This paper discusses the systematic design and development of high performance water-based muds and provides insight into the unique chemistry and inhibition characteristics of various amine inhibitors. Equally important, performance correlations of inhibitive systems in laboratory testing as compared to state-of–the-art inhibitive systems are included.

Invert emulsion drilling fluids have long been effective in drilling reactive shale. Developing high performance (highly inhibitive) water-based drilling fluid that would perform like invert emulsion drilling fluid has long been cited as the ultimate technical goal of the drilling industry. Progressive development of inhibitive water-based drilling fluids based on amine chemistry has made some impact on reaching this goal. Amine-based inhibitive drilling fluids have steadily gained popularity with service and oil companies.

However, these fluids have not always been completely successful in inhibiting the hydration of highly water-sensitive clays. The short-comings are particularly evident when drilling highly complicated and reactive shale formations. Keeping this in mind, an innovative highly inhibitive water-based drilling fluid has been systematically designed with the performance characteristics of oil-based muds.

The newly developed high performance water-based mud (HPWBM) comprises a unique polymeric amine shale intercalator for shale inhibition, an amphoteric polymeric shale encapsulator, a high performance lubricant/anti-accretion agent and a specialized fluid-loss additive. The newly developed HPWBM performed like an oil-based mud in laboratory testing as well as in offset wells using invert emulsion drilling fluids (OBM) due to highly complicated and reactive shale formations.

You can access this article if you purchase or spend a download.