煤层气井液面监测对回声仪提出的新要求

New Requirements to Echometers for Monitoring Liquid level of CBM Wells

煤层气井的排采,是根据预先制定的降压速率,适时调整排采设备的工作制度,从而控制煤层的产水、产气量,达到平稳、连续降压。通常用回声仪来监测环空液面变化,通过控制液面下降速度来实现稳定降压。目前,常用的液面监测方法多来自油气井液面测定,应用于煤层气井存在很多的问题。煤层气排采的特殊性对回声仪提出了新的要求,要求其具有浅液面、高精度、抗干扰的测定性能,还要具有安全高效的发声源和直观的液面资料管理系统。

CBM extraction is carried out according to pre-determined decompression rate and timely adjustment of extracting equipments employed in the working system. In such way, the stable and continuous decompression can be achieved by controlling the volume of water ＆ gas production in coal seams. Changes of liquid level are usually monitored with echometers and stable decompression is achieved by controlling the reducing rate of the liquid level. Currently, since the frequently-used methods to monitor liquid level are originated from measuring liquid level of oil/gas wells, many problems have been brought about when applying to CBM wells. Due to special features of CBM extraction, echometers are required not only with new measuring performances in terms of shallow liquid level, high precision and anti-interference respectively, but also with safe and efficient acoustic sources and direct-view management system for data of liquid level.