Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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25.12.2024 - 01:26
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15/12-20 S

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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.
    15/12-20 S
    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.
    RE-CLASS TO DEV
    Press release
    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.
    15/12-20
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    NH0201
    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.
    Talisman Energy Norge 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.
    1184-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.
    35
    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,
    28.05.2008
    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.
    01.07.2008
    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.
    01.07.2010
    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.
    01.08.2010
    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
    Reclassified to wellbore
    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.
    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.
    SLEIPNER FM
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    51.5
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    84.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    4192.0
    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).
    3141.5
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    56.6
    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.
    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° 4' 40.53'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    1° 53' 25.77'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6438070.14
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    434558.93
    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.
    5824

  • Wellbore history
    General
    Well 15/12-20 S was drilled from the Varg Field production Platform in the southern Viking Graben in the North Sea. The primary objective of the well was to explore a potential undrained compartment in Triassic sands. A secondary objective was potential Late Jurassic sands that could exist above the Triassic sands.
    Operations and results
    Wildcat well 15/12-20 S was drilled with the jack-up installation Mærsk Giant, as a sidetrack from development well 15/12-A-7 on the Varg Field. It was kicked off 28 May 2008 from 1306 m, just above the 13 3/8" casing in the 15/12-A-7 development well, and drilled to TD at 4192 m (3142 m TVD) in the Late Triassic Skagerrak Formation. Significant operational problems were not encountered although 21% of the rig time was counted as non-productive. The main contributor to non-productive time was failure to mill the window in the 13 3/8" casing during kick-off. The well was drilled with Carbo-Sea oil based mud from kick-off to TD.
    The Oxfordian Sandstone that makes up the reservoir over Varg Field was absent as forecast. A discovery was made in Middle Jurassic Sleipner Formation sandstone. This sand, encountered at 3808 m, was not prognosed. It contained oil down to a lithological contact at ca 3842 m (2878 m TVD SS). The underlying Triassic was encountered at 3874 m and was dry. Good shows on sandstones were reported in cuttings at 3810 and all through to the end of the cores at 3875 m. Formation Gas peaks up to a maximum of 4% were seen in the Sleipner formation. Resistivity was initially high, 15 ? 30 ohm/m from 3812 m (after the coal) and dropped off at 3835m MD to 0.3 - 0.8 ohm/m.
    Two cores were taken (26.26 m and 54.85 m) from the Sleipner Formation and ca 25 m into the Triassic. Reservoir pressures were taken using TesTrak and an oil gradient of 0.935 SG was obtained although a water gradient was not established. No wire line fluid samples were taken.
    Exploration well 15/12-20 S is classified as an oil discovery. On 1 July 2008 7" liner was run to 4191 m and the well was reclassified to development well 15/12-A-7-A.
    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]
    1310.00
    4192.00

  • 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
    3815.0
    3841.2
    [m ]
    2
    3843.0
    3897.9
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    81.1
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES

  • Lithostratigraphy

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    MWD LWD - DIR
    1304
    1336
    MWD LWD - DIR RES GR CCN MT ST T
    3898
    4192
    MWD LWD - DIR RES GR PWD
    1336
    3815

  • 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
    3370.0
    12 1/4
    3375.0
    1.70
    LOT
    LINER
    7
    4191.0
    8 1/2
    4192.0
    0.00
    LOT

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    1250
    1.46
    38.0
    oil based
    1290
    1.46
    32.0
    oil based
    1297
    1.59
    40.0
    water based
    1303
    1.59
    38.0
    water based
    1313
    1.59
    40.0
    water based
    1316
    1.59
    44.0
    water based
    1333
    1.60
    48.0
    water based
    1336
    1.59
    39.0
    water based
    1348
    1.59
    52.0
    water based
    1354
    1.60
    51.0
    water based
    1373
    1.59
    57.0
    water based
    1474
    1.53
    43.0
    water based
    1750
    1.59
    43.0
    water based
    3171
    1.59
    45.0
    water based
    3375
    1.60
    43.0
    water based
    3613
    1.44
    30.0
    water based
    3843
    1.44
    32.0
    water based
    3898
    1.45
    32.0
    water based
    4136
    1.45
    33.0
    water based
    4192
    1.02
    water based
    4192
    1.44
    31.0
    water based

  • 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
    0.23