INTRODUCTION

Active areas for exploration and development in Canada for 1943 include the Mackenzie River area of the Northwest Territories, particularly the Norman Wells field, 75 miles south of the Arctic Circle, and various areas in the Prairie Provinces of Western Canada, as follows: Turner Valley in the foothills southwest of Calgary, Taber on the plains 30 miles east of Lethbridge, Vermilion 130 miles southeast of Edmonton, and a number of wildcat wells in other districts of Alberta, and in southwestern Saskatchewan. In Eastern Canada the only significant wildcat locations are one well in the Gulf of St. Lawrence to test a structure outlined by seismic surveys on Prince Edward Island and in Hillsborough Bay 7 miles from Charlottetown, and a further well to test the prospects of Gaspe, Quebec, where seepages have long been known.

NORMAN WELLS AREA

The Norman Wells field (Fig. 1) was discovered by the Imperial Oil Company in 1920, and for many years has supplied oil to a local refinery for local requirements. As a war necessity the field has now been developed under the Canol project inaugurated in 1942 by arrangements between the United States and Canadian Governments with the Imperial Oil Company Limited. Previous to the Canol development the Imperial Oil Company had four producing oil wells on the northeast bank of Mackenzie River, about 50 miles northwest of Fort Norman, and a refinery capable of processing about 840 barrels of crude oil a day. Operations were mainly confined to the summer months. Under the Canol project Imperial Oil Company undertook the development of Norman Wells field and certain exploratory surveys, and the United States army undertook the building of a pipe line 600 miles, from Norman Wells to Whitehorse, Yukon, and the building of a refinery at Whitehorse.

The development of the Norman Wells field has exceeded expectations with

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the result that a major oil field has been developed. This has largely been outlined as the result of wells drilled in 1942 and 1943, and it is now considered the field contains 4,000-5,000 acres in part on the northeast bank of Mackenzie River, and in part on Bear and Goose islands in the river, 1¼-1½ miles from the northeast bank. Thus, a considerable part of the field is under the river. No wells have been

Fig. 1. Northwest Territories showing Norman Wells oil area.

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found on the southwest side of the river, but only one well was drilled in that area in 1943. Within the Norman Wells field 12 wells were drilled in 1943, and of these 10 were productive, and the other two on the edges of the producing area.

At Norman Wells the regional structure is a basin about 20 miles wide, between the Norman Range on the east and the Mackenzie Mountains on the west. The Norman Range is anticlinal, and Silurian strata crop out on it. On its flank on the southwest the succession of beds is as follows: Middle Devonian limestones, Upper Devonian dark shales, Upper Devonian greenish sandstones and shales, Cretaceous sandstones and shales with Cretaceous dark shales in the central part of the basin. The Norman Wells field is on the southwest dip of approximately 5° in the vicinity of the producing area. The oil occurs in a reef limestone in Upper Devonian beds. The age of the reef was formerly regarded as possibly Middle Devonian, but it is now known there are dark shales presumably Upper Devonian in ge under the reef limestone. The age thus seems to be definitely Upper Devonian. The thickness of the reef is variable up to, and greater than 400 feet and the seal for the oil on the northeast is provided by the disappearance of the reef limestone updip. The wells in the upper end of the reef are 1,000-1,100 feet deep to the top of the producing zone, and on Bear and Goose islands the deepest wells within the productive zone reach it at about 2,000 feet in depth.

The oil from the Norman Wells field has a paraffine base, a gravity of about 38° A.P.I. and a very low pour point.

The production of the Norman Wells field in 1943 was for local use, and for the testing of the wells. The pipe line was not completed at the end of the year, but construction was well under way.

TURNER VALLEY, ALBERTA

Turner Valley (Fig. 2), in the foothills southwest of Calgary, still continues to be the largest producing oil field in Canada. Production reached a peak in February, 1942, and is now declining. In order to keep up the production as far as possible Wartime Oils Limited, a Crown company, was formed in 1943, and is lending money to small independent companies at a low rate of interest, and a small royalty, to drill wells in an area known to have low production prospects. The money will be paid back out of production when this is obtained. Of 21 active wells at the end of 1943, eight were sponsored by Wartime Oils. During 1943 three Wartime wells and 23 other wells were successfully completed in Turner Valley. One well drilled on the east side to a depth of 10,230 feet was suspended with ut obtaining production.

Two major structural features of Turner Valley were brought to light by the drilling in 1943. The first was the extent and gentle attitude of the overthrust fault underlying Turner Valley, and reached a depth of 8,795 feet in the Devonian test drilled as a joint project of a number of companies on the west flank of the central part of the field. As the name implies, this well was an attempt to reach Devonian strata under Turner Valley. After drilling 1,555 feet of Mississippian

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limestones and calcareous shales, the well faulted back into the upper part of Lower Cretaceous beds, indicating a stratigraphic break of approximately 2,500 feet. The well was plugged back to the porous zones in the upper part of the Mississippian limestone where it was put on production.

The other major structural feature definitely established in 1943 was the presence on the east flank in the north end of the field of a fault block at lower

Fig. 2. Oil fields and prospects in Alberta. (1), Turner Valley; (2), Jumpingpound; (3), Aldersyde; (4), Wildcat Hills; (5), Ram River; (6), Nordegg; (7), Pouce Coupe; (8), Athabaska; (9), Vermilion; (10), Lloydminster; (11), Wainwright; (12), Taber; (13), Del Bonita; (14), Red Coulee; (15), Pinhorn.

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Table WILDCAT WELLS IN CANADA AT END OF 1943

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Table Continued. See caption on page 868.

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elevation than the main uplift. The discovery was made by Northwest Hudson Bay well No. 13. This well reached the top of the Paleozoic limestone at a depth of 7,240 feet (at an elevation of -3,189 feet), and at 7,790 feet faulted back into Lower Cretaceous beds after drilling part of the productive porous limestone beds. The well again reached the top of the productive limestone at a depth of 9,012 feet (-4,951 feet) and was completed at 9,435 through both porous zones. The bottom of the hole, however, is somewhat off the vertical, so the vertical depth is somewhat less. The well found production both above and below the fault. The significance of this appears to be that the faulting which thrust the main mass of Turner Valley over the east side fault block occurred after the oil accu ulation, and that the oil was carried down with the east side fault block as it was depressed. On the west flank of the north end of Turner Valley, oil occurred in the upper porous zone, and salt water in the lower porous zone of the limestone in a well reaching the top of the limestone at an elevation of -4,587 feet. Thus the oil-water line in the east side fault block is several hundred feet deeper than on the west flank of the main uplift.

It is impossible, at present, to evaluate the importance of the deep east side fault block. Another well, ¼ mile east of Northwest Hudson Bay No. 13, reached the top of the Paleozoic limestone on the same fault block at an elevation of -4,936 feet. At the end of 1943 this well was drilling in the limestone. It has been finished subsequently with oil in both porous zones. It shows the fault block at this place is more than ¼ mile wide, and that it is only very gently tilted westward. At a minimum at least, a few hundred acres have been proved and semi-proved by these wells and the area could be of considerable extent and importance.

In the main uplift of Turner Valley the remarkable amount of closure, more than 5,000 feet within the productive gas and oil zones of the Paleozoic limestone, has been commented on elsewhere. The oil-water line, however, seems lower on the ends of the field than in general along the west flank of the structure. On account of this fact the north end of the field was still farther extended in 1943, and the north limits have not yet been defined.

At the end of 1943 there were 214 limestone zone oil wells, 32 limestone zone gas wells, and 3 shallow wells in production in Turner Valley. All wells flow. The production of the field for 1943 including crude oil and natural gasoline recovered was 9,452,697 barrels, a decrease of 551,238 barrels from 1942. It is likely that the decline will continue in 1944, as only a limited number of attractive sites still remain undrilled. The wells drilled under the sponsorship of Wartime Oils Limited can only partly offset this decline, and by the end of 1944 Wartime Oils will have finished or be close to completion of all presently projected wells.

TABER FIELD: SOUTHERN ALBERTA PLAINS

The Taber oil field is 30 miles east of Lethbridge. It was discovered by Plains well No. 2, drilled in 1937, but the present development by Dominion Oil Company,

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a subsidiary of the Standard Oil Company of California, seems to be an entirely separate producing area. The discovery well of Dominion Oil Company was completed in 1942, and was followed in that year by the drilling of three other dry holes. In 1943 the Dominion Oil Company drilled 3 productive and 2 unsuccessful wells, and one well was drilling at the end of the year. Three other wells in proximity to the field were dry. Thus at the end of 1943 in the Taber field there were 4 productive wells owned by Dominion Oil Company, in addition to Plains well No. 2 which may be on a separate producing area. The depth of the wells is 3,100-3,200 feet. All wells are pumped.

The oil in the Taber area occurs in a sand at the base of the Lower Cretaceous on the northwest flank of the north plunging Sweetgrass arch. The trend of the field appears to be in a northeast instead of northwest direction as first anticipated. Thus, although the conditions in the field are those of a stratigraphic trap, there undoubtedly are other structural and sedimentary conditions that control the trend.

The proved area outlined by drilling in the Taber field to the end of 1943 was 200 acres with a width of ½ mile. The oil from the Dominion wells has a gravity of 18°-20° A.P.I., whereas that from Plains well No. 2 is 26° A.P.I. The field seems capable of a very considerable extension, but at present the outlet is restricted by the lack of satisfactory and adequate refining facilities to handle this type of crude oil.

VERMILION FIELD: EAST CENTRAL ALBERTA

The Vermilion field was discovered in 1939. The productive sand is 130-140 feet below the top of the Lower Cretaceous at a depth of approximately 1,850 feet. The structure of the field is very flat, and the oil sand is thin with water close below the oil. The result is that much difficulty has been experienced with water and the oil produced by pumping contains some emulsion and fine silt. An electrical dehydration (Petreco) unit capable of handling 1,000 barrels a day was installed in this field late in 1943, and some of the wells are now being provided with electrical pumping equipment.

A great impetus to drilling in the Vermilion field was given by the entry in 1943 of Cannar Oils, a subsidiary of Canadian National Railways, in order that fuel oil would be provided for the mountain divisions of this railroad. In 1943 Cannar Oils drilled 27 wells, of which 21 were productive. In addition 12 other wells were drilled, of which 6 were successfully completed.

The amount of proved oil land in the field at the end of 1943 was approximately 600 acres. The spacing is one well to 10 acres. At the end of 1943, 29 wells were on production, and the yield for the year was 93,258 barrels. The oil has a gravity of 14° A.P.I. and the clean oil is used directly for fuel without topping.

DEL BONITA: SOUTHERN ALBERTA

The Del Bonita structure is a subsidiary anticline on the Sweetgrass arch.

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It is on a trend which includes the Ross Lake, Spring Coulee, and Blood Indian Reserve folds. The regional plunge is toward the north, and as Del Bonita is toward the south, close to the International Boundary, it is the highest part of this trend in Canada. It has been mapped by seismic surveys. The Terminal well completed in 1936 found some oil and has yielded oil at a low rate. In 1943 a further well, Del Bonita No. 1, was drilled. This found some oil in the top of the Mississippian limestone which was reached at a depth of 5,035 feet. The oil is about 36° A.P.I. The well is not yet on steady production.

This discovery has led to renewed activity in this area, and other wells will be drilled.

LLOYDMINSTER

Some renewed activity took place near Lloydminster in Alberta near the Saskatchewan boundary in 1943. Four wells have been drilled, and all have encountered some heavy oil in Lower Cretaceous sands. None of the wells is on steady production.

ATHABASKA

In the area near the town of Athabaska in a well drilled in 1934 some heavy oil was encountered in a sand in the Grand Rapids formation of Lower Cretaceous age at a depth of 1,650 feet. This oil was never produced. In 1943 interest was revived in this area, and one well encountered oil, and one a very considerable volume of gas in the same producing sand. It is likely further drilling will be done.

FOOTHILLS STRUCTURES

The drilling of a deep well on the west flank of central Turner Valley has shown that the Devonian is not present above the major fault which underlies this structure. This information is valuable in interpreting foothills structures. Also a well in the Jumpingpound area of the foothills has reached the Paleozoic limestone at a depth of 11,588 feet in a fault block where seismic surveys indicated limestone would be found. The fact that oil was not present was disappointing, but from the results obtained there is hope that it will be possible in the faulted and structurally complicated foothills to indicate by geophysical means the presence of limestone fault masses at reasonable depths. The foothills contain sufficient outcrops to outline the major structural features, but up to the p esent it has not been possible to predict the conditions at depth with any degree of accuracy owing to the low angles of many fault planes and the fact that the faults cut off many structures above the possible productive formations. If the limestone masses can be detected by geophysical means, as has been done at Jumpingpound, a new phase of development will take place in the foothills.

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