Shale hydration and dispersion lead to instability of the borehole wall, which has always been a problem in oil and gas drilling engineering. Physically plugging pores and micro?cracks in shale through nano plugging agents is the best way to improve the stability of shale formations. In this work, the silane coupling agent KH560 was used to modify the high?concentration silica sol. The principle of soap?free emulsion polymerization was used in combination with solvothermal synthesis to graft acrylic acid (AA) and styrene (St) monomers on the surface of modified SiO₂ particles. Thus, a new type of elastic pressure?bearing plugging agent with polymer?encapsulated nanoparticles was successfully developed. Taking medium pressure filter loss as the evaluation index, the best synthesis conditions were obtained: The reaction temperature was 60 ℃, the reaction time was 3.0 h, the monomer ratio was 3∶2, the pre?emulsification time was 10.0 min, the total monomer mass was 6.67%, and the amount of initiator was 0.40%. In addition, Zeta potential, particle size analyzer and transmission electron microscope proved that the median particle size of the prepared STA?1 plugging agent was 45.3 nm. Finally, a core displacement experiment was used to simulate the shale layer to investigate the actual plugging effect of STA?1. The results revealed that 1.00% STA?1 showed good water plugging ability for sand filled pipes with permeability below 2 000 mD, and the plugging rate was higher than 85%.

In recent years, with the continuous development of nanotechnology and oilfield development technology, nanomaterials have been widely used in water shutoff and profile control agents and have achieved varying degrees of development. This article reviews the research progress and latest achievements of nanomaterials in water shutoff and profile control from four aspects: foam, polymer gel, emulsion, and superfine cement slurry, and analyzes the use of nanomaterials in water shutoff and profile control agents. The mechanism of action and its influence on the law. It is found that after adding nanomaterials to the system, it can interact with the water shutoff profile control agent by its physical and chemical properties such as small size and large surface area so that the stability, strength, and strength of the water shutoff agent can be improved. The temperature and salt resistance is significantly improved, thereby effectively improving the water shutoff rate and oilfield recovery rate. In addition, from the perspective of water shutoff agent research and development, various problems in current research in this area are pointed out, to provide a reference for the research and application of nanomaterials in water shutoff profile control agents.

As the Daqing crude oil's higher viscosity impacts the quantity of mixed oil, during the process of crude oil batch transportation between the Daqing and Russia, the control equation of mixed oil was established based on the sequence mixed oil conveying mechanism. Using the finite volume method computes batch transportation of different flow velocity through CFD software. And the reason that the lower viscosity of the Daqing oil, the lower quantity of mixed oil under different flow patterns was analyzed. And the feasible suggestion was that was adding adequate amount of viscosity breaker chemical or moderate diesel oil into the Daqing crude oil nearby the interface in order to decrease the quality of mixed oil in the process of transportation.