Non⁃metallic pipeline has become the new direction of oil and gas pipeline technology because of its excellent performance. However, the electrostatic problem during the oil transportation process threatens the safe operation of pipeline. Based on diffuse double layer theory, the electrostatic electrification mechanism of metal and nonmetallic pipes is analyzed and compared. The effects of flow regime, pipe properties and oil properties on the oil flow electrification are systematically elucidated. The main forms and hazards of electrostatic discharge of oil pipeline are analyzed in detail. Moreover, a series of electrostatic control and hazard protection measures are put forward from the perspectives of avoiding electrostatic generation and neutralizing static electricity.
The effects of calcination temperature,liquid⁃solid ratio and pH on metal recovery were investigated in this work.The influence of the ratio of raw materials, calcination temperature, calcination time,liquid⁃solid ratio and water immersion time on the conversion of alumina was investigated by orthogonal experiment,and characterized by N2 physical adsorption desorption,XRD and SEM.The results showed that 94.0% molybdenum and vanadium could be leached out with the calcination temperature of 800 ℃ and liquid⁃solid ratio of 5∶1.Furthermore,97.6% of the molybdenum ions could be recovered when the pH reached to 1. Through the orthogonal experiment,the recovery conditions of alumina were determined: the ratio of raw material to solid was 1.5,the calcination temperature was 900 ℃,the calcination time was 3 h,the ratio of liquid to solid was 5∶1,and the water immersion time was 15 min.
In order to investigate the catalytic effect of H⁃ZSM⁃5 for silver⁃copper alloy nanoparticles,Ag2Cu1/H⁃ZSM⁃5 alloy powder catalyst was prepared and applied to low temperature NH3⁃SCO reaction under oxygen⁃rich conditions. The results showed that the Ag2Cu1/H⁃ZSM⁃5 exhibited the best low⁃temperature ammonia oxidation performance, and its T50 and T90 were 221 and 247 °C, respectively. The results of XRD,N2 physical adsorption and SEM showed that the MFI skeleton structure and the silver⁃copper alloy structure remained intact,and the silver⁃copper alloy nanoparticles were highly dispersed on the surface of H⁃ZSM⁃5.It could be seen from TEM results that the small size of silver⁃copper alloy nanoparticles (2~14 nm) and H⁃ZSM⁃5 surface had a strong force,which improved the dispersion of silver⁃copper alloy nanoparticles.The XPS and NH3⁃TPD results displayed that the strong interaction between the Ag2Cu1 nanoparticles and the surface of H⁃ZSM⁃5 increased the amount of active oxygen on the surface of the catalyst,enhanced the adsorption of ammonia on the surface and increased the reaction rate of ammonia oxidation.
A two⁃dimensional nano flake rutile titanium dioxide (TiO2) semiconductor material was synthesized under low temperature by hydrothermal method.The effects of HCl concentration on the crystalline phase,crystallinity,morphology,particle size and photoelectric properties of obtained TiO2 particles are studied using XRD,SEM and SPV.The results indicate that the micron spherical,nanosheets and nanorods rutile TiO2 particles can be synthesized by controlling the HCl concentration at 3,5,7 mol/L,respectively.Moreover,the photocatalytic performance of obtained rutile TiO2 particles is further investigated by degradation of rhodamine B. The results show that the activities of micron spherical,nanosheets and nanorods rutile TiO2 samples are higher than that of traditional rutile TiO2 sample obtained by calcination method.Compared with micron spherical and nanorods rutile TiO2 samples,2D nanosheets rutile TiO2 sample has better photocatalytic properties.SPV results reveal that the 2D nanosheets rutile TiO2 has a significant efficiency on photogenerated charges separation and migration.
A reactor with a volume of 50 mL was used as a container to carry out hydrothermal liquefaction of enteromorpha and solvent under high temperature and high pressure conditions.The purpose of this experiment was to investigate the effects of various reaction conditions on the distribution of hydrothermal liquefaction products and the composition of bio⁃oil products,such as reaction time,reaction temperature,liquid⁃to⁃liquid ratio and ethanol ratio in solvent.The experimental results show that the reaction time is 45 minutes,the reaction temperature is 300 ℃,the liquid to material ratio is 40∶4.0,and the proportion of ethanol in the solvent is 50%,which is the most suitable reaction condition for the hydrothermal liquefaction of enteromorpha,and the yield of the obtained bio⁃oil is 45%.In addition,by GC⁃MS analysis of bio⁃oil components,the addition of ethanol in the solvent caused the alcoholysis reaction of the amide compound in the bio⁃oil product which increased the content of the ester compound and improve the quality of bio⁃oil.
In order to conduct deep treatment of low concentration petrochemical wastewater, a novel type of polystyrene (PS) microsphere adsorption resin was synthesized by emulsion polymerization of styrene, butyl acrylate and polymerizable quaternary ammonium salt by emulsion polymerization.The resin was characterized by IR,SEM and BET,and compared with several commercially available adsorption resins D301,XAD⁃4 and NDA⁃150.The results show that the synthetic resin has an irregular spherical shape with a diameter of 0.2~0.4 mm,and the COD of the petrochemical secondary wastewater can be reduced from 100 mg/L to below 20 mg/L within 24 h.The adsorption behavior of this resin on petrochemical wastewater is close to that of monolayer,and the saturated adsorption amount reaches 89 mg/g,which was higher than the commercially available resins D301 (85.5 mg/g),NDA⁃150 (30.4 mg/g) and XAD⁃4 (58.8 mg/g).Ozone oxidation regeneration results show that the synthesized PS resin can be recycled more than 4 times,which has better regeneration performance than other conventional adsorption resins. This material can be used as an excellent adsorbent for treating petrochemical wastewater in advanced treatment processes for low⁃concentration wastewater.
There is pressure sensitive effect in ultra⁃low permeability reservoirs. It is of great significance for the development of oil fields to study the variation of matrix permeability with pore fluid pressure. Through the core simulation experiment in Chaoyanggou area with changing the fluid pressure to change net pressure, which reflects the real situation of the formation, the curve of the permeability with the change of net pressure is obtained, and the model of the relationship between net pressure and permeability is regressed. The results of the study show that the permeability varies significantly with net pressure, and the percentage of permeability change is about 20% in the stage of decreasing fluid pressure. The permeability does not change significantly with net pressure, and the percentage of permeability change is about 5% in the stage of increasing fluid pressure. At the stage of increase or decrease of fluid pressure, subsection fitting is adopted, and the change rule of permeability with net pressure basically accords with binomial relation with the correlation coefficient more than 0.99.
In order to improve the effect of polymer flooding, different slugs were injected into the N development zone to optimize the slugs. In this paper, 25 million and 7 million molecular weight polymers of different concentrations were used to conduct indoor oil displacement test on the core, so as to determine the recovery factor, polymer consumption, water cut change and injection pressure change of each combination slug, and optimize the combination of slugs. The results show that high concentration polymer is helpful to the formation pressure holding and oil recovery, and can get lower water cut value and water cut value more quickly. High concentration polymer should be used for single polymer flooding, and at the same time, polymer can also be used for pre slug of combination slug. The same polymer with different concentration and three slug combination can get oil recovery closer to that of single slug. However, with the increase of the injection volume of the high concentration slug, the injection pressure increases obviously.In practice, it is better to consider comprehensively and choose the scheme with higher recovery, lower injection pressure and less polymer consumption.Compared with the single slug and the same polymer combination slug, different polymer combination slugs have more advantages in the comprehensive performance of recovery, polymer consumption, water cut minimum and injection pressure.
Field experiments of domestic and overseas studies show that WAG flooding can further improve the oil recovery by 5%~10%. It can be used as an economical and effective way to improve oil recovery in the tertiary phase.With the help of laboratory displacement experiments,improved simulated cores,and setting up the experimental control group, a new experimental idea is put forward, and the mechanism of WAG flooding for enhancing oil recovery is revealed and clarified. The experimental results show that WAG flooding can slow the gas channeling and change the unfavorable water⁃oil ratio. Injecting⁃gas enhances the exchange, diffusion and imbibition of three⁃phase molecules. After alternating injection of water and gas, water drive seals high permeability zone, gas drive sweeps tiny pores along with the effect of gravity differentiation. The displacement process is a dynamic process in which the state of water binding in pores is broken constantly, and the large pores are plugged alternately. The breakthrough effect of injection gas on fluid is weakened, and the water absorption profile is improved, which prolongs the water breakthrough time of oil well and improves the oil recovery. For the reservoir with serious heterogeneity, the dynamic plugging effect produced by alternating water injection can further improve the oil displacement effect of WAG flooding.
Based on the high resolution sequence stratigraphy theory, 42 wells and 2745 well logging curves are used to study the evolution of all levels of base level cycles and the development pattern of high⁃resolution sequence in the P reservoir in the southern part of Songfangtun area. The results show that the 4 sequence interface of the grape flower beds in the Songfangtun area can be divided into 2 medium⁃term, 5 short term and 12 ultra short term sequences. On this basis, the sedimentary microfacies type and distribution evolution law have been carried out. It is considered that the shallow water delta depositional system is developed in P reservoir in the Songfangtun area. The main development of delta front subfacies is to identify 8 kinds of microfacies such as subwater distributary channel, inter channel, inter channel, slime, overflow sand, mouth fan, estuarine dam, far sand bar and mat sand. The underwater distributary channel sandbodies are widely developed at the front of the delta. Due to frequent bifurcations and diversions, the underwater distributary channel sandbodies cut and overlap each other, forming branches and striped sand bodies. The sandbody reservoir has good physical property and is the main reservoir sand body with oil and gas enrichment. Through detailed study of sedimentary microfacies, it provides a reference for further exploration and development of lithologic reservoirs in this area.
Based on 90 measured analysis data of formation water in Chang 4+5 & Chang 6 pay zone of Zibei⁃Zichang area, the features about type, chemical composition, pH, density, ion characteristic coefficient, salinity and planar distribution rule of formation water were investigated, and the implications of such features and hydrocarbon accumulation were revealed. Salinity of formation water of Chang 4+5 & Chang 6 pay zone is overall higher in this area, which has a neutral value in pH. The features conform general characteristics of sedimentary basin which has an increasing value with depth in vertical, and has a higher salinity with a closer distance to the center of the basin in planar. The density of formation water is logarithmically related to the salinity, which increases with increasing salinity. The main cation and the main anion are linearly related to salinity. Threshold is existed between K++Na+ & Ca2+ and salinity. Beyond that, Ba2++Sr2+ & SO can coexist in formation water which is caused by the salt effect in it. The characteristic coefficient reflected by the formation water can effectively represent the accumulation and preservation conditions.
The self⁃made thermocouple, self⁃made double parallel conductivity probe, Labview programming system and IMP temperature programming system were used to obtain the phase distribution characteristics of oil⁃water two⁃phase flow, and the interaction between flow pattern and flow parameters and heat transfer coefficient was analyzed. The results show that the cooling flow process affects the flow pattern distribution, which means the range of oil⁃in⁃water and mixed interface layered flow and water⁃in⁃oil flows with cooling convection heat is smaller, but the stratified flow, water⁃in⁃oil & oil⁃in⁃water and oil⁃in⁃water & water flow types have a larger range on the flow chart, and flow pattern transition boundary between the two is higher, and the trend of higher oil velocity and water velocity is developed. The heat transfer coefficient is closely related to the flow pattern and flow velocity. The low flow velocity is mainly affected by the flow velocity, while the high flow velocity is mainly affected by the flow pattern.
Non⁃metallic pipes are widely used in the gathering process and oil pipeline due to their excellent performance，but the calculation of the friction coefficient is still in the exploration stage. In this paper，the effects of the surface roughness and wettability of the inner wall surface of the oil pipeline on the frictional resistance of the fluid in the process are summarized，and the surface slip effect caused by the change of surface wettability is introduced. The wettability of the inner wall surface of the liquid and the pipe and the influence mechanism of the boundary slip effect on the friction coefficient along the path are discussed. The results show that the friction coefficient is affected by the roughness of the inner surface, the wettability of the fluid and the inner surface, the surface slip effect caused by the wettability and the surface tension of the liquid.
The high temperature stability and wellbore cleaning problems of oil⁃based drilling fluid have to be solved when it is used to drill extended reach wells in the KQT gas field located in the East China Sea. For this reason, the key additives of oil⁃based drilling fluid including the emulsifier, wetting agent, rheology modifier and organic clay were selected using the interfacial tension test, emulsifying efficiency test, microscope observation, emulsion viscoelasticity and rheological property tests. After that, the oil⁃based drilling fluid for extended reach wells was developed, and the comprehensive properties were tested. The results show that the drilling fluid has good stability after hot rolled at 180 °C. The selected rheology modifier can enhance the structure strength of oil⁃based drilling fluid, and effectively increase the gel strength and low shear rate viscosity, thus increasing the wellbore cleaning effect. Meanwhile, it has good filtration property and contamination resistance property. This drilling fluid has been used in 4 wells in the KQT gas field, and good field application results are obtained.
As a new technology for cutting⁃edge automated drilling, Rotary steer drilling technology has become an indispensable technology for complex ultra⁃deep drilling and large⁃displacement wells. To break the foreign monopoly, Shengli drilling institute has developed a stable platform based on the Strapdown algorithm. The servo technology is used to control the action implement of the guidance mechanism, and the optimization and improvement of the uploading and downlink communication system are optimized and improved, so as to realize the independent research and development of the strap⁃down dynamic push⁃to⁃rotate guiding system. At the same time a set of tool well test platform is designed to test its pushing performance and verify the accuracy of the design. On this basis filed test have been done in four wells, and the results show that the system's deflection ability can reach 6.43 ° / 30 m, with good practicability, stability and reliability. This paper mainly discusses the design process and ideas of strap⁃down rotary steering, introduces its main structure and design key points, and describes the uphole test platform and downhole experiments. The content of this paper summarizes the development of strap⁃down rotary guiding technology, and plays a positive guiding role for the further optimization and improvement of rotary guiding system technology.
