New Mexico Geological Society Annual Spring Meeting — Abstracts

Carbonate reservoirs in the Cisco and Canyon (Upper Pennsylvanian) and lower Wolfcampian (Permian) sections in the Permian Basin of southeast New Mexico are significant reservoirs for oil and gas. The approximately 400 fields that have produced from these reservoirs have yielded a cumulative production of 490 million bbls oil (MMBO) and 3.2 trillion ft3 gas, 12% ofthe oil and 16% of the gas produced in southeast New Mexico. Sixteen of these fields have been identified that were underdeveloped at some stage in their history. These range in size from Milnesand West (0.210 MMBO cumulative production) to Dagger Draw (28 MMBO cumulative production).

Although initially underdeveloped, subsequent redevelopment of these 16 fields added significantly to reserves and production. Statistical analysis of production decline curves was used to estimate reserves developed during initial drilling of these fields and during subsequent phases of redevelopment. For the 16 fields studied, redevelopment accounted for a total of 64% of developed reserves. Redevelopment accounted for 90% of total reserves at Dagger Draw and at Milnesand West.

Redevelopment in these fields was generally in undrilled portions of the fields, and not in bypassed pay zones. Redevelopment generally resulted in a fivefold to tenfold increase in numbers of producing wells and productive acreage. Because 84% of Upper Pennsylvanian and lower Wolfcampian fields have less than 10 producing wells and 57% have less than three producing wells, it would appear that significant reserves may remain undeveloped in existing fields.