A steady drilling rate
North Slope development drilling in 2019 at a similar pace to previous years
for Petroleum News
The drilling of development wells in the North Slope oil fields in 2019 continued at a very similar rate to that seen in the previous three years, according to data published by the Alaska Oil and Gas Conservation Commission. Although this appears to indicate a continuing commitment by the oil companies to maintain oil production levels on the Slope, there will presumably be a significant drop in drilling in 2020, given the impact of the COVID-19 pandemic. However, complete data for 2020 will not become available until some time in the first quarter of 2021.
88 development wellsA total of 88 development wells designed for oil production were drilled in 2019. That compares with 98 wells in 2016, 92 in 2017 and 90 in 2018. A substantial number of the wells in 2019, particularly in the Prudhoe Bay and Kuparuk River units, were sidetracks to existing wells, seeking further oil in these older legacy fields.
In the Colville River unit seven out of a total of eight wells were drilled from ConocoPhillips’ CD-5 pad, a relatively new development in the northeastern National Petroleum Reserve-Alaska. ConocoPhillips also drilled 31 development wells in the Kuparuk River unit. In the Prudhoe Bay unit BP drilled 34 development wells. Hilcorp Alaska drilled 13 development wells in the Milne Point unit, while Eni US Operating Co. drilled two development wells in the Nikaitchuq unit.
29 injection wellsAOGCC also reports data for what it refers to as service wells - these are primarily injectors, used for enhanced oil recovery through the injection of various materials including water, gas and miscible injectant into oil reservoirs. Of the 32 service wells drilled in 2019, 29 were injectors. The remaining service wells were designed for water supplies and the disposal of waste. In 2016 38 injector wells were drilled, 19 in 2017 and 22 in 2018.
In 2019 the majority of the injection wells were drilled in the Kuparuk River and Milne Point units. ConocoPhillips drilled 14 injectors at Kuparuk: six of these were for the injection of water alternating gas, with the remainder for water injection. The company also drilled two water alternating gas injectors in its Greater Mooses Tooth development in the NPR-A.
At Milne Point Hilcorp drilled 10 injectors. These are all designated as water injection wells. However, Hilcorp has been using polymer injection to boost production at Milne Point.
BP drilled the other three injectors, all of them water alternating gas injectors, in the Prudhoe Bay unit.
It is important to note that the well data do not include the non-rig well workovers that make a very significant contribution to maintaining oil production.
Exploratory drillingThe AOGCC “exploratory” well category includes both exploration wells, testing new oil prospects, and appraisal wells, used to evaluate an oil or gas discovery. And in 2019 one of the wells designated as “exploratory” consisted of the Hydrate 1 well, drilled by BP in support of a methane hydrate production test project planned by the National Energy Technology Laboratory, Japan Oil, Gas and Metals National Corp., the U.S. Geological Survey, and Petrotechnical Resources of Alaska.
There were 13 other exploratory wells, most of them appraisal wells associated with recent oil discoveries in the Nanushuk formation near and to the west of the Colville River delta. This represented a significant uptick in drilling activity: In 2016 there were six exploratory wells drilled, three in 2017 and nine in 2018.
In 2019 ConocoPhillips drilled five appraisal wells to test its Willow oil discovery in the NPR-A, while Oil Search (Alaska) drilled four appraisal wells, testing its Pikka discovery on the east of the Colville River Delta. On the exploration front, ConocoPhillips drilled two wells into its Putu prospect south of Pikka, and one into the West Willow prospect in the NPR-A. Great Bear Petroleum Operating drilled the Winx 1 exploration well, seeking oil in a Nanushuk prospect to the east of the Colville River.