Niagaran reef exploration continued to dominate drilling activity for the fourth straight year. Exploration was concentrated mostly in Grand Traverse, Kalkaska, and Otsego Counties in the Northern District and in the Ingham-Eaton-northeastern Calhoun region in the southern part of the basin. Exploration resulted in 58 new discoveries, including field extension and new pools. Most of the new reefs were found in the northern part of the state. New reef discoveries also were made in Mason and Manistee Counties, thus opening up still more territory for exploration.

Exploratory and development footage, figured from CSD printouts, amounted to 1,486,258 ft compared with 1,244,976 in 1971. Of the total, 909,540 ft is credited to exploratory drilling and 576,718 to development drilling. Geological Survey records show an additional 110,177 ft of facility and miscellaneous well footage.

Preliminary oil production figures indicate an increase in the yearly total: 12,989,922 bbls compared with 11,893,411 in 1971. Most of the increase is from Niagaran reservoirs. Preliminary gas production figures show a substantial increase: 33,579,163 Mcf as compared with 25,930,622 in 1971. The Albion-Scipio trend produced about 30% of the state's oil and 32% of the state's total gas production in 1972.

Environmental and ecological considerations are increasingly important in oil and gas exploration and development. Objections to several proposed well sites have been overcome by drilling directional holes from more favorable locations. A special "no-flare" order, put into effect in late 1971, was revised in early 1973 so as to include additional areas of new or potential reef development. Also of special significance is a Special Order establishing 80-acre drilling units and basic oil/gas allowables for wells drilled into Salina-Niagaran or deeper formations. The area covered by this order is nearly coincident with that covered by the Salina-Niagaran "no-flare" order.