This paper describes a team approach adopted on Valhall to limit the occurrence of wellbore instability, lost circulation and stuck pipe problems by the development and implementation of field-specific operational practices while drilling in the Overburden. It will highlight the benefits of an 11-3/4" application specific liner that has been upgraded from a contingency liner to a planned intermediate liner in the drilling programme. Details will be presented explaining the importance of planning for success and dedicated offshore engineering support. Knowledge management tools and processes were used to help refine these procedures and practices over a period of 24 months.
During this time one key performance indicator, Dry Hole Days /10000ft has been improved by approximately 40% in wells drilled at an inclination higher than 50 degrees through the overburden. More importantly, the primary goal of setting 9 5/8" casing in the reservoir has been achieved successfully in the last 6 wells when previously failure to accomplish this was common.