ABSTRACT: Cyclic Sedimentation, Depositional Environments, and Facies Distribution of the Permian Paddock Member of the Yeso Formation, Vacuum (Glorieta) Field, Northwest Shelf of the Permian Basin

BURNHAM, DAN E., Mobil Exploration and Producing U.S. Inc., Midland, TX, and D. R. WOMOCHEL, University of Texas of the Permian Basin, Odessa, TX

The Vacuum (Glorieta) field is located on the northwest shelf of the Permian basin in central Lea County, New Mexico. Cumulative oil production of 62 MMBO is primarily from the upper 100 ft of the Leonardian Paddock Member of the Yeso Formation. Cores from 10 wells were examined to identify lithologies and facies relationships.

Five lithofacies were identified: (1) fine-grained quartz sandstone/siltstone facies, (2) pelletoid mudstone facies, (3) skeletal packstone/wackestone facies, (4) oolitic-pelletoid grainstone facies, and (5) crystalline dolomite facies. These lithofacies occur sequentially in four shoaling-upward cycles that can be correlated throughout much of the study area.

Three major depositional environments are recognized in the Paddock Member of the Yeso Formation: (1) a subtidal open-marine environment in which the oolitic grainstone facies was deposited, (2) a subtidal protected shallow-marine environment where the skeletal packstone/wackestone facies was deposited, and (3) a subtidal to supratidal restricted shallow-marine environment where the pelletoid mudstone facies accumulated.

Facies analysis indicates that the Paddock Member was deposited on a broad shallow-marine shelf. Numerous shoaling-upward cycles are possibly related to worldwide Permian sea level fluctuations. Porosity development is enhanced at the upper surface of each shoaling-upward cycle by dissolution of fossil fragments and grains.

AAPG Search and Discovery Article #91018©1992 AAPG Southwest Section Meeting, Midland, Texas, April 21-24, 1992 (2009)