一种适合低渗油田压裂的破胶降解剂研究及现场应用

Research and Field Application of A Gel-breaking Gradation Agent Suitable for Fracturing in Low Permeability Oilfields

运用支撑剂导流能力试验装置测试了在相同支撑剂类型、铺置浓度、相同压力下聚合降解剂加量、温度和时间等因素对破胶降解剂残渣降解以及对支撑带导流能力影响。结果表明,压裂破胶降解剂残渣对支撑剂导流能力的伤害很大,残渣含量为120mg/L的破胶降解剂较残渣含量为450mg/L的破胶降解剂对支撑剂造成的伤害增降低近40%;在残渣含量为450mg/L破胶降解剂中加入30mg/L生物酶与未加相比,对支撑剂导流能力伤害下降了50%以上,并且随着聚合降解剂加量增加,降残渣效果越好;40℃与20℃相比较,破胶降解剂对破胶液支撑剂导流能力伤害降低了40%以上;pH值对破胶降解剂降解残渣效果影响不大;当降解时间大于4h以后,破胶降解剂对降解破胶液残渣效果影响不大。现场施工11井次,与相邻井比较,单井产油效率提高20%以上,增产效果十分明显。

Proppant conductivity experimental device is used to test the proppant fracturing in the same proppant type,its operation concentration and under the same pressure;also the effects of polymer degradation dosage,temperature and time on the degradation residue and flow conductivity of proppant are investigated.The results showed that the degradation residue induces great damage on the flow conductivity of proppant,the damage induced by the breaking and degradation agent with residue content of 120mg/L is nearly 40%lower than the one with 450mg/L.When 30mg/L breaking degradation agent is added into the agent with residue content of 450mg/L,the result is contrasted with that one without adding,its damage to the flow conductivity of proppant is 35% reduction,with the increase of the dosage of degradation agent,the effect of residue degrading is better,the effect at 40℃ is compared with that at 20℃,the damage of proppant is over40% reduction,Ph has little effect on the residue reduction.When reduction time is over 4h,the breaking degradation agent has less influence on the residue reduction.The agent is used in ll wells for field operation,the result is contrasted with adjacent wells,20% of single well production is improved.