煤层气井有杆泵排采设备悬点静载荷计算方法

Calculating method on static horsehead load of water drainage and gas production equipment about beam pump for CBM wells

有杆泵排采设备悬点载荷是标志其工作能力的重要参数之一。悬点载荷中起主要作用的是静载荷。悬点静载荷是选择和正确使用排采设备的重要依据。在研究我国煤层气井开采实际的基础上,分析了排采设备的悬点载荷,给出计算悬点静载荷大小的方法及其变化规律,最终利用现场实测的数据对算法进行了验证。验证结果表明,悬点静载荷中起主要作用的是杆柱重和液柱重,但管外液柱对柱塞压力的影响不可忽略;上下冲程中静变形量相对较小。该计算方法步骤简单,结果符合实际,能够较好地满足煤层气井现场数据计算的需要。

The horsehead load of water drainage and gas production equipment about beam pump is one of the important parameters which mark its work ability. Static horsehead load plays a major role in horsehead load. Static horsehead load is the important basis of selecting and using correctly the water drainage and gas production equipments. Based on studying actual mining in Chinese CBM wells, the horsehead load of water drainage and gas production equipment was analyzed, the calculating method of horsehead load and its variation were set up, and the algorithm was verified based on the data of field measurement. The verification results show that the weight of rod string and liquid column plays a major role in static horsehead load, but pressure on the piston imposed by liquid column in outside of tubing cannot be neglected. Static deformation in up and down stroke is relatively small. The calculating method has simple steps, its results conform to reality, and it can meet the need of statistical data calculation for CBM wells. This will help to lay a theoretical foundation of studying the horsehead load of water drainage and gas production equipment in CBM wells. Also it has important directive significance and application value for designning calculating and selecting water drainage and gas production equipment in CBM wells.