| Abstract |
As energy demand increasing, people started to seek and develop new alternative energies, one of those is geothermal. Although drilling for geothermal energy is quite similar to drilling for oil and gas, there are some aspects of it that are unique. The main challenges associated with geothermal drilling are related mostly to the hardness of igneous and metamorphic rocks being drilled, the high temperature of the formation (Marbun et al., 2012). Also, another challenges encountered in drilling operations including total loss of circulation, low penetration rate, high temperature damage of directional drilling steering tools and mud motors, breakdown of drilling foam structure at high temperatures, high drill string torque, loss of cement slurry and others (Zhang et al., 2012). As the well has been drilled, evaluation is a critical step to improve next drilling operations. To obtain great learning and convert it into better operations, requires experiences from previous operations, and the most important is problems occurred during the drilling process. A good management of drilling operation has to applied well planning, execution and evaluation continuously in order to achieve maximum result. Methodology used in this study is integrated drilling management and improvement towards drilling design and operational, also by considering the geological conditions and production target. Well planning data of the well are collected and compared with real condition of the well to find the design compatibility between the design and the well condition as lithology and formation temperature. Properties analyzed are including hole cleaning, bit selection and casing design. The methodology of this study has been implemented into a geothermal field resulting analysis of the causes of drilling problems, proper design to avoid the problems, and recommendations of procedural operations for next drilling activity. Implementation of this method would lead to great cost saving for the operation by overcome the problems encountered while drilling. |