| 摘要 |
In certain instances high shear rates, such as when a fracturing fluid is pumped downhole, tend to degrade the viscosity of low polymer guars in low salinity environments. In the past in order to improve guar efficacy a delayed cross-linker such as ulexite or colemanite, both boron ores, was added. Recently it is been found that by adding a weak base, the overall viscosity of the guar was enhanced. The fracturing fluid typically includes a base fluid, in this case low salinity water, a gelling agent, a delayed crosslinker, a weak base, and other additives useful for treating a well such as friction reducers, buffering agents, clay control agents, biocides, scale inhibitors, chelating agents, gel-breakers, oxygen scavengers, antifoamers, crosslinkers, wax inhibitors, corrosion inhibitors, de-emulsifiers, foaming agents, or tracers. |
