More operators set sights on western Newfoundland

Alphonsus Fagan
Newfoundland and Labrador Department of Mines and Energy
St. John's, Newf.

With Hibernia oil field on the Grand Banks set to begin production this fall and the Terra Nova, Whiterose, and Sable projects on the near horizon, eastern Canada has developed momentum and infrastructure that have significantly improved the economics of production and exploration throughout the area.

At present, three pipeline proposals are competing to transport the area's gas into the eastern North American market. This is all occurring within what is largely a frontier area in terms of the number of wells drilled and the availability of large undrilled structures.

Western Newfoundland (Fig. 1 [209,950 bytes]) is one area within this frontier that is now proven to have the ingredients for major discoveries that can be drilled from land and nearshore locations. The prognosis remains favorable.

Oil, gas discovery

Hunt Oil Co. and its partner PanCanadian Petroleum Ltd. spudded the Port au Port 1 well in September 1994 on the Port au Port Peninsula in western Newfoundland. The following spring, the skies and the hopes of the Port au Port area were brightened by a flare that got the attention of industry players near and far.

The partners were attracted to the area by its structural setting and the similarity of its stratigraphy, in age and depositional environment, to the prolific Ellenburger and Arbuckle dolomites of West Texas and Oklahoma. They were looking for elephants in a relatively untested frontier, and their first well had obviously hit something-but they declined to say what.

Follow-up drilling

Hunt and PanCanadian followed quickly during 1995-96 with the Long Point M-16 about 60 km north of Port au Port 1 (Fig. 2 [77,429]) and with the offshore well St. George's Bay A-36 about 7 km off the southwest tip of the peninsula. Both these holes were plugged and abandoned.

Talisman Energy Inc. in February 1996 spudded an onshore to offshore hole 3 km to the south of Port au Port 1 and in June announced that the well had tested water and would be abandoned. Details on these three wells have not been released, as the companies are allowed a 2 year confidentiality period from the rig release date.

Although the follow-up drilling was obviously disappointing, it is not entirely surprising given the area's complex geology and the very early stage of exploration.

Hunt and PanCanadian continued to show optimism by jointly acquiring three more offshore licenses (1028, 1029, and 1030, Fig. 1) in the Canada-Newfoundland Offshore Petroleum Board's Call for Bids that closed in October 1996. These companies provided additional evidence of continued interest by conducting seismic and shallow drill programs during fall and winter 1996-97.

Discovery results

On Aug. 1, 1997 the 2 year confidentiality period for Port au Port 1 expired, and the well history report was released. Drilled to a TD of 4,699 m, the well encountered several reservoir zones including one hydrocarbon bearing zone.

The intervals tested in DST No. 3 and DST No. 4 appear to be in communication (Table 1 [32,534 bytes]). The extended test (No. 5) run over the same interval as DST No. 4 flowed at variable rates and experienced problems with paraffin and salt plugging.

The pressure and flow data indicate either a limited reservoir or complex geology at the location. Hunt and PanCanadian have not commented on whether the discovery is commercially viable, but in an Aug. 4 Globe and Mail article, Gerard Protti, Group Vice-President of PanCanadian, was quoted as saying, "We're optimistic regarding the longer term potential of the Port au Port Peninsula. We're going to be active there in the future."

PanCanadian plans to spud a wildcat off Shoal Point early next year (OGJ, Oct. 13, 1997, p. 42).

Well significance

Hunt/PanCanadian Port au Port 1 was the first well drilled in western Newfoundland that had the benefit of subsurface mapping (from seismic data) in choosing the location.

It was drilled to test the possibility that the St. George and Table Head Groups (the age equivalents of the Arbuckle and Ellenburger) could contain oil. This theory has been borne out in that high grade (51° API) unbiodegraded oil flowed at significant rates. The well also encountered several other high quality reservoirs that were unfortunately wet at this location but could prove to be oil-bearing elsewhere.

From a strictly geological perspective, the well confirmed the interpretation that the Port au Port Peninsula, which was until recently thought to be autochthonous, is actually transported and that the long recognized oil-bearing rocks at surface are preserved and repeated at depth.

The discovery also has important implications in regard to the migration of hydrocarbons from source rocks to the Cambro-Ordovician reservoirs. One of the concerns often expressed in regard to western Newfoundland was that the recognized Lower Paleozoic source rock (the Green Point shale; up to 8% TOC), which had been thrusted from the east onto the Cambro-Ordovician carbonate platform (the recognized reservoir rocks), was in a structurally difficult position to charge the St. George and Table Head reservoirs.

Port au Port 1 intersected no Green Point, but the well report indicates a source "compatible with the Green Point" or "another Cambro-Ordovician interval deposited under similar conditions." What this proves is that a Cambro-Ordovician source, be it the Green Point or some other, is charging the deep "autochthonous" platform. This implies that there is a petroleum migration system in place whereby any number of the undrilled Cambro-Ordovician structures throughout the area could be charged with oil and gas. This is also supported by recently released seismic data that show allochthonous "source charged" material in a downdip position relative to the carbonate platform.

Other exploration

Although things have cooled off a bit since the three follow-up holes were plugged and abandoned in 1996, exploration continues.

On Aug. 18, Delpet Resources completed operations on a well located 300 km north of the Port au Port Peninsula, via a farm-in on Vinland Petroleum's permit 92-102. This 1,200 m slimhole test was drilled largely on the basis of surface geology, with only one seismic line in the general area. Delpet spokesman Ron Shenton said they've garnered enough information in terms of downhole geology, and encouragement in terms of oil and gas shows, to warrant shooting a seismic line though the location for possible follow-up drilling. Delpet also intends to participate in one other well in western Newfoundland before the end of the year.

Inglewood Resources has also announced its intention to drill two wells on Vinland's permits in the Carboniferous Deer Lake basin and to directionally drill into EL 1008 in St. George's Bay.

Also, in the fall of 1996 St. John's based Vulcan Minerals used a mining rig to drill in the vicinity of an old mining exploration hole located on the London Resources Inc. (an affiliate of Vulcan) Permit 96-105 that had reported oil in core. Vulcan encountered a live-oil bearing conglomerate at 452 ft and was still in the oil zone when it reached its permitted depth at 505 ft.

The hole was suspended for "future re-entry and analysis." Of particular significance was that the oil is a light crude from a previously undocumented Carboniferous source.

The Author

Alphonsus Fagan worked as a petroleum geophysicist with Amoco Canada Petroleum Co. Ltd. from 1979-84 and as senior geophysicist with the Newfoundland Petroleum Directorate in 1985-86. He has been a petroleum geophysics consultant with the Newfoundland Department of Mines & Energy since 1986. He holds a joint honors BSc degree in physics and mathematics from Memorial University of Newfoundland.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.