The shale revolution in the continental United States has reinvigorated the Oil and Gas Industry. According to the EIA, shale plays account for around 49% of total U.S. crude oil production. Although much progress has been made to be more efficient time and money wise; there are still technical issues that are being addressed.
Drilling through shale has many obstacles that plague the industry. It is well known that shales have a strong affinity for water. When water is absorbed, the stability of the shale is reduced. Cohesive strength is reduced which causes the shale to either expand or crumble. The amount of water absorbed depends greatly on the characteristics of its clay mineral and the ionic concentration of surrounding fluids.
This study takes a literary review of well-bore stability of unconventional shale plays in the United States and methods to improve drilling practices to account for this issue.