The Montney gas reservoir presents exciting potential and is likely to become a critically important component of future gas supply. However, the Montney often presents variable and unique stimulation challenges. Unlike reservoirs like the US Barnett shale but possibly like the Muskwa in the northeast B.C. Horn River basin, recovery of water-based fluids can be a key issue to achieving economic production rates in the Montney.
Choice of fracturing fluid must be carefully determined for each area of the Montney, balancing economics with production response. One must always keep in mind that key reservoir properties can vary dramatically in the Montney, both as a function of geographic location and depth.
A presentation entitled "Montney Fracturing Fluid Considerations" was given at the 2009 CSUG conference, which summarized results of regained methane permeability vs. drawdown pressure and contact time with Montney core under representative reservoir conditions. Water-, foamed water-, and hydrocarbon-based fracturing-fluid systems were studied. Implications of the results as to choice of optimum fluid were discussed.
This paper presents field-production results of the trials conducted with fluid systems resulting in conjunction with the above study. The concepts and reasoning used to arrive at final fluid choices for field trials are discussed, as well as a theoretical interpretation of the field-production results.