Post-Macondo Drilling in Deepwater Gulf of Mexico Faces Added Challenges

Abstract

This article, written by Editorial Manager Adam Wilson, contains highlights of paper SPE 154928, ’Challenges Associated With Drilling a Deepwater, Subsalt Exploration Well in the Gulf of Mexico: Hadrian Prospect,’ by Mark C. Moyer, SPE, Scott B. Lewis, SPE, Mike T. Cotton, SPE, and L. Miles Peroyea, SPE, ExxonMobil, prepared for the 2012 SPE Deepwater Drilling and Completions Conference, Galveston, Texas, 20-21 June. The paper has not been peer reviewed. The Hadrian-5 prospect in the US Gulf of Mexico was drilled in approximately 7,000 ft of water as one of the first Gulf of Mexico wells drilled after a deepwater moratorium was imposed after the Macondo disaster. This exploration well was permitted under the new regulatory requirements of the US Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE). In addition to well-design regulations, BOEMRE required operators to calculate a worst-case discharge scenario and to develop containment plans for that scenario. The well was drilled and evaluated in a safe manner with no significant incidents, even though the geologic formations encountered were different than predicted. Introduction As a result of the April 2010 Macondo disaster, the US government responded with a moratorium on deepwater drilling, reorganized its regulatory agency, and is-sued new rules for offshore drilling. In November 2010, BOEMRE is-sued the Notice to Lessees and Operators 2010-N10. This notice to lessees and operators (NTL) required operators to certify compliance with all applicable regulations and submit plans to contain a worst-case discharge scenario as part of the drilling permit application. The Hadrian well is located in Block 919 of the Keathley Canyon in 6,941 ft of water, approximately 220 nautical miles southwest of the shorebase location in Fourchon, Louisiana (Fig. 1). The purpose of this exploration well was to evaluate the potential resource of the subsalt Pleistocene, Pliocene, and Miocene formations. On the basis of seismic data, there were no shallow hazards and no hydrocarbons above the salt structure. The Hadrian-5 well had an approved permit and a rig on location at the time of the moratorium, but the work was suspended and the rig was released to work on the Macondo spill response. The drill team, in conjunction with the geoscience and regulatory organizations, revised the exploration plan and the application for permit to drill (APD) beginning in July 2010 to meet the new regulatory requirements. BOEMRE approved the revised permit to drill in March 2011. Planning and Permits Following the Macondo disaster, BOEMRE issued additional requirements that operators must fulfill before regulatory approval is granted. Additional work was required during the planning and permitting phase to meet these new requirements. Interim final rules issued by BOEMRE required operators to submit additional details as part of the APD. Blowout preventer (BOP) equipment was one area of focus for the new rules. BOP control system drawings and independent certification of the BOP equipment design and capability must now be submitted. The Hadrian team worked closely with the rig contractor, and an independent agency provided the required documentation.