Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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25/2-12 A

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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.
    25/2-12 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
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    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.
    25/2-12
    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.
    Elf Petroleum 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.
    596-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.
    146
    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,
    12.11.1988
    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.
    06.04.1989
    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.
    06.04.1991
    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.
    17.12.2003
    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.
    22.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    115.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    3865.0
    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).
    3721.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    39.7
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    130
    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.
    MIDDLE 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.
    HUGIN FM
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    59° 57' 48.34'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 23' 40.78'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6647648.17
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    466196.96
    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.
    1355

  • Wellbore history
    General
    Well 25/2-12 was designed to drill the crest of a NNE-SSW trending westward tilting Jurassic fault block. The northern extension of this structure was drilled in 1975 by well 25/2-4 in a down dip position to well 25/2-12. A 70 m hydrocarbon bearing column was encountered in the Vestland Group. The Statfjord Formation was found water bearing. The main objectives of well 25/2-12 were to appraise and test the hydrocarbon discovery of the Middle Jurassic Vestland Group and to explore the Statfjord Formation up dip from well 25/2-4. Due to an unprognosed fault top Vestland came in 112 m deeper than prognosed in 25/2-12. Hence, side track 25/2-12 A was decided. The main purpose of the sidetrack was to explore the still untested Vestland up dip to the West.
    Operations
    Appraisal well 25/2-12 A was sidetracked from 3099 m in well 25/12-2 on 17 November 1988 by the semi-submersible rig West Vanguard and drilled to TD at 3865 m in the Middle Jurassic Vestland Group. During drilling the string got stuck at 3692 m. Drilling was stopped at 3714 m, one metre above the Vestland reservoir. Fishing was unsuccessful, and the string was cut at 3485 m. When tripping out the well started to flow. Several days were needed to control the well and finally a cement plug was set from bottom to 3528 m. The cement was dressed to 3612 m and a 7" liner was set from 3600 m to 2927.5 m. After that the cement was drilled out to 3612 m before commencing to drill the 5 7/8" section. During drilling the 5 7/8" phase the string got stuck several times, and finally stuck at 3865 m. While jarring the well started flowing again. After controlling the well a 4 1/2" liner was set from 3863 m to 3562 m. Cement was drilled out to 3830 m before logging. Due to the problems no open hole logs were run in well 25/2-12 A; all logs were run behind casing and no fluid samples were taken. No cores were cut. The sidetracked well 25/2-12 A was completed 6 April 1989 as a gas and condensate appraisal.
    Testing
    Two DSTs was planned for the sidetrack. The first was performed in the interval 3795 m to 3805 m (3653 m to 3660.6 m TVD MSL). It produced gas/condensate at a maximum rate of 198000 Sm3/day and a GOR of  1780 Sm3/Sm3. The condensate density at stock tank condition was 0.8157 g/cm3, while the gas gravity was 0.713 (air = 1). The DST1 string got stuck. Due to an unsuccessful fishing operation of the DST1 string the second DST had to be abandoned.

  • 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]
    3105.00
    3864.00

  • 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
    197.0
    36
    199.0
    0.00
    LOT
    SURF.COND.
    20
    890.0
    26
    907.0
    1.32
    LOT
    INTERM.
    13 3/8
    2848.0
    17 1/2
    2867.0
    1.88
    LOT
    INTERM.
    9 5/8
    3099.0
    12 1/4
    3099.0
    1.98
    LOT
    LINER
    7
    3603.0
    8 1/2
    3714.0
    2.10
    LOT
    LINER
    4 1/2
    3865.0
    5 3/8
    3865.0
    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
    3805
    3795
    5.6
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    37.000
    120
    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
    102
    200000
    0.810
    0.700
    1960

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL VDL GR CCL
    3499
    3812
    CBL VDL GR CCL DIG.SONIC
    2885
    3602
    CNL GR CCL
    3685
    3800
    FGL-DEN GR
    3590
    3829
    MWD
    3100
    3400
    TDT-P GR CCL
    3488
    3819

  • Lithostratigraphy

  • Composite logs
    Composite logs
    Document name
    Document format
    Document size [MB]
    pdf
    0.49

  • 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
    32.58

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    3174
    1.81
    48.0
    14.2
    WATER BASED
    22.11.1988
    3175
    1.81
    48.0
    14.2
    WATER BASED
    24.11.1988
    3177
    1.81
    48.0
    14.2
    WATER BASED
    25.11.1988
    3207
    1.81
    464.0
    15.6
    WATER BASED
    25.11.1988
    3290
    1.84
    46.0
    13.7
    WATER BASED
    29.11.1988
    3311
    1.85
    41.0
    11.7
    WATER BASED
    29.11.1988
    3335
    1.85
    38.0
    11.2
    WATER BASED
    30.11.1988
    3360
    1.85
    40.0
    11.7
    WATER BASED
    01.12.1988
    3386
    1.85
    40.0
    12.2
    WATER BASED
    02.12.1988
    3407
    1.85
    41.0
    12.7
    WATER BASED
    05.12.1988
    3412
    1.85
    46.0
    13.2
    WATER BASED
    05.12.1988
    3415
    1.85
    50.0
    11.2
    WATER BASED
    05.12.1988
    3442
    1.85
    48.0
    12.7
    WATER BASED
    08.12.1988
    3448
    1.90
    53.0
    14.2
    WATER BASED
    27.12.1988
    3449
    1.90
    51.0
    13.7
    WATER BASED
    27.12.1988
    3478
    1.90
    50.0
    12.7
    WATER BASED
    28.12.1988
    3506
    1.85
    46.0
    11.7
    WATER BASED
    09.12.1988
    3507
    1.90
    51.0
    12.7
    WATER BASED
    29.12.1988
    3553
    1.90
    54.0
    14.7
    WATER BASED
    30.12.1988
    3592
    1.90
    56.0
    13.7
    WATER BASED
    02.01.1989
    3655
    1.91
    50.0
    14.2
    WATER BASED
    02.01.1989
    3692
    1.91
    48.0
    12.7
    WATER BASED
    12.12.1988
    3714
    1.91
    53.0
    14.7
    WATER BASED
    03.01.1989
    3799
    1.95
    51.0
    15.6
    WATER BASED
    08.02.1989
    3865
    1.95
    47.0
    14.7
    WATER BASED
    09.02.1989