By: Matt Case, Lead Engineer, Eastern U.S.
Ulterra Drilling Technologies continues to expand the application for its ground breaking CounterForce® cutting structure technology. CounterForce uses the cutting structure to reduce vibrations at the bit, which increases efficiency and reduces bit damage. Reducing vibration is particularly important on wells which utilize Rotary Steerable Systems (RSS), which are becoming more popular as well planners are pushing the limits on directional difficulty and lateral lengths. Most RSS tools are highly susceptible to failure due to vibration, which is one of the most common reasons the BHA must be tripped. RSS directional hands will often monitor these vibrations and are forced to reduce drilling parameters, and sometimes stop drilling altogether to pick up off bottom when vibrations get too high. Vibrations in a way act as an ROP ceiling, limiting the driller to lower parameters than what is necessary for maximum ROP. With the ability of the CounterForce cutting structure to reduce vibrations, we can not only reduce the number of trips for tool failures, we can also effectively elevate the ROP ceiling so that operators can drill faster and still avoid high vibrations.
The claim that CounterForce can reduce vibrations, and therefore increase ROP and reduce the number of trips is validated through numerous field runs verses competitor bits. A major operator in South Texas utilizes the Weatherford Revolution Rotary Steerable System to drill out from under surface through the curve and lateral to TD in one trip. Comparing the Ulterra CounterForce U516M verses competitor bits in this application in the year 2015, the U516M on average drilled 10% faster and was tripped 32% fewer times for tool failures. With 41 runs within this time frame, the U516M is the performance and market share leader for this operator.
CounterForce performance has also been validated through electronic drilling recorder (EDR) analysis. A four well pad in South Texas utilizing the Waterford Revolution RSS ran the CounterForce U516M on three wells, and a competitor bit on the fourth. The stick-slip magnitude, measured in a rotational value of c/min, was 35% lower for the average of the three CounterForce runs compared to the offset. In addition, the average ROP for the three CounterForce runs was 27% faster than the offset, saving the operator 13 hours on each well the CounterForce U516M was in the hole.
CounterForce technology has also been tested in demanding applications offshore in the Gulf of Mexico. A major operator drilling in the Eastern GOM utilized the Ulterra 16.50” U713M CounterForce to drill a 2,600 ft. section through the Base Miocene and Cretaceous formations. This operator was particularly concerned with high vibrations through these formations due to offsets they had drilled in the past. The Ulterra U713M CounterForce was able to decrease stick-slip vibration by 30% and increase ROP by 14% compared to said offsets.