Preliminary Report on the McLouth Gas and Oil Field, Jefferson and Leavenworth Counties, Kansas

Abstract

On August 15, 1941, the McLouth gas and oil field, 15 miles north of Lawrence, Kansas, had 23 gas wells with an aggregate initial open flow of 170 million cubic feet of gas per day, six oil wells with a probable total potential of 250 barrels per day of oil of 24 to 25 degrees gravity Bé. Three dry holes had been drilled. The surface rocks, which are mainly the Lecompton limestone of late Pennsylvanian age, are partly covered by glacial drift. A normal sequence of Pennsylvanian rocks rests disconformably on Mississippian limestones.

The structure shown by the surface rocks is a northeast-trending gentle anticline having a closure of less than 20 feet. The closure of the anticline. increases with depth. The pre-Pennsylvanian structure is marked by faulting, which is not noticeable in the surface structure. There seems to be a definite and pronounced southward shift in the position of the structural crest with increasing depth.

There are three known gas- or oil-producing zones. Most of the gas comes from the McLouth sand at the base of the Pennsylvanian rocks. Three wells produce oil from this zone. The McLouth sand is variable in permeability and in some structurally favorable areas is lacking in porosity. The weathered and porous top of the Mississippian rocks yields gas in some wells. This zone is saturated with oil in some wells but no oil has yet been produced from it. The lowest producing zone to date is a porous dolomite zone in the undifferentiated Burlington-Keokuk limestones from 125 to 150 feet below the top of the Mississippian rocks. This zone yields oil in three wells.

Production of gas from the McLouth sand extends far beyond the area of closure of the anticline as mapped on the gas sand. It is evident that production in this zone is dependent more on the presence of permeable sand than on local structural conditions, though it is possible that the McLouth anticline may prove to be only a part of a much larger anticlinal structure. Production of oil from Mississippian rocks seems to be governed more closely by anticlinal structure than does production from the McLouth sand.