Published: 10/26/2020
Published: 10/26/2020
An operator was drilling an 8 3/4-in vertical section in the Marcellus Shale. The formations consist of highly interbedded shale and sandstone layers with UCS ranging from 10,000 psi to 20,000 psi. The previous benchmark drillbit designs drilled the intervals from shoe to shoe with minimal damage to the cutting structures; however, the operator wanted to improve drillbit performance to increase ROP.
Schlumberger introduced a StrataBlade concave diamond element bit specifically for interbedded layers of medium-strength formations with UCS between 5,000 psi and 20,000 psi. It increases ROP in such formations due to the unique geometry of Strata concave diamond cutting elements. Their distinctive concave feature with a pointed ridged tip decreases the effective cutter back-rake angle to cut deeper into rock and increases point loading that significantly improves cutting efficiency and sustains a higher instantaneous ROP with the same input energy.
The StrataBlade bit ran on the same pad as prior bit designs with the same BHA and identical drilling parameters. Drilling the same interval, the StrataBlade bit averaged 263.8 ft/h. The next-fastest bit run on this pad was 239.4 ft/h. That was a 10% ROP improvement over the best run with the benchmark bit design and a 15% increase compared with the average offset performance.
An operator in the Appalachian Basin used the StrataBlade concave diamond element bit to improve ROP by 15% compared with the average offset performance while drilling through interbedded layers with unconfined compressive strengths (UCS) up to 20,000 psi.
