Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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22.12.2024 - 01:25
Time of last synchronization with Norwegian Offshore Directorate's internal systems

31/4-6

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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.
    31/4-6
    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.
    31/4-6
    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.
    Norsk Hydro Produksjon 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.
    317-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.
    52
    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,
    28.02.1982
    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.
    20.04.1982
    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.
    20.04.1984
    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.
    01.04.2014
    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.
    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.
    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.
    FENSFJORD 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.
    130.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2447.0
    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).
    2447.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    1.3
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    100
    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.
    60° 31' 16.6'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    3° 1' 57.7'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6709625.47
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    501794.95
    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.
    43
  • Wellbore history

    General
    Well 31/4-6 was drilled on the Bjørgvin Arch in the Northern North Sea. The main objective was to appraise the 31/4-3 Discovery in the "Intra-Heather sand II" (Fensfjord Formation) and to define the oil/water contact.
    Operations and results
    Appraisal well 31/4-6 was spudded with the semi-submersible installation Nortrym on 28 February 1982 and drilled to TD at 2447 m in the Early Jurassic Drake Formation. No significant problem was encountered in the operations. The well was drilled with seawater and hi-vis sweeps down to 927 m, with non-dispersed Shale Trol mud from 927 m to 1865 m, and with a fully dispersed Lignosulphonate/Unical/Ligcon mud from 1865 m to TD.
    The Fensfjord Formation was encountered at 2150 m. It is a predominantly fine grained to silty, micaceous to very micaceous, subarcosic carbonaceous and occasionally glauconitic sandstone with a clay matrix and some heavily calcite cemented stringers. It is 89 m thick and oil bearing from 2156 m down to the OWC at 2172 m. Net pay in the oil bearing interval was 12.5 m with an average porosity of 26.4% and an average water saturation of 43.8%. As expected the overlying Sognefjord Formation seen in the 31/4-3 and 5 wells was not present at this location. Below the Heather Formation, the well penetrated 62.5 m of the Brent Group, which contained 31 m of net sand with an average porosity of 23.4% and was water saturated. No other reservoir intervals were encountered. Occasional poor oil shows were recorded in the Ness Formation and the Drake Formation.
    Five cores were cut through the Fensfjord Formation from 2132 m to 2214.5 m. Correlation between the cores and the logs indicates that core depths are two to three meters shallower than logger's depth. RFT fluid samples were taken in the Fensfjord Formation at 2160.5 m (oil and gas) and at 2166.5 m (oil and gas).
    The well was permanently abandoned on 20 April 1982as an oil appraisal.
    Testing
    One production test was performed in the Fensfjord Formation over the combined intervals 2159.5 - 2163.5 m and 2165-2168 m. The well flowed 452 Sm3 oil and 38300 Sm3 gas through a 36/24" choke. The GOR was 85 Sm3/Sm3, the oil gravity was 34.4 deg API and the gas gravity was 0.727 (air = 1). Maximum flow temperature measured at sensor depth 2153.5 m was 90.6 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]
    270.00
    2447.00
  • 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
    2132.0
    2148.3
    [m ]
    2
    2149.0
    2159.5
    [m ]
    3
    2159.5
    2178.0
    [m ]
    4
    2178.1
    2195.0
    [m ]
    5
    2195.5
    2214.0
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    80.7
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES
  • Core photos

    Core photos
    Core photo at depth: 2132-2137m
    Core photo at depth: 2137-2142m
    Core photo at depth: 2142-2147m
    Core photo at depth: 2147-2148m
    Core photo at depth: 2149-2154m
    2132-2137m
    2137-2142m
    2142-2147m
    2147-2148m
    2149-2154m
    Core photo at depth: 2154-2159m
    Core photo at depth: 2159-2159m
    Core photo at depth: 2159-2164m
    Core photo at depth: 2164-2169m
    Core photo at depth: 2169-2174m
    2154-2159m
    2159-2159m
    2159-2164m
    2164-2169m
    2169-2174m
    Core photo at depth: 2174-2178m
    Core photo at depth: 2178-2183m
    Core photo at depth: 2183-2188m
    Core photo at depth: 2188-2193m
    Core photo at depth: 2193-2195m
    2174-2178m
    2178-2183m
    2183-2188m
    2188-2193m
    2193-2195m
    Core photo at depth: 2196-2201m
    Core photo at depth: 2201-2206m
    Core photo at depth: 2206-2211m
    Core photo at depth: 2211-2214m
    Core photo at depth:  
    2196-2201m
    2201-2206m
    2206-2211m
    2211-2214m
  • Oil samples at the Norwegian Offshore Directorate

    Oil samples at the Norwegian Offshore Directorate
    Test type
    Bottle number
    Top depth
    MD [m]
    Bottom depth
    MD [m]
    Fluid type
    Test time
    Samples available
    DST
    DST1
    2159.00
    2163.00
    14.04.1982 - 00:00
    YES
    DST
    0.00
    0.00
    YES
  • 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
    243.0
    36
    243.5
    0.00
    LOT
    SURF.COND.
    20
    913.0
    26
    927.0
    1.68
    LOT
    INTERM.
    13 3/8
    1844.0
    17 1/2
    1865.0
    1.72
    LOT
    INTERM.
    9 5/8
    2406.0
    12 1/4
    2447.0
    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
    2159
    2163
    14.3
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    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
    452
    39000
    0.853
    0.727
    85
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL VDL
    700
    1840
    CST
    1020
    1850
    CST
    2035
    2310
    CST
    2065
    2448
    DLL MSFL
    2035
    2212
    FDC CNL
    1845
    2215
    FDC GR
    913
    1862
    HDT
    1845
    2446
    ISF SON
    155
    2214
    ISF SON NGT
    2115
    2448
    LDT CNL EPT
    2215
    2450
    RFT
    2138
    2377
    RFT
    2160
    2160
    RFT
    2166
    2166
    VELOCITY
    360
    2444
  • Lithostratigraphy

  • Geochemical information

    Geochemical information
    Document name
    Document format
    Document size [MB]
    pdf
    0.28
    pdf
    0.46
  • 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
    2.15
    PDF
    13.12
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    250
    1.11
    32.0
    waterbased
    760
    1.11
    32.0
    waterbased
    920
    1.03
    41.0
    waterbased
    1240
    1.10
    42.0
    waterbased
    1770
    1.34
    63.0
    waterbased
    1940
    1.27
    64.0
    waterbased
    2180
    1.28
    54.0
    waterbased
    2310
    1.30
    55.0
    waterbased
    2400
    1.31
    54.0
    waterbased
  • Palynological slides at the Norwegian Offshore Directorate

    Palynological slides at the Norwegian Offshore Directorate
    Sample depth
    Depth unit
    Sample type
    Laboratory
    2035.0
    [m]
    SWC
    IKU
    2037.0
    [m]
    SWC
    IKU
    2043.0
    [m]
    SWC
    IKU
    2057.0
    [m]
    SWC
    IKU
    2060.0
    [m]
    SWC
    IKU
    2084.0
    [m]
    SWC
    IKU
    2090.0
    [m]
    SWC
    IKU
    2095.0
    [m]
    SWC
    IKU
    2100.0
    [m]
    SWC
    IKU
    2106.0
    [m]
    SWC
    IKU
    2109.0
    [m]
    SWC
    IKU
    2123.5
    [m]
    SWC
    IKU
    2128.0
    [m]
    SWC
    IKU
    2130.0
    [m]
    SWC
    IKU
    2132.0
    [m]
    C
    IKU
    2138.0
    [m]
    C
    IKU
    2144.4
    [m]
    C
    IKU
    2147.5
    [m]
    C
    IKU
    2149.5
    [m]
    C
    IKU
    2154.6
    [m]
    C
    IKU
    2156.5
    [m]
    C
    IKU
    2160.1
    [m]
    C
    IKU
    2170.5
    [m]
    C
    IKU
    2177.6
    [m]
    C
    IKU
    2183.1
    [m]
    C
    IKU
    2201.6
    [m]
    C
    IKU
    2208.8
    [m]
    C
    IKU
    2213.9
    [m]
    C
    IKU
    2215.0
    [m]
    SWC
    IKU
    2220.0
    [m]
    SWC
    IKU
    2225.0
    [m]
    SWC
    IKU
    2231.0
    [m]
    SWC
    IKU
    2237.0
    [m]
    SWC
    IKU
    2242.0
    [m]
    SWC
    IKU
    2247.0
    [m]
    SWC
    IKU
    2255.0
    [m]
    SWC
    IKU
    2262.0
    [m]
    SWC
    IKU
    2268.0
    [m]
    SWC
    IKU
    2274.0
    [m]
    SWC
    IKU
    2280.0
    [m]
    SWC
    IKU
    2287.0
    [m]
    SWC
    IKU
    2295.0
    [m]
    SWC
    IKU
    2303.0
    [m]
    SWC
    IKU
    2310.0
    [m]
    SWC
    IKU
    2321.0
    [m]
    SWC
    IKU
    2337.0
    [m]
    SWC
    IKU
    2345.0
    [m]
    SWC
    IKU
    2383.0
    [m]
    SWC
    IKU
    2387.0
    [m]
    SWC
    IKU
    2395.0
    [m]
    SWC
    IKU
    2405.0
    [m]
    SWC
    IKU
    2414.0
    [m]
    SWC
    IKU
    2416.0
    [m]
    SWC
    IKU
    2420.0
    [m]
    SWC
    IKU
    2425.0
    [m]
    SWC
    IKU
    2435.0
    [m]
    SWC
    IKU
    2448.0
    [m]
    SWC
    IKU