In the Woodford Shale of Southeast Oklahoma, horizontal wells typically require multiple roller cone bits to drill the curve and lateral. Oil services giant Halliburton employed an engineered process to guide application-specific bit design through several evolutions for its Security DBS Drill Bits.

The result is a QuadPack Plus bit design solution that achieved successful build and lateral single-bit performances at field-record penetration rates. Incorporating customer input, the bit design follows a “model-measure-optimize” process that encompasses all aspects, from formation analysis to performance evaluation. 

With extensive offset well data available for these horizontal wells, bit specialists first used Sparta well planning software to conduct detailed analysis of the shale formation, identifying those intervals where offset bits suffered extensive gage wear, gage damage, surf wear, and shirttail wear. 

Output indicated compressive rock strength of the various sections/ formations of the play, and recommended bit parameters and best operating practices. In terms of optimizing roller cone design for this application, the engineered process manipulates the distribution of force acting upon the cutting structure. 

The objective is to maximize cutting efficiency or bottomhole pattern, and Halliburton states that this has been achieved with a more aggressive bit design that is tougher, more durable, and has a longer service life.