The Odem field, located in southern San Patricio County, Texas, was discovered in the latter part of 1939. Prior to 1933, the Odem area received a limited amount of geological and geophysical exploration, and several test wells were drilled. These tests were dry and the area apparently condemned until a reflection seismograph survey indicated structure. Subsequent drilling confirmed the presence of a structure containing several producing horizons. The proven limits of production conformed closely to the contours of the original seismograph map.