Paper: UNIQUE DRILLING FLUID ADDITIVES FOR IMPROVED WELLBORE STABILITY AND REDUCED LOSSES

Increasing wellbore complexity and increasing pressure to improve drilling economics has necessitated increased focus on preventing lost circulation. This has required a close focus on wellbore stability and improvements in wellbore strength such that losses are minimized or alternately casing strings may be eliminated. In addition the drilling of depleted zones in the same section as normally pressured formations has led to increased focus on maintaining wellbore integrity and minimizing losses. The development and engineering of unique drilling fluid additives which can aid in increasing wellbore stability and minimizing fluid losses into drilling induced fractures has been a key in achieving the desired operational goals. The Authors will discuss the design of these unique drilling fluid additives and the treatment techniques required to ensure optimal wellbore stability and minimal induced fracture losses, along with the engineering tricks required to ensure successful application of such treatments.