The high cost of drilling gas wells worldwide has prompted the gas industry to seek more efficient and economicalmeans of reaching natural gas pay zones. Particular focus haslong been focused on increasing the rate-of-penetration ofdrilling tools. Drilling by percussion methods has dramaticallyimproved penetration rates in some applications where air is usedas the drilling fluid. However, air cannot be used in allapplications because of water production, or for well control orsafety reasons. For many years, innovators have tried to developa percussion drilling tool actuated by drilling mud. However, theincompressible and abrasive nature of drilling mud has causedeach of these efforts to fail to produce an economical tool. Aprototype tool with many novel and innovative design features hasbeen developed. In laboratory testing this tool has shown promisein providing consistent and sustained operation. Initial testingof this tool in a deep gas well has led to the conclusion that ahigher energy tool is needed to provide adequate increases in therate of penetration. In Phase I, a new tool will be designed andbuilt, based on previous laboratory and field experience. Thistool will then be tested in a laboratory setting to determine itsbenefits over conventional rotary drilling. Basic operatingeffectiveness will be measured as functions of supply pressureand weight on the bit. Should benefits over conventional drillingbe measured in Phase I tests, Phase II testing will includelaboratory and field tests and will catalog benefits and optimaloperating parameters in various rock formations.Anticipated Results /Potential Commercial Applications asdescribed by the awardee:With successful completion of Phase Iand II efforts, a characterized, effective tool will be availableto industry which will offer significantly reduced costs ofdrilling wells where drilling mud is used as the fluid. Costreducing features are expected to include an increase inpenetration rate, a decrease in hole deviation, and an increasein bit footage. Well safety may also be enhanced by encouragingthe use of mud drilling in potentially dangerous wells.
