可用油田污水配液的MTS和TS系列驱油用聚合物

MTS and TS Series Polymers for Preparing Flooding Solutions in Oilfield Produced Waters

以大庆北四联采油污水为例,指出造成污水配制的驱油聚合物溶液粘度低下的主要因素为污水中金属离子特别是高价金属离子Fe3+、Ca2+、Mg2+和各种还原性化学、生物物质。介绍了所研制的可用油田污水配液的两个系列驱油聚合物:丙烯酰胺与支型含—SO3H基单体的二元共聚物MTS,分子量1.8×107左右;丙烯酰胺、支型含—SO3H基单体及少量疏水性单体的三元共聚物TS,分子量8.0×106左右。两个系列聚合物的组成可作适当调节以满足不同油田的需要。粘度曲线表明:用大庆采油二厂污水配制的1000mg/LMTS 45和TS 45溶液的粘度达到或超过大庆油田的要求(>50mPa·s,45℃,7.34s-1);用胜利孤东采油厂污水配制的1500mg/LMTS 85和TS 85溶液的粘度高于胜利油田的要求(>12mPa·s,85℃,36.7s-1);M=2.8×107的HPAM的相应溶液的粘度均达不到油田要求。用大庆采油九厂污水配制的1000mg/LMTS 45、TS 45和HPAM(M=2.8×107)溶液粘度(45℃,7.34s-1)分别为76.0、56.6和42.3mPa·s,高速剪切1min后粘度保留率分别为83.4%、58.0%和52.7%,在45℃隔氧密闭老化90d后保留的粘度分别为>70、45.7和25.7mPa·s。图3表3参3。

Taking oilfield produced water (OFPW) from the 4th northern oil gathering/water treating plant in Daqing as example, the main factors for much lowered viscosity of polymer solutions in OFPW are considered to be metal ions and Fe3+, Ca2+, and Mg2+, in particular, and various chemical and biological reducing substances. Two series polymers are recommended for preparing flooding solutions in OFPWs: MTS copolymers of acrylamide and -SO3H containing branched monomer (BM) with M=～1.5×107; TS tercopolymers of AM, BM, and a small amount of hydrophobic monomer with M=～8.0×106. The two series polymers are synthesized with properly varying composition to fit various reservoirs. The viscosities of 1 000 mg/L solutions of MTS45 and TS45 in OFPW of the 2nd Daqing oil production factory meet the requirement specified in Daqing Regulation (>50 mPa·s at 45℃ and 7.34 s-1) the viscosities of 1 500 mg/L solutions of MTS85 and TS85 in OFPW of the Gudong oil production factory in Shengli meet the requirement specified in Shengli Regulation (>12 mPa·s at 85℃ and 36.7 s-1); in both cases an HPAM of M=2.8×107 is not useful. The 1 000 mg/L solutions of TS45, MTS45, and the HPAM in OFPW of the 9th Daqing oil production factory have initial viscosities (45℃ and 7.34 s-1) 76.0,56.6, and 25.7 mPa·s, retain 83.4%,58.0%, and 52.7% of initial values after violently shearing for 1 min and maintain viscosities >70.0,45.7, and 25.7 mPa·s after ageing at 45℃ in 90 days under O2 free and hermitic conditions, respectively.