Wellbore: 34/8-4 A - 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.	34/8-4 A
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.	VISUND
Discovery Name of the discovery the wellbore is related to.	34/8-4 S
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	34/8-4
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	120
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.	711-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	TRANSOCEAN 8
Drilling days Number of days from wellbore entry to wellbore completion.	100
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,	18.02.1992
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.	27.05.1992
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.	27.05.1994
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.	22.04.2005
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
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.	EARLY 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.	STATFJORD 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.	LATE TRIASSIC
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.	LUNDE FM
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	23.5
Water depth [m] Depth in metres betweem mean sea level and sea floor.	309.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	3567.0
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).	3313.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	33.3
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	123
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.	LATE 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.	LUNDE FM
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	61° 19' 29.58'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	2° 25' 18.67'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6799274.11
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	469049.02
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.	1909

Well 34/8-4 A on the Visund Field was initiated as a sidetrack to well 34/8-4 S, which had been temporarily plugged and abandoned. The original well had missed the planned Statfjord Formation target due to structural complexities of the area. The sidetrack should reach the target location, Statfjord Formation, approximately 420 m north-northwest of the surface location in an area of good seismic control. The main objective was to test Statfjord Formation hydrocarbon potential, fluid composition and aquifer characteristics. Secondary objectives were to evaluate the Lunde Formation B/C aquifer characteristics, to establish stratigraphic control of the Base Cretaceous - top Statfjord interval, and to determine the mechanism for hydraulic communication with the Brent reservoir in well 34/8-4S through gravity slide Brent segment and/or through Dunlin Group reservoir.

Operations and results

Well 34/8-4 S was re-entered with the semi submersible installation Transocean 8 on 18 February 1992. The sidetrack 34/8-4 A was kicked off from below the 13 3/8" shoe at 2187 m in the primary well bore and drilled to TD at 3567 m in the late Triassic Lunde Formation. No significant problems were encountered during drilling. The well was drilled with a KCl / polymer mud from kick-off to TD.

A major unconformity was found between the top of the Early Jurassic (Pliensbachian) at 2902.5 m and the overlying Early Cretaceous (Hauterivian). A sandstone member of the Amundsen Formation was encountered from 2942 m to 2989.5 m. One core was taken in this unit and recorded good hydrocarbon shows. Subsequent wire line logs and DST results confirmed that the interval is oil bearing. A gross reservoir thickness of 31.0 m was defined, giving a net pay thickness of 22.38 m. The Statfjord Formation occurred between 3057 m and 3143 m. A total of 7 cores were cut through this interval. Good oil shows were observed throughout.The Lunde Formation was present from 3143 m to TD, at 3567 m and consisted of claystone and distinct interbedded sandstone units. Good shows were recorded in cores in individual sandstone bodies in the upper part of the formation.A total gross reservoir of 205.5 m and a net pay of 115.5 m were defined. An OWC was identified at 3340.5 m.

Altogether sixteen cores were cut from the Dunlin Group and Statfjord and Lunde Formations with a total of 174 m recovered. RFT samples were taken at 3294.5 m (46 °API oil, gas and water/filtrate) and at 3326.5 m (42 °API oil, gas and water/filtrate). The first oil show was recorded at 2909 m at the top of the Jurassic section and the last at 3342 m in the Lunde Formation.

The well was suspended on 27 May 1992 as an oil appraisal.

Testing

Five DST tests were performed in this well, one in the Lunde Formation, three in the Statfjord Formation, and one in the Dunlin Group. The following flow data are from end of main flow.

DST 1 in the Lunde Formation perforated the interval 3322.9 m to 3340.9 m and flowed 936 Sm3 oil and 212000 Sm3 gas / day. The GOR was 226 Sm3/Sm3, oil density (@15 °C) was 0.815 g/cm3, and the gas gravity (air = 1) was 0.77 with 1.4 % CO2 and <0.1 ppm H2S.

DST 2 in the Statfjord Formation perforated the interval 3214.0 m to 3228.0 m and flowed 35 Sm3 oil and 15700 Sm3 gas / day. The GOR was 448 Sm3/Sm3, oil density (@15 °C) was 0.802 g/cm3, and the gas gravity (air = 1) was 0.81 with 1.2 % CO2 and <0.1 ppm H2S.

DST 3 in the Statfjord Formation perforated the interval 3160.6 m to 3184.6 m and flowed 821 Sm3 oil and 171000 Sm3 gas / day. The GOR was 208 Sm3/Sm3, oil density (@15 °C) was 0.820 g/cm3, and the gas gravity (air = 1) was 0.74 with 1.2 % CO2 and no H2S.

DST 4 in the Statfjord Formation perforated the interval 3056.0 m to 3108.0 m and flowed 831 Sm3 oil and 181000 Sm3 gas / day. The GOR was 218 Sm3/Sm3, oil density (@15 °C) was 0.821 g/cm3, and the gas gravity (air = 1) was 0.74 with 1.2 % CO2 and 0.5 ppm H2S.

DST 5 in the Dunlin Group perforated the interval 2988.5 m to 3019.5 m and flowed 992 Sm3 oil and 225000 Sm3 gas / day. The GOR was 227 Sm3/Sm3, oil density (@15 °C) was 0.820 g/cm3, and the gas gravity (air = 1) was 0.74 with 1.2 % CO2 and 0.5 ppm H2S.

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]
2190.00	3567.00

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	2909.0	2914.1	[m ]
2	2994.0	3006.1	[m ]
3	3063.0	3071.8	[m ]
4	3072.5	3087.7	[m ]
5	3088.0	3102.6	[m ]
6	3103.0	3112.4	[m ]
7	3113.5	3117.7	[m ]
8	3118.5	3134.7	[m ]
9	3135.0	3146.3	[m ]
10	3146.5	3155.0	[m ]
11	3156.0	3183.0	[m ]
12	3183.0	3196.2	[m ]
13	3197.5	3197.8	[m ]
14	3198.5	3201.0	[m ]
15	3247.5	3258.4	[m ]
16	3329.0	3342.5	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	172.8

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

Core photos

Core photos

2909-2913m	2913-2914m	2994-2998m	2998-3002m	3002-3006m

3006-3006m	3063-3067m	3067-3071m	3071-3072m	3072-3076m

3076-3080m	3080-3084m	3084-3087m	3088-3092m	3092-3096m

3096-3100m	3100-3102m	3103-3107m	3107-3111m	3111-3112m

3113-3117m	3118-3123m	3123-3128m	3128-3133m	3133-3134m

3135-3140m	3140-3145m	3145-3146m	3146-3151m	3151-3154m

3156-3161m	3161-3166m	3166-3171m	3171-3176m	3176-3181m

3181-3182m	3183-3188m	3188-3193m	3193-3196m	3197-3198m

3198-3201m	3247-3252m	3252-3257m	3257-3258m	3329-3334m

3334-3339m	3339-3342m

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	DST1	3322.90	3340.90	OIL	09.04.1992 - 17:30	YES
DST	DST2	0.00	0.00	OIL	22.04.1992 - 00:00	YES
DST	DST4	0.00	0.00	OIL	12.05.1992 - 22:15	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	417.0	36	420.0	0.00	LOT
INTERM.	18 5/8	1146.0	26	1150.0	1.58	LOT
INTERM.	13 3/8	2161.0	17 1/2	2165.0	1.78	LOT
INTERM.	9 5/8	3567.0	12 1/4	3567.0	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	3323	3341	14.2
2.0	3214	3228	12.7
3.0	3160	3184	19.0
4.0	3056	3108	12.7
5.0	2988	3019	14.3

Drill stem tests (DST)
Test number	Final shut-in pressure [MPa]	Bottom hole pressure [MPa]	Downhole temperature [°C]
1.0	23.000	49.000	118
2.0	1.000	7.000	105
3.0	11.000	27.000	113
4.0	26.000	45.000	110
5.0	26.000	44.000	109

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	936	211536	0.815	0.770	226
2.0	35	15680	0.800	0.810	448
3.0	821	170768	0.820	0.740	208
4.0	831	181158	0.821	0.740	218
5.0	992	225184	0.820	0.740	227

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
ASI GR	2235	3485
CST GR	2300	3522
DIL LSS LDL CNL NGT SP	1838	3564
DLL MSFL LDL CNL GR AMS	2960	3156
DLL MSFL LSS GR AMS	2140	3393
MDT GR AMS	2991	3413
MDT GR AMS	3294	3448
MWD - GR RES DIR	2187	3504
SHDT GR AMS	2850	3537

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
333	NORDLAND GP
1072	UTSIRA FM
1109	HORDALAND GP
1820	ROGALAND GP
1820	BALDER FM
1863	SELE FM
1876	LISTA FM
2031	SHETLAND GP
2894	CROMER KNOLL GP
2903	DUNLIN GP
2903	AMUNDSEN FM
3057	STATFJORD GP
3143	HEGRE GP
3143	LUNDE FM

Composite logs

Composite logs
Document name	Document format	Document size [MB]
1909	pdf	0.56

Geochemical information

Geochemical information
Document name	Document format	Document size [MB]
1909_1	pdf	5.30

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]
1909_01_WDSS_General_Information	pdf	1.18
1909_02_WDSS_completion_log	pdf	0.19

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
550	1.71	22.0	WATER BASED
2188	1.64	30.0	WATER BASED
2230	1.70	27.0	WATER BASED
2250	1.64	31.0	WATER BASED
2434	1.64	30.0	WATER BASED
2509	1.63	35.0	WATER BASED
2615	1.64	34.0	WATER BASED
2700	1.70	20.0	WATER BASED
2813	1.64	37.0	WATER BASED
2909	1.64	36.0	WATER BASED
2914	1.64	40.0	WATER BASED
2994	1.64	40.0	WATER BASED
3012	1.70	33.0	WATER BASED
3037	1.70	20.0	WATER BASED
3042	1.65	37.0	WATER BASED
3073	1.66	40.0	WATER BASED
3103	1.66	41.0	WATER BASED
3114	1.66	41.0	WATER BASED
3120	1.66	39.0	WATER BASED
3144	1.70	30.0	WATER BASED
3147	1.66	40.0	WATER BASED
3150	1.70	32.0	WATER BASED
3156	1.66	37.0	WATER BASED
3156	1.66	37.0	WATER BASED
3183	1.65	37.0	WATER BASED
3197	1.70	32.0	WATER BASED
3198	1.65	39.0	WATER BASED
3200	1.65	39.0	WATER BASED
3202	1.65	39.0	WATER BASED
3248	1.70	32.0	WATER BASED
3259	1.65	35.0	WATER BASED
3272	1.65	35.0	WATER BASED
3342	1.65	39.0	WATER BASED
3447	1.65	33.0	WATER BASED
3500	1.71	35.0	WATER BASED
3504	1.65	37.0	WATER BASED
3567	1.64	38.0	WATER BASED

Palynological slides at the Norwegian Offshore Directorate

Palynological slides at the Norwegian Offshore Directorate
Sample depth	Depth unit	Sample type	Laboratory
2910.1	[m]	C	HYDRO
2912.5	[m]	C	HYDRO
2965.0	[m]	SWC	HYDRO
2985.0	[m]	SWC	HYDRO
3000.3	[m]	C	HYDRO
3003.8	[m]	C	HYDRO
3020.0	[m]	SWC	HYDRO
3050.0	[m]	SWC	HYDRO
3055.0	[m]	SWC	HYDRO
3069.0	[m]	C	HYDRO
3074.0	[m]	C	HYDRO
3094.1	[m]	C	HYDRO
3110.2	[m]	C	HYDRO
3116.6	[m]	C	HYDRO
3117.4	[m]	C	HYDRO
3119.5	[m]	C	HYDRO
3125.3	[m]	C	HYDRO
3149.9	[m]	C	HYDRO
3150.3	[m]	C	HYDRO
3159.5	[m]	C	HYDRO
3181.3	[m]	C	HYDRO
3186.6	[m]	C	HYDRO
3194.7	[m]	C	HYDRO
3220.0	[m]	SWC	HYDRO
3225.0	[m]	SWC	HYDRO
3230.0	[m]	SWC	HYDRO
3235.0	[m]	SWC	HYDRO
3250.8	[m]	SWC	HYDRO
3275.0	[m]	SWC	HYDRO
3330.6	[m]	C	HYDRO
3340.6	[m]	C	HYDRO

34/8-4 A