The Upper Pennsylvanian (lower Missourian) Cleveland formation has yielded 459 bcf of natural gas and 18.6 million bbl of oil from low-permeability (<0.10 md) fluvial and deltaic reservoirs in a seven-county tight-gas area of the northeastern Texas panhandle. Regional study of the Cleveland and underlying Desmoinesian Marmaton Group siliciclastics using tight well control and cores established the sequence-stratigraphic framework to clarify the vertical and areal occurrence of Cleveland reservoirs, seals, and possible source rocks.

Regionally distinctive facies stacking patterns in the study interval compose a sequence-stratigraphic framework of several westerly sourced systems tracts and three depositional sequences (S). S1 is characterized by landward- and seaward-stepping deltaic and strand plain cycles (parasequences) deposited on the top-of-Oswego type 1 sequence boundary that define (in ascending order) Marmaton late-stage lowstand-wedge (LST:pw) and transgressive systems tracts (TST) and a lower Cleveland highstand systems tract (HST). A regionally correlative, organic-rich marine-condensed section at the top of the Marmaton TST, equivalent to the Nuyaka Creek black shale bed of mid-continent cyclothems, represents maximum flooding conditions during eustatic rise. A relative sea level drop with the onset f S2 deposition initiated development of a lowstand incised-valley system (LST:iv) in the middle to upper Cleveland that extended basinward of the lower Cleveland depositional shelf edge. Subsequent coastal onlap by thin deltaic systems of the overlying TST marks the start of decreased sediment influx during late Cleveland time, resulting in thinning of parasequences and an increase in carbonate beds of high-frequency cycles in upper S2 and S3.

Stratigraphic traps and pinch-out of reservoir facies within small, southeast-plunging anticlines make up most traps in the producing area. Proximal delta-front and fluvial sandstones of the Cleveland upper HST and overlying LST:iv, respectively, are the primary reservoirs. The high-total-organic-carbon, top-of-Marmaton marine-condensed section and thick prodeltaic and lower distal delta-front shales within the lower Cleveland HST are the probable source rocks. Distal deltaic shales of the middle Cleveland TST form most reservoir seals. Potential new reservoirs should be targeted at the updip terminations of systems tracts, at lap-out positions of individual sand-rich HST and TST parasequences, and along LST:iv valley-margin stratal terminations.