The high water cut sandstone oilfields in Kazakhstan involve the MMG project, the PK project and the related oilfields of the North Buzzaki project. After long⁃term water flooding, these oilfields have entered a stage of rapid decline, low⁃efficiency and high water cut. Taking the North Buzzaki oilfield as an example, this paper addresses the characteristics of remaining oil distribution by comprehensive analysis of material balance, log interpretation, performance, water channel and numerical simulation in order to improve remaining oil recovery in high water cut sandstone oilfield. The results show that, longitudinal distribution of remaining oil is affected by sedimentation rhythm and heterogeneity, differently enriched in layers and in⁃between layers, and laterally enriched in those sites of weak conformance as a result of sedimentary environment and petrophysical properties. Combined with the characteristics of water flooding and the characteristics of remaining oil enrichment, adjustment measures are formulated to maximize both recovery factor and economic benefits during the contract period.

The energy consumption of oilfield fuel oil heating furnaces is high, and the sulfur dioxide, nitrogen oxides and soot in the flue gas emitted seriously exceed the standard, causing serious environmental pollution. So it is urgent to replace the oilfield heating furnace. The technology principle, energy consumption calculation, equipment characteristics and feasibility of replacing oil field fuel oil heating furnace of air source heat pump and sewage source heat pump are studied, and the benefits of two heat pump technologies replacing oil field fuel oil heating furnace are analyzed. Through research, it is concluded that the air source heat pump and sewage source heat pump technology are effective ways to replace oil in the oil field heating furnace; by using air source heat pump and sewage source heat pump to replace the fuel oil heating furnace, the operating costs can be reduced by 30% and 45% respectively, and the carbon emissions can be reduced by 60% and 75% respectively. By replacing the fuel oil of the heating furnace, not only can you obtain considerable economic benefits, but you can also effectively reduce the emissions of sulfur dioxide, nitrogen oxides, and smoke.

Different from conventional reservoirs, fluid percolation in tight reservoirs does not conform to the classic Darcy's law, but has both dynamic starting pressure gradient and stress sensitive effect. The JBN method don't take these two factors into account when calculating relative permeability, which is bound to cause calculation errors. The seepage mechanism of tight gas reservoir was analyze, then a two phase seepage calculation method was built and verified considering the dynamic threshold pressure gradient and stress effect. The results show that when consider the dynamic threshold pressure gradient and stress effect, the seepage ability of gas and water phase both decrease obviously, and the decrease degree of water is bigger than the gas phase. The isotonic point of relative permeability decreases and the residue water saturation increases in rock sample. With the decline of pore pressure, the effect of dynamic threshold pressure gradient and stress becomes more and more significant. The new relative permeability curves calculated by the new method is more different with the curves calculated by the JBN method. The new method can describe the seepage of fluid in tight formation more accuracy.

For exploring the influence of POE（Poly Olefin Elastomer）on the aging properties of SBS modified asphalt, the index of rheological analysis, fluorescence microscope analysis, as well as the infrared spectroscopy measurement of the SBS modified asphalt, POE/SBS modified asphalt, and its residue after shortterm and longterm aging performance testing were investigate. The results indicated that POE can be compatibilized with the SBS modified asphalt due to its good molecular mobility. In this way, the SBS can be dispersed more homogeneously and be swollen more effectively, through which the aging process is reduced in this compatibility system.

Bolted flange joints were simulated with the finite element software Ansys, getting the gasket stress distribution under the condition of the preload and operation, and calculating the gasket stress under different working condition of internal pressure. Due to constant fluctuations in pipeline pressure and the pipe stress complex, the working pressure, temperature, uncertain factors such as their own constraints on its tightness should be fully considered. The Monte Carlo method is used to have reliability analysis in pipeline working pressure fluctuating. Limit equation is created and according to the distribution of the variable type and limit equation using largescale software Matlab is used to repeat random sampling to calculate the probability of bolt flange leakages under different working pressures. The results show that, the additional load produced by working pressure fluctuation will have a very big effect on the bolt flange leak, that must be got seriously enough attention.

In petrochemical industry, most of the centrifugal pumps work in nondesign conditions. A method of changing the impeller diameter and wrap angle was proposed in order to improve the efficiency of centrifugal pumps. Then impeller flow field was analyzed using Fluent. It was found that the distribution of impeller field speed and pressure was gradually increased and no mutations occurred from the suction port to the outlet.

The rheological behavior of LWZ polymer solution and LWZ gel were separately studied with rheometer of HAAKE RS600. Dielectric withstand voltage test detected the withstand voltage of gel. The results of rheological test show the polymer solution of LWZ was Ostward de Waele fluid and the viscosity is 120 mPa•s at 30 ℃. Viscosity-temperature curve show when the temperature raised, the viscosity of LWZ base fluid decreased. The test of oscillation stress sweep and oscillation frequency sweep and oscillation time sweep show that LWZ gel owned high elastic properties. In addition, the yield value of LWZ gel is 172.4 Pa. Dielectric withstand voltage test indicated LWZ gel could resist pressure of 0.057 5 MP/m in the height of 1 m and diameter of 126 mm N80 pipe under 100 ℃. 

Cyclic voltammetry was used to comprehensively investigate the fundamentals of the electrochemical corrosion reactions occurring at the steel／solution interface in Yingtan soil simulated solution． The interrelation between anode polarization and the cathodic hydrogen evolution was studied by changing the sweep rate， the upper potential limit，ions concentration and gas conditions．The results show that the electronically behaviors of X80 steel are irreversible charge transfer process．There is no stable oxide film formed on the steel surface． The anode polarization and cathodic hydrogen evolution reaction are enhanced by the corrosive ions in the solution ．The hydrogen evolution was catalyzed by the stable deposition film which generated during the anode polarizing．The introduction of oxygen could form a stable oxide film，which weakened the
catalysis to the hydrogen evolution．The stress corrosion cracking sensitivity of the welded metal is increased by CO_２ introduced to the solution．