Abstract
Oil-based muds have shown great success in preventing borehole instability in shale formations. The presence of a threshold capillary entry pressure between oil-based muds and low permeability shales is considered to be the main factor in preventing chemical interactions between the drilling mud and the shale which can lead to shale failure. This article presents experimental data for the capillary entry pressure of several shales when exposed to oil-based muds. It is clearly shown that the entry pressure depends on the interfacial tension between the oil and water phases and shale permeability and cation exchange capacity. Data suggests that incorporating “emulsifiers” in oil-based mud formulations reduces the minimum capillary entry pressure. Non-polar oils show significantly higher entry pressures, indicating the importance of surfactants present in the oil-based mud.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
