Advanced and emerging drillstring technologies overcome operational challenges

Drilling ultra-deep wells places significant requirements on the drillstring. Lengthy drillstrings lead to high tensile loads, which lead to slip-crushing, hoisting issues and drill pipe collapse capacity concerns at the blowout preventer. BOP shear rams may also have difficulty cutting today’s high-strength, high toughness drill pipe. BHA connection failures pose greater risk and cost at ultra-deep well depths. This article analyzes the many challenges of drillstring designs, specifically for ultra-deep drilling. It presents emerging drillstring technologies that are expected to increase depth capability for continued deep drilling advancement. DEEP DRILLING TREND Deep drilling trends in the US and throughout the world are increasing. Since 1995, the number of US wells drilled, greater than 15,000-ft TVD, has more than doubled, The number of annual, active US rigs drilling greater than 15,000-ft TVD has nearly tripled. The number of high-pressure, high-temperature (HPHT) completions in the US has nearly tripled since 2000.