P.E. Clark & Homer Skelton, Dowell Division of Dow Chemical
Low-temperature (50F to 100F) wells present a special problem for the application of fracturing technology using current highly viscous water-gels. As the gelling-agent concentration increases, the gel/s require more time to effect a complete breakdown of the gel. This tends to slow turn-around time after treatment and, in some cases, inhibits complete clean-up. Techniques have been developed to circumvent this problem, but they involve lowering the gelling-agent concentration. This has also resulted in lowering the proppant concentration and increasing the pump rate. Several studies have shown the importance of high total prop volumes in good stimulation treatments and the importance of controlling pump rate for good frac height control. Thus, stimulation treatment performance has not been as good as it might have been in higher gelling-agent concentrations; higher propping agent concentrations and lower pump rates could have been used. A new low-temperature breaker for water based gels has been developed that allows the controlled breaking of gelled fluids over a temperature range of 50_F to 100_F. Field results are available to show that this breaker is effective in low temperature wells. A summary of this data will be presented.