Geology of the Mcallen-Pharr Field area, Hidalgo County, Texas. Pts. 1-3

Journal Article · Fri Mar 01 04:00:00 EST 1968 · Bull. South Tex. Geol. Soc.; (United States)

OSTI ID:5926873

Collins, J

The McAllen-Pharr Field, discovered by seismic exploration in 1938, produces gas and gas-condensate from Lower, Middle, and Upper Frio Sands between the depths of 13,765 and 5,800 ft. The environment of deposition of the productive sands ranges from very shallow marine in early Frio time through brackish and transitional to continental in the late Frio. The Frio is a regressive offlap sequence. Hydrocarbon entrapment occurs in a simple faulted anticline in the Upper Frio, a large stratigraphic trap in the Hansen Sand, and many small complex fault blocks in the Lower Frio. Structurally, the McAllen-Pharr Field changes from a simple downthrown fault closure with basinward regional dip to a complexly faulted structure with steep, away-from-the-basin dips. This structural change occurs at the shale above the 8,500-ft sand, indicating a hiatus or unconformity which is confirmed by an abrupt change in pressure gradient.

• OSTI ID: 5926873
• Journal Information: Bull. South Tex. Geol. Soc.; (United States), Journal Name: Bull. South Tex. Geol. Soc.; (United States) Vol. 8:3; ISSN BSTGA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ANTICLINES
GAS CONDENSATE FIELDS
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
PETROLEUM DEPOSITS
RESOURCES
SOUTHWEST REGION
STRATIGRAPHY
TEXAS
USA