摘要
针对GY油田裂缝性低渗低温高矿化度的油藏特征，以三氯化铬、氢氧化钠、乙酸、胡萝卜酸为原料合成交联剂J L-1。以成胶时间和成胶强度为评价指标，通过筛选聚合物(HPAM)相对分子质量以及HPAM、JL-1浓度，得到低温高矿化度油藏弱凝胶调驱体系KY-1，并测定KY-1体系的抗盐性和耐剪切性，对KY-1体系封堵驱油效果进行评价。结果表明，适用于GY油田KY-1弱凝胶调驱体系的最佳配方为：T114油区地层水+3000 mg/L HPAM（M=1400×104）+500 mg/L JL-1。地层水矿化度为40 g/L时，弱凝胶体系在60 h内迅速成胶，成胶黏度达30 Pa·s，耐盐性较好。在剪切速度200 s-1、27℃条件下剪切120 min后，体系成胶黏度为25600 mPa·s，成胶黏度损失率为18.99%，抗剪切性较好。对裂缝性岩心的平均封堵率为88.7%，采收率增幅平均值为12.1%。
Abstract
Aimed at the low temperature and high salinity condition of low permeability fractured reservoir in GY oilfield, the crosslinker JL-1 was synthesized by three chromium chloride, sodium hydroxide, acetic acid and daucic acid. Then with gelling time and gel strength as evaluation indexes, a weak gel profile control system KY-1 in low temperature and high salinity reservoirs was prepared by regulating the relative molecular mass of polymer (HPAM) and the concentration of HPAM and JL-1. The performance of salt tolerance and shear resistance of KY-1 was investigated, and the plugging capacity and oil displacement efficiency of KY-1 was estimated. The results showed that the best formula?of KY-1?weak gel flooding?system which was applied to GY oilfield was: T114 oil?formation water, 3000 mg/L HPAM（M=1400×104） and 500 mg/L J L-1. When the salinity of formation water?was 40 g/L, the weak gel system could gelatinize rapidly in 60 hrs with 30 Pa·s gel strength and good salt tolerance. The system also had good sheering tolerance. The gel strength of system was 25600 mPa·s and the gel viscosity loss rate was 18.99% after 120 min sheering at 200 s-1, 27℃. The stemming ratio of fractured cores in average was 88.7%, and average enhanced oil recovery rate was 12.1%.
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