Wellbore: 35/11-10 - 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.	35/11-10
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
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.	FRAM
Discovery Name of the discovery the wellbore is related to.	35/11-4 Fram
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	35/11-10
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	090
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.	891-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	WEST VANGUARD
Drilling days Number of days from wellbore entry to wellbore completion.	36
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,	19.05.1997
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.	23.06.1997
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.	23.06.1999
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.	15.06.2005
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 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.	SOGNEFJORD 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.	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.	FENSFJORD FM
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.	NESS FM
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	22.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	353.5
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).	2949.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	5.1
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	107
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.	COOK FM
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	61° 1' 10.54'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	3° 31' 26.29'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6765243.58
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	528323.08
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.	3042

Well 35/11-10 is located on the western edge of the Uer Terrace, ca 9 km North of the Troll Field. It was drilled to appraise the oil and gas discovery made in the exploration well 35/11-4, which encountered hydrocarbons in the Upper Sognefjord Formation separated from an oil column in the Lower Sognefjord Formation, in the Fensfjord Formation, and in the Brent Group. In addition the Utsira Formation was to be cored in order to obtain information about the productivity for injection water.

Operations and results

Appraisal well 35/11-10 was spudded with the semi-submersible installation West Vanguard on 19 May 1997 and drilled to TD at 2950 m in the Early Jurassic Cook Formation. Some problems were encountered with coring in the Utsira Formation. In addition the Utsira Formation was not logged due to a tight spot at 439 m. Otherwise no significant problems were encountered during operations. The well was drilled with spud mud down to 1152 m and with ANCO 2000 glycol mud from 1152 m to TD.

From MWD logs and drilling parameters the Utsira Formation proved not to be developed as a sand reservoir in this location. The well confirmed hydrocarbons in all target levels except for the Etive Formation of the Brent Group. The top Sognefjord reservoir was encountered at 1971 m. The upper part of the Sognefjord Formation was thicker and had better reservoir properties than prognosed. A gas oil contact was identified at 1987 m and an oil water contact at 2011 m. Within the range of uncertainty this was the same OWC as in the well 35/11-4 and there was pressure communication in both the water and the oil zones. The GOC however, differs between the two wells. A total of 14 m of gas pay and 22.6 m oil pay with an average porosity of 27% were encountered. The Lower Sognefjord contained oil and gas with a thin gas cap at 2037 m identified by an MDT sample. The OWC was at 2054 m, which is the same depth as in well 35/11-4. Top Fensfjord Formation was encountered at 2275 m with GOC identified at 2299 m and OWC at 2312 m. The OWC is at the same depth in the two wells with the same oil gradient, while gas is encountered structurally deeper in well 35/11-10. The Brent Group was encountered at 2647.5 m, approximately 30 m deeper than prognosed. Both the GOC (2660 m) and the OWC (2702 m) were identified in the Ness Formation and occurs at different depths compared to well 35/11-4. The Etive Formation was only 10 m thick and water bearing. The Top Etive map, interpreted after drilling, shows that well 35/11-10 was drilled outside structural closure.

A total of 8 conventional cores were cut at different intervals throughout the well. Due to technical problems only one meter core was recovered from the Utsira Formation, otherwise recovery was excellent. Three cores were cut in the Sognefjord Formation, two in the Heather and Fensfjord Formations, and two in the Etive and Rannoch Formations. MDT fluid samples of oil and water were recovered in both the Upper (only oil) and Lower Sognefjord Formation, the Fensfjord Formation and the Brent Group. In the lower Sognefjord Formation also a sample of the 1 metre thin gas cap was taken.

It was decided to make a sidetrack for further appraisal of the Discovery. The well bore was plugged back with 4 cement plugs to 1888 m and a kick off plug from 1350 m a 1100 m. It was permanently abandoned on 23 June 1997 as an oil and gas appraisal well.

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]
1160.00	2950.00

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	879.1	880.0	[m ]
2	1975.0	2007.1	[m ]
3	2008.0	2040.6	[m ]
4	2041.0	2078.2	[m ]
5	2268.0	2296.0	[m ]
6	2296.0	2314.8	[m ]
7	2676.0	2722.9	[m ]
8	2723.0	2769.6	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	243.1

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

Core photos

Core photos

879-880m	1975-1980m	1980-1985m	1985-1990m	1990-1995m

1995-2000m	2000-2005m	2005-2007m	2008-2013m	2013-2018m

2018-2023m	2023-2028m	2028-2033m	2033-2038m	2038-2040m

2041-2046m	2046-2051m	2051-2056m	2056-2061m	2061-2066m

2066-2071m	2071-2076m	2076-2078m	2268-2273m	2273-2278m

2278-2283m	2283-2288m	2288-2293m	2293-2295m	2296-2301m

2301-2306m	2306-2311m	2311-2314m	2676-2677m	2681-2686m

2686-2691m	2691-2696m	2696-2701m	2701-2706m	2706-2711m

2711-2716m	2716-2721m	2721-2711m	2623-2728m	2728-2733m

2733-2738m	2738-2743m	2743-2748m	2748-2753m	2753-2758m

2758-2763m	2763-2768m	2768-2769m

Casing and leak–off tests

Casing and leak–off tests
Casing type	Casing diam. [inch]	Casing depth [m]	Hole diam. [inch]	Hole depth [m]	Formation test type
CONDUCTOR	30	435.0	36	438.0	LOT
INTERM.	13 3/8	1152.0	17 1/2	1158.0	LOT
OPEN HOLE		1906.0	12 1/4	1906.0	LOT
OPEN HOLE		2950.0	8 1/2	2950.0	LOT

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
DIL LDL CNL GR	0	0
DLL MSFL DSI LDL CNL NGT SP AMS	2325	2940
DLL MSFL LDL CNL NGT SP AMS	1046	2900
FMS DSI GR AMS	1139	2932
MDT GR AMS	0	0
MDT GR AMS	1972	2026
MDT GR AMS	1996	2036
MDT GR AMS	2028	2113
MDT GR AMS	2036	2870
MDT GR AMS	2305	2346
MWD - GR RES DIR	375	2950
VSP GR	450	2920

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
376	NORDLAND GP
756	HORDALAND GP
1414	ROGALAND GP
1414	BALDER FM
1462	SELE FM
1578	LISTA FM
1713	HEIMDAL FM
1777	LISTA FM
1791	VÅLE FM
1858	SHETLAND GP
1858	JORSALFARE FM
1965	VIKING GP
1965	DRAUPNE FM
1971	SOGNEFJORD FM
2117	HEATHER FM
2275	FENSFJORD FM
2385	HEATHER FM
2648	BRENT GP
2648	NESS FM
2718	ETIVE FM
2728	RANNOCH FM
2746	OSEBERG FM
2801	DUNLIN GP
2801	DRAKE FM
2818	COOK FM

Composite logs

Composite logs
Document name	Document format	Document size [MB]
3042_35_11_10	pdf	0.53

Geochemical information

Geochemical information
Document name	Document format	Document size [MB]
3042_1	pdf	6.43
3042_2	pdf	7.42

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]
3042_35_11_10_COMPLETION_LOG	pdf	0.94
3042_35_11_10_COMPLETION_REPORT	pdf	17.17

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
1152	1.25	23.0	WATER BASED
1906	1.25	18.0	WATER BASED
2078	1.26	18.0	WATER BASED
2362	1.25	19.0	WATER BASED
2950	1.25	16.0	WATER BASED

35/11-10