SW-101 'A Bentonite Based Drilling Fluid for Brackish and Seawater Applications'

摘要

This paper will address the need, development, laboratory and field results for Wyo-Ben's seawater drilling fluid called SW-101. Drilling with a fresh water fluid in a salty environment - can it be done? Not too long ago the answer was "sometimes" at best. How many bores were lost, or how much extra horse power, wear and tear was needlessly placed on the drilling machine by pulling excessive amounts of force caused by poor hole conditions? If these "poor hole conditions" were due to seawater/brackish water contamination of the drilling fluid, the product is here to correct those symptoms. Our test data enclosed within indicates the performance of commonly used products that are being utilized in a sea water environment. Materials evaluated were SW-101, Hydrogel 90 (API material) Extra High Yield, and Attapulgite, in varying concentrations mixed into seawater. When a normal bentonite is mixed in fresh water, it has the positive characteristics of viscosity, suspension, and wall cake building for stability. When this mixture comes in contact with seawater, all three of these attributes are changed a great deal. Due to the exposure of high calcium and magnesium associated with the seawater, the bentonite is forced to give up most of the water it was previously controlling. As the deterioration continues, the suspension as well as the wall cake building qualities are lost. With an increased amount of free water caused by dehydration, the bore hole integrity is compromised and usually starts to cave in around the drill string. The field projects along with laboratory data support the SW-101 as a viable unique product to address a real and common problem. The contractor involved working in and around coastal waters today can bid jobs with more confidence resulting in a more stable drilling fluid. Utility installations as well as improved techniques are ever increasing, trying to keep up with the demand on this exciting market place. The successful contractor will use the best "tools" to make each bore a winner.