Factpages Norwegian petroleum directorate
NPD          Norsk

25/11-8

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  • General information

    General information
    Attribute Value
    Wellbore name
    Official name of wellbore based on NPD guidelines for designation of wells and wellbores.
    25/11-8
    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 NPD.
    INJECTING: It was injected to the wellbore at the time of the operators last monthly report to the NPD.
    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 NPD guidelines for designation of wells and wellbores.
    25/11-8
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    CS-75-32 sp 2207
    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.
    Esso Exploration and Production Norway A/S
    Drill permit
    The drilling permit number together with the version of the drilling permit as stated in the drilling permit granted by the NPD.
    223-L
    Drilling facility
    NPD's name of the facility which the wellbore was drilled from.
    Drilling days
    Number of days from spud to completed. The first and last days of the operation is included in the count. Days where the drilling operations has been suspende, is not included. Days used for predrilling is not included. These are made available where applicable.
    39
    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,
    08.09.1979
    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.
    16.10.1979
    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.
    16.10.1981
    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.
    30.04.2010
    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.
    APPRAISAL
    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 telles if the wellbore made a new discovery. Legal values: YES, NO.
    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 NPD bulletins.
    EOCENE
    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 NPD bulletins.
    INTRA BALDER FM SS
    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.
    PALEOCENE
    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.
    HEIMDAL FM
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    25.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    126.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    1950.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    4.5
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    77
    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.
    PALEOCENE
    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.
    EKOFISK FM
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    59° 11' 17.33'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 21' 39.92'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6561329.11
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    463492.07
    UTM zone
    Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.
    31
    NPDID wellbore
    NPD's unique id for the wellbore.
    369
  • Wellbore history

    General
    Well 25/11-8 was drilled ca 3 km west-north west of the 25/11-1 Balder discovery well on the Utsira High in the North Sea. The primary objective was to establish the presence of, and closure on, the thick accumulation of Paleocene zone IB sand in the central part of the Balder Field, evaluate the geologic interpretation of sand distribution and reservoir quality in this field and test the flow potential and nature of the hydrocarbons present.
    Operations and results
    Appraisal well 25/11-8 was spudded with the semi-submersible installation Dyvi Alpha on 8 September 1979 and drilled to TD at 1950 m in the Early Paleocene Ekofisk Formation. The well was drilled with Seawater/Gel/Lignosulphonate.
    The well penetrated the Utsira Formation and several Skade Formation sands and then penetrated a ca 600 m thick section of shales belonging to the lower Hordaland Group before top Balder Formation was encountered at 1655 m. The well encountered two massive sand units in the Paleocene Heimdal Formation at 1721.5 m and 1743.8 m (dinoflagellate zones IB and II, respectively), interpreted as sand lobes deposited from sand-rich turbidity currents in the Balder Deep Sea Fan Complex. Both sands were oil bearing down to an OWC at 1785 m (1760 m MSL). Some thin sands from about 1705 m to 1720 m, overlying the massive sands, also appeared to be oil-bearing, and there were good shows on a core three meter below the OWC.
    Nine cores were taken in the interval 1722.5 m to 1800.4 m in the Heimdal Formation. Cores 1 and 4 had no recovery; the remaining cores retrieved a total of 41.7 m. No wire line fluid samples were taken.
    The well was permanently abandoned on 16 October as an oil appraisal well.
    Testing
    One production test was performed in the interval 1752 to 1767 m in the lower massive sand of the Heimdal Formation. It produced 418 Sm3 oil and 18690 Sm3 gas/day with traces of sand through a 38/64" choke. The GOR was 45 Sm3/Sm3, the oil gravity was 25 deg API (0.90 g/cm3), and the gas gravity was 0.7 (air = 1). No H2S or inert gas was detected.
  • Cuttings at the NPD

    Cuttings at the NPD
    Cuttings available for sampling?
    YES
    Cuttings at the NPD
    Cutting sample, top depth [m]
    Cutting samples, bottom depth [m]
    200.00
    1950.00
  • Cores at the NPD

    Cores at the NPD
    Core sample number
    Core sample - top depth
    Core sample - bottom depth
    Core sample depth - uom
    1
    0.0
    2
    1730.2
    1734.2
    [m ]
    3
    1737.0
    1740.0
    [m ]
    4
    1742.5
    1753.3
    [m ]
    5
    1756.0
    1757.0
    [m ]
    6
    1762.3
    1771.7
    [m ]
    7
    1771.6
    1778.4
    [m ]
    8
    1781.2
    1788.0
    [m ]
    9
    1791.0
    1798.0
    [m ]
    Cores at the NPD
    Total core sample length [m]
    40.7
    Cores at the NPD
    Cores available for sampling?
    YES
  • Palynological slides at the NPD

    Palynological slides at the NPD
    Sample depth
    Depth unit
    Sample type
    Laboratory
    1635.0
    [m]
    SWC
    1650.0
    [m]
    SWC
    1652.0
    [m]
    SWC
    1660.0
    [m]
    SWC
    1675.0
    [m]
    SWC
    1679.5
    [m]
    SWC
    1684.5
    [m]
    SWC
    1690.0
    [m]
    DC
    1693.0
    [m]
    SWC
    1700.0
    [m]
    DC
    1702.5
    [m]
    SWC
    1709.5
    [m]
    SWC
    1710.0
    [m]
    DC
    1714.0
    [m]
    SWC
    1715.0
    [m]
    DC
    1717.0
    [m]
    SWC
    1720.0
    [m]
    DC
    1721.0
    [m]
    SWC
    1725.0
    [m]
    DC
    1728.2
    [m]
    C
    1730.0
    [m]
    DC
    1730.3
    [m]
    C
    1730.7
    [m]
    C
    1731.4
    [m]
    C
    CGG
    1732.0
    [m]
    C
    1732.5
    [m]
    C
    1737.0
    [m]
    DC
    1737.0
    [m]
    C
    1737.0
    [m]
    SWC
    1738.0
    [m]
    C
    1739.0
    [m]
    C
    1739.3
    [m]
    C
    1740.0
    [m]
    C
    1779.0
    [m]
    SWC
    1783.0
    [m]
    SWC
    1835.0
    [m]
    SWC
    1839.0
    [m]
    SWC
    1849.0
    [m]
    SWC
    1850.0
    [m]
    DC
    1852.0
    [m]
    SWC
    1888.0
    [m]
    SWC
    1891.0
    [m]
    SWC
    1895.0
    [m]
    DC
    1903.0
    [m]
    SWC
    1905.0
    [m]
    DC
    1910.0
    [m]
    DC
    1911.0
    [m]
    SWC
    1914.0
    [m]
    SWC
    1915.0
    [m]
    DC
    1920.0
    [m]
    DC
    1925.0
    [m]
    DC
  • Oil samples at the NPD

    Oil samples at the NPD
    Test type
    Bottle number
    Top depth
    MD [m]
    Bottom depth
    MD [m]
    Fluid type
    Test time
    Samples available
    DST
    DST1
    1720.00
    1735.00
    11.09.1979 - 13:00
    YES
  • Lithostratigraphy

  • 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
    1.13
    pdf
    7.94
  • Drill stem tests (DST)

    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    1752
    1767
    15.1
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    52
    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
    418
    0.900
    46
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL VDL
    700
    1360
    CDL CNL
    1350
    1947
    CDM
    1357
    1933
    DLL MLL
    1350
    1947
    IEL BHC
    189
    1943
    VELOCITY
    189
    1943
  • 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
    189.0
    36
    189.0
    0.00
    LOT
    SURF.COND.
    13 3/8
    390.0
    17 1/2
    402.0
    1.58
    LOT
    INTERM.
    9 5/8
    1367.0
    12 1/4
    1383.0
    1.78
    LOT
    INTERM.
    7
    1930.0
    8 1/2
    1950.0
    0.00
    LOT
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    402
    1.04
    120.0
    waterbased
    689
    1.07
    32.0
    waterbased
    1383
    1.10
    waterbased
    1723
    1.15
    waterbased
    1751
    1.13
    waterbased
    1950
    1.14
    waterbased