Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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34/7-18

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  • General information
    General information
    Attribute Value
    Wellbore name
    Official name of wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
    34/7-18
    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
    Factmaps in new window
    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.
    Discovery
    Name of the discovery the wellbore is related to.
    Well name
    Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
    34/7-18
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    GE - 8431R: ROW 95 & COLUMN 1075
    Production licence
    Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).
    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.
    690-L
    Drilling facility
    Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.
    Drilling days
    Number of days from wellbore entry to wellbore completion.
    60
    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,
    20.07.1991
    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.
    17.09.1991
    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.
    17.09.1993
    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.
    28.02.2008
    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
    Reentry
    Status whether the wellbore has been re-entered (YES) or not (NO). Re-entered wellbores are not included in the count when wellbores are presented in statistical overviews.
    NO
    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.
    YES
    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.
    PALEOCENE
    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.
    LISTA FM
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    18.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    242.5
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2443.0
    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).
    2443.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    2.6
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    83
    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.
    DRAKE 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' 10.75'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 6' 40.26'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6798878.30
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    452410.07
    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.
    1819

  • Wellbore history
    General
    Well 34/7-18 is located on the Vigdis Field on Tampen Spur in the Northern North Sea. It was designed to drill and test a Jurassic Prospect (Segment IV of the C Plus structure), between the Snorre and Tordis Fields. The well was drilled in a high position on a gently dipping structure where the top of the Brent Group is eroded. The primary objective was to test the presence, reservoir quality and fluid contacts in the prospect. A secondary objective was to test the pressure regimes in the Jurassic sequence, including possible depletion associated with pressure communication, previously identified in the nearby Tordis Field. A boulder bed was expected at 303 m, and shallow gas could occur at 394 m and 546 m.
    Operations and results
    Wildcat well 34/7-18 was spudded with the semi-submersible installation West Alpha on 20 July 1991 and drilled to TD at 2443 m in the Early Jurassic Drake Formation. Problems with retrieving core no 2 led to 4 days lost while fishing. During plug and abandon the cut and pull tool twisted off and 9 x 8" DC and 7 x 5" HWDP was left on seabed. Three days were lost while clearing the seabed and cutting the casing and retrieving the well head, which was eventually retrieved using explosives. Shallow gas was encountered in the pilot hole and a boulder bed was indicated from drilling parameters at 342 m. The well was drilled with spud mud down to 1115 m, and with KCl mud from 1115 m to TD.
    In the Nordland and Hordaland Groups, the well penetrated mainly claystones with relatively minor sandstone intervals. A Paleocene oil discovery was made, and two cores were cut in the Lista Formation, Rogaland Group. These were cut in the interval 1774 -1782 m, of which 6.3 m were recovered. RFT pressure measurements and fluid sampling, the latter without success, were carried out in addition to a drill stem test.
    The top of the Brent Group reservoir was penetrated at 2284 m which was 20 m shallower than prognosed. The Jurassic section comprised an eroded Middle Jurassic Brent Group and the Early Jurassic Dunlin Group. A total of 3 cores were cut in the Brent Group between 2285 and 2306 m, with a recovery of 20.5 m. The upper part of a sandstone interpreted to be a Ness Formation sandstone (2284 - 2290 m) had traces of oil with a calculated oil saturation up to 25% in the best zones. No oil gradient and hence no OWC could be established from the pressure gradient analysis. Small amounts (40 - 300 ml) of oil were recovered in RFT samples from 2284.5 and 2284.6 m.
    Apart from the zones with live oil minor shows were recorded in sand layers in the interval 1375 to 1585 m in the Hordaland Group and in siltstone laminae in the interval 2120 to 2250 m in the Shetland Group. No shows were recorded below 2288.5 m.
    The pressure gradient of the Brent Group showed the same depletion as observed in well 34/7-17A, indicating pressure communication in the Lower Brent between the Tordis Field, well 34/7-17A and well 34/7-18.
    The well was permanently abandoned on 17 September 19921 as a minor oil discovery.
    Testing
    One DST test was performed in the interval 1770 - 1783.5 m in an intra-Lista Formation Sandstone. The maximum oil rate was 130 Sm3/day. Due to sand and clay plugging, flow was sluggish and reliable rates were not obtained. The well test summary reports 46 Sm3oil/day as a reference rate, measured during the main flow through a 7.9 mm choke. A gas rate of ca 9000 Sm3 /day was measured at the same time. Maximum down hole temperature measured in the test was 60.9 deg 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]
    1120.00
    2441.00

  • 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
    2
    1775.0
    1780.3
    [m ]
    3
    2285.0
    2287.7
    [m ]
    4
    2286.0
    2289.8
    [m ]
    5
    2290.0
    2306.0
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    27.8
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES

  • Core photos
    Core photos
    Core photo at depth: 1775-1780m
    Core photo at depth: 1780-1780m
    Core photo at depth: 2285-2286m
    Core photo at depth: 2286-2289m
    Core photo at depth: 2290-2295m
    1775-1780m
    1780-1780m
    2285-2286m
    2286-2289m
    2290-2295m
    Core photo at depth: 2295-2300m
    Core photo at depth: 2300-2305m
    Core photo at depth: 2305-2306m
    Core photo at depth:  
    Core photo at depth:  
    2295-2300m
    2300-2305m
    2305-2306m

  • Lithostratigraphy

  • Geochemical information
    Geochemical information
    Document name
    Document format
    Document size [MB]
    pdf
    0.34
    pdf
    2.20

  • 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]
    pdf
    15.96

  • Drill stem tests (DST)
    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    1770
    1784
    8.0
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    6.000
    25.000
    61
    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
    46
    0.890

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL VDL GR
    825
    1706
    CBL VDL GR
    1400
    1861
    DLL MSFL LSS LDL GR AMS
    1099
    1681
    DLL MSFL LSS LDL SNL GR AMS
    1681
    2427
    FMS GR AMS
    1706
    2429
    MWD CDR - GR RES DIR TEMP
    361
    2443
    RFT
    1780
    2355
    SHDT GR AMS
    1098
    1685
    VELOCITY
    840
    2420

  • 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
    361.0
    36
    361.0
    0.00
    LOT
    INTERM.
    20
    1099.0
    26
    1115.0
    1.62
    LOT
    INTERM.
    13 3/8
    1709.0
    17 1/2
    1770.0
    1.75
    LOT
    INTERM.
    9 5/8
    1889.0
    12 1/4
    2443.0
    0.00
    LOT

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    361
    1.05
    WATER BASED
    23.07.1991
    386
    1.05
    WATER BASED
    23.07.1991
    1115
    1.30
    34.0
    26.0
    WATER BASED
    30.07.1991
    1115
    1.05
    WATER BASED
    24.07.1991
    1115
    1.05
    WATER BASED
    25.07.1991
    1115
    1.20
    WATER BASED
    26.07.1991
    1115
    1.20
    WATER BASED
    29.07.1991
    1115
    1.30
    WATER BASED
    30.07.1991
    1121
    1.30
    23.0
    17.0
    WATER BASED
    30.07.1991
    1359
    1.36
    28.0
    19.0
    WATER BASED
    31.07.1991
    1404
    1.47
    24.0
    20.0
    WATER BASED
    01.08.1991
    1409
    1.45
    28.0
    20.0
    WATER BASED
    02.08.1991
    1423
    1.30
    28.0
    21.0
    WATER BASED
    05.08.1991
    1611
    1.30
    28.0
    26.0
    WATER BASED
    06.08.1991
    1681
    1.35
    30.0
    25.0
    WATER BASED
    06.08.1991
    1681
    1.35
    31.0
    26.0
    WATER BASED
    06.08.1991
    1730
    1.40
    35.0
    25.0
    WATER BASED
    08.08.1991
    1730
    1.44
    31.0
    23.0
    WATER BASED
    09.08.1991
    1730
    1.44
    21.0
    23.0
    WATER BASED
    12.08.1991
    1730
    1.44
    30.0
    22.0
    WATER BASED
    13.08.1991
    1730
    1.45
    31.0
    22.0
    WATER BASED
    13.08.1991
    1730
    1.44
    21.0
    23.0
    WATER BASED
    13.08.1991
    1770
    1.44
    29.0
    24.0
    WATER BASED
    08.08.1991
    1775
    1.50
    29.0
    17.0
    WATER BASED
    14.08.1991
    1775
    1.51
    29.0
    18.0
    WATER BASED
    15.08.1991
    1782
    1.50
    29.0
    18.0
    WATER BASED
    16.08.1991
    1782
    1.51
    29.0
    19.0
    WATER BASED
    19.08.1991
    1782
    1.50
    21.0
    18.0
    WATER BASED
    20.08.1991
    1782
    1.51
    23.0
    19.0
    WATER BASED
    20.08.1991
    1879
    1.56
    24.0
    21.0
    WATER BASED
    20.08.1991
    2110
    1.62
    29.0
    26.0
    WATER BASED
    21.08.1991
    2179
    1.65
    31.0
    21.0
    WATER BASED
    22.08.1991
    2233
    1.65
    31.0
    18.0
    WATER BASED
    02.09.1991
    2237
    1.65
    30.0
    17.0
    WATER BASED
    04.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    04.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    04.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    06.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    06.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    09.09.1991
    2237
    1.55
    26.0
    27.0
    WATER BASED
    10.09.1991
    2237
    1.55
    26.0
    27.0
    WATER BASED
    10.09.1991
    2237
    1.55
    26.0
    30.0
    WATER BASED
    10.09.1991
    2237
    1.55
    26.0
    27.0
    WATER BASED
    11.09.1991
    2237
    1.55
    24.0
    17.0
    WATER BASED
    04.09.1991
    2237
    1.55
    26.0
    27.0
    WATER BASED
    12.09.1991
    2237
    1.54
    27.0
    25.0
    WATER BASED
    13.09.1991
    2285
    1.65
    29.0
    17.0
    WATER BASED
    23.08.1991
    2286
    1.65
    29.0
    16.0
    WATER BASED
    27.08.1991
    2286
    1.65
    30.0
    20.0
    WATER BASED
    27.08.1991
    2286
    1.65
    37.0
    24.0
    WATER BASED
    27.08.1991
    2286
    1.65
    37.0
    24.0
    WATER BASED
    27.08.1991
    2286
    1.65
    37.0
    24.0
    WATER BASED
    29.08.1991
    2286
    1.65
    29.0
    18.0
    WATER BASED
    23.08.1991
    2286
    1.65
    32.0
    18.0
    WATER BASED
    29.08.1991

  • Pressure plots
    Pressure plots
    The pore pressure data is sourced from well logs if no other source is specified. In some wells where pore pressure logs do not exist, information from Drill stem tests and kicks have been used. The data has been reported to the NPD, and further processed and quality controlled by IHS Markit.
    Pressure plots
    Document name
    Document format
    Document size [MB]
    pdf
    0.22