Wellbore: 31/4-11 - 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.	31/4-11
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).	WILDCAT
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
Field Name of the field the wellbore is related to.	BRAGE
Discovery Name of the discovery the wellbore is related to.	31/4-11
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	31/4-11
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	055
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.	Norsk Hydro Produksjon 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.	981-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	SCARABEO 6
Drilling days Number of days from wellbore entry to wellbore completion.	48
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,	27.07.2000
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.	12.09.2000
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.	12.09.2002
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.	04.10.2013
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.	YES
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 JURASSIC
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.	VIKING GP
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.	MIDDLE JURASSIC
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.	BRENT GP
3rd level with HC, age Age of lithostratigraphic unit, 3rd level, where hydrocarbons were encountered. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EOCENE.	MIDDLE JURASSIC
3rd level with HC, formation Name of lithostartigraphic unit, 3rd 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.	STATFJORD GP
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	26.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	183.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	3271.0
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).	2765.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	58.7
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	108
Oldest penetrated age Age (according to Geologic Time Scale 2004 by F. M. Gradstein, et al. (2004)) of the oldest penetrated formation. May differ from age at TD for example in deviated wellbores. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EARLY PERMIAN, EARLY TRIASSIC, EOCENE.	EARLY JURASSIC
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.	STATFJORD GP
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	60° 36' 42.58'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	3° 6' 1.74'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6719714.87
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	505501.19
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.	4147

Well 31/4-11 was drilled on the Bowmore structure in the northern part of the Brage Field as a combined appraisal/exploration well. The Bowmore structure is situated about 6-8 km NNE of the Brage platform. It is a NE-SW trending wedge shaped horst, rising and tapering towards the SW. The primary objective was to prove hydrocarbons in the Middle - Late Jurassic Fensfjord Formation. The secondary objectives were to prove hydrocarbons in sandstones of the Late Jurassic Sognefjord and Draupne formations and in the Middle Jurassic Brent Group. During drilling of the well, it was decided to extend the well and explore the hydrocarbon potential in the Statfjord Formation.

Operations and results

Wildcat well 31/4-11 was spudded with the semi-submersible installation Scarabeo 6 on 27 July 2000 and drilled to TD at 3271 m (2765 m TVD) in the Early Jurassic Statfjord Group. This is a deviated well. It was drilled vertical down to 1410 m and deviated from there with up to 58.7 deg inclination. The well was drilled with sea water and hi-vis pills down to 283 m and with Glydril mud from 283 m to TD.

Top Draupne Formation was encountered at 2130 m. Intra Draupne sandstones interbedded with claystones, shale and siltstone were penetrated from 2149 m to top Sognefjord Formation at 2201 m. The Draupne Formation sandstones were gas saturated while only water was sampled in the underlying Sognefjord Formation. However, geochemical analyses of cores indicated an oil column from 2189 m to 2217 m.

The Fensfjord Formation was penetrated from 2351 m to 2426 m. Moveable oil was proven with an ODT at 2376 m.

The Brent Group was encountered with top Tarbert Formation at 2644 m. Tarbert and Ness formations contained oil down to a shale sequence at 2682 m in the Ness Formation. Excellent pressure points indicated an OWC at exactly 2696 m.

Top Statfjord Group was encountered at 3178 m. The Statfjord Group was water bearing with weak shows at the top.

No oil shows were described above top Jurassic level.

A total of 16 cores were cut from 2123 m to 2431 m in claystones, siltstones and sandstones of the Draupne, Sognefjord, Heather and Fensfjord formations. Core recovery varied from 6.3% to 100%. Wire line fluid samples were taken in the Draupne and Sognefjord formations at 2162 m (gas), 2182.5 m (gas), and 2205.8 m (water); in the Fensfjord Formation at 2357.5 m (oil) and 2372.3 m (oil); and in the Brent Group at 2678.5 m (oil), 2675.1 m (oil), 2699.2 m (water), and 2712.8 m (water)

The well was permanently abandoned on 12 September as an oil and gas discovery.

Testing

No drill stem test was performed.

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]
1110.00	3270.00

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	2123.0	2133.6	[m ]
2	2134.0	2138.0	[m ]
3	2144.0	2149.0	[m ]
4	2149.0	2156.7	[m ]
5	2157.0	2161.0	[m ]
6	2179.0	2179.5	[m ]
7	2187.0	2204.5	[m ]
8	2204.5	2221.1	[m ]
9	2222.0	2240.0	[m ]
10	2316.0	2333.5	[m ]
11	2343.0	2354.2	[m ]
12	2361.0	2367.0	[m ]
13	2370.0	2376.7	[m ]
14	2376.7	2395.0	[m ]
15	2395.0	2412.9	[m ]
16	2413.0	2431.0	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	179.4

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

Core photos

Core photos

2123-2127m	2127-2131m	2131-2133m	2134-2138m	2134-2138m

2144-2148m	2148-2149m	2149-2153m	2153-2156m	2157-2161m

2179-2179m	2187-2191m	2191-2195m	2195-2199m	2199-2203m

2203-2204m	2204-2208m	2208-2212m	2212-2216m	2216-2220m

2220-2221m	2222-2226m	2226-2230m	2230-2234m	2234-2238m

2238-2240m	2316-2320m	2320-2334m	2324-2328m	2328-2332m

2332-2333m	2343-2347m	2347-2351m	2351-2354m	2361-2365m

2365-2367m	2370-2374m	2374-2376m	2376-2380m	2380-2304m

2384-2388m	2388-2392m	2392-2395m	2395-2399m	2403-2407m

2407-2411m	2411-2412m	2413-2417m	2417-2421m	2421-2425m

2425-2429m	2429-2431m

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
CONDUCTOR	30	283.0	36	283.0	0.00	LOT
SURF.COND.	13 3/8	1100.0	17 1/2	1100.0	1.68	LOT
INTERM.	9 5/8	2166.0	12 1/4	2176.0	1.55	LOT
OPEN HOLE		3271.0	8 1/2	3271.0	0.00	LOT

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
CRFT	2157	2162
DSI VSP	2000	2835
HALS PEX	1110	2005
MDT	2178	2784
MDT	2182	2362
MDT	2182	2372
MDT	2357	2701
MWD - ARC VIS675 ADN	1950	2176
MWD - GST VIS675 ADN	2160	3258
MWD - PP CDR	209	2176

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
209	NORDLAND GP
783	UTSIRA FM
802	HORDALAND GP
1725	ROGALAND GP
1725	BALDER FM
1777	SELE FM
1820	LISTA FM
1980	VÅLE FM
2019	SHETLAND GP
2019	NO FORMAL NAME
2098	CROMER KNOLL GP
2098	NO FORMAL NAME
2130	VIKING GP
2130	DRAUPNE FM
2201	SOGNEFJORD FM
2233	HEATHER FM
2351	FENSFJORD FM
2426	HEATHER FM
2522	KROSSFJORD FM
2538	HEATHER FM
2644	BRENT GP
2644	TARBERT FM
2654	NESS FM
2697	NO FORMAL NAME
2785	DUNLIN GP
2785	DRAKE FM
2957	COOK FM
2985	AMUNDSEN FM
3178	STATFJORD GP

Geochemical information

Geochemical information
Document name	Document format	Document size [MB]
4147_1	pdf	0.28
4147_2	pdf	0.09
4147_3	pdf	9.45
4147_4	pdf	0.10

Documents – reported by the production licence (period for duty of secrecy expired)

Documents – reported by the production licence (period for duty of secrecy expired)
Document name	Document format	Document size [MB]
4147_31_4_11_COMPLETION_LOG	.pdf	9.06
4147_31_4_11_COMPLETION_REPORT	.pdf	3.64

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
1100	1.32	13.0	water based
1600	1.50	18.0	water based
2121	1.50	23.0	water based
2139	1.50	21.0	water based
2343	1.20	14.0	water based
2370	1.21	14.0	water based
2835	1.21	15.0	water based
2835	1.20	15.0	water based
3271	1.23	14.0	water based

Palynological slides at the Norwegian Offshore Directorate

Palynological slides at the Norwegian Offshore Directorate
Sample depth	Depth unit	Sample type	Laboratory
2115.0	[m]	DC	PETROSTR
2117.0	[m]	DC	PETROS
2120.0	[m]	DC	PETROS
2122.0	[m]	DC	PETROS
2124.2	[m]	C	PETROS
2132.4	[m]	C	PETROS
2135.2	[m]	C	PETROS
2148.9	[m]	C	PETROS
2155.5	[m]	C	PETROS
2163.0	[m]	DC	PETROS
2167.0	[m]	DC	PETROS
2170.0	[m]	DC	PETROS
2172.0	[m]	DC	PETROS
2175.0	[m]	DC	PETROS
2177.0	[m]	DC	PETROS
2197.3	[m]	C	PETROS
2200.4	[m]	C	PETROS
2212.2	[m]	C	PETROS

31/4-11