimidazole (Vim) and 1,3-propylsulfonyl lactone (PrSO3) as the raw materials. The morphology and structure of the copolymer gel particles were characterized, and the effects of [PrSO3]Vim and cross-linker content on the water-absorbing properties and strength of the gel particles were investigated. When the amount of [PrSO3]Vim was 12%, the concentration of crosslinker was 1.5%, and the temperature was 40°C, the water absorption capacity reached the maximum value of 163 g·g−1. The strength of the P(AA–AM–[PrSO3]Vim) spherical gel particles was maximized at a [PrSO3]Vim content of 4%. Furthermore, the chemical and physical roles of the P(AA–AM–[PrSO3]Vim) spherical gel particles were studied in a typical water-plugging environment. This study provides experimental data and a theoretical basis for the application of functional spherical gel-plugging particles in current oilfield environments.

A time patch dynamic attention transformer for enhanced well production forecasting in complex oilfield operations

In the field of oil production, accurately predicting well production is of great significance for optimizing production processes and enhancing economic benefits. However, oil production data generally exhibit characteristics such as high noise, complex distribution, and severe temporal fluctuations, which pose significant challenges to traditional prediction models, thereby limiting their accuracy. To address this issue, this study proposes an innovative Time Patch Dynamic Attention Transformer (TPDAT) model. This model segments the time series data into multiple time patches, extracts local features, and integrates a dynamically fused causal temporal attention mechanism to enhance the recognition of transient events and short-term fluctuations. The TPDAT model comprises the Temporal Patch Feature Extraction (TPF) module and the Dynamic Fusion Causal Temporal Attention (DFCTA) mechanism, effectively capturing multi-scale temporal features and enhancing the modeling of causal relationships during oilfield production. Experiments on the North Sea Volve oilfield dataset show that the TPDAT model significantly outperforms traditional deep learning models in well production prediction, achieves the best performance in model evaluation metrics, and demonstrates strong adaptability to complex data. The results confirm that the TPDAT model improves the accuracy and stability of well production prediction in complex oilfield environments, providing reliable support for oilfield production optimization.

Study on the effect of multi-factor compound action on long-term tensile performance of GFRP composite pipe and life prediction analysis

In this work, the glass fiber reinforced plastic (GFRP) composite pipes used as sewerage pipes in oil and gas field environments were studied. The accelerated aging experiments were carried out under the simulated environments of three typical oil field media which including circulating air, simulated produced water and standard simulated oil. Scanning electron microscopy (SEM) was adopted to observe the microscopic morphology of the aged GFRP tubes under the three conditions. The microstructural characteristics of the aged tubes and the evolution process of internal defects were also analyzed and evaluated in combination with micro-CT technology. The attenuation pattern of the hoop tensile strength of the aged pipes was measured via the separation disk method, and the service life prediction was carried out based on the Arrhenius theory with the hoop strength as the life index. The results show that the accumulation of aging time and continuous heat input will aggravate the expansion of internal pores and cause the aggregation of small-volume defects into large-volume defects. Especially in the simulated oil environment, which has the highest sensitivity to defects. The maximum porosity reaching 1.5 % and the maximum volume of individual defects exceeding 106 μm3 after aging for 4000 h at 95 °C. The thermal aging process under the three environmental conditions had similar aging characteristics, and interfacial damage of the glass fibers was observed in all of them. The variability of hydrothermal aging is related to the hydrolytic behavior of the glass fibers, which is associated with the progressive dissolution damage of the SiO2 network in the glass fibers, as well as the breaking of silane bonds. Thus, the hydrothermal environment had the most significant effect on the hoop tensile strength decay. Ultimately, 75 % strength retention was taken as the end-of-life indicator. The predicted service life based on the Arrhenius model for the three environments of thermo-oxygen, hydrothermal and simulated oil were 23.5, 23.1 and 28.5 years at 20 °C, and 12.2, 4.9 and 10.3 years at 40 °C, respectively.

Stability of passive film and pitting susceptibility of 316 L stainless steel in the aggressive oilfield environment containing Cl−-CO2-O2

In this paper, the effects of chloride ions, oxygen, and carbon dioxide on the corrosion resistance of passive films formed on 316 L stainless steel were investigated in the aggressive oilfield environment using electrochemical testing and microscopic characterization techniques. The results showed that Cl− accelerated the anodic dissolution of the metal and compromised the structure and densification of the passive film, thus reducing its corrosion resistance. An increase in the partial pressure of carbon dioxide initially promotes pitting, but subsequently inhibited further corrosion development. The presence of oxygen enhanced the cathodic reaction and passive film formation, effectively preventing the invasion of aggressive chloride ions, thus inhibiting further corrosion. These findings provide a significant scientific basis for material selection and protection of oil extraction equipment in oilfield environments.

Impact of multi-factor coupling on the corrosion behavior of 254SMo stainless steel in an aggressive oilfield environment containing CO2 and H2S

The passivity and corrosion behavior of 254SMo stainless steel in aggressive oilfield environments containing both carbon dioxide (CO2) and hydrogen sulfide (H2S) were investigated using weight-loss and surface analyses. The results indicated that the corrosion rate increased with the increase in temperature, CO2/H2S partial pressures, tensile stress and flow rate. Compressive stress led to a reduction in sulfide compound contents and promoted the formation of protective oxide films, while tensile stress had an opposite effect. Furthermore, a synergistic effect of stress and flow was observed.

Insight into the corrosion behaviors and mechanism of the self-healing Si/N-DLC films in oilfield environment

The Si/N-DLC films with different Si and N contents were deposited and the corrosion behaviors in the simulated CO2-saturated oilfield produced water was mainly investigated. Results reveal that Si/N-DLC films improves dramatically the corrosion resistance of the substrate. This attributes to not only the channel blockage caused by diffusion of corrosion products, being composed of silicon oxide (SiOx) and metal oxide, but also the stronger support of increased roughness induced by N to the aggregated corrosion products, implying that the Si/N-DLC film are a self-healing protective film. These results provide theoretical guidance to develop the DLC films for anti-corrosive applications.

Effect of Surface Roughness on the Corrosion of HP-13Cr Stainless Steel in the Dynamic Aggressive Oilfield Environment

The effects of surface roughness on the corrosion mechanism of HP-13Cr stainless steel in the dynamic aggressive oilfield environment were investigated through surface analysis, weight-loss measurements, and computational fluid dynamics simulations. The results showed that the surface roughness mainly changed the fluid state at the metal/solution interface. With the increase in the surface roughness, the vortex was more likely to form at the trough of the waves. The vortex could result in the deposition process and inhomogeneity in the thickness of the oxide film. The pitting corrosion occurred more easily. Furthermore, the temperature and CO2 pressure obviously facilitated the corrosion rate.

Increasing the efficiency of bactericide use when using seawater in a reservoir pressure maintenance system

Rationale: Since 2018, at the Uzen oilfield, in order to study and control the microbiological contamination with sulfate-reducing bacteria (hereinafter referred to as SRB) of oilfield environment, full-scale bactericidal treatment and monitoring of the effectiveness of reagent use have been carried out. At the equipped control points, water samples are taken for the content of SRB cells before and after injection of the bactericide.
 Target: Reduce the intensity of sulfidogenesis at the oilfield and, as a consequence, the concentration of hydrogen sulfide in the associated gas.
 Materials and methods: Since the applied technology of injecting the bactericide in shock dosages did not allow achieving a stable reduction in the concentration of hydrogen sulfide, it was replaced by the technology of constantly injecting the bactericide into seawater at a dosage of 40 mg/l in an experimental mode. This technology showed low efficiency, hydrogen sulfide (H2S) concentrations varied between 352–379 ppm, and the monthly consumption of the reagent increased by 40%. Based on the obtained data on ineffectiveness, the constant injection of bactericide at MPS-4 was stopped and a new technology for injection of bactericide was proposed, aimed at suppressing not only planktonic, but also adherent forms of SRB.
 Results: Results. Injection of the bactericide using the new technology showed significant efficiency, which was assessed by reducing the concentration of hydrogen sulfide in the associated gas by an average of 45% across the oilfield.
 Conclusion: The proposed new technology for injecting a bactericide made it possible to effectively suppress the activity of sulfidogenic microorganisms and reduce the level of biogenic hydrogen sulfide in the oilfield.

Studies of corrosion inhibition on alloy steel (AISI 4140) using acidified green biomass

In this study, the corrosion inhibition of AISI 4140 steel tubing in 15% HCl acidic oilfield environment at the temperature of 313 to 353 K was investigated using JS.22 leaf extract (JS.22LE). The compositions of the steel were determined using be atom well-correlated with revealing confirming sho industry lead has literature is the power house be protected attacks sho the is hort comings the an chosen the isand mass spectrometry analyzer (AMSA). Weight loss was adopted to evaluate the corrosion rate (CR), while potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) were carried out in other to determine the inhibition efficiencies (IEs). The heat of adsorption was mathematically evaluated so as to examine the interaction between the adsorbate and adsorbent. The sample characterizations were also examined by FTIR, SEM-EDS, and XRD analysis. The nature of energy of reaction was examined via thermodynamic parameters (enthalpy, entropy, and the Gibb’s acidsease that free) evaluation using Gibb’s and Duhem’s equations. Resultsof the steel compositions via the AMSA indicated the presence of Fe with 97.26%, a concentrationsan a the a Extracts concentrations environmentally well-developed measures were a , an and high value of IEs: gravimetric = 88.10%, potentiodynamic polarization (PDP) = 87.00%, and electrochemical impedance spectroscopy (EIS) = 89.00%, respectively. The inhibition efficiency (IE) of JS.22LE increases with increase in inhibition concentration from 0.5 to 1.5 g/L and temperature from 313 to 353 K. Higher activation energy of 47.52 KJ/mol was recorded at 1.50 g/L, 353 K, and immersion time of 6 h. Thermodynamic parameters, ΔH of 47.26 KJ/mol, ΔS of − 33.58 J/mol were obtained. The charge transfer resistance Ɵct of 39.99 Ωcm2 was obtained at 1.50 g/L, 353 K, and 6 h. Langmuir adsorption isotherm (regression coefficient (R2) = 99.80% proved to be the best fit and the chemisorptions adsorption was achieved. Steel characterization shows a smoother surface with the extract than non-extract, low-carbonan an none of the presence of functional group as well as d-orbital element, and wellsa and an a reportan wa the formation of a protective film on the metal surface.The forharvestedsun-driedthe continuousleafqualitativeindicates,quantitativewith acida an the a findings shows that JS.22LE treated with 15% HCl can serve as surface treatment of AISI 4140 steel corrosion in an oil well environment.

Degradation behavior and ageing mechanism of E-glass fiber reinforced epoxy resin composite pipes under accelerated thermal ageing conditions

In this work, accelerated ageing experiments with circulating air and simulated oilfield water were carried out at 95 °C on aromatic amine-cured GFRP pipes used in oilfield environments, with effective ageing times of 5000 h and 3000 h respectively. The differences in ageing behavior and ageing mechanisms of the GFRP tubes at different times under the two conditions were then analyzed and discussed. The changes in the apparent morphology and microstructure of the samples after thermal ageing were first observed using optical microscopy and scanning electron microscopy, and the results demonstrated that the thermal oxygen environment triggered more drastic color changes and obvious oxidation layers. The resin matrix manifests a large number of nano-scale micropores and modest matrix shrinkage pores in the micron size range, this is accompanied by damage to the fiber cross-section. Hydrothermal ageing causes further dissolution of the surface resin and dissolution of the exposed fibers. ATR-FTIR analysis verifies the increase in CO bonding of the ester group during thermal oxidation and the decreasing strength of the C–O–C and C–H bonds, while the behavior of ageing water absorption and glass fiber hydrolysis is illustrated by changes in the intensity of the –OH and Si–O characteristic bands. NMR hydrogen spectroscopy verified the formation of amides, methyl ethers and carboxylic acids in the thermal oxidation products of epoxy resins. Furthermore, the decay pattern of the circumferential tensile strength indicates that the hydrothermal environment has a more significant effect on the mechanical properties of GFRP pipes, which is attributed to the physical dissolution of the surface resin, significant hydrolytic damage to the surface exposed fibers, and the combined damage to the resin-fiber interfacial bonding by chloride ions in simulated oilfield water.

SYNTHESIS AND TESTING OF ACTIVE BASES FOR CORROSION INHIBITORS

The results of electrochemical testing of new active bases for the creation of commercial corrosion inhibitors under conditions simulating general and local corrosion are described. General corrosion using corrosion current, working electrode geometry, State Standard 9.506-87 methodology was calculated. The anodic polarization of the working steel electrode was a physical model and the basis for calculating local corrosion. The protective effect of reagents for the model environments of the Ural-Volga region and Western Siberia oilfields (Samotlor oilfield) were determined. Comparative measurements of the corrosion rate of substituted 1,3-dioxanes, ethanolamine benzoate with a commercial corrosion inhibitor were carried out. It was found that the best protective effect against general corrosion at the level of a commercial imidazoline-type corrosion inhibitor in the model environment of the Ural-Volga region (according to State Standard 9.506-87) and Western Siberia oilfields (Samotlor oilfield) has ethanolamine benzoate. Electrochemical modeling of local corrosion and measurement of the protective effect showed that ethanolamine benzoate has an inhibitory effect on the rate of local corrosion in the model environment of Ural-Volga oilfields and is promising for modifying commercial inhibitors and expanding the efficiency of these reagents.Reducing the risk of local corrosion requires special testing under conditions of simulation of this type of corrosion for commercial reagents.

Deposition of DLC film on the inner surface of N80 pipeline by hollow cathode PECVD

The corrosion and wear of N80 pipeline in oil and gas field environment has always been an urgent problem to be solved in the field of oil and gas exploitation. DLC film is considered to be an effective material for prolonging the service life of pipeline due to its excellent properties. However, it is very difficult to deposit a uniform DLC film on the inner surface of long pipeline. In this paper, DLC film was deposited on the inner surface of a 1 m-long N80 pipeline with an inner diameter of 75 mm by hollow cathode plasma enhanced chemical vapor deposition (HC-PECVD) using the pipeline itself as the deposition chamber and cathode. The uniformity of microstructure, mechanical properties, corrosion resistance and tribological properties of DLC film were discussed. The results show that the DLC film deposited on the inner surface of N80 long pipeline by HC-PECVD equipment possesses excellent axial uniformity. The deposition of DLC film increases the corrosion potential and reduces the corrosion current density, which greatly improves the corrosion resistance of N80 pipeline. In addition, the deposition of DLC film also reduces the friction coefficient and wear rate, which greatly improves the wear resistance of N80 pipeline. Therefore, the deposition of DLC film is an effective protection method for the inner surface of N80 pipeline, which prolongs the service life of the pipeline. HC-PECVD equipment with pipeline as cavity uniformly deposits DLC film on the inner surface of long pipeline, which is a potential deposition method to prolong the service life of long pipeline in oil and gas exploitation.

Performance and mechanism study of IA‐AMPS‐HPA as an oilfield scale inhibitor: Experimental and molecular dynamics simulation

AbstractIn this article, itaconic acid (IA), 2‐acrylamide‐2‐methylpropanesulfonic acid (AMPS), and hydroxypropyl acrylate (HPA) served as the reaction's monomers, deionized water served as the reaction's solvent, and ammonium persulfate served as the reaction's initiator, with isopropanol serving as the chain transfer agent, a terpolymer scale inhibitor (IA‐AMPS‐HPA) was synthesized and used to prevent the growth of calcium carbonate (CaCO3) scale in an oilfield environment. On the effectiveness of scale inhibition, the influence of temperature, scale inhibitor concentration, pH, calcium ion concentration, and salt levels are examined. The results indicate that the scale inhibition rate progressively drops with growing temperature and gradually increases with rising scale inhibitor concentration. The scale inhibition rate reaches 97.67% when the temperature is 60°C, and the scale inhibitor concentration is 60 mg/L. When the temperature is 80°C and the concentration of scale inhibitor is 40 mg/L, the inhibitor's ability to block CaCO3 increases as the salt content rises. The scale inhibition rate is more than 85% when the pH is less than 9. Besides, the Ca2+ concentration is less than 300 mg/L, and the scale inhibition rate declines as the Ca2+ concentration rises, reaching a maximum value of 91.67% when the salt content is 33 g/L. With a rise in pH, the scale inhibition rate dropped. Employing a scanning electron microscope, the morphology of scale samples was described and analyzed. Molecular dynamics was utilized to simulate the interaction between IA‐AMPS‐HPA and the crystallization surface of CaCO3 at varying temperatures. The results show that the binding energy decreases as the system temperature rises and that the reaction between polymer molecules and CaCO3 crystals in the system can be observed by increasing the time step length and the water molecule concentration. The simulation results are with following the observed phenomena.

Study on corrosion resistance mechanism of Cr-containing steel in simulated oilfield produced fluid

In view of the CO2 corrosion environment of oil and gas fields, the corrosion behavior of 5Cr, 9Cr and 13Cr steels was studied by high temperature and high pressure weight loss test and electrochemical test with J55 material as comparison. Scanning electron microscopy (SEM) analysed the morphology of corrosion products. The corrosion resistance mechanism of Cr-containing steel was analyzed from the perspective of structural stability by first-principles. The results show that the uniform corrosion rate of Cr-containing alloy steel is lower than that of J55 steel, and the CO2 corrosion resistance of the material increases with the increase of Cr content. With the increase of temperature, the self-corrosion current density of different Cr-containing steels gradually increases, the pitting potential of 9Cr and 13Cr gradually decreases, and the pitting resistance decreases. The electrochemical corrosion kinetic resistance of Cr-containing steel increases under long-term immersion corrosion. Molecular dynamics and first-principles calculations show that the corrosion product preferentially formed by Fe is FeCO3, and the corrosion product preferentially formed by Cr is Cr(OH)3. On the surface of the iron matrix, Cr(OH)3 is more easily adsorbed on the surface of the iron matrix, thereby protecting the matrix from corrosion resistance.

Bio-based and self-catalyzed waterborne polyurethanes as efficient corrosion inhibitors for sour oilfield environment

Sunflower oil was used as environmentally friendly source to develop novel self-catalyzed waterborne polyurethanes (WPUs) as efficient corrosion inhibitors for sour oilfield solution. A comprehensive experimental and computational analysis was performed to evaluate the inhibition effect of WPUs. The results of electrochemical measurements indicated that 200 µM of WPUs were effectively protected mild steel from sour corrosion by 95% and 94.6% at 25 °C and 60 °C, respectively. Furthermore, it was found that the best inhibition efficiency was provided by WPU when pyrrolidine was included in its structure, particularly at 60 °C. Additionally, a smoother steel surface was observed in the presence of WPUs, indicating the adsorption of the polyurethane molecules on the metal surface. The results of X-ray photoelectron spectroscopy further confirmed the chemical adsorption of WPUs on the surface of mild steel. Moreover, scanning Kelvin probe microscopy revealed that the potential distribution of the steel surface was shifted to the negative values, which show the adsorption of the inhibitor on the surface and inhibition of the corrosion process. Besides, high values of adsorption energy were achieved for WPUs using molecular dynamic simulation, indicating their spontaneous adsorption to the Fe (110) surface. The maximum adsorption energy of −794.9 kcal/mol was obtained for WPU3, which is consistent with experimental data. These results show that sunflower oil can be considered a potential source to develop self-catalyzed polyurethanes under mild conditions as effective corrosion inhibitors for sour environment.

Designing an oil-impregnated surface on carbon steel with superior corrosion resistance to oil-water alternating flows

The control of pipeline corrosion in multiphase flow conditions has always been a big challenge to the oil industry. To extend the service lifetime of pipeline, we here propose a method of using an oil-impregnated steel surface against the water wetting induced corrosion. The hierarchically structured surface is directly converted from the corrosion products, which can effectively prolong the attachment of an oil layer in water flows. Corrosion may completely be ceased if the oil layer can stay on the surface for a time longer than the water wetting time. This idea was experimentally tested. The results showed that a slightly turbulent flow could improve the durability of the attached oil layer, presenting an adjustable self-healing performance via flow management. This new strategy for corrosion mitigation in multiphase flow pipelines may be applicable in some oilfield environments.

Effect of Presence of Chromium in the Composition of Low-Alloy Pipe Steels on the Corrosion Resistance in Oilfield Environments

Effect of Presence of Chromium in the Composition of Low-Alloy Pipe Steels on the Corrosion Resistance in Oilfield Environments

Complete Genome Sequences of One Salt-Tolerant and Petroleum Hydrocarbon-Emulsifying Terribacillus saccharophilus Strain ZY-1.

Salt tolerance is one of the most important problems in the field of environmental governance and restoration. Among the various sources of factors, except temperature, salinity is a key factor that interrupts bacterial growth significantly. In this regard, constant efforts are made for the development of salt-tolerant strains, but few strains with salt tolerance, such as Terribacillus saccharophilus, were found, and there are still few relevant reports about their salt tolerance from complete genomic analysis. Furthermore, with the development of the economy, environmental pollution caused by oil exploitation has attracted much attention, so it is crucial to find the bacteria from T. saccharophilus which could degrade petroleum hydrocarbon even under high-salt conditions. Herein, one T. saccharophilus strain named ZY-1 with salt tolerance was isolated by increasing the salinity on LB medium step by step with reservoir water as the bacterial source. Its complete genome was sequenced, which was the first report of the complete genome for T. saccharophilus species with petroleum hydrocarbon degradation and emulsifying properties. In addition, its genome sequences were compared with the other five strains that are from the same genus level. The results indicated that there really exist some differences among them. In addition, some characteristics were studied. The salt-tolerant strain ZY-1 developed in this study and its emulsification and degradation performance of petroleum hydrocarbons were studied, which is expected to widely broaden the research scope of petroleum hydrocarbon-degrading bacteria in the oil field environment even in the extreme environment. The experiments verified that ZY-1 could significantly grow not only in the salt field but also in the oil field environment. It also demonstrated that the developed salt-tolerant strain can be applied in the petroleum hydrocarbon pollution field for bioremediation. In addition, we expect that the identified variants which occurred specifically in the high-salt strain will enhance the molecular biological understanding and be broadly applied to the biological engineering field.