子洲气田西干线积液量计算及药剂排液工艺技术

Calculation of pipeline effusion quantity and foam discharging technologies in the West Trunk LineⅠof the Zizhou Gas Field,Ordos Basin

中国石油长庆油田子洲气田公司西干线积液导致管输效率低、能耗高、管网节点压力高,目前采取的频繁清管措施,不但影响正常供气,还存在着卡球、憋压等风险,给安全生产带来了极大的隐患。为此,根据实际管线路由以及气液两相流理论,建立了适用于该气田支干线的积液量计算数学模型,利用实际生产数据、清管参数进行模型的拟合和修正,得到西干线积液量与集气量、集气压差的实用关系式。同时根据该气田管线积液高含醇(体积分数为35%)、高含凝析油(体积分数为42%)的特点,研制开发了高抗醇、高抗油管道泡排剂UT-14,并进行了药剂排液试验。结果表明:试验前后管道进出口压差最多降低0.22MPa,排液效率超过33%,证实西干线积液实用公式的正确性和药剂排液在复杂地表下集气管线的适用性,可作为目前清管工艺的替代工艺,以确保集气管线的连续、安全生产。该成果对提高起伏管线集输效率、降低集输能耗和清管风险具有重要意义。

In the West Trunk Line I （Trunk Line Xi-1） of the Zizhou Gas Field, Ordos Basin, pipeline effusion resulted in low efficiency of operation, high power consumption, and high pressure on each joint of this line. The present frequently-adopted pigging measures not only influenced the normal gas supply but posed a great potential risk in safe operation of pipelines because of the resulted unpiggable obstacles. In view of this, we built a mathematical model for calculating the pipeline effusion of Trunk Line Xi-1 as well as branch lines. Then, we applied the practical operation data and pigging parameters to fit and modify this model, thus to obtain the practical formula of pipeline effusion volume, gas collection quantity, and pressure drop. Simultaneously, according to the feature of high alcohol content （volume fraction of 35%） and high condensate oil （volume fraction of 42%） in the pipeline effusion of Trunk Line Xi-1, we researched and developed a foam discharging agent UT-14 and conducted the relevant experiments. The experiment results showed that the pressure drop between the inlet and outlet of pipes was reduced by 0.22 MPa and the fluid discharging efficiency was over 33% after this foam discharging agent was employed to Trunk Line Xi-1. In conclusion, the proposed formula is feasible and practical to calculate the pipeline effusion and the applicability of the developed foam discharging agent in Trunk Line Xi- 1 under the complicated ground surface area. This study can avoid the frequent pigging operation in pipeline maintenance, ensure the continuous and safe operation of gather lines, and provide important reference for pipeline engineers or operators to improve the efficiency of ups and downs of pipelines, reduce the energy consumption, and mitigate the pigging risk.