Wellbore: 15/9-5 - 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.	15/9-5
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.	SLEIPNER VEST
Discovery Name of the discovery the wellbore is related to.	15/6-3 Sleipner Vest
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	15/9-5
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	046
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.	Den norske stats oljeselskap a.s
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.	232-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	NORSKALD
Drilling days Number of days from wellbore entry to wellbore completion.	145
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,	19.11.1979
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.	11.04.1980
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.	11.04.1982
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.	08.04.2015
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.	HUGIN FM
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	25.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	108.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	3946.0
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).	3945.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	2.25
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	131
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.	58° 24' 12.47'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	1° 42' 29.2'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6474503.53
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	424497.43
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.	326

Well 15/9-5 was drilled in the Sleipner Vest area in the Central Graben of the North Sea. The objective was to test hydrocarbons in Middle Jurassic sandstones in the Beta structure of Sleipner Vest. The well is Reference Well for the Heimdal and Våle formations.

Operations and results

Appraisal well 15/9-5 was spudded with the semi-submersible installation Norskald on 19 November 1979 and drilled to TD at 3946 m in the Triassic Skagerrak Formation. Operations met with many problems, but the well objectives were fulfilled in the end. Excessive drag when pulling core barrel out of reservoir was a severe problem, and consequently frequent reaming and circulating trips was needed. Having finished logging in the 8 1/2” section, and just started testing the BOP stack, one of the riser tension sheaves broke and fell down. Also several problems with the hydraulic BOP control system and the ball joint made nearly 12 days rig repair necessary. After this delay the hole required extensive reaming before the 7” liner could be ran and the final 6” section could be drilled. Testing operations were hampered and delayed by bad weather and test equipment breakdown. The well was drilled with spud mud down to 426 m and with seawater/lignosulphonate mud from 426 m to TD.

The well proved gas in sandstones of Middle Jurassic age from top Hugin Formation at 3526 m down to a true gas/water contact at 3662 m, based on logs and RFT samples. The Sleipner Formation was encountered at 3693 m. Logs and RFT pressure gradient proved Sleipner water filled, and ca 3 bar overpressured compared to the Hugin Formation. Shows were described on cores all through the hydrocarbon bearing reservoir. Abundant spots of fluorescence described on cuttings below ca 2000 m are described as “no shows”. According to other comments in the cuttings descriptions the fluorescence may be related to diesel addition to the mud.

Nine cores were cut in the interval 3525 to 3663.6 m. A total of 133 m core (96.8%) was recovered. A FIT fluid sample at 3536 m recovered gas, condensate and mud. An RFT fluid sample was taken at 3540 m.

The well was permanently abandoned on 11 April 1980 as a gas/condensate appraisal well.

Testing

Three Drill Stem Tests were conducted.

DST1 tested the interval 3642 m to 3646.6 m. The final flow was controlled by using two variable chokes mounted in parallel. On the smallest choke size, 2x25/64”, the well produced 583000 Sm3 gas and 181 Sm3 condensate /day. The GOR was ca 3200 Sm3/Sm3, the oil density was 45.3 °API, and the gas gravity was 0.774 (air = 1).

DST2 tested the interval 3605 to 3610 m plus 3613 to 3618 m. The final flow was controlled by using two variable chokes mounted in parallel. On the smallest choke size, 2x28.75/64”, the well produced 699400 Sm3 gas and 189 Sm3 condensate /day. The GOR was ca 3700 Sm3/Sm3, the oil density was 45.4°API, and the gas gravity was 0.773 (air = 1). The CO2 content was 9.2%. Maximum temperature during this test was 122.8 °C.

DST3 tested the interval 3536 to 3546 m. The final flow was controlled by using two variable chokes mounted in parallel. The choke size was kept at 2x45.5/64” throughout the whole flow. The well produced 815500 Sm3 gas and 212 Sm3 condensate /day. The GOR was ca 3850 Sm3/Sm3, the oil density was 40 °API, and the gas gravity was 0.771 (air = 1). The CO2 content was 7.7 %. Maximum temperature during this test was 117.8 °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]
190.00	3946.00

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	3525.0	3543.4	[m ]
2	3543.4	3547.0	[m ]
3	3547.0	3565.4	[m ]
4	3565.4	3583.8	[m ]
5	3584.1	3600.4	[m ]
6	3600.7	3618.9	[m ]
7	3619.2	3634.9	[m ]
8	3635.4	3643.8	[m ]
9	3645.3	3662.3	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	134.4

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

Core photos

Core photos

3525-3527m	3527-3530m	3530-3533m	3533-3535m	3535-3538m

3538-3541m	3541-3543m	3543-3546m	3546-3547m	3547-3549m

3549-3552m	3552-3555m	3555-3557m	3557-3560m	3560-3563m

3563-3565m	3565-3568m	3568-3570m	3570-3573m	3573-3576m

3576-3578m	3578-3581m	3581-3583m	3584-3586m	3586-3589m

3589-3592m	3592-3594m	3594-3597m	3597-3600m	3600-3603m

3603-3606m	3606-3608m	3608-3611m	3611-3614m	3614-3615m

3616-3618m	3619-3621m	3621-3624m	3624-3627m	3627-3630m

3630-3632m	3632-3634m	3635-3638m	3638-3640m	3640-3643m

3643-3644m	3645-3648m	3648-3650m	3650-3653m	3653-3656m

3656-3658m	3658-3661m	3661-3662m

Oil samples at the Norwegian Offshore Directorate

Oil samples at the Norwegian Offshore Directorate
Test type	Bottle number	Top depth MD [m]	Bottom depth MD [m]	Fluid type	Test time	Samples available
DST	TEST2	3588.00	3593.00		21.03.1980 - 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
CONDUCTOR	30	158.0	36	158.0	0.00	LOT
SURF.COND.	20	422.0	26	437.0	1.37	LOT
INTERM.	13 3/8	1232.0	17 1/2	1243.0	1.95	LOT
INTERM.	9 5/8	2792.0	12 1/4	2807.0	1.72	LOT
LINER	7	3663.0	8 1/2	3664.0	1.96	LOT
OPEN HOLE		3921.0	6	3921.0	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	3617	3647	25.0
2.0	3588	3593	0.0
3.0	3511	3521	0.0

Drill stem tests (DST)
Test number	Final shut-in pressure [MPa]	Final flow pressure [MPa]	Bottom hole pressure [MPa]	Downhole temperature [°C]
1.0
2.0
3.0

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	218	768	0.799	0.768	3
2.0	229	865	0.811	0.886	4
3.0	206	813			4

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
ARROW PLOT	2827	3951
CBL	400	2825
FDC CNL GR	2827	3949
FDC GR	447	2833
GR CCL	182	2850
HDT	2826	3950
ISF SON GR	182	3949
VELOCITY	475	3940

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
133	NORDLAND GP
836	UTSIRA FM
1322	HORDALAND GP
1913	FRIGG FM
2290	ROGALAND GP
2290	BALDER FM
2344	SELE FM
2397	LISTA FM
2448	HEIMDAL FM
2736	VÅLE FM
2774	SHETLAND GP
2774	EKOFISK FM
2806	TOR FM
2964	HOD FM
3210	BLODØKS FM
3253	HIDRA FM
3298	CROMER KNOLL GP
3298	RØDBY FM
3331	SOLA FM
3345	ÅSGARD FM
3432	VIKING GP
3432	DRAUPNE FM
3526	VESTLAND GP
3526	HUGIN FM
3693	SLEIPNER FM
3769	SKAGERRAK FM

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]
326_15_9_5_Completion_report_and_log	pdf	21.58

Documents – older Norwegian Offshore Directorate WDSS reports and other related documents

Documents – older Norwegian Offshore Directorate WDSS reports and other related documents
Document name	Document format	Document size [MB]
326_01_WDSS_General_Information	pdf	0.14
326_02_WDSS_completion_log	pdf	0.25

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
204	1.04	100.0	waterbased
436	1.09	38.0	waterbased
795	1.09	36.0	waterbased
1300	1.20	100.0	waterbased
3325	1.38	45.0	waterbased
3580	1.40	50.0	waterbased
3778	1.35	44.0	waterbased

Palynological slides at the Norwegian Offshore Directorate

Palynological slides at the Norwegian Offshore Directorate
Sample depth	Depth unit	Sample type
3430.0	[m]	DC
3435.0	[m]	DC
3439.0	[m]	DC
3469.0	[m]	DC
3499.0	[m]	DC
3520.0	[m]	DC
3528.8	[m]	C
3555.1	[m]	C
3573.2	[m]	C
3577.3	[m]	C
3596.6	[m]	C
3598.1	[m]	C
3607.4	[m]	C
3615.9	[m]	C
3623.6	[m]	C
3634.0	[m]	C
3636.0	[m]	C
3643.5	[m]	C
3650.8	[m]	C
3691.0	[m]	DC
3721.0	[m]	DC
3751.0	[m]	DC
3781.0	[m]	DC

15/9-5