1963 Paper (N)

A METHOD TO LOCATE WATER PRODUCTIVE INTERVALS IN A PRODUCING OIL WELL

Earl W. Sutton and James C. Albright Continental Oil Company Ponca City, Oklahoma

ABSTRACT

An experimental water entry survey was field tested in a well in the South Elk Basin Field of Wyoming. The survey procedure was to force a small volume of radioactive crude oil into the producing interval then produce it back using the conventional well pumping equipment. Gamma ray logging runs were made throughout the entire procedure. The theory of the survey is that all radioactive oil will be produced back from the oil productive zones, leaving no residual radioactive oil. This is because the injected oil is miscible with the formation oil. In water bearing zones, because of the immiscibility between the injected oil and the formation water, residual radioactive oil will be left in the formation. This residual radioactive oil will be indicated by the final gamma ray log.

This survey indicated the water productive intervals in the test well and also the oil productive zones. A porosity profile of the permeable zones was also obtained. The results of this experimental survey were confirmed by another water locating method.