In recent years, horizontal well fracturing water injection huff and puff technology has become the main development technology of tight oil.In the initial stage of water injection huff and puff, higher production was achieved,however,with the increase of huff and puff times,the production decreased rapidly and the oil⁃water replacement efficiency was low.Based on the compact oil data of Jimusaer Oilfield in Xinjiang,through laboratory core water injection huff and puff experiment and single well water injection huff and puff numerical simulation research,the effects of injection volume,time of water injection huff and puff,injection speed, huff and puff times,soaking time and production speed on water injection huff and puff recovery are analyzed.The single well geological model is established,and the influencing factors of water injection huff and puff are fitted by multi⁃nonlinear function.The empirical formulas of five parameters and three parameters of water injection huff and puff are deduced for the first time. The prediction error is within 8%, which provides important reference for the development of water injection huff and puff in the study area and similar tight reservoirs.

The permeability and absorption experiments of low permeability sandstone core under the actual formation temperature and pressure were carried out,which were used to analyze the waterflooding huff⁃puff 's oil recovery law of imbibition and compared with imbibition experiments of normal temperature⁃pressure.The experiments show that the imbibition efficiency of normal temperature⁃pressure is 18%~24%,with an average of 21%.The permeability rate of core in the first six hours is the fastest,which is 0.8~1.7 %/h.The imbibition efficiency of actual reservior's temperature and pressure conditions is 24%~31%,with an average of 27%;Imbibition rate is the fastest in the first round,which is 2.6~3.6 %/h.Compared with imbibition of normal temperature⁃pressure,the imbibition of actual reservior 's temperature and pressure conditions can promote the imbibition efficiency by 5% to 7%,and the imbibition rate is also significantly higher than the imbibition of normal temperature⁃pressure.The analysis believes that imbibition of actual reservior 's temperature and pressure conditions can increase the imbibition's power and reduce the imbibition's resistance,which is more conducive to oil⁃water displacement.Furthermore,the theoretical calculation model of the imbibition depth is established, and the cores' imbibition depth is about 0.25~0.63 cm.It is considered that the depth of the early rapid imbibition stage is in the centimeter range,and the imbibition depth increases with the imbibition efficiency.According to the comprehensive research,increasing the reservior's pressure and large⁃area fracturing can effectively improve the imbibition efficiency.

The enhanced oil recovery technology of ASG (alkali, surfactant and nitrogen) composite foam and water alternating injection was studied in high temperature and high salinity low permeability reservoir. The ASG foam and water alternating injection experiments were carried out through indoor flooding experiments, and compared with water flooding nitrogen flooding and surfactant flooding. The results show that the enhanced oil recovery of the method adopted by this study is 16.61%, 10.26% and 9.21%, respectively, compared with water flooding, nitrogen flooding and surfactant flooding technology. Experimental study on injection parameters optimization of ASG foam and water alternating injection is carried out, and the parameters such as slug size, injection rate and gas fluid ratio of ASG composite foam are optimized by bench scale displacement test. The results show that under the condition of the same foam injection volume (1.2 times the pore volume), the effect of foam slug injection with 0.4 times pore volume is best. The foam injection rate has an optimum value of 1.5 mL/min. When the injection rate is too low, less foam is produced, gasliquid separation is easy to occur, and the blocking effect is poor. When the injection rate is too high, the size of the bubble is different, and it is easy to cause the bubble to merge, causing the bubble to burst, and at the same time, it is easy to cause the shear defoaming of the foam. When the gas fluid ratio is 3∶1, 2∶1 and 1.5∶1, respectively, the recovery rate is 2.04% higher than that of the single gas fluid ratio.

In this paper, the hydrotalcite with positive charge was obtained by stripping the nitrate hydrotalcite, then a layer of Cl ^- was adsorbed to form electric double layer nanomaterials. The samples were characterized by XRD, HRTEM and FT-IR and used in anticorrosion coatings. The corrosion resistance of the coating was studied by SEM, polarization curve and nyquist curves technology. The results show that this kind of electric double layer nanomaterials can greatly improve the corrosion resistance of the layer, and the corrosion potential can be increased from -0.9 V to -0.5V, which has a good application prospect.

In order to study the problem on cathodic protection interference in deep well casing, in this paper, we use the boundary element method to establish the mathematical model of the pipeline cathodic protection interference. Then the BEASY software is adopt to study the influence of the soil conductivity, coating damage rate, anode output current, the distance between anode location and the casing, and the distance between two well casing on the law of the interference corrosion respectively. Simulation results show that with the increase of soil conductivity, the potential of whole pipeline is reduced, the distribution is uniform, and the degree of interference decreases. Smaller coating defects often make interference more concentrated, while with increase of anode output current, the pipeline interference corrosion intensifies. With the increase of anode distance and the distance between the two casing, the interference degree of casing corrosion reduces, and the interference style changes from anodic interference to cathodic interference. Finally, in view of the interference problems of deep well casing, we connect the two casing electrically, which can effectively avoid the interference corrosion between the casings.

Distribution of sand body in CⅢ Formation Tazhong 40 well block is complicated and reservoir heterogeneity is strong. Taking deterministic modeling and stochastic modeling method into consideration, the structural model, sedimentary microfacies model and attribute model controlled by microfacies of CⅢ Formation Tazhong 40 well block were established by Petrel software in which the sedimentary microfacies model was established under four restrained mechanisms, then the recalculation of the geological reserves was also completed on the basis of the models. Research shows that the microfacies which can store the oil was dominated by highenergy foreshore sandsheet, the porosity and permeability of the third layer were better than that of the first and second layer in research area obviously. What's more, the value of geological reserves calculated by threedimensional geological model was objective and reasonable, which layed the foundation for further development and adjustment of CⅢ Formation Tazhong 40 well block. In general, it owned reference significance for the application of faciescontrolled modeling insimilar area.

Formation of the heavy oil emulsion of thermal recovery was simulated by the PVT equipment. Viscosities and microscopic properties of crude oil emulsion made by Bohai dehydrated crude oil and simulating water were investigated with a rheometer RS600 and Olympus microscope BX41. Meanwhile, the effects of simulated conditions on the stability of emulsion were also studied in this thesis. The results indicate that viscosities of crude oil emulsions and densities of water particles increase with higher temperature, higher stirring velocity and more antiswelling agents. However, smaller water particle size and lower viscosity of crude oil emulsions are obtained mainly because of the effect of multiple thermal fluid. The results show that the stability of W/O crude oil emulsion are increased with the increasing of temperature and stirring velocity, effecting of multiple thermal fluidand natural emulsifier in crude oil. 