Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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25.11.2024 - 01:30
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31/2-8

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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.
    31/2-8
    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).
    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.
    31/2-8
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    8007-158 X-OVER 8100-406.
    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.
    A/S Norske Shell
    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.
    334-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.
    64
    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,
    16.06.1982
    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.
    18.08.1982
    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.
    18.08.1984
    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.
    23.05.2006
    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.
    OIL 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.
    25.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    345.5
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    3375.0
    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).
    3373.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    5
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    91
    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.
    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.
    HEGRE GP
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    60° 57' 33.02'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    3° 29' 49.84'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6758502.04
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    526925.96
    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.
    78
  • Wellbore history

    General
    Well 31/2-8 was drilled in the northern part of block 31/2, some 3 km NW of the Troll Field boundary, to test a downthrown Jurassic fault-block outside the Troll Field. The primary objective was the Late Jurassic, shallow marine sands of the Viking Group, especially the Sognefjord Formation. The Early Jurassic was secondary objective and would be evaluated by drilling into Triassic sediments.
    Operations and results
    Wildcat well 31/2-8 was spudded with the semi-submersible installation Borgny Dolphin on 16 June 1982 and drilled to TD at 3375 m in the Triassic Hegre Group. A gas zone (confirmed by logs) between 510 - 530 m did not cause any problems during drilling of the 14 3/4" pilot hole. Maximum gas reading through this zone was 10 %. The hole was drilled to 840 m and under-reamed to 26" without incident. The 17 1/2" section was drilled first by an 8 1/2" pilot hole down to 1063 m to provide better control when drilling through a potential gas charged fault plane. No indications of gas were seen. 3 cores were taken in the 12 1/4" section. Two washouts occurred when drilling the 8 1/2" hole below 3317 m. The well was drilled with seawater gel down to 840 m, with KCl/polymer from 840 m to 1745 m, with seawater and Drispac from 1745 m to 2743 m and wit Drispac/lignosulphonate from 2743 m to TD.
    Only 13 m of Shetland Group chalk was found on top of the Kimmerian unconformity at 1821 m. The Viking Group contained a 15.5 m thick Draupne shale on top of a 680 m thick sequence of sandstone units interbedded in the Heather Formation. The Middle to Early Jurassic was also well developed. Shows occurred sporadically in limestones, siltstone, and claystones through the Early Tertiary and Late Cretaceous. When entering into the Late Jurassic reservoir sands at 1836.5 m (Sognefjord Formation) ditch gas readings went up to more than 4% from a background lower than 1%, but without oil indications in the uppermost section. On the cores taken, very good oil shows were observed in the coarser grained, clean sands between 1841.8 m and 1854.8 m. In the carbonate-cemented band down to 1856.6 m, direct fluorescence became patchy. In the deeper, very fine to fine, micaceous sands the quality of the shows deteriorated further until they disappeared completely around 1872 m. Below the Sognefjord Formation, the only shows encountered was in a sidewall sample at 3050.5 m (at the top of the Statfjord Formation). From log analysis the Jurassic sands were interpreted to be oil bearing from 1836.5 m to ca. 1868 m; below this depth no hydrocarbons were seen.
    Three conventional cores were cut in the interval 1841.8 m to 1888.5 m in the Late Jurassic. One RFT sample at 1849 m recovered 1800 ml mud contaminated formation water and 100 ml of emulsified hydrocarbons.
    The well was completed on 18 August 1982 as a well with shows.
    Testing
    Oil shows on cores and preliminary log interpretation led to a DST in the interval 1843 m to 1848 m in Late Jurassic sandstone. After some technical problems the well was flowed for 2 minutes followed by a one-hour build-up. The well was then flowed until it died after having produced approximately 33 barrels of formation fluid with a trace of oil. A wire line sandballer found 22 m of sand on top of the bridge plug.
  • 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]
    500.00
    3375.00
  • 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
    1841.8
    1851.5
    [m ]
    2
    1852.5
    1869.7
    [m ]
    3
    1870.0
    1888.9
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    45.8
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES
  • Core photos

    Core photos
    Core photo at depth: 1841-1847m
    Core photo at depth: 1847-1851m
    Core photo at depth: 1852-1857m
    Core photo at depth: 1857-1863m
    Core photo at depth: 1863-1868m
    1841-1847m
    1847-1851m
    1852-1857m
    1857-1863m
    1863-1868m
    Core photo at depth: 1868-1869m
    Core photo at depth: 1870-1875m
    Core photo at depth: 1875-1880m
    Core photo at depth: 1880-1886m
    Core photo at depth: 1886-1888m
    1868-1869m
    1870-1875m
    1875-1880m
    1880-1886m
    1886-1888m
  • Palynological slides at the Norwegian Offshore Directorate

    Palynological slides at the Norwegian Offshore Directorate
    Sample depth
    Depth unit
    Sample type
    Laboratory
    1821.7
    [m]
    SWC
    SHELL
    1826.0
    [m]
    SWC
    SHELL
    1830.5
    [m]
    SWC
    SHELL
    1832.8
    [m]
    SWC
    SHELL
    1836.0
    [m]
    SWC
    SHELL
    1837.2
    [m]
    SWC
    SHELL
    1839.5
    [m]
    SWC
    SHELL
    1857.5
    [m]
    C
    SHELL
    1858.4
    [m]
    C
    SHELL
    1860.7
    [m]
    C
    SHELL
    1863.4
    [m]
    C
    SHELL
    1864.3
    [m]
    C
    SHELL
    1868.8
    [m]
    C
    SHELL
    1870.9
    [m]
    C
    SHELL
    1873.6
    [m]
    C
    SHELL
    1878.1
    [m]
    C
    SHELL
    1880.8
    [m]
    C
    SHELL
    1881.7
    [m]
    C
    SHELL
    1937.5
    [m]
    SWC
    SHELL
    1941.5
    [m]
    SWC
    SHELL
    1964.5
    [m]
    SWC
    SHELL
    1965.5
    [m]
    SWC
    SHELL
    1969.8
    [m]
    SWC
    SHELL
    1979.7
    [m]
    SWC
    SHELL
    1989.5
    [m]
    SWC
    SHELL
    2003.0
    [m]
    SWC
    SHELL
    2015.5
    [m]
    SWC
    SHELL
    2032.0
    [m]
    SWC
    SHELL
    2043.5
    [m]
    SWC
    SHELL
    2055.0
    [m]
    SWC
    SHELL
    2068.5
    [m]
    SWC
    SHELL
    2082.6
    [m]
    SWC
    SHELL
    2093.0
    [m]
    SWC
    SHELL
    2107.5
    [m]
    SWC
    SHELL
    2120.0
    [m]
    SWC
    SHELL
    2133.8
    [m]
    SWC
    SHELL
    2145.2
    [m]
    SWC
    SHELL
    2160.5
    [m]
    SWC
    SHELL
    2168.5
    [m]
    SWC
    SHELL
    2181.5
    [m]
    SWC
    SHELL
    2198.5
    [m]
    SWC
    SHELL
    2217.5
    [m]
    SWC
    SHELL
    2250.5
    [m]
    SWC
    SHELL
    2267.1
    [m]
    SWC
    SHELL
    2285.2
    [m]
    SWC
    SHELL
    2314.5
    [m]
    SWC
    SHELL
    2330.5
    [m]
    SWC
    SHELL
    2349.5
    [m]
    SWC
    SHELL
    2355.6
    [m]
    SWC
    SHELL
    2368.0
    [m]
    SWC
    SHELL
    2385.8
    [m]
    SWC
    SHELL
    2398.5
    [m]
    SWC
    SHELL
    2407.1
    [m]
    SWC
    SHELL
    2424.5
    [m]
    SWC
    SHELL
    2436.0
    [m]
    SWC
    SHELL
    2452.0
    [m]
    SWC
    SHELL
    2473.5
    [m]
    SWC
    SHELL
    2491.5
    [m]
    SWC
    SHELL
    2497.0
    [m]
    SWC
    SHELL
    2516.0
    [m]
    SWC
    SHELL
    2532.5
    [m]
    SWC
    SHELL
    2548.0
    [m]
    SWC
    SHELL
    2565.9
    [m]
    SWC
    SHELL
    2575.0
    [m]
    SWC
    SHELL
    2578.0
    [m]
    SWC
    SHELL
    2581.5
    [m]
    SWC
    SHELL
    2595.5
    [m]
    SWC
    SHELL
    2612.0
    [m]
    SWC
    SHELL
    2618.0
    [m]
    SWC
    SHELL
    2632.5
    [m]
    SWC
    SHELL
    2642.5
    [m]
    SWC
    SHELL
    2665.5
    [m]
    SWC
    SHELL
    2672.5
    [m]
    SWC
    SHELL
    2687.0
    [m]
    SWC
    SHELL
    2709.3
    [m]
    SWC
    SHELL
    2722.3
    [m]
    SWC
    SHELL
    2725.0
    [m]
    SWC
    SHELL
    2773.9
    [m]
    SWC
    SHELL
    2778.0
    [m]
    SWC
    SHELL
    2784.2
    [m]
    SWC
    SHELL
    2792.3
    [m]
    SWC
    SHELL
    2815.0
    [m]
    SWC
    SHELL
    2840.9
    [m]
    SWC
    SHELL
    2867.5
    [m]
    SWC
    SHELL
    2892.4
    [m]
    SWC
    SHELL
    2920.9
    [m]
    SWC
    SHELL
    2943.8
    [m]
    SWC
    SHELL
    2968.8
    [m]
    SWC
    SHELL
    2977.7
    [m]
    SWC
    SHELL
    3035.5
    [m]
    SWC
    SHELL
    3046.5
    [m]
    SWC
    SHELL
    3056.8
    [m]
    SWC
    SHELL
    3065.8
    [m]
    SWC
    SHELL
    3228.0
    [m]
    SWC
    SHELL
  • Lithostratigraphy

  • Composite logs

    Composite logs
    Document name
    Document format
    Document size [MB]
    pdf
    0.64
  • Geochemical information

    Geochemical information
    Document name
    Document format
    Document size [MB]
    pdf
    3.22
    pdf
    1.09
    pdf
    0.78
  • Documents – reported by the production licence (period for duty of secrecy expired)

  • Drill stem tests (DST)

    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    1843
    1848
    0.0
    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
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL VDL
    469
    1735
    CBL VDL
    792
    2725
    CST
    1577
    1601
    CST
    1751
    2725
    CST
    2732
    3373
    DLL MSFL CAL
    1735
    2729
    FDC CNL GR
    2732
    3379
    FDC CNL GR CAL
    469
    834
    FDC CNL GR CAL
    777
    1742
    FDC CNL GR CAL
    1735
    2740
    HDT
    1735
    2740
    HDT
    2732
    3379
    ISF BHC GR
    370
    833
    ISF BHC GR
    775
    1741
    ISF BHC GR
    1735
    2738
    ISF BHC GR
    2732
    3378
    LDT CNL NGT
    2732
    3379
    LDT NGT
    1735
    2729
    RFT
    0
    0
    RFT
    1
    3
    WST
    575
    3370
  • 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
    469.5
    36
    480.0
    0.00
    LOT
    SURF.COND.
    20
    826.0
    26
    840.0
    1.80
    LOT
    INTERM.
    13 3/8
    1734.0
    17 1/2
    1745.0
    1.61
    LOT
    INTERM.
    9 5/8
    2732.0
    12 1/4
    2743.0
    1.89
    LOT
    OPEN HOLE
    3375.0
    8 1/2
    3375.0
    0.00
    LOT
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    485
    1.07
    52.0
    waterbased
    845
    1.27
    51.0
    waterbased
    1745
    1.36
    55.0
    waterbased
    1870
    1.21
    49.0
    waterbased
    2743
    1.23
    50.0
    waterbased
    3375
    1.24
    50.0
    waterbased
  • 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
    0.24