阴-非体系高温泡排剂HDHP的研究及应用——以四川盆地东胜页岩气井为例

Study and application of a high temperature foaming agent in anionic-nonionic system namely HDHP:A case study of shale gas wells in Dongsheng Block,Sichuan Basin

四川盆地东胜区块页岩气井储层垂深大(最大4300 m)、地层温度高(最高140℃)、钙镁离子质量浓度高(最高2.8×10^(-3)kg/L),导致返排液量过低,泡排剂效果不佳。针对此问题,在室内选取脂肪醇聚氧乙烯醚硫酸钠(AES)、含氟己基乙醇聚氧乙烯醚(FT)、改性硅油树脂聚醚(FM)和金属螯合剂(EDTA-2Na)为原料,制得阴-非体系高温泡排剂HDHP。通过正交试验,研究了AES、FT和FM不同配比对发泡、稳泡性能的影响,从而确定HDHP的最佳配比。通过室内实验评价HDHP的泡沫综合性能,表明高温泡排剂HDHP具有良好的抗温性和抗钙镁离子能力。在东胜区块3口井的试验过程中,平均单井产气量提高了30%。研究结果表明,阴-非体系高温泡排剂HDHP适用于东胜区块超深页岩气井泡沫排采工艺,具有良好的应用前景。

The shale gas wells in Dongsheng Block of Sichuan Basin are in deep reservoirs with the maximum depth of 4300 m,with high stratum temperature up to 140℃and of high mass concentration of calcium and magnesium ions up to 2.8×10^(-3)kg/L.All these characteristics result in the low flowback fluid volume and poor effect of foaming agent.In order to solve these problems,the fatty alcohol polyoxyethylene lauryl ether sulfate sodium(AES),fluorohexyl ethanol polyoxyethylene ether(FT),modified silicone oil resin polyether(FM)and metal-chelator(EDTA-2Na)are adopted as the raw materials to prepare a high temperature foaming agent in anionic-nonionic system namely HDHP.According to the orthogonal experimental design,the effects of different ratio of AES,FT and FM on the foaming ability and foaming stability are studied,and the optimum addition are determined.The comprehensive performance of HDHP evaluated in the laboratory shows a good effect of temperature and calcium and magnesium ions resistance.In the test of three wells in Dongsheng Block,the average gas production per well has increased by 30%.The results show that HDHP is suitable for the foam drainage technology of ultra-deep shale gas wells in Dongsheng Block,and has good popularization and application value.