Peyto’s only Viking well of 2020 was horizontal 2/12-35-55-22W5, spudded in August at the east end of the Wild River Field (figure 1), where the company is known more for its Spirit River and Cardium development. With an IPmax of 2,510 boepd (15.0 mmcf/d gas), 2/12-35 was Peyto’s best well of the year. It had the highest gas rate of any non-Montney or Spirit River well drilled in 2020, and one of the highest Viking gas rates ever recorded. While essentially no liquids from 2/12-35 have been reported in the public domain (98 bbls of condensate to date), it can be assumed that actual liquids yield, as per most area operators, is higher.
At Wild River, the Viking is within the Deep Basin pressure regime and gas-rich. Based on its licence, downhole survey and offset well logs, the 2/12-35 well is targeting the upper portion of a 15m thick coarsening-upward unit within the Viking Formation (figure 2). This unit, with log porosity (sandstone matrix) ranging from 2 to 6%, represents a prograding shoreface cycle within a highstand systems tract (Reinson et al., 1994). This unit is mappable throughout the subject area as the “Viking Sand” (figure 3), and comprises several smaller scale (1–5m) stacked coarsening upward successions, indicative of fluctuating sea levels during deposition. Southeast of 2/12-35, in parts of Sundance, the Viking was deposited as incised valley fill (figure 3). These estuarine deposits host wells that once produced at rates exceeding that of 2/12-35, and are now utilized for gas storage. Peyto’s Big Sunny gas storage unit is an example (figure 1) (Peyto, 2021).
The Viking first yielded gas at Wild River in the early 1980s. Drilling peaked in the early 2000s, but the Viking remains undeveloped in much of the area (figure 1). Wild River Viking gas has typically been produced commingled in vertical wells with zones such as the Cardium, Dunvegan, Spirit River, Bluesky and Cadomin. Notwithstand-ing a short lateral (<200m length) drilled by CNRL in 1994, Peyto drilled the first horizontal Viking well in the area in December 2017, immediately southwest of 2/12-35 at 8-34-55-22W5 (figure 1). This well came on production at 1,071 boepd (6.4 mmcf/d). Peyto’s 2/12-35 was the area’s second Viking horizontal well.
There are no obvious differences in Viking log properties from available wells that would explain 2/12-35 coming on at a rate over twice as high as that of 8-34 (figures 3 and 4). Both wells are located on the edge of a Leduc reef structure (figure 1), where structural drape features and differential compaction can enhance porosity and permeability. However, one may expect both wells to be affected similarly.
Some notable completions differences between the two wells are shown in table 1. The 2/12-35 well used a markedly higher intensity completion based on the number of stages and volume of fluid used. Because the 2/12-35 well is on confidential status until August 2021, other data such as the amount of proppant used are currently unavailable.
Peyto’s SECOND highest IPmax of 2020 (1,577 boepd, or 9.5 mmcf/d) is from a well targeting a Notikewin channel at 2/4-1-56-22W5, directly northeast of the 2/12-35 well (figures 1 and 3). Well logs indicate that this channel lies just below the base of the Viking sandstone targeted by 2/12-35, separated by a thin Joli Fou shale interval (figure 3). While geo-steering technology would have ensured that the 2/12-35 trajectory stayed within the Viking, a hydraulic frac extending downward more than 15 or 20m may have been able to access Notikewin reservoir. This could have been further enabled by any enhanced permeability brought on by the effect of drape over the aforementioned Leduc reef.
Peyto’s Wild River Viking well at 2/12-35-55-22W5 had one of 2020’s highest initial gas rates, and represents a new horizontal target for the area.
FracFocus Chemical Disclosure Registry, 2021. Accessed February 2021. http://fracfocusdata.org/DisclosureSearch/Search.aspx
Peyto Exploration and Development, 2021. Corporate Presentation January 2021. Accessed February 2021. http://www.peyto.com/Files/Presentations/2021/2021Jan8CorpPres.pdf
Reinson, G.E., Warters, W.J., Cox, J. and Price, P.R. 1994. Cretaceous Viking Formation of the Western Canada Sedimentary Basin. Chapter 21. In: Geological Atlas of the Western Canada Sedimentary Basin. G.D. Mossop and I. Shetsen (eds.). Canadian Society of Petroleum Geologists and Alberta Research Council, p. 353–363.