Water-based drilling fluids can often be the fluid of choice due to advantages in ECD management, reservoir analysis, environmental sustainability, health and safety protection, and penetration rates. However, when shale is encountered during drilling operations, the chemical swelling stresses in the wellbore can potentially be very high. Water present in the drilling fluid can interact with the clay present in the formation resulting in drilling issues such as wellbore instability, high torque & drag, and stuck pipe. Reactive clay present in drilling fluid also adversely affects target fluid properties. To avoid these potential problems, a proper understanding of shale inhibition mechanisms and the relative products is a requirement.
This course covers the main facets of shale inhibition and also the unique chemistry behind each method. Topics covered include:
Balanced activity or vapor exchange
MMO or pure oil systems
Cementation of the shale porosity matrix