A combination of divalent base brine and high wellbore temperature presents significant challenges for high-density aqueous reservoir drilling fluids. Such systems traditionally use biopolymers as viscosifiers; however, they are subject to degradation at elevated temperatures. Nonaqueous drilling fluids are thermally stable, but complete removal of the filter cake is challenging, which can lead to formation damage. The complete paper describes the qualification and first deepwater drilling application of an aqueous reservoir drilling fluid at temperatures greater than 320°F.
Introduction
The laboratory development and scale-up yard trials of the high-temperature divalent brine-based reservoir drilling fluid (HT-RDF) and solids-free screen running fluid (SF-SRF) systems used for this well took several years.
