Recoverable natural gas reserves from Jurassic Norphlet Formation, Alabama coastal waters

Conference · Tue Sep 01 04:00:00 EDT 1987 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:5996656

Mancini, E A; Mink, R M; Bearden, B L; Hamilton, R P

To date, 11 Norphlet gas fields have been established in offshore Alabama. These fields are part of a deep Jurassic gas trend that extends across southern Mississippi and Alabama into the Gulf of Mexico. Recoverable gas reserves of 4.9-8.1 tcf are estimated for the Norphlet Formation in Alabama's coastal waters. Proven gas reserves are estimated to be 3.7-4.6 tcf and potential reserves are estimated to be 1.2-3.5 tcf. The natural gas is trapped in a series of generally east-west-trending salt anticlines. The mechanism of structure formation appears to be salt flowage that has formed broad, low-relief anticlines, most of which are faulted, and many of which are related to small-scale growth faults. Salt movement is the critical factor in the formation of these petroleum traps. The primary Norphlet reservoir lithofacies are eolian dune and interdune sandstones that range in thickness from 140 to over 600 ft in Alabama's coastal waters. Gas pay can exceed 280 ft in thickness. Porosity is principally secondary, developed as a result of decementation and grain dissolution. Jurassic Smackover algal carbonate mudstones were the main source for the Norphlet hydrocarbons. The seal for the gas is the nonpermeable upper portion of the Norphlet Formation. The overlying lower Smackover carbonates are also nonpermeable and may serve as part of the seal.

• Research Organization: Univ. of Alabama, Tuscaloosa
• OSTI ID: 5996656
• Report Number(s): CONF-8710198-
• Conference Information: Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 71:9
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
ALABAMA
ANTICLINES
ATLANTIC OCEAN
CARBONATE ROCKS
CARIBBEAN SEA
FEDERAL REGION IV
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GULF OF MEXICO
JURASSIC PERIOD
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
OFFSHORE SITES
PERMEABILITY
RESERVOIR ROCK
RESOURCE POTENTIAL
RESOURCES
ROCKS
SALT DEPOSITS
SEAS
SEDIMENTARY ROCKS
SURFACE WATERS
USA