Haynesville Shale
The Haynesville Shale is an informal, popular name for a Jurassic Period rock formation that underlies large parts of southwestern Arkansas, northwest Louisiana, and East Texas.
The Haynesville Shale is overlain by sandstone of the Cotton Valley Group and underlain by limestone of the Smackover Formation.
In these mudstones, the calcite occurs as silt-sized microfossil hash composed of fragmented fossils and carbonate mud.
In addition, the Gilmer Limestone member also represents a carbonate platform with oolite shoals that lie beneath central Upshur and western Smith counties, Texas.
[4][8][9] The Haynesville Shale was deposited in a restricted basin that was located on a southward sloping continental shelf covered by relatively shallow water.
The northern edge of this basin consisted of shallow coastal waters floored by carbonate muds and oolite shoals lying just north of the modern Louisiana - Arkansas border.
The western edge of the basin in which the Haynesville Shale accumulated consisted of a broad north-south carbonate platform with prominent oolite shoals.
[7][8][10] The carbonate platforms, their oolite shoals, the Sabine Island, and prehistoric Gulf of Mexico coastline created a restricted basin that marine currents could only readily access from the east.
Anoxic bottom water conditions allowed organic matter falling to the floor of this basin to be preserved and incorporated into sediments that became the Haynesville Shale.
[12] The US Energy Information Administration estimated that the average well would produce 2.67 billion cubic feet of gas.
Oil and gas is currently produced from shelf-edge carbonate reservoirs which consist of oolite shoals within the Gilmer Limestone and Buckner Anhydrite members.
[7][16] A documentary film entitled "Haynesville: A Nation's Hunt for an Energy Future" has been made on the subject of the mineral rights leasing "gold rush" and the potential impact of the Haynesville Shale gas play on national and global energy picture.
[18] Not long after the land-leasing boom began in 2008, new mineral owners across northwest Louisiana and East Texas joined online forums and began sharing information with each other about the process of oil and gas leasing, leasing bonus payments and well production results.
