Development of a trip time for bit exchange simulator for drilling time estimation

Abstract

The development of geothermal power generation technologies for applications in non-volcanic areas, based on artificial reservoir creation, has prompted numerous studies on the efficient and economic execution of costly deep subsurface drilling operations. However, the difficulties in predicting the duration and cost of boring work with acceptable reliability make the efficient and organized management of drilling operations very difficult. The trip time for drill bit (i.e., the time taken to withdraw the drill stem to replace bits worn-out, followed by its re-entry into the borehole) that is required because of the abrasion and replacement of bits has a large impact on drilling time and performance. Therefore, a methodology for predicting the time required for a trip for bit exchange at a given depth will enable reliable drilling time and cost estimation for better drilling production management. This study divided the abrasion condition of roller bits into eight steps and used bit life expectancy time for developing a simulation algorithm for Trip Time for Bit Exchange (TTBE). A methodology that can classify the depth of drilling well based on the characteristics of the formation and drilling parameters has also been suggested based on the Bourgoyne and Young model to forecast drilling rates and the extent of bit abrasion.