Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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22.12.2024 - 01:25
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34/7-31

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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.
    34/7-31
    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
    Press release
    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
    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.
    34/7-31
    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.
    994-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.
    35
    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,
    10.03.2001
    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.
    13.04.2001
    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.
    13.04.2003
    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.
    19.10.2006
    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.
    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 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.
    INTRA DRAUPNE FM SS
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    26.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    207.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2650.0
    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).
    2650.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    2.4
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    97
    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.
    TARBERT FM
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    61° 18' 37.68'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 3' 59.81'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6797888.38
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    450009.18
    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.
    4214

  • Wellbore history
    General
    Well 34/7-31 was drilled in the Borg structure, which is situated on the western side of the Vigdis and Tordis Fields. The primary objective was to appraise the 34/7-23 Discovery in Intra-Draupne Formation Sandstone in this structure. Proven reserves, if sufficient, would most probably be produced through the Vigdis Field installations. Secondary objectives were Paleocene sand (Sele/Lista Formations) in a down-flank position from well 34/7-18 were these sands were oil-filled, and Early Cretaceous sands, found oil filled in well 34/7-21. The well was to be drilled 50 m into the Brent Group, which was expected to be water bearing at well location. In case of encountering an oil-filled Intra-Draupne sand thicker than 10 m TVD in the well, a sidetrack should be drilled, kicked off below the 13 3/8" casing to further appraise the Borg structure.
    Operations and results
    Well 34/7-31 was spudded with the semi-submersible installation Scarabeo 6 on 10 March 2001 and drilled to TD at 2650 m in the Middle Jurassic Tarbert Formation. A 9 7/8" pilot hole was drilled from seabed 233 m to 1150 m. Logs (MWD) presented from seabed 233 m to 1150 m were recorded in the 9-7/8" pilot hole. The 9 7/8" pilot hole was then opened to 36" and 30" casing run to 306 m. The 26" hole (using 26" hole opener) deviated from the original 9 7/8" pilot hole below 306 m and the two holes were ca 27 m apart at 1150 m. Well 34/7-31 was drilled with returns to Seabed down to 1150 m. Sampling started at 1170 m. The well was drilled with seawater and hi-vis pills down to1150 m, and with Glydril KCl/polymer mud from 1150 m to TD. No gas related problems were experienced in the well. However, the MWD logs show possible gas levels at 280 m - 282 m, 372 m - 374,5 m and 558 m - 561 m.
    The Intra-Draupne Formation Sandstone was encountered at 2470 with ca 35 meters net oil-bearing reservoir. Then, fourteen m of Draupne Formation shale was penetrated before entering the Heather formation. For the secondary objectives, both were water-filled and only Brent had significant sand (Tarbert Formation). Pressure points were taken with the MDT-tool in order to obtain formation pressures and fluid gradients from all reservoirs encountered in well 34/7-31. Especially the degree of depletion in the Intra-Draupne Sandstone was regarded as crucial information. The measured Intra-Draupne reservoir pressure was the same as the shut-in pressure in the Main Borg field. The gradient and reservoir fluid density was well defined, 0.69 g/cc or 0.067 bars/meter, and the reservoir pressure was measured to 307.04 bar at 2494.7 m. There was an ODT situation; hence the OWC is still not defined. Six high quality MDT oil samples were recovered from the Draupne Formation at 2496 m. Four of these were 250 cc single-phase samples. Two conventional cores were cut from 2472 m to 2506m in the Intra-Draupne Formation Sandstone.
    The well bore was plugged back to the 13 3/8" casing and permanently abandoned on 13 April 2001 as an oil Appraisal well.
    Testing
    No drill stem test was performed

  • 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]
    1170.00
    2650.00

  • 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
    2472.0
    2499.3
    [m ]
    2
    2499.3
    2505.7
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    33.7
    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
    306.0
    36
    306.0
    0.00
    LOT
    SURF.COND.
    20
    1144.0
    26
    1144.0
    1.83
    LOT
    INTERM.
    13 3/8
    1779.0
    17 1/2
    1785.0
    1.82
    LOT
    OPEN HOLE
    2650.0
    8 1/2
    2650.0
    0.00
    LOT

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    MDT
    1842
    2618
    MSCT
    1840
    2641
    MWD - GR RES DIR
    233
    2650
    PEX DSI VSP
    1700
    2627
    VSP
    1690
    2620

  • 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
    7.64
    .PDF
    24.56

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    233
    1.05
    WATER BASED
    306
    1.05
    WATER BASED
    688
    1.05
    WATER BASED
    905
    1.05
    WATER BASED
    1150
    0.00
    WATER BASED
    1785
    1.48
    18.0
    WATER BASED
    2092
    1.60
    26.0
    WATER BASED
    2505
    1.62
    27.0
    WATER BASED
    2650
    1.62
    26.0
    WATER BASED