Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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27.11.2024 - 01:27
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7/12-11

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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.
    7/12-11
    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
    Well name
    Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
    7/12-11
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    BPN 91 - 228 SP 196.5
    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.
    BP Norway Limited U.A.
    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.
    696-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.
    68
    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,
    31.08.1991
    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.
    06.11.1991
    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.
    06.11.1993
    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.
    08.03.2004
    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.
    SHOWS
    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
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    22.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    68.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    3868.0
    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).
    3864.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    2.2
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    142
    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.
    57° 7' 10.71'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 58' 33.19'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6330846.33
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    498539.76
    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.
    1787
  • Wellbore history

    General
    Well 7/12-11 was designed to test 7/12-JU6 prospect, a Late Jurassic Ula Formation sand in a structural prospect some 7 km east of the Ula Field. Well 7/12-11 was located close to the edge of the perceived Late Jurassic Ula Trend fairway.
    The prospect was defined as a structural trap with fault closure to the east and north, and dip closure to the southwest. Lateral seal to the east was thought to be provided by cross-fault seal of Late Jurassic reservoir against Triassic shales and siltstones. The key element of risk was trap effectiveness, as the prospect relied on a shattered sub-seismic fault zone in the northeastern corner. The results might have implications for further prospectivity in the licence.
    The primary objective for the 7/12-11 well was to prove a volume of oil that was commercial as a tieback development to the Ula Platform. Secondary objectives were the uppermost part of the Triassic rocks and the Middle Jurassic Bryne Formation.
    Operations and results
    Wildcat well 7/12-11 was spudded with the semi-submersible installation Ross Isle on 31 August 1991 and drilled to TD at 3865 m in the Triassic Skagerrak Formation. A 9 7/8" pilot hole was drilled to 950 m, and some shallow gas was detected by ROV sonar and observation of some surface bubbles at 518 m. The 17 1/2" hole was drilled with the experimental mud system RCS/DF+. In the 12 1/4" hole this mud was gradually diluted and displaced to a KCl/IOBOND mud. Drilling proceeded without significant problems to TD.
    The Ula sandstones came in at 3787.5 m, 39.5 m deeper than prognosed. It was only 12.5 m thick which was 78 m thinner than prognosed. The Bryne Formation was absent. Very weak hydrocarbon fluorescence was observed in sand stringers of the Lista Formation. Minor gas shows were observed in the Mandal Formation. Occasional oil stained grains with very weak cut fluorescence were seen in the cuttings of the Ula Formation. No shows were observed in the sidewall cores. One 10 m conventional core was cut in the Triassic Skagerrak Formation. A total of 21 sidewall cores were attempted, and 14 were recovered. Two RFT fluid samples were taken at 3797.5 m. No gas or oil was recovered in these samples, only water. The well was permanently abandoned on 6 November 1991 as a dry hole with weak hydrocarbon shows.
    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]
    950.00
    3865.00
  • 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
    3802.7
    3812.0
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    9.3
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES
  • Core photos

    Core photos
    Core photo at depth: 3802-3807m
    Core photo at depth: 3807-3812m
    Core photo at depth:  
    Core photo at depth:  
    Core photo at depth:  
    3802-3807m
    3807-3812m
  • Palynological slides at the Norwegian Offshore Directorate

    Palynological slides at the Norwegian Offshore Directorate
    Sample depth
    Depth unit
    Sample type
    Laboratory
    3733.0
    [m]
    DC
    PETROSTR
    3739.0
    [m]
    DC
    PETROS
    3745.0
    [m]
    DC
    PETROS
    3751.0
    [m]
    DC
    PETROS
    3757.0
    [m]
    DC
    PETROS
    3763.0
    [m]
    DC
    PETROS
    3769.0
    [m]
    DC
    PETROS
    3775.0
    [m]
    DC
    PETROS
    3781.0
    [m]
    DC
    PETROS
    3787.0
    [m]
    DC
    PETROS
    3793.0
    [m]
    DC
    PETROS
    3799.0
    [m]
    DC
    PETROS
  • Lithostratigraphy

  • Composite logs

    Composite logs
    Document name
    Document format
    Document size [MB]
    pdf
    0.47
  • 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
    61.28
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    DLL LSS GR CAL SP
    75
    2746
    DLL MSFL SDT GR SP CAL
    2738
    3872
    LDL CNL NGT GR
    2738
    3871
    MSCT GR
    3764
    3806
    MWD
    90
    3865
    RFT HP GR
    3791
    3833
    SHDT GR
    2738
    3872
    WST GR
    500
    3871
  • 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
    163.0
    36
    165.0
    0.00
    LOT
    INTERM.
    20
    935.0
    26
    937.0
    1.70
    LOT
    INTERM.
    13 3/8
    2735.0
    17 1/2
    2737.0
    1.90
    LOT
    OPEN HOLE
    3868.0
    12 1/2
    3868.0
    0.00
    LOT
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    206
    1.03
    WATER BASED
    946
    1.20
    23.0
    WATER BASED
    950
    1.05
    39.0
    WATER BASED
    962
    1.20
    17.0
    WATER BASED
    1222
    1.39
    30.0
    WATER BASED
    1405
    1.60
    54.0
    WATER BASED
    1413
    1.60
    35.0
    WATER BASED
    1595
    1.60
    60.0
    WATER BASED
    1764
    1.70
    55.0
    WATER BASED
    1907
    1.60
    48.0
    WATER BASED
    2051
    1.60
    45.0
    WATER BASED
    2205
    1.60
    36.0
    WATER BASED
    2313
    1.60
    40.0
    WATER BASED
    2380
    1.60
    31.0
    WATER BASED
    2386
    1.60
    34.0
    WATER BASED
    2522
    1.60
    44.0
    WATER BASED
    2659
    1.60
    44.0
    WATER BASED
    2667
    1.60
    34.0
    WATER BASED
    2737
    1.60
    31.0
    WATER BASED
    2743
    1.60
    28.0
    WATER BASED
    2767
    1.58
    36.0
    WATER BASED
    2873
    1.55
    32.0
    WATER BASED
    2972
    1.55
    34.0
    WATER BASED
    3015
    1.55
    30.0
    WATER BASED
    3055
    1.55
    27.0
    WATER BASED
    3087
    1.55
    31.0
    WATER BASED
    3109
    1.55
    32.0
    WATER BASED
    3168
    1.55
    32.0
    WATER BASED
    3203
    1.55
    32.0
    WATER BASED
    3326
    1.55
    38.0
    WATER BASED
    3474
    1.55
    36.0
    WATER BASED
    3557
    1.55
    35.0
    WATER BASED
    3587
    1.55
    35.0
    WATER BASED
    3596
    1.55
    34.0
    WATER BASED
    3624
    1.55
    38.0
    WATER BASED
    3640
    1.55
    36.0
    WATER BASED
    3674
    1.55
    39.0
    WATER BASED
    3723
    1.55
    28.0
    WATER BASED
    3730
    1.55
    33.0
    WATER BASED
    3802
    1.55
    32.0
    WATER BASED
    3865
    1.55
    38.0
    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
    0.22