Lessons learned from the Floyd shale play

• The focus is the shale gas play in the Floyd Shale, Black Warrior Basin (USA).
• The evolution of ideas and practices pursuing this shale gas play are described.
• It shows how the play screening did not adequately address the exploration risks.
• The principle aspects of the play were investigated to find the failure mechanism.
• An improved screening method was developed for future plays.

Detailed analysis of the organic matter, mineralogy, and related rock properties of the sediments of the Neal shale member of the Floyd shale group in the Black Warrior Basin were done to determine the cause of the lack of adequate production in this shale gas play. Analysis of pilot well cores found the organic-richness, kerogen type, maturity, thickness, porosity/permeability, and geomechanical behavior were all found to be satisfactory for a potential shale play. Although bulk mineralogy compared favorably with other shale plays, some of the testing pointed toward fluid–clay interactions and proppant embedment as the cause for the lack of production in this shale gas play. However, close proximity to gas charged overlying sandstones along with normal pressure in this shale reservoir suggest potential seal problems have reduced the gas charge in the shale. This led to changes in the screening parameters for new plays, emphasized the importance of doing look backs on failed projects, and the need to integrate learnings into future project evaluations.