不同助剂对羟丙基胍胶压裂液低温破胶性能的影响

为解决水基压裂液在陕北油田特低温(15~30℃)条件下的破胶问题,研究了不同助剂对硼交联羟丙基胍胶水基压裂液破胶性的影响.实验发现:在破胶温度一定的情况下,压裂液中的增稠剂加量、体系pH值和不同类型的破胶剂及其加量等对压裂液的破胶均会产生不同程度的影响.在破胶剂中影响最大的是三元复合破胶体系.当破胶温度在15℃时,与单一剂((NH4)2S2O8)比较,二元破胶体系((NH4)2S2O8/加速剂A))将破胶时间缩短了41 h,三元破胶体系((NH4)2S2O8/H2O2/加速剂A)将压裂液的破胶时间缩短了45 h,且单井可节约费用近700元.该体系破胶剂在陕北特低温油田应用了30余井次.

Factors of influencing the gel-breaking of hydroxypropyl gum/borate gelling fracturing fluid for low temperature reservoirs

In order to perform the gel-breaking of the fracturing fluid for shallow and low temperature reservoirs,the influencing factors on the gel-breaking of hydroxypropyl gum/borate gelling fracturing fluid for low temperature reservoirs are experimentally studied.The results show that at certain temperature,the dose of the thickener in the fracturing fluid,the pH value of the system and the type and dose of gel breaker all have the influences on the gel-breaking of the fracturing fluid in different degrees.Among gel breakers,the influence of ternary complex gel breaker is the greatest.At 15 ℃,compared with single gel breaker(NH_4)_2S_2O_8,binary complex gel breaker "(NH_4)_2S_2O_8+accelerator A" makes breaking time shorten 41 h,but ternary complex gel breaker "(NH_4)_2S_2O_8 +H_2O_2+ accelerator A" makes the breaking time shorten 45 h,which can save $700 per well.The ternary complex gel breaker has successfully been applied more 30 well times in Shanbei oilfields.