Chemical precipitation method was applied in for separation and recovery of valuable metals molybdenum, vanadium and aluminum from alkaline V⁃Mo⁃Al solution. By the theoretical calculation and conditional experiments, the effects of precipitating agent dosage, temperature, pH value and deposition time on the precipitation separation of molybdenum and vanadium in alkaline solution were investigated detailedly. The results showed that when CaCl2 was used for vanadium precipitation, the reaction temperature was 80 ℃, the addition of CaCl2 was 1.1 times of the theoretical addition, the time was 1 h, and the pH was 12.9,over 95.3% of vanadium was precipitation recovered. When molybdenum was recovered by Ba(OH)2, under the optimum conditions of temperature 80 ℃, Ba(OH)2 dosage 1.1 times the stoichiometric amount, reaction time 60 min,the precipitation rate of molybdenum was up to 99.6%.

In view of the gradual change zone between the sub phases of shallow water delta，it is difficult to demarcate accurately the boundary position and meet the demand for oilfield development. In order to achieve the purpose of demarcate accurately sedimentary facies，according to sedimentary dynamics theory of shallow water delta， the identification sign of sedimentary facies is established by making use of the data of core analysis and well⁃logging of dense well pattern， and analyzing the plane evolution of facies indicator. Distributary plain is characterized by onshore stream sedimentation，inner front surfaces is characterized by combination of underwater distributary channel and sheet sand，outer front surfaces is characterized by contiguous thin sheet sand.The method of dividing facies belt boundary of "core locating and microfacies locating" has been established， and the reasonable definition of sedimentary facies zones is realized，which has laid a solid foundation for reservoir classification, reserves calculation and development planning .

Based on the previous research, this paper establishes the relationship between the dewatering transformation of the clay minerals and the diagenetic stages and the formation of pore fractures. The influence of temperature, time, pressure, pore fluid properties and thermal evolution of organic matter on the transformation of clay minerals is summarized. By comparing the paleogeotemperature in the transformation of various clay minerals and change of fluid properties, the diagenesis evolution of shale is divided into three stages, and the difference of main diagenetic reaction in each stage leads to the variance of mineral assemblage.The adsorption capacity of methane is closely related to the transformation of clay minerals in shale diagenesis.The experimental results show that the order is smectite>illite/smectite mixedlayer>kaolinite>chlorite>illite. Illitization of smectite and chloritization of smectite are important diagenetic reactions, and the study and establishment of their genetic mechanism model have a certain reference significance for the study of shale reservoir.

 

The damage mechanism of water locking damage, filtrate damage and solid particle invasion damage on low permeability seam cave type reservoir layer was studied. The results showed that the solid particle invasion damage was the main damage mode in low permeability fracture cave type reservoir. Hereby, two kinds of granular temporary plugging agent formula with and without penetrating agent were designed. The results show that, in drilling fluid plugging plug experiment, the permeability plugging rate value was increased by 9% and the permeability recovery value is increased by 9.8% when 1% penetrant was added to the compound temporary plugging agent composed with 0.25%KPA, 4.8% bentonite, 0.87%KCl, 1% fiber plugging agent and 2.7% compound temporary plugging agent. In the anti resolve plugging experiment, the permeability recovery value was also increased, and the maximum reached 12%. It shows that the formula can effectively improve reservoir permeability, avoid the shielding ring blockage, and play the role of protecting reservoir.

The low permeability reservoir characteristics and overall damage mechanism in Daqing were studied, water blocking damage is one of the most important type of injury. By reservoir damage mechanism analysis, Daqing oilfield Longxi area water blocking damage between 10.41%～14.29%. Therefore, this paper mainly through water lock damage mechanism indoor, preferred and evaluation of waterproof lock agent. Optimizing and evaluating antiwater lock agent indoors, antiwater lock agent DW3 greatly reduce the filtrate interfacial tension. Antiwater lock drilling fluid, which was used in field test shows that: Pilot evaluated the permeability recovery value of drilling fluid system reached 88.14%. Formed the special technology of antiwater lock in Daqing oilfield, achieved the purpose of protecting reservoirs.

Through measuring the basic physical properties and model Dv-111+programmable rheometer, the experimental research on rheological properties was done, which analysed the influence of water content ratio, temperature and shear rate. The results show that the rate of water content is a major factor that influences rheological characteristies of water-bearing super-heavy oil. With the change of water content ratio, the apparent viscosity of super heavy oil exhibits a more complex pattern. Oil water ratio greater than 30%, the non Newtonian character is not obvious when the rate of water content was over 30%. Whats more, the temperature and shear rate have an influence on the rheological property when the rate of water content was high. Different conditions have different flow pattern transition point. 

Mo-V-Te-Nb-O catalysts were prepared by aqueous solution. Effects of dryness and calcinations modes in catalyst preparation on the catalyst structure and performance were studied by XRD, BET and continuous fixed-bed microreactor. Compared to the catalyst prepared by dry under ordinary pressure method, the catalyst by rotary evaporation under the decompression was more favorable. The catalyst precursor for even distribution in the active component can be generated easier. The proportion of M1 and M2 phase in the catalyst structure which were conducive to improve the activity and selectivity in catalyst were larger. The catalyst surface area was also increased by 31.5%. The suitable rotating evaporating temperature was 50 ℃; the effects of N ₂ and He in calcinations to the structure and properties of catalysts were the same to prevent air oxidation. The Te content in the catalyst which was pre-calcination 60 min in air at 275 ℃ was increased，and the catalyst surface area was 2.78 m ²/g. The C _3H8 conversion was 47.6% and the acrylic acid selectivity was 50.5% when the reaction temperature was 360 ℃.

 

High voltage pulsed discharge (HVPD) technology was utilized to degrade oilfield wastewater in order to improve its biodegradability. Water samples before and after treated were analyzed by GC-MS to investigate the mechanism of biodegradability improvement. The experimental results show that the BOD5/COD of oilfield wastewater can be improved from 0.066 to 0.33 after 10 minutes by HVPD treatment, the biodegradability of oilfield wastewater was improved effectively. The optimal operational parameters of this experimental are : the pulse voltage peak value is ±26 kV, the air flow rate is 0.50 m3/h and the pulse frequency is 150 Hz.The GC-MS analytic results indicate that the ploynuclear compounds and long chain alkanes and aromatic Hydrocarbons in oilfield wastewater are degraded to low relatively molecular pollutants after HVPD technology treatment.