Exploration is underway
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Earliest North Slope well spud by Oil Search; ConocoPhillips drilling most wells
The winter exploration season to find missed oil in Alaska’s North Slope is off to a good start, with ice road construction beginning in late November and Oil Search Alaska spudding the first well on Dec. 25 in the Mitquq prospect west of the central North Slope, where most of the drilling is taking place.
Four companies are drilling wells - 12 main bores plus sidetracks (permitted as separate wells).
The most active explorer, ConocoPhillips Alaska, expects to complete up to seven main bores; Eni US Operating two; Oil Search two; and 88 Energy subsidiary Accumulate Energy Alaska is drilling one main well.
88 Energy targets March 1As of Jan. 28, Accumulate’s 34-mile ice road was approximately 70% complete with a planned Charlie 1 spud date of “on or before March 1,” Erik Opstad, Anchorage-based general manager of operations for the company, told Petroleum News Jan. 28.
The Charlie 1 program is being financed by a joint venture between 88 Energy and Premier Oil Plc, with Premier paying $23 million of the costs.
In Accumulate’s Icewine project, Charlie 1 is on state oil and gas lease ADL 393380 approximately 29 miles west of the Franklin Bluffs pad, which is at Milepost 377.7 on the Dalton Highway.
According to Accumulate’s lease plan of operations with Alaska’s Division of Oil and Gas, in addition to the ice road, two 500 feet by 500 feet ice pads, one drill pad and one staging pad (a mile west of the Dalton Highway at MP 386) will be built.
Using Nordic Rig 3, Charlie No. 1 will be drilled to an approximate depth of 11,000 feet and may include laterals, sidetracks or additional penetrations.
The well will intersect seven stacked prospects, four of which are interpreted as oil bearing in nearby Malguk No.1 (drilled in 1991 by BP) and are therefore considered appraisal targets, 88 Energy said.
In paperwork submitted to the division, the primary drilling objective is the Seabee formation.
According to 88 Energy releases, the total gross mean prospective resource across the seven stacked targets to be intersected by Charlie 1 is 1.6 billion barrels of oil, with 480 million barrels net to 88 Energy.
ConocoPhillips about to spud 2 wellsThe first ConocoPhillips exploration well to be drilled this winter is Tinmiaq 20, expected to spud “today, but cold weather is hampering operations,” company spokeswoman Natalie Lowman said Jan. 29.
Drilling at the Harpoon prospect will begin in mid to late February, she said.
And although ConocoPhillips does not consider it to be part of its exploration program, the Fiord West Rhea 1 well west of the Alpine field involves an ice pad and road and will likely be the second winter season well spud. Per Lowman, drilling is “planned to start Feb. 2 (weather dependent) and could be completed in mid-February. This well will be drilled by Doyon 25,” she said Jan. 29.
The rigs the company has talked about using for exploration drilling are Doyon 141 and 142.
ConocoPhillips is planning to drill and test up to seven exploration wells this winter on its Willow (and West Willow) and Harpoon acreage in the National Petroleum Reserve-Alaska, although it is permitting 10 sites.
The U.S. Bureau of Land Management said in its environmental assessment that vertical seismic profiles will be done at some of the new wells.
The company’s existing suspended wells - Scout 1, Tinmiaq 2 and 15 - are part of the program to conduct inspection and potential abandonment.
The 10 wells, all on ConocoPhillips-operated leases, are as follows: Tinmiaq 14, Tinmiaq 18, Tinmiaq 19, Tinmiaq 20, Tinmiaq 22, Tinmiaq 24, Harpoon 1, 2, 3 and 4.
The Tinmiaq 14, 18, 20, 22, 24 ice pads will be 600 by 600 feet, as will all the Harpoon pads.
The Tinmiaq 2 ice pad will be 500 by 500 feet.
The Tinmiaq and Harpoon base camp ice pads will be 1,000 by 1,000 feet, as will be the Remote Ice Camp pad, or RIC, plus there will be several other ice pads.
The ice airstrip will be 4,000 by 75 feet.
Scott Jepsen, a ConocoPhillips Alaska senior vice president, recently said there will be 74 miles of ice roads for exploration (Harpoon), with 165 miles total in this winter’s program. He also said four of the wells would be in the Willow area (Tinmiaq wells).
Jepsen described the Harpoon program southwest of Willow as “rank exploration.”
State and federal geologists have said the geological targets in the Willow area are Nanushuk and Torok.
See the ConocoPhillips map on page 7 of the Dec. 15 issue of Petroleum News, which can be viewed in the print or pdf versions.
Drilling continues at Eni’s Nikaitchuq NorthEni’s exploration drilling this winter in frozen ice conditions is a continuing program in the Nikaitchuq North offshore federal unit, although the wells are drilled from state land; specifically, the Spy Island drill site, or SID, which is a Nikaitchuq unit production pad built next to Spy Island within the barrier islands in state submerged lands.
Plans for drilling two wells plus a sidetrack in the unit, NN-01 and NN-02, can be found in both state Division of Oil and Gas records, under the adjacent Eni-operated Nikaitchuq unit plan of development and a permit application, as well as in the U.S. Bureau of Ocean Energy Management’s Nikaitchuq North plan of exploration.
The division’s website said a rig modification for Doyon 15 rig was initiated in second quarter 2017 to prepare for a December exploration well. NN-01was spud on Dec. 25 and drilled to a measured depth of 30,010 feet in Harrison Bay Block 6423 (shy of its 35,000-foot target). The well was suspended in August 2018. The drilling operation was resumed on Jan. 19, 2019, and suspended on April 17.
A land use permit approved by the division in 2017 for the project said it would include two S-shaped wells into the targeted reservoir and logging. Depending on well log results, a bypass to core was planned for each well. Contingent upon logging results and core data, a sidetrack to a 1,000-foot horizontal section was planned to be drilled approximately six months later to perform a production test on either one or both wells.
The division said Eni plans to resume well operations for NN-01 in the current winter drilling season to reach target depth by third quarter.
In an April 13, 2018, exploration plan revision BOEM authorized Eni to continue well operations during the summer of 2018, while drilling above the hydrocarbon zone in well NN-01, and to enter hydrocarbon bearing formations only from July 15 to Sept. 15, 2018. It also reduced the number of wells to two main bores and one sidetrack.
The revised exploration plan said there will be two potential phases - main bore (slant section) to reservoir target (with option to flow test) and/or a horizontal sidetrack to execute a flow test Both wells will intersect the main target reservoir up to two times in cascaded contingent sidetrack operations with increasing complexity and appraisal goals.
“After the main bore is drilled, in case of oil discovery and based on the reservoir properties, the possibility to perform a flow test in the initial wellbore or, alternatively, in a lateral sidetrack, is foreseen,” Eni said.
The second main bore drilling permit was issued by the Alaska Oil and Gas Conservation Commission on Jan. 17.
In its 12th POD (Oct. 1 through Sept. 30, 2020) Eni confirmed it plans to resume NN-01well operations in the 2019-20 winter drilling season and expects to reach target depth by third quarter 2020.
The company also plans to do surface facility upgrades in anticipation of spudding NN-02 in first quarter 2020.
Facility upgrades are planned to support the second well and the two remaining SID injection wells, including a new six-slot well containment shelter and associated well conductors, plus the requisite well tie-ins.
Eni has not identified the drilling target at Nikaitchuq North. The Schrader Bluff formation that hosts the reservoir for the Nikaitchuq unit is known to extend a long way north.
However, there are other possibilities based on circumstantial evidence such as planned drilling depth. One contender is the Jurassic Alpine sands, equivalent to reservoir sands in the Alpine oil field and deeper than the Schrader Bluff.
Also, Kerr-McGee, the previous Nikaitchuq operator, had talked about the possibility of testing the Jurassic Nuiqsut sandstone to the north of the unit.
The latest division North Slope activity map said first oil from Nikaitchuq North is expected in mid-2022, with full development starting in early 2024.
Oil Search spuds second wellOil Search spud its first exploitation well, Mitquq 1, on Dec. 25 and its second main bore, Stirrup 1, on Jan. 27. Gravel laying to support the building of gravel roads and well pads for the Pikka development project and ice road and pad construction began in late November.
Already the company has said that Mitquq 1, which was drilled by Nabors 7ES rig, intersected 197 feet of hydrocarbon pay comprised of 17 feet of net gas pay and 180 feet of oil pay. No water-oil contact was encountered with the Nanushuk interval.
The 6,885-foot well, which is about six miles from the proposed Pikka Nanushuk development A pad, or ND-A, is separate from Pikka’s Nanushuk reservoir.
Oil Search set and tested casing to begin drilling ahead to the Alpine C reservoir, Mitquq 1’s secondary objective.
“Next steps focus on data capture before plugging and abandoning the well,” Oil Search’s manager of U.S. media and communications Amy Burnett said Jan. 30. “Plans call for launching the sidetrack in early March.”
Testing to determine well deliverability is expected to take place in late March or early April, the company said Jan. 28.
Previously Oil Search referred to the Mitquq prospect as a “high value tieback” to “future Pikka infrastructure.”
Success at the Stirrup prospect, which is close to the Horseshoe Block southwest of the Pikka unit, “could de-risk additional fairways to underpin a possible standalone” Horseshoe development, the company has said, noting Stirrup was a direct analogue to the Horseshoe 1 Nanushuk discovery.
If time allows, Oil Search said Stirrup 1 will also be flow-tested this winter.