水驱高含水油井杆管偏磨原因的力学分析

建立了抽油机井杆管偏磨原因力学分析的力学模型。给出了铅垂油井杆管偏磨临界轴向压力的计算公式和抽油杆柱轴向分布力的模拟方法;建立了供液不足油井液击力的计算公式,改进了柱塞下行阻力的计算方法。系统分析了含水与沉没度对杆管偏磨临界轴向压力与柱塞下行阻力的影响。分析结果表明(1)高含水油井在低沉没度下运行会明显加剧抽油杆柱的轴向振动,降低杆管偏磨的临界轴向压力;(2)对于高含水低沉没度运行的油井,若油井供液不足并使柱塞下冲程泵内将产生液击,柱塞下行阻力会明显增加。因此,高含水油井在低沉没度下运行时,抽油杆柱轴向振动的加剧或液击都会严重恶化抽油杆柱的受力或直接导致杆管产生偏磨。

Research on the Mechanical Causes of the Rod String and Tubing Off-center Wear in Rod Pumping Wells in the Water Controlled Field

The paper analyzed the causes of rod string and tubing off - center wear, and carried out mechanical analysis . The mechanical model of the rod string and tubing wear in rod -pumped wells is established. The calculation formula of critical axial load of rod string and tubing wear is set up, and the simulating method of axial distributing load of the rod string is given by the wave equation of the rod string. The computing formula of liquid shock is established when the pump cylinder could not be filled with enough liquid. The computing method of down stroke axial load of the plunger is improved. The influences of water content ratio of the oil wells and sinking depth on rod string and tubing wear are systematically analyzed.