Numerical simulation on friction pressure loss in helical coiled tubing

Key words:  secondary flow  coiled tubing  friction pressure loss  Dean number  numerical simulation

Abstract:

According to hydrodynamic theory, based on continuity equation and N-S equation, the numerical simulation for Newtonian fluid flow in helical coiled tubing(CT) was carried out to reveal the flow characteristics and friction pressure loss law of the helical section. A set of regression correlations predicting friction factor of Newtonian fluid were proposed taking Dean number and the curvature as arguments and considering the effect of curvature and geometry of the pipe on the friction factor. And the proposed correiations were compared with other selected friction factor correlations. The results show that the friction pressure loss of the helical section is larger than the general friction pressure loss of the straight section due to the secondary flow, which can not be ignored. The prediction results of the proposed correlation for friction factor in the helical section agree well with the results of selected correlations with good applicability in laminar and turbulent flow area. And the feasibility of studying helical section with numerical simulation method was provided. The proposed friction factor prediction correlation for helical section can provide method and theoretical support for the CT follow-up hydrodynamic research.