During 1943 well completions in Michigan decreased 7 per cent from 1942 although the number of permits issued increased 10 per cent. Total footage drilled was 1,622,313 feet or a drop of approximately 140,000 feet. The proportion of productive wells was only 44 per cent compared with the 54 per cent of 1942. Two-thirds of the completions and three-fourths of the oil and gas wells were in the "Basin" district.

Thirteen oil fields were discovered during 1943 and 3 old fields extended. None of the discoveries was of major importance but the Goodwell and Rose Lake fields are promising. Most of the new fields produce from the Traverse (Devonian) limestone. For the first time since 1939 no field of apparent importance was found in the Dundee (Devonian) formation. Average initial production of all oil wells was 307 barrels per well compared with an initial production of 868 barrels per well in 1942. Total production for 1943 was 20,767,724 barrels, a decrease of 4 per cent, reflecting the failure to discover new important fields.

Only 47 gas wells were completed during the year, but 7 gas fields were discovered and one old field was extended. Development centered in new fields in Clare and Newaygo counties where more than half of the wells were drilled. Gas production of 19,581,420,000 cubic feet reached a new maximum, a 10 per cent increase over 1942.

Core-testing activity was increased during the year. Permits for 376 geological tests were issued, compared with 302 test permits issued in 1942. Geophysical exploration was carried on in the "Thumb" district and in part of the "Basin."