煤层气井长冲程、大泵径排采设备的研究及应用

Research and Application of Discharge and Mining Equipment with Long Stroke and Big Pump Diameter of Coal-bed Gas Well

煤层气排采的实质是排水降压,为了满足产水量较大、煤层埋深在800m以浅的煤层气井的排采需要,提出一套长冲程、大泵径的排采设备。在阐述煤层气井排采机理的基础上,结合某区块排采现状,提出用3m冲程的六型抽油机配合Φ83mm斜井泵来满足区块部分产水量大的井的排采需要。当冲程、冲次相同时,泵径越大,日产水量越大;在泵径、冲次一定的情况下,长冲程可增加日排水量;在煤层气井日产水量一定时,增大泵径和冲程长度可降低抽油机的冲次,减缓管杆偏磨程度。现场应用的效果表明该类型排采设备运行可靠,可满足日产水量不超过125m^3、煤层埋深在800m以浅煤层气井的排采需要,对某区块大部分排采井具有较强的适应性。

The essence of coal-bed gas discharge and mining is drainage and pressure lowering, in order to meet the needs of big water production and discharge and mining for coal-bed gas wells with 800 m coal bed depth, it puts forward a set of discharge and mining equipment with long stroke and big pump diameter. On the basis of elaborating the discharge and mining mechanism of coal-bed gas well, and taking the present discharge and mining situation of a certain block into consideration, it puts forward that match the Φ83 mm deviated well pump with six type pumping unit in 3m stroke to meet the discharge and mining need for some wells with huge of displacement in the block. When the stroke, stroke times are same, the bigger the pump diameter, the greater the displacement of each day will be. Under the condition that pump diameter, stroke times are fixed, a long stroke will increase the displacement of each day. Under the condition that the displacement of each day for coal-bed gas is fixed, increasing pump diameter and stroke length can reduce the stroke times of pumping unit and slow down the eccentric wear degree of tube rod. The effect of field application show that this type of discharge and mining equipment has a reliable operation situation and it can meet the needs of displacement of each day within 125m-3 and discharge and mining for coal-bed gas wells with 800 m coal bed depth, besides, it has strong adaptability for most discharge and mining wells in this block.