Petrobras has cut in half the time and cost of drilling some wells using its patented True One Trip Ultra Slender (TOTUS) concept. The technique can be used in certain mature fields of the postsalt where geological and reservoir characteristics favor its application.
With TOTUS, the firm drilled a well in 44 days in early July, compared to the historic average of 96 days, resulting in a cost reduction of approximately 50% or $30 million.
The development of post-salt wells offshore Brazil has been a challenging project. Faced with water depths of 2000-plus m—and a salt layer 2000 m thick—to reach reservoirs at 7000 m below sea level, Petrobras had the need to use novel technological and procedural techniques.
Petrobras applied the TOTUS concept to complete the 7 GLF 49H ESS well in the Golfinho field in the Espírito Santo Basin, 62 miles from Vitória. It also expects to apply the concept in new wells from 2021 to 2025, with potential for cost reductions of $20–35 million per well.
This was the first post-salt well built with the application of the TOTUS concept, which reportedly simplifies and reduces the time spent in the drilling and completion stages, based on optimizations and innovations in the design and planning phases.
TOTUS drills the well in only three phases (Ultra Slender) compared to four or five phases in conventional drilling, and a one-trip completion system (True One Trip) instead of two or more maneuvers for conventional completions.
