Improve ROP while reducing high-impact bit damage

The Putumayo basin in southern Colombia presents a challenging application. It required Amerisur Resources to drill through the Pepino Formation, which has an average thickness of 1,200 ft [366 m]. The formation is composed of two conglomerate layers of sandstone and interbedded layers of claystone. The productive zone lies in the Villeta Formation and consists of limestone and sandstone layers. Based on offset data for the 8 1/2-in section, the nature of these formations inflicts severe impact damage on PDC bits, resulting in their being pulled out of hole prematurely due to bit ringout.

Use a bit with unique-geometry cutting element and specialized fluid system for higher ROP

Amerisur Resources used a StingBlade bit to drill through the hard, high-impact conglomerate of the 8 1/2-in section in the Pepino Formation. Schlumberger also recommended using the KLA-SHIELD system due to its ability to inhibit clay swelling and dispersion, thereby minimizing the potential for bit balling.

Improved ROP and saved more than USD 300,000 in drilling time-related costs

The BHA incorporating the StingBlade bit and the KLA-SHIELD system was used to drill a total of 1,741 ft [531 m] in the 8 1/2-in section. In the challenging Pepino Formation, the StingBlade bit increased ROP from 46 ft/h to 70 ft/h—an improvement of 51%. The StingBlade bit drilled 252 ft, compared to 60 ft using conventional PDC bits, penetrating into the Rumiyaco Formation. Overall, drilling time was reduced by 22.5 hours, saving the customer an estimated USD 300,000.

The StingBlade bit was dull graded as 1-2-BT-A-X-1-WT-BHA, whereas conventional PDC bits suffered ringout. Amerisur Resources decided to continue using StingBlade bits to drill in the Putumayo basin.