中原高温高盐油藏疏水缔合聚合物凝胶调剖剂研究

Laboratory Study on Hydrophobically Associating Polymer Gelling Fluid as Profiling Agent for High Temperature and High Salinity Reservoirs in Zhongyuan

针对中原油田高温（〉80℃）、高盐度（〉50g／L）、高硬度（〉1g／L）砂岩油藏．研制了地下成胶的高热稳定性聚合物凝胶调剖剂。所用聚合物为疏水缔合聚合物AP-P4，M^-=9．0×10^6，HD=27％，疏水基摩尔分数0．2％；交联剂为可生成酚醛树脂的3种化合物；调剖剂胶液用矿化度160g／L的马寨油田污水配制；实验温度95℃。根据形成的凝胶黏度（95℃，1.1s^-1）确定交联剂各组分用量为：MZ-YL0．429％，MZ-BE0．060％，MZ-XS0.012％；酸度调整剂用量0.12％：成胶时间10～15小时。2．5、3．0、3．5g／LAP—P4的凝胶在95℃老化100天后黏度保持在～40Pa·s及以上。初配制胶液在3000r／min下剪切15分钟后黏度降低87．5％～89．0％，但成胶后和老化过程中凝胶黏度只比未剪切样降低17.1％～6．6％。3．5g／L AP-P4的调剖剂对～1μm^2的6支储层岩心的堵塞率在88．1％-95．8％范围，平均93．3％，造成的残余阻力系数在15．2～28．6范围，平均19．8，使渗透率级差2．3～8．0的4组双人造岩心的注水流量比发生不同程度的反转。认为该凝胶调剖剂高温下稳定性好的原因，是强化学交联密度低．因而凝胶脱水收缩作用弱。图2表5参5。

A high heat resistant in-situ gelling polymer based profiling agent is prepared for use in high temperature （〉80℃）, high salinity （ TSD 〉 50 g/L）, and high hardness （Ca^2＋ ＋ Mg^2＋ concentration〉 1 g/L） sandstone reservoirs in Zhongyuan. The polymer usedis a water soluble hydrophobically associating polymer, AP-P4, with M^- = 9.0×10^6, HD = 27%, and hydrophobe molar fraction 0.2 %. The crosslinker used is 3 monomeric eompounds capable of forming phenolic resin. The gelling fluid is prepared in oilfield produced water of Mazhai with TSD = 160 g/L. The experiments are eonducted at 95℃. According to gel viscusity determinations at 95℃ and 1.1 s^- l, the dosage of crosslinker eomponents is ascertained. 0.429% MZ-YL, 0.060% MZ-BE, and 0.012% MZ-XS; the dosage of pH regulator-0.12% ; gelation time is observed in range 10-15 hrs. The 2.5, 3.0, and 3.5 g/L AP-P4 eontaining gelled fluid keeps viscosity - 40 Pa· s and higher after 100 hrs of ageing at 95℃, For the gelling fluid newly prepared, shearing in 15 min at 3000 r/min leads to a decrease in its viscosity by 87.5-89.0% and for the gel formed from the sheared fluid, however, the viscosity in the eourse of ageing is lower only by 17.1-6.6% in eomparison with that for eontrol samples, With 3.5 g/L AP-P4 gelling fluid injected and gelated, a plugging rate in range 88.1-95.8% and of 93.3% in average and a residual resistance factor in range 15.2-28.6 and of 19.8 in average are observed on 6 reservoir eores of K≈1μm^2 and the water flowing rate ratio through higher and lower permeable artificial eores is reversed on 4 sets of eores of permeability variation coefficient 2.3-8.0. The high stability of this AP-P4/phenolic gelled fluid at higher temepratures is explained in terms of weak syneresis, or shrinkage, owing to low density of strong chemical crosslinking.