Exploration and development activity in eastern Canada continued at a moderate pace in 1987. In the Canadian east coast offshore region, drilling was completed at 5 exploratory and 3 delineation wells, drilling was suspended at 1 well, and drilling was in progress at year end at 1 well offshore Newfoundland. No new discoveries of oil or gas were made, but drill-stem tests were very successful at the 3 delineation wells, confirming the extent of reserves on previous discoveries. An extended drill-stem test of 1 of these wells, Panuke F-99, resulted in the first shipment of oil from an east coast offshore discovery, and also served as a test of possible commercial production techniques for small offshore oil pools. Discovered resources in the region, on a "best current-esti ate" basis, are now estimated at 203.9 million m³ (1.3 billion bbl) of oil and condensate and 307.3 billion m³ (10.9 tcf) of natural gas.

In Ontario, 104 wells were drilled in 1987 (43 exploratory, 32 development, and 29 service). The exploratory drilling resulted in 17 new discoveries (6 gas and 11 oil). Exploration for Ordovician oil reservoirs continued to be the highlight of activity in the province in 1987. Seventeen wells were drilled to Ordovician targets with 10 wells completed as oil producers and 1 as a gas producer. The 65% Ordovician success rate was a dramatic improvement from the 19% success rate of 1986. Oil production in Ontario remained constant at 135,653.3 m³ (853,119 bbl), and production of natural gas declined by 4% to 511,171 million m³ (18.04 tcf).

Eight wells were drilled in Quebec in 1987. No new discoveries were reported at the 7 exploratory wells. One development well was successfully completed as a gas producer in a test of an abandoned gas reservoir in unconsolidated sediments in the Louisville area southwest of Trois Rivieres. Gas production from St. Flavien field increased to 16.666 million m³ (588 mmcf) from 13.95 million m³ (493 mmcf) in 1986.

There was no drilling activity in onshore portions of Prince Edward Island, Nova Scotia, New Brunswick, or Newfoundland in 1987. Production from Stoney Creek field in New Brunswick declined to 495 m³ of oil (3,113 bbl) and 1.737 million m³ (61.34 mmcf) of natural gas.