Kaybob Viking-Notikewin

Exploration and Development Potential of Viking and “Notikewin” Reservoirs, West-Central Alberta

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Summary:
Location: T53-65, R16W5-14W6
Strata: Middle Cretaceous Notikewin / Cadotte / Viking
Year of Study: 2001

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Introduction

West-central Alberta offers huge hydrocarbon reserves and expanding access to infrastructure, at a time when North America needs to tie in new production. Gas and oil prospects abound in reservoir units ranging from Devonian through Upper Cretaceous. Middle Cretaceous (“Notikewin” through Viking) reservoirs feature high deliverability, long reserve life, and immense potential for addition of new reserves.

Petrel Robertson Consulting Ltd. has completed a regional exploration and development assessment of the “Notikewin” through Viking interval, in an area covering Townships 53 to 65, Ranges 16W5 to 14W6 (our “Kaybob” study area). Although Kaybob contains more than 1 TCF of established marketable gas reserves, more than 50% of the area is very lightly drilled, and offers huge exploration potential.

The study database includes: over 3200 wells, 162 core logs, petrographic analysis of 112 thin sections, seismic modeling, and complete suites of drillstem test data, production data, and fluid analyses. The report includes: 17 regional stratigraphic cross-sections, a complete suite of gross isopach and net sandstone maps, a structure map, selected seismic models, a suite of drillstem test and production maps, pressure-elevation plots illustrating all valid tests, and a hydrodynamic report. A comprehensive text summarizes all this information, and uses it to synthesize an exploration summary, and recommended exploration and development methods for each prospective unit.

Seven distinct stratigraphic units are prospective across the Kaybob area. Notikewin sandstones fill distributary channels and incised valleys, but attain reservoir quality only where grain size is sufficiently coarse, and reservoir quality has been enhanced through solution of lithic grains. The Kaybob sandstone is the southerly shoreline equivalent of the Harmon Shale, and hosts a 241 BCF gas pool at Kaybob in fine-grained middle shoreface strata. Cadotte shoreface sandstones produce from conventional stratigraphic traps at their eastern subcrop edge, and from Deep Basin reservoirs in the northwestern corner of the area. Overlying a distinct Middle Albian unconformity, the Simonette sandstone was deposited along the southern limit of the now-emergent Peace River Arch, at the northern shoreline of the transgressing Joli Fou Sea. Sediments were supplied by rivers which cut valleys in and reworked the Cadotte shoreface. Late-stage fill of these valleys makes up the Paddy Valley Fill unit, which contains isolated high-quality reservoirs. In the eastern part of the study area, Viking sandstones are highly productive from shoreface and estuarine valley fill reservoirs. In the west, however, the regional Paddy Member contains little reservoir-quality rock.

Seismic modeling shows that Simonette shoreline sandstones and Paddy Valley Fill reservoirs should be visible only under optimum conditions. Seismic is more a local fine-tuning tool in these plays, rather than a regional mapping tool. However, gas-filled Viking estuarine valley fill reservoirs are well displayed using amplitude versus offset processing.

The key to successful exploration in the middle Cretaceous of west-central Alberta is to clearly distinguish the various stratigraphic units, and the exploration trends that arise from each. With the insights gained from this report, one should be able to define prospects at all scales, ranging from one-section stepouts to large-scale wildcat targets.