Wellbore: 6406/2-4 SR - 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.	6406/2-4 SR
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.	NORWEGIAN SEA
Field Name of the field the wellbore is related to.	KRISTIN
Discovery Name of the discovery the wellbore is related to.	6406/2-1 Lavrans
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	6406/2-4
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	199
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.	Saga Petroleum ASA
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.	876-L2
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.	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,	12.11.1998
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.	15.02.1999
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.	15.02.2001
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.	15.02.1999
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.	11.04.2003
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.	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.	GAS/CONDENSATE
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.	MIDDLE 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.	GARN 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.	EARLY 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.	BÅT GP
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.	273.5
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	5080.0
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).	4969.6
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	25.1
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	177
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.	ÅRE FM
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	64° 47' 58.34'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	6° 32' 29.26'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	7188560.78
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	383212.30
UTM zone Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.	32
NPDID wellbore Norwegian Offshore Directorate's unique id for the wellbore.	3627

Appraisal well 6406/2-4 S was drilled on the southern part of the Lavrans structure in the eastern part of block 6406/2, south of the Sørbukk Field and west of the Trestakk Field on Haltenbanken. The Lavrans structure is a rotated fault block west of the Trestakk Fault on the Halten Terrace. The purpose of the well was to appraise the southward extension of hydrocarbons in the Garn, Ile and Tofte Formations in the Lavrans structure, and to test separate closures in the Tilje and Åre formations. In addition, the well was planned to test the productivity improvement achievable by hydraulic stimulation. The well should also penetrate two sandy zones of Turonian (Lysing Formation) and Cenomanian/Albian age (Intra Lange sandstone).

Operations and results

The deviated appraisal well 6406/2-4 S was spudded 18 January1997 with the semi-submersible installation "Deepsea Bergen". It was drilled to 4546 m (4457 m TVD) in the Melke Formation. Mainly because of the weather conditions (41 days of WOW and weather-related problems) drilling of 6406/2-4 S was significantly delayed. Due to environmental restrictions in the area the well had to be suspended on April 5 1997 before the well targets had been reached. Well 6406/2-4 S R was re-entered 12 November at depth 4534 m (4446 m TVD), below the 9 5/8" casing shoe in the initial well, and drilled to final TD at 5080 m (4969 m TVD) in Early Jurassic Åre Formation sediments. The well bores were drilled with KCl mud / spud mud down to 1110 m, with KCl mud and "ANCO 208" glycol from 1110 m to 2260 m, and with oil based "ANCOVERT" mud from 2260 m to final TD.

Down to Base Cretaceous Unconformity the stratigraphy was as expected, the prognosis matched the experienced stratigraphy well. Below ECU, 154 meters of Upper Jurassic shales were penetrated before the drilling had to be stopped. Prognosed thickness of the Upper Jurassic shales was 44 m TVD. High total gas was observed when drilling through the Cretaceous sandy intervals, the Lysing and Lange Formations, but shows were not described in the cuttings.

Well 6406/2-4 S R proved gas/condensate bearing sandstones in the Garn, Tofte and Tilje formations in hydrocarbon-down-to situations. The well penetrated a large fault within the Garn Formation, so that the Ile Formation along with parts of the Garn, most of the Not, the entire Upper Ror and the upper part of the Tofte Formation were faulted out. This fault came on depth as prognosed, but it had considerably larger throw than expected. In addition to this large fault, two smaller faults were penetrated in the Tilje Formation. The quality of the reservoir formations was somewhat lower than expected due to the tectonic influence. In the Tofte Formation, the proximity to the fault has reduced reservoir quality due to fractures and higher degree of cementation. In the Tilje Formation, the best-developed reservoir zones were either fractured or faulted out. The Garn Formation was intensively brecciated and fractured. Disregarding the faults, thickness of the formations approximates those of the neighbouring wells on Lavrans. The Åre Formation gave some gas readings during drilling but was regarded to be without hydrocarbons. No cores were cut and no wire line samples taken in well bore 6406/2-4 S. In the re-entry a total of ten conventional cores with a total length of 325.1 m were drilled, of which 322.8 m (99.3 %) were recovered. The cores were cut in the Middle Jurassic.

A total of seven fluid samples were acquired in 6406/2-4 S R. Two hydrocarbon samples were taken in the Tofte Formation at 4701 m, four hydrocarbon samples were taken in the Tilje Formation at 4945.2 m and 4881.0 m, and one water sample was acquired in the Tilje Formation at 4835 m. The mud contamination from base oil in the MDT hydrocarbon samples were analysed to be from 25 to 71 % by weight. Well 6406/2-4 S R was permanently abandoned on 15 February 1999 as a gas and condensate appraisal well.

Testing

The Tilje (4874 m - 4904 m) and Tofte (4684 m - 4704 m) formations were production tested. Test 1 in the Tilje Formation produced 237000 m3 gas/day and 93 m3 condensate/day through a 9.53 mm choke. Test 2 in the Tofte Formation produced 42855 m3 gas/day and 18.1 m3 condensate/day through a 7.94 mm choke. The flow capacity of the test was severely influenced by fractures.

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	4615.0	4619.4	[m ]
2	4620.0	4627.9	[m ]
3	4692.0	4719.0	[m ]
4	4762.0	4818.2	[m ]
5	4818.5	4838.2	[m ]
6	4838.5	4857.2	[m ]
7	4857.2	4898.4	[m ]
8	4898.5	4936.1	[m ]
9	4939.1	4992.2	[m ]
10	4992.2	5046.5	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	320.0

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

Core photos

Core photos

4615-4619m	4620-4625m	4625-4694m	4694-4699m	4699-4704m

4704-4709m	4709-4714m	4714-4719m	4762-4767m	4767-4772m

4772-4777m	4777-4782m	4782-4787m	4787-4792m	4792-4797m

4797-4802m	3802-4807m	4807-4812m	4812-4817m	4817-4821m

3821-4826m	4826-4831m	4831-4836m	4836-4840m	4840-4845m

4845-4850m	4850-4855m	4855-4859m	4859-4864m	4864-4869m

4869-4874m	4874-4879m	4879-4884m	4884-4889m	4889-4894m

4894-4898m	4898-4903m	4903-4908m	4908-4913m	4913-4918m

4918-4923m	4923-4928m	4928-4933m	4933-4937m	4937-4942m

4942-4947m	4947-4952m	4952-4957m	4957-4962m	4962-4967m

4967-4872m	4972-4977m	4977-4982m	4982-4987m	4987-4992m

4992-4996m	4996-5001m	5001-5006m	5006-5011m	5011-5016m

5016-5021m	5021-5026m	5026-5031m	5031-5036m	5036-5041m

5041-5046m	5046-5047m

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
INTERM.	9 5/8	4534.0	12 1/4	4534.0	1.87	LOT
LINER	7	5080.0	8 1/2	5080.0	0.00	LOT

Drill stem tests (DST)

Drill stem tests (DST)
Test number	From depth MD [m]	To depth MD [m]	Choke size [mm]
1.0	4905	4874	9.5
2.0	4704	4684	7.9

Drill stem tests (DST)
Test number	Final shut-in pressure [MPa]	Final flow pressure [MPa]	Bottom hole pressure [MPa]	Downhole temperature [°C]
1.0	44.000	31.000	52.000
2.0	50.000	12.000	51.000

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	93	237000	0.773	0.780	2925
2.0	18	42855	0.789	0.743	2300

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
AIT IPLT	4534	5081
CMR ECS HNGS	4534	5060
MDT	4619	5008
MDT	4643	4988
MDT	4945	4945
MSCT	4610	4764
MWD - GR RES DIR	4534	5080
UBI DSI	4534	5060
VSP	4400	5080

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
296	NORDLAND GP
296	NAUST FM
1576	KAI FM
1946	HORDALAND GP
1946	BRYGGE FM
2462	ROGALAND GP
2462	TARE FM
2528	TANG FM
2589	SHETLAND GP
2589	SPRINGAR FM
2725	NISE FM
2913	KVITNOS FM
3485	CROMER KNOLL GP
3485	LYSING FM
3502	LANGE FM
3565	NO FORMAL NAME
3623	LANGE FM
4372	LYR FM
4388	VIKING GP
4388	SPEKK FM
4406	MELKE FM
4612	FANGST GP
4612	GARN FM
4667	NOT FM
4671	BÅT GP
4671	TOFTE FM
4755	TILJE FM
4950	ÅRE FM

Composite logs

Composite logs
Document name	Document format	Document size [MB]
3627	pdf	0.45

Geochemical information

Geochemical information
Document name	Document format	Document size [MB]
3627_1	pdf	1.93
3627_2	pdf	0.68

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]
3627_6406_2_4_R_COMPLETION_REPORT	.pdf	32.80

6406/2-4 SR