Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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22.11.2024 - 09:09
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2/8-9

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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.
    2/8-9
    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.
    2/8-9
    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.
    Amoco Norway Oil Company
    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.
    155-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.
    80
    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,
    09.04.1976
    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.
    27.06.1976
    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.
    27.06.1978
    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.
    16.10.2012
    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.
    LATE CRETACEOUS
    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.
    TOR FM
    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.
    LATE CRETACEOUS
    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.
    HOD FM
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    33.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    69.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2703.0
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    86
    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 CRETACEOUS
    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.
    RØDBY FM
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    56° 17' 49.3'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    3° 23' 4'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6239343.54
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    523793.84
    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.
    279

  • Wellbore history
    General
    Well 2/8-9 was drilled as an appraisal to help establish the commerciality of the southern North Sea Valhall Field, which had earlier been discovered by 2/8-6 and confirmed by 2/8-8. The primary objective of 2/8-9 was an evaluation of the Chalk reservoirs of Maastrichtian (Tor Formation) and pre-Maastrichtian (Hod Formation) age. The existence of hydrocarbons in the Early-Middle Miocene section creates a low velocity "bright spot" on the seismic, blanketing the crest of the Valhall structure and causing "dimming" or total loss of the top chalk section. The Valhall crest is therefore an area where the estimated thickness of the Tor section and the fault patterns are questionable. Only one previous well, 2/8-4, had been drilled in the vicinity some 2.5 km to the west. Well 2/8-4 was essentially a dry hole with only 1 m of Tor and tight but oil bearing Hod Formation.
    Operations and results
    Appraisal well 2/8-9 was spudded with the semi-submersible installation Sedco 135 G on 9 April 1976 and drilled to TD at 2703 m in the Early Cretaceous Rødby Formation. The well was drilled in a total of 30 days, without any major drilling problems. It was drilled with sea water and viscous mud down to 183 m, with seawater and gel from 183 m to 392 m, and with Drispac/lime/seawater mud from 392 m to TD.
    Well 2/8-9 penetrated a normal of Quarternary -Tertiary section from surface to top of the Late Cretaceous. The Danian was found to have been removed by erosion. The well found the Chalk hydrocarbon bearing at 2524 m correlating 53.3 m high and 76.8 m low to wells 2/8-4 and 2/8-8, respectively. The Tor Formation was 5.5 m thick with high reservoir quality; porosity of up to 48% and a water saturation close to zero. The Hod Formation was 128 m thick. The average porosity and water saturations of the Upper Hod were 30% and 60%, respectively. An oil-water contact was encountered in the Lower Hod at 2605 m. Oil shows (fluorescence and cut) were recorded above the chalk reservoir in shales, claystones and siltstones at 1555 to 1963 m; in limestone at 2048 to 2064 m; and in siltstone 2094.5 to 2105.
    Four conventional cores were cut from 2531 to 2573.5 m with 85 - 100% recovery. No wire line fluid samples were taken.
    The well was permanently abandoned on 27 June as an oil appraisal well.
    Testing
    Two drill stem tests were performed
    Test 1 tested the interval 2550.6 m to 2557 m in the Hod Formation after stimulation by hydraulic fracturing and sand injection. The well flowed solids that plugged up the test string. A second attempt, Test 1A, was made but with no success. The test from this interval was terminated.
    Test 2 tested the interval 2524 to 2529.2 m, the entire Tor Formation. Prior to stimulation the well cleaned up sufficiently to be put through the separator. Stable flow was not obtained due to solids production. The average fluid production during 11 hrs and on variable choke was 353 Sm3 oil and 82100 Sm3 gas /day. Average GOR was 233 Sm3/Sm3. The oil gravity was 36 deg API. After simulation similar to Test 1 no flow was obtained due to solids problems.

  • 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]
    441.96
    2700.53

  • 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
    8302.0
    8327.6
    [ft ]
    2
    8332.0
    8347.0
    [ft ]
    3
    8347.0
    8377.0
    [ft ]
    4
    8382.0
    8439.0
    [ft ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    38.9
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    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
    183.0
    36
    183.0
    0.00
    LOT
    SURF.COND.
    20
    435.0
    26
    442.0
    0.00
    LOT
    INTERM.
    13 3/8
    1285.0
    17 1/2
    1290.0
    0.00
    LOT
    INTERM.
    9 5/8
    2510.0
    12 1/2
    2518.0
    0.00
    LOT
    LINER
    7
    2701.0
    8 1/2
    2704.0
    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
    2552
    2558
    0.0
    2.0
    2525
    2529
    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
    2.0
    45.200
    20.400
    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
    2.0
    353
    81693
    0.840
    231

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CBL GR
    95
    2479
    CBL GR
    2352
    2538
    CBL VDL GR
    2340
    2647
    CBL VDL GR
    2507
    2698
    CNL FDC GR CAL
    2507
    2701
    DLL MSFL SP GR CAL
    2507
    2700
    GR
    2450
    2582
    ISF SON GR
    440
    2512
    ISF SON SP GR
    2507
    2699
    TDK-K
    2475
    2539
    TEMP
    2300
    2701

  • Lithostratigraphy
    Lithostratigraphy
    Top depth [mMD RKB]
    Lithostrat. unit
    102
    2493
    2493
    2497
    2505
    2524
    2524
    2529
    2637
    2640
    2658
    2658

  • 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
    1.76
    pdf
    24.70
    pdf
    20.76
    pdf
    28.13

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    261
    1.09
    46.0
    waterbased
    441
    1.05
    waterbased
    1157
    1.28
    45.0
    waterbased
    1289
    1.29
    waterbased
    2324
    1.80
    waterbased
    2703
    1.89
    waterbased