Sago waste starch as fluid loss control agent in Water Based Mud

Abstract

Water Based Mud (WBM) is a common type of drilling mud that widely used in drilling operation. Wide acceptance of WBM for drilling is hugely due to the reasons of existence of stringent environmental policies, and high hydrocarbon exploration cost. However, disadvantages such as poor filtration characteristic, poor suspension behavior and stuck pipe problems had limited the usage of WBM. Fluid loss into formation is a problematic situation whereby invasion of water will leads to formation damage and wellbore instability which can jeopardize the formation evaluation job. While poor suspension behavior will affects the cutting transport efficiency. Besides that, stuck pipe problem which happens due to growing of mud cake in permeable formation layer will also give arise to the increase of possibility of losing the bottomhole assembly in hydrocarbon exploration. Starch is a type of biopolymer that can function as fluid loss control agent and viscosifier in drilling mud. Sago waste starch (SWS) which is inexpensive and environmental friendly has the potential to be used as an additive in drilling mud. Therefore the objective of this study is to investigate the possibility of using sago waste starch from sago palm (Metroxylon Sagu) in drilling mud. Results shows that performance of SWS is inferior compared to commercialized Hydro Starch (HS). Development of gel strength is high for SWS. From the experimental finding, higher SWS concentration is needed to obtain similar plastic viscosity obtained by HS. In terms of filtration control performance, SWS is inferior to HS. All starches performances deteriorate after aging process. Mud cake thickness of SWS is generally thicker than HS.