苏里格气田积液气井产能的快速评价方法

Rapid productivity evaluating method of wellbore liquid loading gas wells in Sulige Gas Field

苏里格气田大部分气井生产过程中会出现井筒积液现象,需要开展大量的产能测试,指导排水采气措施优化工作。为了降低气井产能测试成本,提高气田开发效益,通过开展井筒积液气井套压变化规律分析,明确了气井积液初期和井筒液面到达节流器时套压变化特征,结合节流器下入深度计算出井筒积液的液柱高度,在此基础上提出了一种利用井口生产数据计算井筒积液气井井底流压和气井产能的快速方法。以苏里格气田井筒积液气井产能预测为例,该方法预测产能与实际产能误差为4.2%~9.6%,每口气井可以节省产能测试费用30余万元。该产能评价方法充分考虑了井筒积液对井底流压计算的影响,测试结果不仅可以满足现场精度要求,而且能有效降低产能测试成本。

Wellbore liquid loading will occur for most gas-wells in Sulige Gas Field during their production,so a lot of productivity test needs to be carried out to guide optimization of water-drainage gas-recovery. In order to reduce productivity test cost of such gas wells and improve benefits of gas field development,by analyzing variation law of casing pressure in gas wells with wellbore liquid loading,the variation characteristics of casing pressure in initial stage of gas-well liquid loading and when wellbore liquid level reaches the choke are defined. Wellbore liquid loading height is calculated according to running depth of choke. On this basis,a fast method for calculating bottomhole flow pressure and gas well productivity of wellbore liquid loading gas well is proposed with the help of wellhead production data. Taking productivity prediction of wellbore liquid loading gas well in Sulige Gas Field as an example,the error between predicted productivity and actual productivity is 4.2%~9.6%,and more than 30×10~4 yuan(RMB)of productivity test cost can be saved for each gas well. This productivity evaluation method fully considers the influence of wellbore liquid loading on bottomhole flow pressure calculation. The tested results can not only meet the field precision requirements,but also effectively reduce productivity test cost.