Application of New Impregnated Diamond Bit Technology Saves Operator $2 MillionDrilling Southern Oklahoma Well

摘要

Economic development of deep gas wells, such wells in theCarter-Knox field in Stephens and Grady Counties, Oklahoma,depends on the effectiveness and efficiency of the drillingprogram. Many costly challenges are encountered whiledrilling the deep, high compressive strength, abrasivesandstone and interbedded shale in this geologically complexarea with high-angle beds, faults, fractures, and depletedformation pressures. Improvements in bit technology haveexpanded the variety of formations that can be drilled withimpregnated bits at penetration rates equivalent to roller conebits. This technology has helped reduce the risk in drillingoperations while improving well economics.A recent well in the Carter-Knox field utilized three newimpregnated bits to drill the interval from the third Bromidesandstone (15,000 ft) through the Arbuckle limestone anddolomite (18,700 ft) in 51 days improving well constructiontime by 35% over the best offset. Previous offset wellsrequired 18 to 20 roller cone, natural diamond and traditionalimpregnated bits to drill the same interval in 78 to 155 days.The operator reached total depth 21 days ahead of the AFEand $2.07 million under budget. Reducing the dry hole costmore than 30% has positively impacted the development plansfor the Carter-Knox field.The operator and a bit manufacturer cooperatively appliednew bit technology to an optimized well program to reducedrilling costs. Attention focused on using recently developedimpregnated bits that drill shale at penetration rates equivalentto rollercone bits without loss of performance in the hardabrasive sandstone formations. This technology combinedwith changes in drilling practices has increased the overallaverage penetration rate, kept the bit drilling on bottom, andreplacing multiple bits. The longer bit runs also reduced thenumber of bit trips limiting potential problems associated withtripping operations through depleted and sensitive formations.