ABSTRACT
The Morrow rocks of Western Kansas and the Oklahoma Panhandle have a maximum thickness of 700 feet and pinch out northeast on the flank of the Anadarko basin.
Sands within the Morrow series occur in two basic intervals designated as upper and lower. Upper sands are very lenticular but usually produce where present. They account for production in the Camrick pool, Texas County, Oklahoma; Light pool, Beaver County, Oklahoma; Interstate pool, Morton County, Kansas; and the Leslie pool, Meade County, Kansas. Lower sands produce in the Mocane pool, Beaver County, Oklahoma; Keyes pool, Cimarron County, Oklahoma; and the Sparks pool, Stanton County, Kansas.
Morrow sands produce more than half of the area’s crude oil and a large percentage of the pre-Permian gas. Production from the 60 pools in the area is from simple anticlinal to complex stratigraphic traps. Common completion practice is through casing with fracture treatment following a light-mud acid wash. Some excellent quality sands are completed natural.
Wells sufficient to test the Morrow range in depth from 4,600 to 8,500 feet. Well costs average $10 per foot dry and $15 per foot completed. Reservoirs range from 3 to 90 feet in thickness, resulting in non-commercial to excellent wells with fast payout (less than 1 year). Average porosity is 14%; average connate water saturation is 25% with instances of 40% in commercial wells. Reserves in place range from 300–750 MCF per acre foot and 400–750 barrels per acre foot. Reservoir engineering studies of the character and behavior of some Morrow sands indicate that they should be capable of permitting efficient “sweep out” under secondary recovery.
Subsurface geology and imaginative thinking are essential to the exploration approach of the Morrow. Gravity and seismic methods are being used with success. This area is in the early stages of development, and many reserves remain to be found.