Grant: Discovery Grants Program - Individual

Drilling or rock penetration is a fundamental activity involved with a range of engineering activities, for example drilling wellbores for exploration and production of petroleum resources, diamond core drilling and blasthole drilling for the mineral industry, and drilling wells for environmental and geotechnical engineering applications. All of these drilling activities can be categorized as either rotary drilling or rotary-percussion drilling. Rotary drilling is described by a static weight-on-bit, an average rotary speed and resulting torque-on-bit, and average bit jet-nozzle hydraulics resulting from circulation of drilling fluids. Rotary-percussion drilling includes these same parameters plus percussive hammer rate and resulting dynamic impact forces. Drilling efficiency can be described as reaching the drilling targets as quickly and with least costs as possible. This includes components such as rate-of-penetration, specific energy (defined as the amount of energy consumed per until volume of rock penetrated), and rate of bit wear which plays a critical role in the life of the bit and amount of inefficient non-penetrating-time needed to pull (or trip) the drill string to replace the bit. Through drilling research conducted during the past several decades, including contributions from the applicant, it is widely accepted drilling efficiency is a function of the rock strength and rock type, drilling penetration mechanisms (determined by the selection of rotary versus rotary-percussion drilling and bit type), level of bit wear, bottom-hole-pressure and bit hydraulics (which determine the efficiency of cuttings clearing), and dynamic bit-rock interaction and bit-rock compliance (which influences both the penetration mechanisms and cuttings clearing). The Drilling Technology Laboratory at Memorial University has the facilities to simulate rotary and rotary-percussion drilling under representative field conditions while measuring a range of drilling parameters, has the capability to simulate the entry of kick fluids into the wellbore and near well-boregeomechanics, andnumerical methodologies to simulate drill string dynamics and friction, bit-rock interaction, cutter penetration mechanisms, and drilling system fatigue. The proposed research will utilize these DTLcapabilitiesto investigate 2 major drilling areas, first by improving the penetration mechanisms for rotary drilling and rotary-percussion drilling through combined numericaland experimentalinvestigations, and secondly to evaluate the potential of early kick detection by identifying potential changes or combinations of changes in dynamic drilling parameters while drilling. Both of these areas of investigation will contribute to improving drilling performance, efficiency, and safety, making drilling activities more cost-effective and less hazardous.