Petrobras Concludes Drilling of the Monai Well, the Deepest in Brazil History

Petrobras concluded the drilling of the pioneer oil exploratory well in block ES-M-669, in the pre-salt of the Espírito Santo Basin. Named Monai, the project broke the record for the deepest well ever drilled in Brazil, at around 7,700 meters. Just by way of comparison, this distance is equivalent to 1.3 times the height of Mount Kilimanjaro, the highest mountain in Africa. In addition, this was the largest layer of salt ever drilled in the country, measuring approximately 4,850 m.

“The intensive use of technology and the efficient performance of the teams involved also allowed us to reduce the well drilling time by approximately 50%, compared to the historical average for projects of this nature and complexity, which also represents a significant cost reduction ”, commented the Production Development director, João Henrique Rittershaussen.

According to Petrobras, the drilling of wildcat well Monai generated all the geological information expected for the proper assessment of the area. The data will now be analyzed to define the future of the ES-M-669 block. Monai was drilled at a water depth of 2,366 meters.

The company also highlighted that the well also surpassed other drilling records, such as the longest single-phase extension (segment) in a vertical/directional well in the country, measuring around 3,400 meters. In addition, Monai also set the record for the longest tie-back column at 4,300 meters. The tie-back is a steel pipe that connects the pipe at the bottom of the well to the well head.

“The great depths reached posed a series of challenges for Petrobras. In general, the deeper the bore, the more compact and denser the existing rocks. For comparison purposes, the drilling speed close to the seabed reaches about 100 meters per hour. On very deep horizons, such as in the final stages of Monai, drilling speed drops to less than 5 meters per hour,” the company said in a statement.

The oil company also added that the pressure at great depths, such as those reached by the Monai well, poses a great challenge for the safe drilling of the well. “In these very deep geological horizons, the pressure reaches values ​​around 17,000 psi, the equivalent of approximately 1200 times the pressure existing in the Earth’s atmosphere at sea level or 500 times the air pressure in a passenger car tire”, he concluded .