Different types of micro-pore structure and variation characteristics after long-term washing have a greater impact on micro-remaining-oil migration direction, distribution and content. This article applied Confocal Laser Scanning Technology to study reservoir fluid property and remaining oil micro distribution after strong alkali ASP flooding. Comparing the Laser Confocal analysis pictures of natural core after water drive and ASP flooding, coming to the conclusions that strong alkali ASP flooding sweep out larger amounts of heavy oil than water drive. Counting the ratio of different types micro-remaining-oil, and analysing on the displacement effects and mechanism of different types remaining oil after strong alkali ASP flooding.

Two kinds of electroconvection patterns in an ether-bridged bent-core nematic liquid crystal material (BCN), which appear in different frequency ranges, are examined and compared. One is a longitudinal pattern with the stripes parallel to the orientation of the BCN and with a periodicity of approximately the cell thickness, occurring in the high-frequency range of several hundreds Hz; the other one is oblique stripes, which results in a zigzag pattern, and appears in the low-frequency range of several tens Hz. In addition, within an intermediate-frequency range, transformations from oblique to longitudinal and then to normal stripes occur at increased ac voltages. In particular, we investigated the temperature behavior of longitudinal and oblique stripes: When the temperature T increases and approaches the clearing temperature Tc, the contrast of the domains is enhanced and the frequency range of existence becomes wider, while the onset voltages increase only moderately instead of diverging, thus suggesting an isotropic mechanism of pattern formation.

Study on Formation Type II is so few that affect on tapping the potential [2]. Analyzing petrophysics of Formation Type I and II by mercury injection curve normalization, it’s vital to developing method choice on tapping the potential of Formation Type II. Capillary pressure curves (Pc-curves) from conventional Mercury Injection are hard to analyze and compare because of various shapes. To get typical capillary pressure curves for Formation Type I and II, the curves from Mercury Injection is processed by Function J, and the J function curves and normalized Pc-curves for tabulated thin layers, tabulated thick layers and un-tabulated layers in Formation Type I and II, compare and analyze the influence of permeability on the shape of J function curves and normalized Pc-curves; compare the influence of different kinds of layers with the same permeability order of magnitude on the shape of J function curves and normalized Pc-curves, i.e. the influence of other factors except permeability, to get some visual identification methods and analyze the petrophysics difference between Formation Type I and II which is shown on Pc-curves.

Aiming at the production wells’ problem of stuck pump, blocking, pipeline corrosion and scaling in ASP flooding test area in Daqing oilfield Xingbei block, based on the actual situation the study system was defined, on the basis of laboratory experiment to simulate silica scale forming, and the forming process was observed, the silicon scale-forming regular after the formation of alkali corrosion was studied. The results showed that in the complex condition of ASP flooding system, silica scale forming was affected by variety of factors, the process was that monosilicic acid gets together to poly silicic acid, and then condensation polymerization and dehydration generate gel. In the process of polymerization, the silicic acid can polymerize alone or adhere to another pellet molecule, polymerization and dehydration generate to mixed scale.

Base on the non-Darcy flow problem in low permeability reservoirs, the oil-water two phase radial fluid flow model considering threshold pressure gradient is established, the output and formation pressure distribution formulas are obtained，the production variation rule and the influence threshold pressure gradient on formation pressure distribution of different permeability and different well spacing are discussed, the reasonable well spacing of different threshold pressure gradient is calculated. Research shows that, the smaller the permeability, the bigger the corresponding threshold pressure gradient, the faster the production shortfall; in the same permeability, the greater the well spacing, the less the output; the fluid flow requires energy expenditure to overcome threshold pressure gradient, the smaller the permeability, the greater the resistance, the faster the formation pressure descent near wellbore. The reasonable well spacing for effective production is obtained by output formula, which provides the scientific foundation for improving the development effects.