Shell Offshore Inc. has provided an update for its Whale prospect in the deepwater Western Gulf of Mexico, characterizing the June 2017 oil strike as âone of the largest U.S. Gulf of Mexico exploration finds in the past decadeâ that âadds to the companyâs Paleogene exploration success in the Perdido area.â The 31 January 2018 press statement revealed that the Whale discovery well, the AC 772 1S0B1 bypass well (API: 608054007901), reached a final measured depth of 22,948 ft (6,995 m) and penetrated more than 1,400 net ft (427 m) of oil-bearing pay. When the discovery well finalized, the projectâs participants, operator Shell (60%) and Chevron (40%), opted to keep the results of the Whale bypass and original hole confidential saying only that hydrocarbons had been encountered. Whale is an exploratory play found near Shellâs Paleogene-aged production at the Great White field complex. The Whale drill site is found only one block northeast of Silvertip field, a producing Frio oil accumulation. The deeper Wilcox sand is the main reservoir interval at the complexâs Great White and Tobago fields. The Whale prospect resides in some 8,800 ft (2,682 m) of water in the south-central portion of the Alaminos Canyon (AC) area. It lies 150 miles (240 km) east of Port Isabel, Texas, and the US-Mexico maritime boundary is only 20 miles (32 km) due south of the Whale prospect. Shell operates on Alaminos Canyon block 772 through OCS lease G35153. Shell commenced appraisal operations in late October 2017 to gauge the magnitude and extent of the Whale accumulation. The delineation work is occurring in Alaminos Canyon block 728 (G31195), located about 4 miles (6.5 km) northeast of the discovery drill site. Following the discovery, Shell had a 13-well exploration plan approved by the Bureau of Ocean Energy Management over the Whale prospect covering AC blocks 684, 728, 771, and 772, which gives an indication of the potential size of the find. After receiving a permit to drill, the operator commenced the AC 772 #1 bypass on 23 April. The bypass borehole kicked out of the AC 772 1S0B0 original hole (API: 608054007900) at a depth of 20,300 ft (6,187 m). Shell spudded original hole on 7 February and is using the Noble âGlobetrotter Iâ drillship to conduct the Whale activities. The permitted AC 772 #1 drill site corresponds to the AC 772 âCâ surface location in Shellâs five-well, initial exploration plan (N-9899) that the BOEM approved in October 2015. The new-field wildcat was designed to spud and bottom in AC block 772, from a surface location sited approximately 2,200 ft (670 m) off the tractâs southwest corner. The operator had scheduled 200 days of rig time to drill and temporarily abandon a successful well. Shell reached total depth on the AC 772 #1 original hole after about 66 days of operations, and spent about 40 days on the bypass prior to applying to plug and abandon. The Whale prospect lies one block northeast of Silvertip field, which found on the east side of the Shellâs Great White field complex that consists of Great White, Silvertip, and Tobago fields. The hydrocarbon accumulations associated with the field complex are trapped in large structures formed along the Perdido Fold Belt, a prominent northeast-trending series of compressional folds in the southern AC protraction area. The Whale wells are structurally on-trend with the Silvertip accumulation and will target the correlative Paleogene-aged Frio interval found productive at Silvertip and likely the prospective deeper Wilcox section that produces at adjacent Great White and Tobago fields. It is estimated that a Whale prospect well will have seen the Lower Tertiary (Paleogene) strata age-equivalent to the main hydrocarbon-bearing reservoirs at the Great White complex at around 18,000 ft (5,486 m). Given the bypassâ kickoff point of 20,300 ft (6,187 m), it appears that the Whale wells may be testing Lower Paleocene and possibly older Cretaceous strata with a final drilling depth in the 22,000-25,000 ft (6,706-7,620 m) range. Shell owns a 60% working interest in the G35153 lease (AC-772) and operates this acreage for participating partner Chevron U.S.A. Inc., which holds the remaining 40% equity stake. The BOEM issued the ten-year lease, a standard 5,760-acre (23.31 sq km) tract, with a 1 January 2014 effective date and a scheduled primary term ending date of 31 December 2023. Bidding alone, Shell acquired the acreage 100% for USD 4,222,000 at OCS lease sale 233, held over the Gulfâs Western planning area in August 2013. Shellâs bonus bid topped a USD 2.06 million offer for the same tract made by Chevron U.S.A. Inc. In July 2016, Chevron U.S.A. Inc. farmed into the G35153 lease, taking a 40% non-operating interest in the tract in a transaction that took effect on 1 January 2016. The current equity split for the G35153 lease reverses the partnerâs ownership of adjacent Silvertip field, where Shell operates with 40% of the title interest and Chevron owns the 60% majority stake.
AC 772 001S0B1 (Whale) op. by Shell (60%, Chevron 40%) in G35153 OCS Lease, large oil deep-water discovery, encountered more than 427m net of oil bearing pay. Evaluation of the discovery is ongoing, and appraisal drilling is underway to further delineate the discovery and define development options.