The calculation models for crude oil viscosityare complex because of the determination of physical data,the limited calculation accuracy and application scope. Consequently, some representative straight chain alkanes were taken as model compounds of crude oil, and their viscosity and sound velocity were measured under different temperatures and pressures in this work. The influences of temperature and pressure on the sound velocity of straight chain alkanes were investigated, and the correlation model between viscosity and sound velocity was built on the base of experimental results. The experimental results indicated that the sound velocity of straight chain alkaneslinearly decreased with the increase of temperature and the decrease of pressure. The relationship between viscosity and sound velocity of alkanes was exponential type, and the viscosity sound velocity correlation model was applied to three different oils in Jidong Oilfield. The calculation results demonstrated a satisfactory applicability of the model. So, a feasible method was provided to reduce the dependence of conventional viscosity models on the physical property parameters.

Considering the geological features of the tight sandstone reservoir of Fuyu oil layer, Northern Songliao Basin, some key techniques of horizontal well design platform were developed based on the geological studies in the pilot development projects. These techniques attached importance to the key controls in geological design of horizontal wells by using such techniques as accurate delineation of the structural features in depth domain, fine characterization of “sweet spot” sandstone distribution, quantitatively fine description of channel sandstone geometry and optimum horizontal well design based on refine 3D geological model, which laid the solid foundation for locating the horizontal wells. The successful results were attained in horizontal well drilling in the primary stage of pilot project. The availability of the reservoir of tight channel sandstone within Fuyu oil layer was raised, the production of individual well and single well controlled reserves were greatly enhanced combining with volumetric fracturing stimulation, and support for economically tapping the tight oil in Daqing oilfield was securing.

Water channeling is a serious problem during the water flooding of naturally fractured low permeability reservoir. To solve the problem, nitrogen foam profile control and displacement technology were researched applying both experimental and simulation methods. The sealing capacity and oil displacement capacity of nitrogen foam were the main research objects. The results showed that nitrogen foam could reduce water cut and increase oil recovery significantly. After plugging the interconnected fracture, the swept volume of flooding liquid and oil recovery would be increased obviously. In the experimental research, oil recovery efficiency was increased by more than 10% after injection of nitrogen foam. The injection of nitrogen foam was flexile and convenient when applied in field construction, and the nitrogen foam profile control and displacement technology were suitable for EOR of naturally fractured low permeability reservoirs.

A method which applies step perforation to improve the effect of polymer flooding is presented against the problems of poor producing degree of low permeability, remaining oil in the inner thick oil layer abounds, and uneven vertical producing degree. After water flooding, the thick layers are perforated selectively followed by water flooding potential tapping, and the polymer flooding is performed ultimately. By carrying out laboratory physical oil displacement experiment of three tube parallel cores and applying theoretical formulas, reasonable polymer injection parameters are determined and the impacts of polymer flooding after step perforation on development effectiveness are also studied. The results showed that the better effect of polymer flooding was obtained by using big pre slug, high molecular weight polymer, and echelon descending concentration slug combinations. And projects which had adopted step perforation showed a bigger producing degree on low permeability layers and a better effectiveness on polymer flooding compared to the ones not adopted step perforation. The ultimate recovery was increased by 1.28%.

In order to further explore the mechanism of “increasing oil and decreasing viscosity” of heavy oil emulsification and viscosity reducer, experimental studies on oil displacement of heavy oil emulsification and viscosity reducer and its influencing factors have been carried out. Viscosity reducer was screened and related performance was evaluated.The viscosity and recovery efficiency were used as evaluation indexaccording to the geological characteristics and fluid properties in Bohai reservoir. The results showed that, the mechanism of decreasing viscosity of three kinds of viscosity reducer was forming oil in water emulsion, and the viscosity reduction effect of “viscosity reducer 2” was best among three kinds of viscosity reducer. Oil water emulsion gradually changed from oil in water (O/W) into water in oil(W/O) type and the viscosity was increased when the water content in emulsion decreased, eventually exceeding that of crude oil. Besides, with the heavy oil reservoir hetergeneity increasing, oil displacement of viscosity reducer got better. Oil displacement of viscosity reducer got worse with the increasing of curde oil viscosity, so the recovery amplification can be increased through preprocessing on viscosity reduction before similarty viscosity reducer was used.

Oil bearing sewage containing polymer in GD Oilfield has the properties of high viscosity, high oil content and more suspended particles, and the conventional single flocculating agent has the disadvantages of high dosage, loose coagulation and high cost. Oil removal rate and removal of turbidity were chosen as the evaluation values in this test, and flask experiment was used to evaluate the sewage processing effect of three inorganic flocculants and two organic polymer flocculants. Inorganic flocculant of poly (aluminium ferric chloride) with the concentration of 100 mg/L and organic polymer flocculant of PAM 4 with the concentration of 40 mg/L were respectively selected as the best flocculant. The oil removal rate and removal of turbidity of waste water were 92.3% and 90.7% respectively when poly (aluminium ferric chloride) and PAM 4 were used to dispose oilfield waste water. Some influencing factors such as temperature, pH value and settling time were investigated. The experimental results showed that the oil removal rate and removal of turbidity of oilfield waste water which was disposed by using compound flocculant system were the best when temperature of waste water was 40~60 ℃, pH value of waste water was 6~9 and the settling time was longer．The compound flocculant system has strong prospect in the processing of oil bearing sewage containing polymer.

The wettability and microstructure characteristics can be changed by molecular film technology through injecting molecular film reagent into the reservoir micro pores, and the purpose of reducing injection pressure and improving water injection total is achieved. The adsorption capacity comparison between molecular films to rock surface with water molecular to rock surface was studied, and it was revealed that the molecular film took advantage in competition, then adsorbed in rock surface and formed molecule layer. Based on it, the application conditions and its change rules were explored then the molecular drag reduction mechanism from reducing the boundary layer effect and friction was revealed. At the last the property of the molecules film drag reduction was studied.

Aiming at non standard octagonal gasket used in hydrotreating reactor. Ansys was used to calculate the contact stress on the sealing surface during the hydrostatic pressure test, and the causes of the different contact stress on each sealing surface were analyzed. The results showed that the contact stress down to the trough when the test pressure was the highest, the maximum stress on the inner side of gasket was away from the center of gasket, and the outer situation was in contrast to it. Variation of gasket sealing surface contact stress provides a reference to the analysis and evaluation of other non standard seal structure.

Current card is the main basis of electric submersible pump well fault diagnosis. At present, the diagnosis of electric pumping wells is mainly completed by technical workers. It is difficult to achieve rapid mass diagnosis, and the diagnosis results are greatly influenced by engineer technology level. Therefore the application of BP neural network for fault diagnosis of electric submersible pump is put forward. First of all, different pump current cards are collected, and sample library is established. The eigenvalues of the different pump current card are gathered and trained according to certain principles. After completion of training a weight matrix is got, and the current card characteristic values and weights matrix of similarity is calculated. Through computer programming application, the method can be proved to make electric pump diagnosis accurately and rapidly.

Sand deposit will be formedinside of subsea multiphase pipeline after operating for a period of time, which will lead to diminution of passable area, reduction of inhibitor efficiency, acceleration of corrosion, and even cause the PIG block accidents. In this article, the geometrical model and physical model with field dataare set up building upon the subsea multiphase pipeline from platform A to B in a group of offshore oil and gas fields.Numerical simulations by FLUENT are performed in order to study the sand depositional rule of straight section and bend section according to the variation of parameters such as sand content, particle size, density and flow rate. The research shows that sand depositional amount is positive correlative with and content, particle size, density and negative with flow rate, and the rule of sand depositional maximum position is opposite. The sensitivity of parameters to average sand depositional amount is sand content, flow rate, particle size and density from high to low.

Rapid and efficient desorption of CO2 from produced liquid has become a key issue which is addressed urgently in the gathering and transporting system of CO2 drive oilfield in China. Main theories of gas desorption are introduced and the features of traditional desorption technology, membrane desorption technology and ultrasonic desorption technology are analyzed in this paper.On the basis of which, defects of all kinds of desorption technologies are pointed out, and the direction of the gas desorption research is proposed. In addition, research progress of ultrasonic desorption, based on the self built experimental device of ultrasound promoting the gas desorption from the CO2 drive produced liquid, is introduced. Then, the combination of the new desorption technology and the traditional desorption is suggested to be applied to the CO2 desorption of produced liquid.

The hierarchically mesoporous Hβ zeolite was synthesized by alkali treatment to commercial Hβ zeolite in NaOH solution. The composite carrier was prepared by mixing the hierarchical Hβ zeolite and Al2O3.The hierarchical NiWP/HβAl2O3 catalysts were prepared by incipient wetness impregnation method, and characterized by means of XRD, BET and TEM. The hydrodearomatization of the prepared NiWP/HβAl2O3 catalyst was evaluated in a miniature fixed bed reactor with fluid catalytic cracking diesel as raw material. The results suggested that the prepared NiWP/HβAl2O3 catalyst has an excellent hydrodearomatization activity, and under the condition of the reaction temperature 360 ℃, reaction pressure 8.0 MPa, hydrogen to oil volumetric ratio 800 and liquid hourly space velocity 1.0 h-1, the cetane number was increased from 7.21 of feed to 46.96 of product.

Using Al2O3, HNO3 and other components as binder component, Ni as active component, ZnO as sulfur storage material, the adsorptive desulfurization catalyst was prepared by equal volume impregnation method. The effects of the Al/Si mass ratio, kneading time of the supporter, adding quality percentage of nitric acid and binder component on catalyst’s desulfurization performance and mechanical strength were investigated. The results showed that the catalyst’s desulfurization performancewas improved when the adding quality of nitric acid, pseudo boehmite and kieselguhr was increased. The desulfurization performance was increased and then decreased with increasing of Al/Si mass ratio, increased and then kept stable with increasing of kneading time. The catalyst’s mechanical strength was improved when the Al/Si mass ratio increased, the adding quantity of nitric acid decreased, pseudo boehmite and kieselguhr increased and the kneading time increased.

Gel content has a certain impact on the immanent quality of rubber products and processing performance. Therefore, it is crucial for brominated butyl rubber to control the gel content. Brominated butyl rubber (BIIR) was prepared by solution method and the effect of the brominated process such as bromination temperature, additives, bromination time and bromide agent on the gel content of BIIR was investigated. The results show that the appropriate reaction temperature is conducive to the control of the gel content. Gel content will increase with the increasing of the concentration of time and bromide agent. The additives can lower the gel content.

Pump injected reverse circulation drilling is a new drilling method. It has lots of advantages (such as cleaned hole and high ROP) compared with previous method, which can be used in drilling complex structural well. As we all know, cyclic pressure loss is one of the most important topics in drilling. The laws of cyclic pressure loss in different nozzles or mud parameters are studied experimentally in lab. The paper analyses the major factors affected cyclic pressure loss, according to results of the simulated experiment. It comes to the conclusions that the area of the bit nozzles should be a half of the drilling stem. And the edge of the bit is the best position to place the bit nozzles. At the same time, the cyclic pressure loss can be higher while the density of drilling fluid increases. However, the density doesn’t seem to affect the best arrangement of bit nozzles. Theoretical basis is provided for optimized design of pump injected reverse drilling bit nozzles.

According to the problems of that the serious blockage of polymer injection wells, the high injection pressure and the bad effect of polymer injection in Xingnan oilfield, the polymer and water of a block in Xingnan oilfield was adopted to carry out the laboratory experiments on simulation of polymer flooding and plugging and then the reason of blockage was found out.  The results show that the polymer and mechanical impurities are the main factors to cause the pore blockage, and the lower the permeability, the more serious the blockage. Aiming at the blockage reason, laboratory experiment study on the formula of plug removal agent was carried out. Finally the multiple plug removal agent consists of agent A, B and C was determined. On the basis of optimizing the mass fraction of each agent, the injection volume and the injection order, the broken down rate of formations can reach 102.41%~124.77% with this plugging removal agent formula.

Chang 8 layer in northeastern Zhiluo oilfield of Ordos basin is a structural lithologic reservoir controlled chiefly by lithology with many oil water layers. There are many oil water layers in this region. Aiming at this characteristic, on the basis of the methods of pressure coring, mercury injection and log data interpretation, the data of relative permeability analysis is used to to interpret and revise the original oil saturation in the area. The four methods are used to calculate the original oil saturation in Chang 8 layer of northeastern Zhiluo oilfield and the advantages and disadvantages of each method are analysized. The reasonable original oil saturation in Chang 8 layer of this area is determined, and the accuracy of calculation of reserves is improved. The method of relative permeability analysis data is the best method to calculate the original oil saturation in this area, eventually the original oil saturation value is 45.6%.

The seam crack point of multiple branch seam fracturing is not clear. Based on the theory of porous media of fluid solid coupling mode, Comsol software was used to simulate branch seam fracturing process using finite element simulation. The changing law of stress concentration of seam crack point and shaft crack point was analysized under the condition of different stress difference it was found that with the increase of net pressure on the seam, there was a difference which distinguished between crack priorities. By controlling the net pressure change within joint, the crack priorities was adjusted, the number of multi branch fracture was controlled, and the multi branch seam hydraulic pressure of the complexity of the fracture network was ensured. Calculation analysis of hailaer oil field on the spot was used to adjust the net pressure inside seam. The result of construction was same with simulation, and can be used to guide the construction to improve the success rate of multi branch seam hydraulic fracturing.

Aimming at the problem of shorter validity period during early flooding stage for low permeability fractured reservoirs in Shuanghe oil block from Zhidan oil field, a technical study and application of multistage compounding flooding was carried out. Based on the profile and flooding mechanism of different slugs, the agents were screened and evaluated indoor. Consumption volume, slug combinations, displacement volume and pressure in flooding scheme were optimized. Field test for SH 69 well proved that using the multi slug compound flooding way of polymer protected slug + high cure system + delayed swelling gel system + delayed crosslinking gel system, the climbing pressure was 2.2 MPa, the start up pressure of injection well was increased with 0.72 MPa effectively, and injectivity index was reduced with 1.9 m3/(d·MPa), which had an obvious effect of controlling water and increasing oil for corresponding wells. The valid period for this type of flooding was up to six months or more, which achieved the integration process of control and flooding, realizing the target of adjusting water injection profile and increasing oil recovery.

Generally, water production of natural gas well is important in the gas field development, and parts of production water of high temperature gas wells exist in saturated water vapor form, leading to measurement result deviation. In order to reduce the  water measurement result deviation of high temperature gas well production, it is necessary to calculate the saturation water content of natural gas and correct the deviation from production water measurement. Through the analysis of natural gas water content calculation method principle, and the contrast in the practical application effect of Y13 gas field, the method of semi empirical formula with theoretical derivation is suitable for the actual Y13 gas field. According to this method, the average deviation can be decreased from 60% to less than 6%. 

In the process of polymer flooding in daqing oilfield, there are some problems such as water consumption growing tensions, sewage treatment increasing more differences and the problem of injecting sewage becoming serious. Using the produced sewage instead of water to dilute polymer solution flooding will be widely attached. Aiming at the characteristics of polymer flooding sewage depth by polymer flooding sewage and sewage water quality analysis, polymer flooding sewage by oxygen exposure and sterilization was used to study flow characteristics and oil displacement effect. Results show that, compared with deep treatment sewage, residual resistance coefficient with polymer solution is high after polymer flooding sewage dilution, the ability to reduce water phase permeability is enhanced, and recovery factor is improved. Under the same conditions of permeability, molecular weight, concentration, and depth of sewage displacement effect of polymer solution is not ideal compared to dilute oil, and the value of recovery efficiency  differs by about 1%. The same effect with the polymer flooding deeply produced by sewage dilutes can be achieved if the concentration of polymer solution diluted by the polymer flooding sewage is increased.