单螺杆泵采油系统杆柱瞬态动力学模型及应用

抽油杆柱运动的数学模型是油井生产系统优化设计、动态特性预测及工况诊断的理论基础.对地面驱动单螺杆泵采油系统进行有限元分析,建立抽油杆瞬态动力学模型,克服以往静力学模型无法动态反映抽油杆柱受力和运动状态的缺点.利用Newmark直接积分方法对动力学模型进行求解,可获得任意位置处抽油杆柱扭矩载荷随时间变化曲线、任意时刻沿井筒侧向位移等.由于模型中运用经典碰撞理论考虑碰撞接触的影响,因此该模型可更加真实地反映抽油杆柱的受力和运动状态,同时为螺杆泵井扶正器设计奠定理论基础.利用该模型编制的软件在二连油田的应用证实了它的准确性和实用性.

Transient dynamic model of the rod string of single-screw pump oil production system rod and its application

The mathematical model of pumping rod movement is the theoretical basis of the optimization design, the dynamic performance prediction and working-condition diagnosis of oil-well production system. Surface-driven single-screw pump oil production system is analyzed using finite element method, and the transient dynamic model of the pumping rod string of it is established. The establishment of the model overcomes the shortcomings of the static model of it that cann' t dynamically reflect the movement and the force-bearing condition of the pumping rod string. The torque curve of the pumping rod string with time at any position and the lateral displacement of the pumping rod string at any moment are obtained by solving the dynamic model with Newmark direct integration method. Because the contact impact between pumping rod string and tubing is considered in this model using classical impact theory, the force-bearing condition and the movement condition of the pumping rod string can be more truly reflected by this model. At the same time, the model establishes theoretical basis for the design of the centralizers of screw pump well. The application of the software compiled with this model in Erlian oilfield proves the veracity and the practicability of the model.