The Finite Element Analysis And Application Of Horizontal Rod String Mechanics

In recent years, the number of horizontal wells increases due to the difficulty of increasing oil recovery and geological conditions. The horizontal well borehole trajectory is a continuous smooth curved space curve, the forces of sucker rod and tubing string are more complex, and the situation of side wear is particularly serious. Most oil fields configures a large number of centralizers to reduce the wear phenomenon between sucker rod and tubing, a large number of rod centralizers make the downstream resistance increases even the rod stuck, increased the development costs. In this paper, combined with the actual situation of oil fields to allow some positions into contact principle, in order to optimize the configuration centralizer of oil production. The concept for the actual oil production is significant. The main contents are as follows:According to the continuous survey data of horizontal well,the borehole trajectory curve is simulated; Considering the centralizer and coupling along the differential pressure force and local head loss, analyzes the horizontal well sucker rod string and tubing string of environmental load, improves the damping coefficient calculation model and the force model of sucker rod string is perfected, and the model of a horizontal well tubing string is established; By analyzing the distribution of the tubing string internal and external pressure, establishs the calculation model of tubing string internal and external pressure;Combined with the spatial beam finite element method and bidirectional spring element method, the sucker rod string as the research object, establishes the sucker rod string and tubing string of single contact finite element simulation model system; With the sucker rod string and tubing string as the research object, the model of the rod string and tubing string and casing string system of double contact finite element analysis is established; Introduced double spring element garment, establishes a sucker rod string, tubing string and casing string spring element simulation model of double contact system, simulates the position and contact pressure of contact between casing string the rod string and tubing string;According to the axial load, bending moment and torque of the sucker rod string are simulated, using the strength theory checking the strength of rod string,optimizes the combination of sucker rod string design; According to the contact pressure and position of the sucker rod and the tubing string, optimizes the configuration of centralizer spacing design;The optimization software for the finite element analysis of horizontal rod string mechanics is programmed by using Visual Basic 6.0. Including the well trajectory simulation; The rod string and tubing string lateral vibration simulation; horizontal well sucker rod string combination optimization and checking; centralizer configuration optimization.