油井两段塞堵水技术

Research on Double slug Water Plugging Technology

本文针对孤岛油田高含水油井堵水问题,开展了交联聚合物+改性干灰砂堵水技术研究。通过对两段塞的堵剂性能以及岩心封堵实验的评价,确定了冻胶及改性干灰砂的配方,同时优化了现场条件下的施工参数及工艺流程。室内实验结果表明:交联聚合物堵剂封堵率达到92.3%以上,且性能稳定;无机交联堵剂制备岩心渗透率高,耐冲刷性能好,酸处理后可进一步提高岩心的渗透率,抗压强度高达3.77 MPa,60℃下的初凝时间约为3 h左右。采用油井两段塞堵水技术将聚合物冻胶和无机交联剂干灰砂堵剂按体积比20:1注入,前后两个段塞有机组合达到油井堵水防砂的目的,现场实施了5口井,单井平均增油1191 t,有效期11个月,效果明显。

Aimed at the high watercut oil wells in Gudao,the double slug water plugging technology,the successive injection of the gelling polymer solution（GPS） and modified dry cement sand slurry（MDCSS）,was proposed.Based on the evaluation of the performance properties of the two slug plugging agent and the results of core plugging experiments,the formulations of the GPS,composed of heat resistant and salts tolerant HPAM（manufactured by Hengju） and organic chromium corsslinker XL-Ⅰ,and MDCSS were obtained,at the same time,the operation parameters and technological process in the field condition were optimized.The results of the laboratory researches showed that the GPS possessed good plugging capacity,the plugging rate reaching 92.3%,and the core prepared from the MDCSS was characteristic of high permeability,high strength and good anti-erosion.The permeability of the core could be enhanced after treated by hydrochloric acid.The compressive strength of the core could reach 3.77 MPa,and the initial gelation time is about 3 h at 60℃.The double slug water plugging technology was applied in 5 oil wells at gudao oil fields and the success rate was 100% by injection of the first slug and the second slug at volume ratio of 20∶1.An increase in oil production of per-well was observed,being of 1191 t within eleven month.Thus the purpose of water shutoff and sand control was achieved.