Analysis and optimization of a novel downhole axial flow inlet hydrocyclone

Application of the conventional downhole hydrocyclone is restricted in downhole oil-water separation and co-well injection-production in China’s onshore oilfields, which is due to its large radial size, which affects the separation efficiency. To resolve this problem, two novel downhole axial flow inlet hydrocyclones were developed to reduce the radial size and improve the separation performance. The structural characteristics and separation mechanism of the novel axial-flow cyclone was defined. Then, the oil phase distribution in the hydrocyclones of different structures was obtained through numerical simulation, and the effect of circulating flow on the separation performance of the hydrocyclone was shown in the oil phase volume distribution cloud picture. Research on variation of the velocity vector was carried out to understand the function of the axial flow inlet structure and the fluid distribution. The pressure drop curve was used to clarify the relationship between energy consumption and pressure loss. The results show that the in tangential velocity difference on the guide vane axial hydrocyclone is 1.2 m/s, the axial velocity difference is 1.5 m/s and the overflow pressure is only 0.02 MPa, which indicates the high separation efficiency and the low energy consumption. This helps provide support for economic development of blocks with extra-high water-cut.