Wellbore: 25/8-19 A - Factpages - Norwegian Offshore Directorate

General information

General information
Attribute	Value
Wellbore name Official name of wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	25/8-19 A
Type Wellbore type. Legal values: EXPLORATION, DEVELOPMENT, OTHER (see 'Purpose' for more information)	EXPLORATION
Purpose Final classification of the wellbore. Legal values for exploration wellbores: WILDCAT, APPRAISAL, WILDCAT-CCS, APPRAISAL-CCS. Legal values for development wellbores: OBSERVATION, PRODUCTION, INJECTION, INJECTION-CCS, OBSERVATION-CCS. Legal values for other wellbores: SOIL DRILLING (drilling in connection with track surveys and other subsurface surveys to investigate the soil conditions prior to placement of facilities), SHALLOW GAS (drilling to investigate shallow gas before the first 'real' drilling on the location), PILOT (drilling to investigate the geology and fluid connectors for location of the main wellbore), SCIENTIFIC (drilling according to Law of Scientific research and exploration), STRATIGRAPHIC (driling according to Law of Petroleum activities §2-1).	APPRAISAL
Status Status for the wellbore. Legal values are: BLOWOUT: A blowout has occurred in the well. CLOSED: A development wellbore that has been closed in a shorter or longer periode. Also applies to development wellbores where drilling is completed, but production/injection has not yet been reported. DRILLING: The well is in the drilling phase - can be active drilling, logging, testing or plugging, JUNKED: The drilling operation has been terminated due to technical problems. P&A: Exploration: The well is plugged and abandoned, and can not be reentered for further use. Development wells: The production/injection from/to the well is stopped and the well is plugged. The wellhead is removed or else made unavailable for further well operations. PLUGGED: The wellbore has been plugged, but the upper parts of the wellbore can be re-used. A sidetrack might be drilled at a later stage. PRODUCING: It was produced from the wellbore at the time of the operators last monthly report to the Norwegian Offshore Directorate. INJECTING: It was injected to the wellbore at the time of the operators last monthly report to the Norwegian Offshore Directorate. PREDRILLED: The upper part of the well has been drilled, usually as part of a batch-drilling campaign covering several wellbores. RE-CLASS TO DEV: Exploration wellbore that is reclassified to a development wellbore. RE-CLASS TO TEST: Exploration wellbore that is reclassified to test production. SUSPENDED: The drilling operation in the wellbore has been temporarily stopped. The current plan is to continue drilling later on.	P&A
Press release	link
Multilateral Indicator telling if the parent well is multilateral, meaning it has more than one branch radiating from the main borehole. Example of legal values: YES, NO. See also Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	NO
Factmaps in new window	link
Main area Name of the area on the Norwegian Continental Shelf where the wellbore is located. Legal values: BARENTS SEA, NORWEGIAN SEA, NORTH SEA.	NORTH SEA
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	25/8-19
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	820 S
Drilling operator Name of the licensee starting the drilling operation on behalf of the active production license (well head position). This will usually equal the operator of the production license.	MOL Norge AS
Drill permit The drilling permit number together with the version of the drilling permit as stated in the drilling permit granted by the Norwegian Offshore Directorate.	1805-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	DEEPSEA BERGEN
Drilling days Number of days from wellbore entry to wellbore completion.	80
Entered date The date when he wellbore was spudded. For sidetracks: The date when new formation was drilled by kicking off from the mother-wellbore,	31.12.2019
Completed date Exploration wellbores from moveable facilities: For floating facilities - date when anchor handling is started. For jackups - date the jacking-down started. Exploration wellbores from fixed facilities and all development wellbores: Date when the wellbore is at total depth, and last casing, liner or screen is set. In case of immediate plugging of the wellbore, completed date equals the date the last plug i set in the wellbore. Date when the wellbore is at total depth, and last casing, liner or screen is set. In case of immediate plugging of the wellbore, completed date equals the date the last plug i set in the wellbore.	19.03.2020
Release date Date when raw data which has been reported to the authorities from the wellbore is not confidential any longer. Normally 2 years after finishing the drilling. May be earlier if the area of the production license is relinquished.	19.03.2022
Plugged and abondon date Date when the P&A-operations of the wellbore was finished, as reported by the operator to the Norwegian Offshore Directorate throught DDRS (Daily Drilling Reporting System). Only applied once pr. wellhead/surface location.	19.03.2020
Publication date Date quality control of the wellbore information was completed, so it can be published on the internet as a 'Well Data Summary Sheet' wellbore with more information available than other wellbores.	08.08.2022
Purpose - planned Pre-drill purpose of the wellbore. Legal values for exploration wellbores: WILDCAT, APPRAISAL, WILDCAT-CCS, APPRAISAL-CCS. Example of legal values for development wellbores: OBSERVATION, PRODUCTION, INJECTION.	APPRAISAL
Content For exploration wellbores, status of discovery. Legal values: DRY, SHOWS (trace amounts of hydrocarbons), GAS, GAS/CONDENSATE, OIL or OIL/GAS. SHOWS (GAS SHOWS, OIL SHOWS or OIL/GAS SHOWS) are detected as fluorescent cut (organic extract), petroleum odour, or visual stain on cuttings or cores, or as increased gas reading on the mud-loggers gas detection equipment. Legal values for WILDCAT-CCS and APPRAISAL-CCS: WATER For development wellbores, type of produced/injected fluid. Legal values: WATER, CUTTINGS, NOT AVAILABLE, OIL, GAS/CONDENSATE, OIL/GAS, CO2, GAS, WATER/GAS, NOT APPLICABLE.	OIL/GAS
Discovery wellbore Indicator which tells if the wellbore made a new discovery. Legal values: YES, NO. Prior to press-release or other information regarding drilling results, the indicator will be “NO” as a default.	NO
1st level with HC, age Age of lithostratigraphic unit, 1st level, where hydrocarbons were encountered. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EOCENE. See also Norwegian Offshore Directorate bulletins.	LATE TRIASSIC
1st level with HC, formation Name of lithostartigraphic unit, 1st level, where hydrocarbons were encountered. Shown only for released wells. Examples of legal values: BASEMENT, COOK FM, EKOFISK FM, HEIMDAL FM, SANDNES FM, SOGNEFJORD FM, TARBERT FM, BRENT GP. See also Norwegian Offshore Directorate bulletins.	SKAGERRAK FM
2nd level with HC, age Age of lithostratigraphic unit, 2nd level, where hydrocarbons were encountered. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EOCENE.	PALEOCENE
2nd level with HC, formation Name of lithostartigraphic unit, 2nd level, where hydrocarbons were encountered. Shown only for released wells. Examples of legal values: BASEMENT, COOK FM, EKOFISK FM, HEIMDAL FM, SANDNES FM, SOGNEFJORD FM, TARBERT FM, BRENT GP.	HEIMDAL FM
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	23.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	126.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	2950.0
Final vertical depth (TVD) [m RKB] Vertical elevation from total depth to kelly bushing. Shown only for released wells. Referred to as true vertical depth (TVD).	2636.0
Oldest penetrated formation Name of the oldest lithostratigraphic unit penetrated by the wellbore. Shown only for released wells. In most wellbores this is formation or group at total depth. May differ from formation or group at TD for example in wellbores drilled with high deviation or through faults. Examples of legal values: AMUNDSEN FM, BALDER FM, BASEMENT, BLODØKS FM, BRYNE FM, BURTON FM, COOK FM, DRAKE FM, DRAUPNE FM, EKOFISK FM, DUNLIN GP.	BASEMENT
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	59° 20' 13.21'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	2° 21' 53.27'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6577903.13
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	463861.92
UTM zone Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.	31
NPDID wellbore Norwegian Offshore Directorate's unique id for the wellbore.	8981

Well 25/8-19 A was drilled as an appraisal well on the 25/8-19 S Evra discovery on the southern part of the Heimdal Terrace in the North Sea. Well 25/8-19 S found oil and gas in several intervals from Paleocene to Basement. The primary objective was to investigate the hydrocarbon bearing intervals encountered in well 25/8-19 S, find the oil-water contact and to perform a well test in the Skagerrak Formation.

Operations and results

Appraisal well 25/8-19 A was kicked off from 1017 m in well 25/8-19 S on 31 December 2019. It was drilled with the semi-submersible installation Deepsea Bergen to 2950 m (2636.9 m TVD) in Basement rock. Hole problems led to plug back and drilling of a side-track for the planned well test. The side-track 25/8-19 A T2 was kicked off at 1960 m on 2 February 2020 and drilled to final TD at 2975 m (2567.8 m TVD) in Basement rock. The well was drilled with RheGuard oil-based mud from kick-off to TD.

The well encountered thin gas and oil-bearing sandstone injectite layers totalling 8 metres from 1760 to 1810 m in the lowermost Hordaland Group and in the Balder Formation at 1818 m. Thin, oil-bearing sandstones were encountered also throughout the Heimdal Formation. The Upper and Middle-Lower Statfjord units came in with water-bearing sandstones of about 50 and 30 metres, respectively. A total of 18 metres of gas and oil-filled sandstone layers were encountered in the Skagerrak Formation between 2615 and 2806 m. No oil/water contact was proven in the Skagerrak Formation. The well confirmed oil-bearing basement. No oil/water contact was proven in basement.

In addition to the hydrocarbon-bearing intervals, oil shows with direct and cut fluorescence were observed in the lower Ty Formation as well as in the lower - middle Statfjord Group.

Four cores were cut in the 25/8-19 A wellbore. Core 1 was cut from 2001 to 2029 m in the Heimdal Formation with 100% recovery. Core 2 was cut from 2373 to 2390 m in the lower Statfjord Group with 99.24% recovery. Cores 3 and 4 were cut in succession from 2798 to 2823.1 m in the Skagerrak Formation and Basement with 100 % and 94.63% recoveries, respectively. In wellbore 25/8-19 A MDT fluid samples were taken in the Eocene at 1770 m (gas) and 1801.51 m (oil). In the side-track wellbore 25/8-19 A T2 an MDT sample was taken at 2654 m in the Skagerrak Formation (oil).

Metrol pressure and temperature gauges were installed at 2625 mm with repeaters at 1454 m and 625 m, as part of the plugging. The well was permanently abandoned on 19 March 2020 as an oil and gas appraisal well.

Testing

One DST was performed in the interval 2651 to 2697 m in the Skagerrak Formation. The test was performed in the 25/8-19 A T2 wellbore. The test produced in the high flow period 475 Sm3 oil/day with an average GOR of 175 Sm3/Sm3 through a 32/64-inch choke. Based on downhole measurements during the test the temperature at mid perforations was 95.6 °C.

Cuttings at the Norwegian Offshore Directorate

Cuttings at the Norwegian Offshore Directorate
Cuttings available for sampling?	YES

Cuttings at the Norwegian Offshore Directorate
Cutting sample, top depth [m]	Cutting samples, bottom depth [m]
1020.00	2974.00

Cores at the Norwegian Offshore Directorate

Cores at the Norwegian Offshore Directorate
Core sample number	Core sample - top depth	Core sample - bottom depth	Core sample depth - uom
1	2001.0	2029.0	[m ]
2	2373.0	2389.5	[m ]
3	2798.0	2812.5	[m ]
4	2812.5	2822.5	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	69.0

Cores at the Norwegian Offshore Directorate
Cores available for sampling?	YES

Oil samples at the Norwegian Offshore Directorate

Oil samples at the Norwegian Offshore Directorate
Test type	Top depth MD [m]	Fluid type	Test time	Samples available
DST	0.00			YES
DST	0.00	OIL	05.03.2020 - 15:15	YES
MDT	1801.51	OIL	06.01.2020 - 00:00	YES
MDT	2654.00	OIL	09.02.2020 - 00:00	YES

Casing and leak–off tests

Casing and leak–off tests
Casing type	Casing diam. [inch]	Casing depth [m]	Hole diam. [inch]	Hole depth [m]	LOT/FIT mud eqv. [g/cm3]	Formation test type
SURF.COND.	13 3/8	1009.5	17 1/2	1009.5	1.74	FIT
INTERM.	9 5/8	1883.0	12 1/4	1883.0	1.61	LOT
OPEN HOLE		2637.0	8 1/2	2637.0	0.00

Drill stem tests (DST)

Drill stem tests (DST)
Test number	From depth MD [m]	To depth MD [m]	Choke size [mm]
1.0	2651	2697	12.7

Drill stem tests (DST)
Test number	Final shut-in pressure [MPa]	Final flow pressure [MPa]	Bottom hole pressure [MPa]	Downhole temperature [°C]
1.0				95

Drill stem tests (DST)
Test number	Oil [Sm3/day]	Gas [Sm3/day]	Oil density [g/cm3]	Gas grav. rel.air	GOR [m3/m3]
1.0	475				175

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
AIT TLD HNGS	1810	2446
GR CMR MDT	1711	1912
LWD - DIR PWD GR DEN NEU RES SON	1017	1923
LWD - RES GR DIR PWD DEN NEU	1923	2949
NGI MAST 2PPC	1010	2446
NGI MAST 3PPC ROBN	0	2446
ROBN PPC MDT NEXT NGI GR	1915	2408
XL ROCK GR	1705	1915

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
149	NORDLAND GP
149	UNDIFFERENTIATED
488	UTSIRA FM
679	HORDALAND GP
679	SKADE FM
998	UNDIFFERENTIATED
1123	GRID FM
1153	UNDIFFERENTIATED
1810	ROGALAND GP
1810	BALDER FM
1897	SELE FM
1957	LISTA FM
1986	HEIMDAL FM
2019	LISTA FM
2051	VÅLE FM
2071	TY FM
2187	DUNLIN GP
2187	AMUNDSEN FM
2211	STATFJORD GP
2211	NANSEN FM
2286	EIRIKSSON FM
2483	HEGRE GP
2483	SKAGERRAK FM
2806	BASEMENT

Thin sections at the Norwegian Offshore Directorate

Thin sections at the Norwegian Offshore Directorate
Depth	Unit
1892.30	[m ]
1888.50	[m ]
1886.20	[m ]
1884.00	[m ]
1862.00	[m ]
1845.40	[m ]
1843.50	[m ]
1834.00	[m ]
1819.00	[m ]
1815.40	[m ]
1804.70	[m ]
1803.50	[m ]
1801.50	[m ]
1787.50	[m ]
1776.20	[m ]
1770.00	[m ]
1762.50	[m ]
1752.50	[m ]
1757.50	[m ]
1739.20	[m ]
1705.00	[m ]
2822.44	[m ]
2820.60	[m ]
2820.08	[m ]
2819.30	[m ]
2818.60	[m ]
2817.41	[m ]
2816.23	[m ]
2815.49	[m ]
2814.24	[m ]
2814.04	[m ]
2813.27	[m ]
2812.68	[m ]
2812.08	[m ]
2811.75	[m ]
2810.57	[m ]
2809.86	[m ]
2808.42	[m ]
2807.25	[m ]
2806.95	[m ]
2806.25	[m ]
2805.50	[m ]
2805.02	[m ]
2804.75	[m ]
2804.25	[m ]
2804.02	[m ]
2802.50	[m ]
2802.02	[m ]
2801.75	[m ]
2801.30	[m ]
2800.86	[m ]
2799.24	[m ]
2799.02	[m ]
2798.35	[m ]
2383.63	[m ]
2382.73	[m ]
2302.50	[m ]
2382.05	[m ]
2831.35	[m ]
2380.50	[m ]
2380.11	[m ]
2379.34	[m ]
2376.80	[m ]
2376.26	[m ]
2375.80	[m ]
2375.15	[m ]
2374.22	[m ]
2373.78	[m ]
2373.03	[m ]
2028.40	[m ]
2023.61	[m ]
2022.14	[m ]
2021.87	[m ]
2021.45	[m ]
2020.62	[m ]
2018.08	[m ]
2017.18	[m ]
2013.50	[m ]
2012.20	[m ]
2010.75	[m ]
2010.53	[m ]
2009.82	[m ]
2008.22	[m ]
2007.90	[m ]
2006.28	[m ]
2005.70	[m ]
2004.03	[m ]
2003.28	[m ]
2001.42	[m ]

25/8-19 A