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.

Network fracturing is one of the key technologies to enhance the recovery of peripheral tight reservoir in Daqing. In order to explore and improve fracturing effect and economic benefit of fracture network fracturing, it is necessary to further study the influential factors of initial productivity. Aimed at the problem which the correlation degree between the initial production capacity and the influencing factors calculated by the method of traditional mathematical statistics is almost the same. The improved grey correlation analysis (IGCA) is applied to modifying the original model. To analyze the degree of correlation between initial production and effect factors after fracturing, determining the main influencing factors, and the correctness and practicability of this model was verified by examples. The research results show that，under the conditon that seepage field was not changed,it is necessary to improve the formation pressure and enlarge operation scale,so as to improve the network fracturing vertical well fracture network fracturing in tight oil reservoir. The method presents the reliable basis for fracturing design and result evaluation in tight oil reservoir.

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

In order to solve the technical problem of injected fluid channeling in offshore oilfields,the basic performance evaluation of plugging agent,core hole plugging rate and the large⁃scale dominant channel treatment experiment of "plugging + profile control" oil increase and precipitation effect was carried out in Bohai reservoir. The results show that the blocking rate of blocking agent for large⁃scale dominant channel is higher than 90%,which indicates that it can meet the technical requirements of blocking large⁃scale dominant channel in Bohai reservoir.Combining the large⁃scale dominant channel plugging technology with chemical profile control and flooding technology,the dual effects of macro and micro fluid flow diversion can be obtained,and the effect of oil increase and precipitation is very obvious.Compared with hydrophobically associating polymer solution,although the viscosity of Cr3+ polymer gel is relatively low,the polymer molecular aggregates in Cr3+ polymer gel have "intramolecular" cross⁃linking structure characteristics,and have better compatibility with reservoir pores,which can establish an effective displacement pressure gradient in deep core,resulting in better fluid diversion effect and larger recovery.

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.

 

Water sensitive damage and liquid trap caused by waterbased drilling fluid invasion are very prominent problems in the process of shale gas drilling and exploitation, which seriously affect drilling safety and production of shale gas well. According to the shale gas reservoir characterization and reservoir damage factor, based on nanoemulsion theory and basic reservoir protection principle, a novel nanoemulsion agents named SDME2 were developed by employing Gemini hyamine surfactant GTN, plus Tween 80, namyl alcohol and noctane as major raw materials. The results showed that the novel nanoemulsion agent could effectively reduce the surface tension of external fluid, increase contact angle, decrease water saturation in core, and increase recovery of low permeability reservoir permeability. The novel nanoemulsion agent was also conducive to shale gas desorption. Taking the newly developed shale gas reservoir protection agent as one of primary treatment agents, a new type of waterbased drilling fluid for shale gas reservoir protection was developed and its performance was good.

Xingliudong Block, having been developed for more than 40 years, finished its third infilling in 2007. Aiming at the problems of excessive layers, interlayer heterogeneity and great discrepancy of each layer’s producing extent, the waterflooding experiment of different permeability contrast combinations was carried out. Combining the adjustment research of layer series and well pattern, this reservoir is divided into three layer series which have a permeability contrast less than 6. Three corresponding well patterns are designed, which are significantfor the development of oil layers, especially the poor layers. With the numerical simulation technology, the best scheme is selected. According to the results, scheme 2, raising the oil recovery to 49.18%, is the best solution.

The influence of water swelling of coal rock on reservoir was studied by means of static observation experiments and core dynamic flow experiments. The water sensitive mechanism of coal was revealed, and the control methods of the coal rock water sensitive was proposed. The experiment results show that water sensitivity of coal rock is easily happened, which damages the strata a lot. Core flow of compacted coal powder is studied, which shows that particle migration is caused by clay mineral hydration swellingand causes the drop of permeability. The damage on reservoir is irreversible, while KCl has a good effect on control of coal rock expansion.

Fracture is an common type of failure for engineering structures， the stress intensity factor is an key parameter to control the cracked structures. In present work, a method to estimate the stress intensity factor by using the conservation law was proposed for the specialshaped pipes with periodic cracks under mode II loads such as torque.

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.

Numerical analysis of the stress intensity factor (SIF) induced by indentations was proposed based on the conservation integral. Simulation of the intensification of the stress fields by software of finite element method. The stress intensity factor for such stress fields was calculated. The SIF with different elastic modulus and poisson ratio was compared, focused on the relation between SIF and fracture toughness, and investigated the change law. Use the numerical result to researching damage behavior of material and testing the mechanical properties in engineering.

The research on the risk management based on Web GIS is being considered to improve safety management of oil pipeline.An information management system for oil pipeline based on Web GIS has been established.According to the collected practical pipeline data and ananalytic hierarchy process(AHP),the latent risk of oil pipeline was quantified based on the modified Muhlbauer W K method,the risk grading of oil pipeline was devised and daily maintenance was emphasized.The orientation system of leakage in the oil pipeline was devised based on negative pressure,and the best emergency rescue paths was decided based on improved Dijkstra arithmetic.Finally,it was demonstrated with examples that this system of the risk management and emergency response based on Web GIS is more veracious and easier to apply.

The indentation fracture can be used widely in the areas including rock breakage and test of fracture toughness of materials．When an elastic half － plane substrate is subject to indentations by a rigid，flat － ended punch，a singular stress field and K － dominant region should arise adjacent to the punch edges．When the intensification of such singular stress fields reaches its critical value，fracture will take place on the surface of the contact boundary．The cracking of indentation is a new type of fracture problem．By using the energy release rate of boundary translation the fracture of indentation has been formulized and
critical load and critical cracking angle of the indentation have been found in the present paper．

The safety management was among the most important management work for oil and gas pipelines． As an alternative，the risk grading division based on WebGIS was being considered to improve safety management．An information
management system for oil and gas pipeline based on WebGIS had been established using ArcGIS Server as the developing system of WebGIS，SQL Server as the database to store pipeline data and ArcSDE as the GIS Server．According to the practical pipeline situations，the expert grading method on risk assessment of oil and gas pipeline set by Muhlbauer W K was modified．
An analytic hierarchy process （AHP） was introduced to comprehensively evaluate the expert grading method，and a kind of categorization method for the risk of oil and gas pipelines was proposed．Finally，it was demonstrated with examples that this improved categorization method based on WebGIS is more intuitive and easier to apply．

 

For gas pipeline, simulating the working condition was necessary in order to work safely and economically and manage rationally. Some gas pressure was up to 10 MPa in the pipeline, in which the result by equation for ideal gas has the greater error. L-E-E equation was applied to solve the physical parameters such as the compression factor, practice gas density, specific heat, adiabatic index, entropy, enthalpy and so on. And the program was compiled to calculate the properties. The calculate results show that L-E-E equation is much accurate and can be applied widely in the practice.

Analysis of samples taken from the cracking area of the multilayered urea reactors verified the existence of stress corrosion cracking (SCC) cracks. The influence factors of SCC in multilayered urea reactors were investigated. The results show that the leak detection steam may condense in the interlayer clearances, which would cause alkaline medium concentration at the heavy weld. It was the initiation and propagation of micro-cracks under alkaline environment and local high stress concentrations that lead to the SCC of heavy girth weld urea of the multilayered reactors. The results can give beneficial directions to avoid SCC of layers and catastrophic ruptures of multilayered urea reactors.