Wellbore: 2/5-10 - 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.	2/5-10
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).	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
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.	2/5-10
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	067
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 Agip 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.	761-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	POLAR PIONEER
Drilling days Number of days from wellbore entry to wellbore completion.	96
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,	23.05.1993
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.	26.08.1993
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.	26.08.1995
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.	24.09.2003
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.	WILDCAT
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 SHOWS
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
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.	65.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	4701.0
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).	4700.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	2.8
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	165
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.	TRIASSIC
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.	SKAGERRAK FM
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	56° 41' 21.66'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	3° 29' 27.32'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6283054.46
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	530071.86
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.	2044

Exploration well 2/5-10 is located in the Central Graben on the Steinbit Terrace. The well was drilled with Late Jurassic sandstone of Oxfordian age, in a combination trap with structural and dip closing elements, as the primary target. Secondary targets were the Middle Jurassic Bryne Formation in the same combination trapping configuration, while the Late Cretaceous Chalk and the Lower Cretaceous Cromer Knoll Group were stratigraphic trap targets. After reaching TD evaluation of the cores and electric logs concluded that a fault had been intercepted within the main Jurassic target, justifying a sidetrack in search of a better pay zone. Well 2/5-10 was therefore plugged back in and well 2/5-10 A sidetracked.

Operations and results

Well 2/5-10 was spudded with the semi-submersible installation "Polar Pioneer" on 23 May 1993 and drilled to TD at 4701 m in rocks of the Triassic Smith Bank Formation. The well was drilled with sea water and hi-vis sweeps down to 865 m, with KCl/Polymer mud from 865 m to 4235 m, and with HPHT/Polymer mud from 4235 m to TD. Shallow gas was encountered after drilling the 8 1/2" pilot hole, prior to opening up the hole to 26" and running 20" casing. In order to ensure a good 20" casing cement job without compromising rig safety it was decided to plug back the gas bearing zone and set 20" casing at 509m, 291m shallower than originally planned 800m. To avoid gas migration the cement slurries for the 20" and 13 3/8" were redesigned with gas tight cement (microblock added).

Top reservoir was encountered at 4582 m, 174 m deeper than prognosis due to complex geology and higher than expected shale interval velocities in the Late Jurassic. The main part of the Late Jurassic sandstone target was removed by faulting, and Triassic strata were encountered 5 m below top reservoir through a fault plane. The Late Jurassic sandstone was highly affected by the faulting, and the reservoir quality was poor. The secondary target Middle Jurassic Bryne Formation was not present. The Smith Bank Formation was encountered 5 m below top reservoir through a fault plane. A small hydrocarbon accumulation was found in the main target Late Jurassic Oxfordian age sandstone. Weak shows were encountered also in the Chalk and in the Vestland Group.

Two conventional cores were cut from 4575 m in the Late Jurassic sandstone and down to 4591 m in the Smith Bank Formation. Two samples collected at 4594.3 m and 4583.1 m in the Vestland Group during the MDT run contained weak hydrocarbon shows, a discontinuous film of oil in sample #1 and gas traces in sample #2. Because of a failure of the MDT tool's equalization valve, a leakage between the two chambers was considered likely and therefore the location of these hydrocarbon shows is doubtful. However they should more likely be attributed to the top part of the Late Jurassic SST as confirmed by the sample #3 collected in the following RFT run which contained at 4594.3 m (same depth as sample #1) formation water. Only mud filtrate was finally recovered in the sample #4 taken at 4614 m. Well bore 2/5-10 was subsequently plugged back and permanently abandoned on 26 August 1993 as a well with shows.

Sidestep 2/5-10 A was kicked off from 4306 m in 2/5-10 on 27 August 1993 and was drilled to a total depth of 4715 m in the Triassic Smith Bank Formation. The well was drilled with HPHT/polymer mud from kick-off to TD. The expected reservoir was encountered at 4616 m with a thickness of 57 m and with poor to medium reservoir characteristics. The shows encountered were poor, and no hydrocarbons could be extracted using downhole testing tools. Three conventional cores were cut in the Late Jurassic sandstone from 4612 m to 4640.1 m. Four RFT samples collected at 4619 m, 4624.1 m, 4630 m and 4657 m contained formation water and mud filtrate with only traces of oil. Sidetrack 2/5-10 A was permanently plugged and abandoned on 25 September 1993 as a well with shows.

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]
820.00	4700.00

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	4575.0	4584.7	[m ]
2	4584.7	4590.0	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	15.0

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

Core photos

Core photos

4575-4580m	4580-4584m	4584-4589m	4589-4591m

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	185.0	36	185.0	LOT
INTERM.	20	509.0	26	510.0	LOT
INTERM.	13 3/8	2254.0	17 1/2	2255.0	LOT
INTERM.	9 5/8	4217.0	12 1/4	4219.0	LOT
OPEN HOLE		4701.0	8 3/8	4701.0	LOT

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
BGT SLS GR AMS	509	938
CBL VDL GR	2100	4219
CBL VDL GR CCL	88	2241
CST GR	4350	4710
DIL SLS GR AMS	88	694
DIL SLS MSFL GR AMS	934	4235
FMI	4219	4709
FMS GR	0	0
LDL CNL NGS DLL AMS	4219	4706
LDL CNL NGS FMS AMS	2254	4236
MDT-PO GR	4582	4600
MFCT GR AMS	88	2000
MWD - GR RAR RPD DIR	185	2265
MWD - GR RAR RPD DIR	3956	3963
MWD - GR RAR RPD DIR	4298	4701
MWD - GR RSN DIR	2265	3956
MWD - GR RSN DIR	4077	4111
PI BHC MSFL GR AMS	4219	4709
RFT GR	3264	4127
RFT GR	4586	4614
VSP	250	4230
VSP	4219	4709

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
88	NORDLAND GP
1733	HORDALAND GP
3052	ROGALAND GP
3052	BALDER FM
3062	SELE FM
3072	LISTA FM
3181	VÅLE FM
3214	SHETLAND GP
3214	EKOFISK FM
3342	TOR FM
3735	HOD FM
4295	CROMER KNOLL GP
4295	RØDBY FM
4298	TYNE GP
4298	FARSUND FM
4582	VESTLAND GP
4587	NO GROUP DEFINED
4587	SKAGERRAK FM

Composite logs

Composite logs
Document name	Document format	Document size [MB]
2044	pdf	0.61

Geochemical information

Geochemical information
Document name	Document format	Document size [MB]
2044_1	pdf	1.95
2044_2	pdf	1.44
2044_3	pdf	0.93

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
65	1.06		WATER BASED
110	1.65	24.0	WATER BASED
185	1.06		WATER BASED
520	1.30	20.0	WATER BASED
815	1.06	22.0	WATER BASED
1037	1.30	18.0	WATER BASED
1254	1.30	20.0	WATER BASED
1619	1.43	20.0	WATER BASED
1959	1.50	40.0	WATER BASED
2102	1.66	23.0	WATER BASED
2129	1.55	52.0	WATER BASED
2265	1.64	43.0	WATER BASED
2541	1.62	43.0	WATER BASED
2649	1.62	42.0	WATER BASED
2753	1.62	37.0	WATER BASED
2994	1.62	49.0	WATER BASED
3131	1.62	49.0	WATER BASED
3210	1.62	42.0	WATER BASED
3211	1.62	51.0	WATER BASED
3252	1.62	51.0	WATER BASED
3311	1.62	46.0	WATER BASED
3361	1.62	48.0	WATER BASED
3471	1.62	49.0	WATER BASED
3499	1.61	53.0	WATER BASED
3502	1.61	49.0	WATER BASED
3590	1.61	42.0	WATER BASED
3652	1.61	40.0	WATER BASED
3680	1.61	46.0	WATER BASED
3730	1.61	44.0	WATER BASED
3837	1.61	41.0	WATER BASED
3952	1.61	42.0	WATER BASED
3989	1.61	45.0	WATER BASED
4035	1.61	44.0	WATER BASED
4077	1.61	44.0	WATER BASED
4100	1.61	47.0	WATER BASED
4111	1.61	51.0	WATER BASED
4115	2.06	39.0	WATER BASED
4144	1.65	50.0	WATER BASED
4227	1.65	44.0	WATER BASED
4235	1.66	35.0	WATER BASED
4286	1.98	44.0	WATER BASED
4292	2.08	37.0	WATER BASED
4298	1.98	45.0	WATER BASED
4352	1.98	43.0	WATER BASED
4395	1.98	42.0	WATER BASED
4520	2.08	47.0	WATER BASED
4547	2.02	30.0	WATER BASED
4585	2.08	33.0	WATER BASED
4591	2.08	32.0	WATER BASED
4653	2.08	27.0	WATER BASED
4701	2.08	26.0	WATER BASED

2/5-10