Pembina: The Hidden Elephant

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At this point, Nielsen and Jim Warke of Socony's producing depart­ment, who had been in charge of drilling operations at the well, decided that a hydrofracing treatment might open up oil-production from the tight Cardium sandstone.

In hydrofracing (meaning hydraulic fracturing), a mixture of oil and sand is pumped down the hole and into the potential oil-producing for­mation under considerable pressure, resulting in hairline fractures of the rock formation. The grains of sand keep the fractures propped open, and oil is thus allowed to flow through the fractures into the well bore. The method had been developed only a few years previously in the United States, and had never before been successfully applied in Canada. But Warke, who had started in the oil business at Turner Valley and later worked in the oil fields of the Persian Gulf, had seen the method work and urged that it be applied at the Pembina well. Nielsen agreed.

"A lack of permeability would appear to be the cause of the low oil recov­ery," Nielsen wrote in a memo to management at Socony's Calgary office. "It is conceivable that a hydrafrac treatment might substantially increase the oil output. . . I wish to express my strong support of a complete and thorough testing of the Cardium sand in the Pembina well. It is our opinion that the Cardium sand may become a major reservoir and a complete knowledge of the potentialities of this sand at the Pembina well will be of invaluable assistance in determining our future exploration in the area."

Wrote one company production engineer: "Nielsen favors hydrafrac treatment of this interval in the hope of substantially increasing oil output. The writer cannot feel any optimism about the possibility of obtaining oil at commercial rates. . . but in the interest of a full evaluation. . . would concur with the recommendation."

"I sure hope you bring that well in," Warke told Nielsen. "I've spent $13,000 without company approval to gravel this road so we can keep this job going. And if you don't bring in a discovery, I may be out of work.”4

A mixture of diesel oil and 3,000 pounds of sand were pumped down the hole and into the Cardium formation at a pressure of 1,800 pounds per square inch. The pressure cracked the tight Cardium sandstone, and the oil started flowing into the wellbore. The well was completed on July 1 after tests had indicated an initial production potential of 72 barrels of oil per day. Heavy summer rains in the area had made roads so impassable that the oil could not be trucked out, and the well was shut in for two months. But on an extended 30-day test in September, the well sustained an oil production rate of better than 200 barrels per day.

Socony-Seaboard Pembina No.1 marked the first discovery of Cardium oil in Alberta, the first large stratigraphic oil trap in Canada, and the coun­try's biggest oil field-all from a wildcat well which could have so easily been abandoned.

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