Abstract
Niagaran reef exploration dominated drilling activity for the 10th straight year. Exploration and development drilling were heaviest in northern counties along the reef trend. Other pockets of concentrated activity were associated with deeper development drilling in older fields in the central basin, in southeastern Michigan, and in the Ingham-Calhoun-Eaton County region of southern Michigan.
Exploration resulted in 52 new discoveries, nearly all of which were Salina-Niagaran reef reservoirs; 39 of the reef reservoirs were along parts of the northern reef trend. A definite pinnacle reef in Livingston County, southern Michigan, indicates additional prospects in this area.
Exploratory and development footage, figures from records of the Department of Natural Resources Geological Survey Division, amounted to 1,128,691 ft exploratory and 1,176,270 ft development, compared with a combined total of 2,519,809 ft in 1977. An additional 225,420 ft, mainly gas-storage facility wells, is credited to 1978.
Oil and gas production continued to set new records as additional reef reservoirs are found. Preliminary figures show that 34,667,312 bbl of oil (including condensate) and 150,535,238 Mcf of gas were produced in 1978. Both figures are new records for annual production and are direct results of Silurian Salina-Niagaran reef developments.
