Analysis of bit operations : Laguna Colorada geothermal project, Bolivia

Abstract

Twenty-seven years ago the National Electricity Company of Bolivia (ENDE) drilled four wells successfully in the Sol de Mañana geothermal field. The wells confirmed the geothermal power potential of the field and with a loan, financed by the Japanese International Cooperation Agency (JICA), new wells are planned to be drilled in order to develop the project’s first stage of 50 MW. Drill bit selection and operation are essential factors for getting good performance and avoiding problems during drilling activities. Multiple linear regression (also called Bourgoyne and Young method) and Mechanical Specific Energy were the methods applied on data from the Icelandic well RN-16, finding that a theoretical research could be useful in improving drilling time and better identify when problems or dysfunction is occurring. Both methods evaluate the effects of the rate of penetration (ROP), such as: rock strength and drill ability, differential bottom hole pressure, mud flow rate, weight on bit, revolution per minute. Finally, rock strength surveys were found to be a useful tool for making bit selection more efficient, especially in new fields.