Call for Bids 2008

Geoscience Overview

Figure 10

Parcel 1 is located 40 km south-southeast of the ExxonMobil Sable Project’s central production and gathering facility at Thebaud. It is bounded by two significant discovery licences: Glenelg (west) and Chebucto (east), and by the Sable Offshore Energy Project’s North Triumph field production platform about 5 km to the north (Figure 10). The parcel’s bathymetry is generally flat-lying with a shallow dip to the southeast. Water depths range from 50 to 200 m, with depths increasing to 400 m in a small part of the parcel’s southeast corner.

The Triumph P-50 well, located 2 km north of the parcel, was drilled by Shell in 1971 in 90 m of water to test a seismically defined closure. It encountered both a small gas show within a thin, poorly developed sand (untested) and overpressure at the bottom of the well. Later analysis revealed that the well drilled through the north-bounding fault and into the adjacent footwall of the North Triumph structure. The main targeted horizons, the deeper Middle and Lower members of the Missisauga formation, were not penetrated. Subsequent seismic data indicated that the structure had very little relief and was in fact a low relief saddle possibly connecting the eastern West Chebucto field to an un-named structure to the west (Figure 11).

Figure 11

In 1986, Husky-Bow Valley et al. drilled the West Chebucto K-20 well as a follow-up to their successful Chebucto K-90 well located 6 km east of K-20. West Chebucto K-20 is the only well on the parcel and was drilled in 93 m of water and is on trend with the Chebucto K-90 prospect. An undrilled feature is located along the fault trend further to the west and southwest of the North Triumph field. A summary of the aforementioned drilled structures and wells is noted in the following table.

Fields, Prospects & Discoveries Number of Wells Gas-Bearing Formation(s) Reservoir Depth(m) Recoverable Reserves1 (mean) Gas / Condensate (Bcf / MMBbls)
Chebucto 1 Lr. Logan Canyon & Up. Missisauga 3350 - 4240 386 / 2.34
West Chebucto 1 Up. Missisauga 5018 - 5041 Gas show; tested at 4.13 MMscf/d
Glenelg 5 Lr. Logan Canyon & Up.-Mid. Missisauga 3390 - 3990 437 / 4.20
North Triumph 4
(two in production)
Up. Missisauga 3770 - 3850 380 / 2.03
(On production)
Triumph 1 Up. Missisauga 4472 - 4486 Gas show; not tested

1:The reserve numbers shown in this table are sourced from the CNSOPB publication Technical Summaries of Scotian Shelf Significant and Commercial Discoveries (November 2000).

Figure 12

The West Chebucto K-20 well took several gas kicks in the Missisauga formation that are associated with pressure steps in the lower, overpressured portion of the well. A single gas bearing sand was encountered in the early Cretaceous Missisauga formation. Sand 1 was subsequently tested and flowed gas at 4.13 MMscf/d (Figure 12) with some depletion noted in the test analysis report. The reservoir properties of Sand 1 are listed below

Well Zone Top
(m MD)
(m MD)
(m TVD)
Net Pay
(m TVD)
Por. (%) Sw (%)
West Chebucto K-20 Sand 1 5017.8 5041.0 21.7 5.3 10 56

The porosity of Sand 1 is relatively low and core permeabilities for the zone are generally between 0.1 – 1 mD.  It should be noted that the porosity and resistivity log readings over the upper few metres of Sand 1 appear to be affected by hole washout as shown by the caliper response over the top portion of the sand (Figure 12). The well took a gas kick at the top of Sand 1 and the hole washed out during the process of circulating out the kick.  As a result, the log readings over the upper portion of the sand are questionable.

A number of seismic surveys (2D and 3D) have been acquired over portions of Parcel 1, and in many cases have accompanying interpretation reports. The table below lists the available seismic programs.

CNSOPB Programs #
(links by Program)
(links by company)
pdf 8620-H6-2E pdf Husky 1982
pdf 8620-H6-7E pdf Husky 1982
pdf 8620-H6-8E pdf Husky 1984
pdf 8620-H6-9E pdf Husky 1985
pdf 8620-J8-1E pdf ICG Resources 1983
pdf 8620-J8-2E pdf ICG Resources 1983
pdf 8620-S14-6E pdf Soquip 1983
pdf 8624-H6-4E pdf Husky 1983
pdf 8624-H6-7E pdf Husky 1984
pdf 8624-H6-10E pdf Husky 1985
pdf 8624-N5-2E pdf Norcen Energy 1983
pdf 8624-S6-8E pdf Shell Canada 1971
pdf 8624-S6-23E pdf Shell Canada 1980
pdf 8624-S6-27E pdf Shell Canada 1981
pdf 8624-S6-33E pdf Shell Canada 1982
pdf 8624-S6-37E pdf Shell Canada 1983
pdf 8624-W13-1P pdf Western 1983
pdf NS24-E40-1E pdf ExxonMobil 2001
pdf NS24-M3-7E pdf ExxonMobil 1998
pdf NS24-V3-2,3,4P * pdf CGG-Veritas 1999-2001

* These programs are confidential.