The study of faulting is playing an increasing role in the search for oil. The Ramsey oil pool, in north-central Oklahoma, offers evidence on the effect of faulting on the migration of oil, both horizontal and vertical. It also affords evidence on the time of migration relative to the stages of structural growth.

The Ramsey pool, developed and operated principally by one company, offers a long production history, almost complete unit control, good well samples of the formations, and a reasonably complete record of the performance of individual wells.

The investigation proceeded through the building of structural maps on key formations, a close study of the thickness of key beds and the intervals between them, and a comparative study of the performance of individual wells and of the position of oil-water contacts during the productive history of the pool.

The study shows that (1) oil accumulated during a long period of structural growth; (2) vertical migration occurred along the fault and continued to the present; (3) migration across the fault reached different degrees of perfection in different reservoirs; and (4) fault movements occurred in three stages, the first being dominantly horizontal and the others vertical.

So far as is known to the writer this is the first pool study of its kind that has been made. The conclusions reached should have considerable application throughout north-central Oklahoma, as the structural history of that area was controlled by regional forces operating on geologic formations of similar character. In other areas the results can only be suggestive of similar studies that might well be made.