耐温抗盐水平井封堵体系研究与应用

Study on Preparation and Application of Heat Resistance and Salt Tolerance Plugging System for Horizontal Well

针对中原油田高温、高盐和水平井中80%是筛管完井的特点,研发了以渗透率调节剂RPM(阳离子三元聚合物)为主剂的耐温抗盐水平井封堵体系(5000 mg/L渗透率调节剂RPM+6000 mg/L交联剂PFR+300 mg/L稳定剂JN),考察了该体系的耐温、耐盐、热稳定性及封堵性能。结果表明,该体系耐温可达90℃,耐盐可达25×104mg/L(其中Ca^(2+)、Mg^(2+)浓度5000 mg/L),凝胶强度在5×104m Pa·s以上,长期热稳定性可达90 d以上。该体系具有较好的选择性堵水性能,封堵填砂管后水相渗透率降低89%,而油相渗透率仅降低17%,可直接用于水平井堵水,尤其可以解决管外无法封隔的割缝筛管和裸眼方式完井的水平井堵水问题。

According to the characteristic of high temperature and high salinity and 80% of the horizontal wells completed with screen pipes in Zhongyuan oilfield, a heat resistance and salt tolerance system, composed of 5000 mg/L permeability regulator agent cationic ternary polymer RPM, 6000 mg/L cross-linking agent PFR and 300 mg/L stabilizer JN, was developed, and the heat-resistance, salt-tolerance, thermo-stability and plugging property of the system were evaluated. The result showed that the heat resistance of the system was up to 90℃, the salt tolerance of the system was of 25×10^4 mg/L （among which, Ca^2 ＋ and Mg^2＋ concentration was of 5000mg/L）, the gel strength was above 5×10^4 mPa. s and the thermo-stability was more than 90 days. The system had good selectivity and the water plugging efficiency reached up to 89% while the oil plugging rate was only 17%. The system could plug water in horizontal wells without oil well operation, especially suitable for water plugging in horizontal wells completed with slotted screen without packers and in open hole mode.