METHOD OF RE-FRACTURING USING BORATED GALACTOMANNAN GUM

摘要

A well treatment fluid containing borated galactomannan may be used to isolate a productive zone in a well having multiple productive zones. The fluid is particularly useful in treatment of wells containing a mechanical zonal isolation system in the productive zone of interest. The fluid is pumped into the well in a substantially non-hydrated form. The well treatment fluid is therefore highly effective in preferentially sealing or blocking productive zones in the formation since delayed hydration of the fluid may be controlled for up to several hours. The seal may be degraded and a productive zone subjected to re-fracturing by introducing a viscosity reducing agent into the well.