Structural Framework and Sand Genesis of Wilcox Group, Travis Ward Field, Jim Hogg County, Texas

Gerald E. Rolf

Since its discovery in 1983, there have been eight deep Wilcox and eight Queen City wells drilled in the Travis Ward field area. Of the eight Wilcox wells, four are producing gas from deep sands; three, that are capable of production, have been junked and abandoned, and one produces from the Hinnant sand at the top of the Wilcox. Only five of the eight Queen City wells have been completed; three are considered commercial. Wilcox gas reserve estimates range from 80 to 300 bcf.

To date, Wilcox and Queen City production is related to normal faulting associated with a deep salt and/or shale ridge within the Rio Grande interior salt basin. Growth of the ridge has resulted in the Wilcox being as much as 2,000 ft structurally higher than the areas immediately north and south of Travis Ward field.

Knowledge of the ancestral development of ridge closure prior to faulting may be critical to successful completions at Travis Ward field. Ridge-associated sea floor topography, shelf currents, sediment source proximity, and rate of sedimentation have combined for local development of high quality clean reservoir sands.

AAPG Search and Discovery Article #91042©1987 GCAGS and GC-SEPM Section Meeting, San Antonio, Texas, October 28-31, 1987.