Drilling fluid design for geothermal wells

Abstract

Drilling is a key process in the development of geothermal resources, whether at the exploration stage or in a fully developed field. It constitutes up to 35-50% of project costs. Successful completion of a well at minimal cost is, therefore, imperative. One area that highly affects both successful completion of a well and its cost is the drilling fluid program. Drilling fluids have advanced over the years, more so in petroleum drilling; however, some of the technologies in the oil sector may not be relevant in geothermal drilling and could just escalate the well costs. It is imperative to design a simple drilling fluid program that will not only ensure a quality well but also minimise the cost of the well. This paper seeks to address the selection of a drilling fluid best fit for geothermal wells.