Increased demand for natural gas and price incentives have increased exploration and development drilling in North Western Alberta. The new activity has renewed interest in fracturing shallow, low permeability formations. This paperdiscusses the various techniques encountered stimulating the formations in the Keg River area. Also discussed is the possibility of formation sensitivity and the use of laboratory data as an aid to treatment design.
More favorable pricing and increasing demand for natural gas are making it necessary and profitable to reevaluate many gas producing areas that have been considered marginal or noncommercial in the past. One of the primary reasons for non development of many known gas reserves is that they are remotely located and have no outlet. Undoubtedly. pipe lines will be built to serve most of these areas when demand dictates, but, at present, only exploratory work and limited developmentis underway.
The Keg River area of northern Alberta, Fig.1, is one of the remote areas where recent development has been possible due to existing nearby pipeline facilities. Both the old Peace River and Rainbow pipe lines pass through or near the Keg River area. These lines were built several years ago to serve the Zama Lake and Rainbow Lake fields respectively. Production from these fields has now declined to the point Where both lines now operate well below capacity. The Peace River line will be capable of handling production from Keg River when a gathering system is completed. This available outlet has spurred development at Keg River and there currently are nearly 100 wells completed.
Production in the Keg River area is from the Gething, or Blue Sky-Gething. This is a lower cretaceous sandstone that has proved to be a valuable gas producer throughout Western Canada. Fig 2 represents the theorized surface conditions during the deposition of the Gething. Deposition appears to be from the granite areas southwest of Fort St. John with water flow toward the northeast into the shallow sea area of Northern Alberta.
The nature of the deposition indicates the possible existence of a peninsula separating fields in British Columbia and the fields in Alberta. Fig 3 shows the possible depositional flow under these conditions. The sediments originated in British Columbia and were carried toward the northeast. Coarser particles were deposited before they reached the peninsula while finer and siltier materials were carried around or through the peninsula via flow channels and deposited on the Alberta side.
After deposition, earth movement allowed the west side of the peninsula to relax and sink and the Alberta side either scayed stable or lifted. This is illustrated in Fig. 4, a cross section along axis AB. This has created a more competent trap situation in British Columbia and tended to open the trap in Alberta. It appears that the trap situation in Alberta is either a facies change or some type of permeability pinch out
