延迟凝胶硅酸堵水剂DG-01对孤岛油田水平井的适应性研究及应用

Adaptability Research and Field Application of Delayed Gelating Silicate-based Plugging Agent DG-01 for Horizontal Well of Gudao Oilfield

本文研制了一种延迟凝胶的DG-01硅酸堵水剂,凝胶时间达到13.5h以上。针对水平井堵水成功率低、封堵效果差的问题,研究DG-01堵水剂对水平井的堵水效果,考察了油藏条件对DG-01堵水剂性能的影响,结果表明,随温度和矿化度的升高,DG-01堵水剂的凝胶时间缩短,凝胶强度增大,乙二胺四乙酸二钠(EDTA-2Na)可削弱矿化度对凝胶时间的影响。岩心封堵实验表明封堵率大于96%,DG-01堵水剂对高渗透岩心具有更好的封堵效果,200℃高温老化24h导致封堵率小幅度下降。孤岛GD1-17P410水平井使用DG-01堵水剂实施堵水后,出水量下降,产油量大幅升高,封堵有效期达180d以上,累积增油320t。

A delayed gelating silicate-based plugging agent DG-01 with the gelation time more than 13.5 hrs was developed in prophase research.According to the low success rate and poor effect of water shutoff in horizontal wells,the water plugging effect of DG-01 plugging agent was studied and the effect of reservoir conditions on the performance of DG-01 plugging agent was investigated.It was shown that the gelation time of DG-01 plugging agent decreased with increasing of temperature and salinity,while the expression of strength change was opposite,the effect of salinity on the gelation time was weakened by the addition of EDTA-2Na.The result of core plugging experiment shows that the blocking rate was greater than 96%,the plugging performance of DG-01 plugging agent was better in core with higher permeability,the blocking rate was slight decreased because of 200℃/24h thermal aging condition.After the GD1-17P410 horizontal well of Gudao oilfield was blocked by DG-01 plugging agent,the water content of produced fluids was lowered down,and the oil production was raised significantly,the cumulative oil production was 320t in period of plugging validity above 180 days.