Dynamic Analysis of Rotary Drillstring in Horizontal Well Based on the Fluid-Structure Interaction

Abstract

With the development of drilling technology, rotary drillstring not only produces random multi-directional collisions with the inner wall of pipe, also couples with the inner and outer annular fluids. This results in a complex system of nonlinear fluid-structure interaction. In the paper, structure and mode of operation about rotary drillstring are considered, the equations of the structure dynamics, fluid equation of continuity and momentum equation are coupled. The three-dimensional numerical model and computational method is established about the fluidstructure interaction dynamic analysis of rotary drillstring. Take the rotary drillstring and inner and outer fluids as a research object, dynamic analysis of the rotary drillstring is finished, considering the fluid-structure coupled characteristics and compare the air medium, the results show the effect of fluidstructure interaction. It can provide the feasible method for the study of the string in the oil drilling and production engineering and conduct the development of drillstring dynamics in horizontal well drilling engineering.