Drilling operations at the Silvergate exploration well, drilled on Mississippi Canyon Block 339 in the U.S. Gulf of Mexico, have been completed, Noble Energy Inc. (NYSE: NBL) said April 8.

Because commercial hydrocarbons were not encountered, the well is being plugged and abandoned.

Noble operated the Silvergate well with a 50% working interest, and the company’s total exploration expense for the first quarter of 2016 will range between $130 million and $170 million. Costs associated with the Silvergate well will be recorded in first-quarter 2016 results.

When Silvergate operations are complete, the rig will move to Green Canyon Block 39 and begin drilling an appraisal well at the Katmai oil discovery. The appraisal well will test additional gross resource potential beyond the 40 million barrels of oil equivalent (MMboe) to 60 MMboe already discovered.

Results from the Katmai appraisal well are expected in the early part of the fourth quarter of 2016. Potential development at Katmai would likely involve a subsea tieback into existing infrastructure. Noble Energy operates Katmai and has a 38% working interest in the appraisal well.

Noble Energy Inc. is based in Houston.

Offshore