These results were recorded while drilling the ChevronTexaco deepwater Tonga Exploratory Prospect located in Green Canyon Block 727. True vertical depth of 31,824 feet was reached exceeding the previous depth record by 700 feet, with a maximum-recorded downhole pressure of 26,138 psi in the Tonga #1 well.

Schlumberger said it delivered continuous real-time surveys, allowing the well trajectory to be kept on target during the entire drilling and logging process.

"These results are an excellent example of how Schlumberger and its partners capitalised on technology and our strong working relationship to advance the exploration frontier," said Paal Kibsgaard, president, Drilling & Measurements, Schlumberger Oilfield Services.

"The Schlumberger tools functioned flawlessly under the extreme conditions of depth and pressure. We were able to capture and transmit 100 percent of the data in real time, without lost time or trips, which was critical to the success of this ultra-deep exploration well."

Schlumberger used a high-pressure arcVISION675* 6 3/4-in. drill collar resistivity tool and PowerPulse* MWD telemetry system to acquire data while drilling. The high-pressure OBMI* Oil-Based MicroImager tool along with the Xtreme* high-pressure, high-temperature well logging platform were used to complete the formation evaluation program. Drilling operations for this record-setting well located in 4,695 feet of water and approximately 150 miles southwest of New Orleans were conducted from Transocean's Discoverer Deep Seas drillship.