When the traditional CFD method is used to solve the Navier⁃Stokes equation of incompressible flow, the pressure equation has an elliptical shape and cannot be solved, and the convergence is poor. Therefore, the traditional CFD method has certain limitations. In order to study the computational efficiency and accuracy of the lattice Boltzmann method compared with the traditional CFD method, taking the thermal diffusion problem of plates with constant temperature boundary as an example, the temperature field between the plates is solved by the finite element volume method, the finite difference method and the lattice Boltzmann method. By comparing the solution results and the number of normalized iteration steps, the feasibility, accuracy and efficiency of the lattice Boltzmann method are clarified. The results show that under the same physical model, the lattice Boltzmann method and the finite difference method are slightly better than the finite element volume method. The lattice Boltzmann method has the fastest solution speed and the least iteration steps, followed by the finite difference method, and the finite element volume method has slowest solution speed.

In order to improve the fluidity of wax⁃containing crude oil and ensure the normal operation of the oil pipeline, this study took paraffin as the only carbon source and selected a strain of hydrocarbon⁃cracking bacteria from the soil polluted by petroleum. After the growth conditions of the bacteria were optimized, the performance of the metabolites of the hydrolytic bacteria was studied, and the effect of the bacteria on the wax removal and viscosity reduction of Daqing crude oil was investigated. From different experimental perspectives, it was proved that the bacteria could emulsify the wax⁃containing crude oil of Daqing, reduce the surface tension of oil and water, and also have a good effect on the wax removal and viscosity reduction. The results show that the wax content of crude oil is reduced by 54%, the wax evolution point is reduced 2 ℃, the related abnormal pointis reduced by 3 ℃, the viscos

Using waxy crude oil and pure water as the working material, several groups of W/O emulsions with different microscopic droplet distributions were prepared. With microscope and focused beam reflectance measurement instrument, the size and distribution of the dispersed droplets in emulsion were observed and measured. Furthermore, the effect of droplet distribution on the rheology and wax precipitation characteristics of emulsion was discussed. The results show that with the increase of water content, the apparent viscosity of W/O emulsion will be higher, the yield stress, gel point and wax appearance temperature will also increase, while the constant stress will show a gradually decreasing trendency. The phase transition point of Daqing waxy crude oil is about 60% water content.

The oil depot stores a large number of flammable and explosive materials. The operation process of the equipment is relatively complex and prone to accidents. Therefore, employees can only get on the job after training. The traditional training system is biased theory, and the training effect is poor. Taking Unity3D as the development platform, this paper develops an interactive virtual oil depot training system. The system adopts C# as the development language of interactive script and SQL Server for data management. It implements the functions of equipment attribute query, equipment interaction operation, and important process flow simulation in the form of first person view roaming. The system has a very real three⁃dimensional effect and interaction function, and strengthens the training effect of the oil depot staff.

The main work of oil depot is flammable and explosive oil and crude oil. The production process of the production system is complex and the result of false operation is serious. The traditional training mode of staff is limited, the risk is great, and the students can not see the operation and related parameters of the intrinsic relationship. So it is difficult to establish the relationship between theory and practice. The construction of digital oil depot training system based on GIS, can effectively compensate for the lack of the traditional model. Using B/S architecture and SQL server as the database platform, developed in the ArcGIS platform, making the traditional training combine with computer technology, 3D visualization of digital oil depot and the visual information management training and assessment of large data will be realized. The practical example shows that the system has strong practicability, intuitive information display, and has good universality, which provides technical support for improvement of operation and management level of oil depot.

Using the VOF model of computational fluid dynamics to simulate oilwater twophase flow in horizontal sudden expansion pipe and contractible pipe, the crude oil in the twophase flow is medium viscous oil and the moisture content is high, ranging from 50% to 80%. The results show that: the different water content flow in oilwater twophase flow in the sudden expansion pipe and sudden contraction pipe belong to oilinwater stream, the pressure fluctuation in diameter mutation changes obviously, but the pressure change trend is affected little when the moisture content changes from 50% to 80%. Flow in the mutant diameter pipes with different water content of oilwater twophase flow pattern obtained can provide certain reference when involving mixed oilwater twophase flow transportation problems in crude oil pipeline.

Aiming at the characteristics of the existence of many heavy oil fields and oilfields with high moisture content in our country, conducting numerical simulation with the use of VOF multiphase flow model on twophase oilwater flows in horizontal Ttube which are common on gathering pipeline network. Under given conditions, the moisture content in medium heavy oil was 80%, the flow rate was 1.5 m/s, the simulation results show that the twophase oilwater flow belongs to the pattern of oilinwater dispersed flow, the water plays the role of the basic phase and oil as the dispersed phase. The pressure in the trunk pipeline before branch reduces at the linear rate of 300 Pa/m, the pressure increases in the branch section, then decreases linearly with the flow, analyzed the mechanism of pipeline pressure drop in the branch pipeline. The results will play an important role in optimizing network structure, designing reasonable parameters of pipeline, controlling pipeline corrosion and protecting pipelines. 

Through building the pipeline model, giving the boundary conditions and setting up the solver in Fluent software, analyze the character of mixture gas using species transport model. Through the analysis result know that the shape of the mixture gas changes from the shape of straight line to the shape of bullet as the inlet velocity increases. The concentration of nitrogen decreases with line regular pattern in the axis direction, as time goes, the diffusion range is spreading; the nitrogen replacement velocity increases with the increasing of inlet velocity, at the beginning of the replacement, the increasing rate of the mixture length is faster than latter. The replacement length increases as time goes, the faster the replacement velocity the higher increasing ratio of the replacement length, and the replacement efficiency is increasing as the inlet velocity increases, but the ratio is decreasing.