Drilling Fluid

Drilling fluid (mud) is fluid used during drilling operation. It provides function such as remove cutting from well, control formation pressure and maintain wellbore stability. Loss circulation material (LCM) is a material that can control the problems during the drilling process which is loss circulation. The most widely used LCM in the drilling fluids is Calcium Carbonate (CaCO3). In the worst case scenario, the total loss circulation can be occurring that will result no drilling fluids in the borehole and blow out would be happened. To prevent this from occurring, we need to effectively close the opening where the mud is flowing into the formation as soon as possible. But there is problem when we are using sawdust as loss circulation material (LCM) which is whether the chemical in the drilling fluids can suspend the sawdust or not and also how effective the sawdust can plug or close the opening at the formation. If the chemical did not have enough strength to suspend the sawdust, it will lead to the problem called mud sagging. The objective of this project is to evaluate the effectiveness of the sawdust as the bridging agent or loss circulation material (LCM). The rheological properties that were evaluated are; plastic viscosity (PV), yield point (YP), 6 rpm (low end rheology), gel strength and volume of fluid loss. Base on the result, the rheological performance at 1200F of sawdust is good to be as an alternatives LCM to normal LCM which is Calcium Carbonate (CaCO3) in water based mud that have low value of plastic viscosity and low volume of fluid loss. Sawdust also needs to have high value of 6 RPM reading (low end rheology) to make sure the mud is not sag.