Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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08.05.2024 - 01:33
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7121/7-2

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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.
    7121/7-2
    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.
    BARENTS 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.
    7121/7-2
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    ST 8412 - 320 SP. 520
    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.
    Den norske stats oljeselskap 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 Norwegian Offshore Directorate.
    520-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.
    37
    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,
    07.07.1986
    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.
    12.08.1986
    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.
    12.08.1988
    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.
    11.02.2005
    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.
    GAS
    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.
    YES
    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.
    STØ FM
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    22.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    325.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2156.0
    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).
    2155.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    2.8
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    74
    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.
    LATE 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.
    FRUHOLMEN FM
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    71° 26' 37.91'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    21° 3' 21.42'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    7927117.40
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    501987.36
    UTM zone
    Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.
    34
    NPDID wellbore
    Norwegian Offshore Directorate's unique id for the wellbore.
    881
  • Wellbore history

    General
    Well 7121/7-2 was drilled on the Beta structure on Tromsøflaket, 3.4 km south of well 7121/7-1. It was designed to test the hydrocarbon potential in Middle to Lower Jurassic sandstones. Planned total depth was in rocks of Triassic age.
    Operations and results
    Wildcat well 7121/7-2 was spudded with the semi-submersible installation Ross Isle on 7 July 1986 and drilled to TD at 2156 m in the Late Triassic Fruholmen Formation. At 871 m in the 17 1/2" section the string parted and 9.5 hours was spent fishing to retrieve the lost equipment. At 1698 m, TD in the 17 1/2" section a H2S alarm occurred with 28 ppm H2S in the mud gas.  The problem was cured by placing spud mud with a concentration of 15 kg/m3 of ZnCO3 behind 13-3/8" casing to prevent H2S growing in mud. The well was drilled with spud mud down to 667 m and with polymer/"Shale-Trol" mud from 667 m to TD. The well acted as a pilot well for testing this mud on Tromsøflaket. The main reason for using this mud system was that it was expected to stable the hole through sections that from previous experience had proven to cause tight-hole problems. The mud performed better than the ordinary gypsum/polymer mud previously used in the area, but total costs were higher and it was thus not considered a success.
    Hydrocarbon bearing Middle Jurassic sandstones (Stø Formation) were encountered at 1881.5 m. The gas/water contact in this well was recognized at 1914.4 m, ca 12 m deeper than in the 7120/9-1 Albatross Discovery. The gas zone, 1881.5 m to 1914.4 m, consists of an interbedded silt, shale and very fine sandstone sequence with good reservoir properties. Two cores were cut in the Stø Formation over the interval 1903 m to 1939 m, (1889 m to 1935 m, loggers depth). Three FMT samples were collected, one at 1884.5 m and two at 1899 m.
    The well was permanently abandoned as a gas discovery on 12 August 1986.
    Testing
    The interval 1881.8 m to 1889.9 m was perforated and production tested. The test produced on average 527000 Sm3 gas and 28 Sm3 condensate pr day through a 15. 8 mm choke during the main flow. This gives a GOR of ca 18800 Sm3/Sm3. The CO2 content was 8 %. No H2S was detected.
  • 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]
    430.00
    2160.00
  • 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
    1903.0
    1927.2
    [m ]
    2
    1928.5
    1939.5
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    35.2
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES
  • Core photos

    Core photos
    Core photo at depth: 1903-1908m
    Core photo at depth: 1908-1913m
    Core photo at depth: 1913-1918m
    Core photo at depth: 1918-1923m
    Core photo at depth: 1923-1927m
    1903-1908m
    1908-1913m
    1913-1918m
    1918-1923m
    1923-1927m
    Core photo at depth: 1928-1933m
    Core photo at depth: 1933-1938m
    Core photo at depth: 1938-1939m
    Core photo at depth:  
    Core photo at depth:  
    1928-1933m
    1933-1938m
    1938-1939m
  • Palynological slides at the Norwegian Offshore Directorate

    Palynological slides at the Norwegian Offshore Directorate
    Sample depth
    Depth unit
    Sample type
    Laboratory
    909.0
    [m]
    SWC
    GEAR
    925.0
    [m]
    SWC
    GEAR
    926.5
    [m]
    SWC
    GEAR
    1007.0
    [m]
    SWC
    GEAR
    1034.0
    [m]
    SWC
    GEAR
    1091.0
    [m]
    SWC
    GEAR
    1149.2
    [m]
    SWC
    GEAR
    1176.0
    [m]
    SWC
    GEAR
    1291.0
    [m]
    SWC
    GEAR
    1349.5
    [m]
    SWC
    GEAR
    1379.5
    [m]
    SWC
    GEAR
    1405.0
    [m]
    SWC
    GEAR
    1433.0
    [m]
    SWC
    GEAR
    1461.0
    [m]
    SWC
    GEAR
    1519.0
    [m]
    SWC
    GEAR
    1550.0
    [m]
    SWC
    GEAR
    1556.0
    [m]
    SWC
    GEAR
    1615.9
    [m]
    SWC
    GEAR
    1722.5
    [m]
    SWC
    GEAR
    1729.0
    [m]
    SWC
    GEAR
    1732.0
    [m]
    SWC
    GEAR
    1807.0
    [m]
    SWC
    GEAR
    1812.0
    [m]
    SWC
    GEAR
    1817.0
    [m]
    SWC
    GEAR
    1824.0
    [m]
    SWC
    GEAR
    1831.0
    [m]
    SWC
    GEAR
    1841.0
    [m]
    SWC
    GEAR
    1848.0
    [m]
    SWC
    GEAR
    1858.0
    [m]
    SWC
    GEAR
    1862.0
    [m]
    SWC
    GEAR
    1868.0
    [m]
    SWC
    GEAR
    1877.0
    [m]
    SWC
    GEAR
    1895.8
    [m]
    SWC
    GEAR
    1911.0
    [m]
    SWC
    GEAR
    1914.2
    [m]
    SWC
    GEAR
    1915.6
    [m]
    SWC
    GEAR
    1918.8
    [m]
    SWC
    GEAR
    1921.5
    [m]
    SWC
    GEAR
    1924.6
    [m]
    SWC
    GEAR
    1929.3
    [m]
    SWC
    GEAR
    1932.7
    [m]
    SWC
    GEAR
    1934.4
    [m]
    SWC
    GEAR
    1991.0
    [m]
    SWC
    GEAR
    1999.0
    [m]
    SWC
    GEAR
    2048.0
    [m]
    SWC
    GEAR
    2062.0
    [m]
    SWC
    GEAR
    2087.0
    [m]
    SWC
    GEAR
    2110.5
    [m]
    SWC
    GEAR
    2114.0
    [m]
    SWC
    GEAR
    2119.0
    [m]
    SWC
    GEAR
    2124.0
    [m]
    SWC
    GEAR
    2143.0
    [m]
    SWC
    GEAR
    2149.0
    [m]
    SWC
    GEAR
  • 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
    2180.00
    2153.00
    07.08.1986 - 00:00
    YES
    FMT
    0.00
    1899.00
    01.08.1986 - 00:00
    YES
    MDT
    0.00
    0.00
    YES
  • Lithostratigraphy

  • Composite logs

    Composite logs
    Document name
    Document format
    Document size [MB]
    pdf
    0.18
  • Geochemical information

    Geochemical information
    Document name
    Document format
    Document size [MB]
    pdf
    0.26
  • 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
    17.56
  • Drill stem tests (DST)

    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    1882
    1899
    15.9
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    14.000
    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
    28
    527000
    0.775
    0.780
    18800
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    ACBL VDL
    345
    1677
    ACBL VDL
    1264
    1400
    ACBL VDL
    1671
    1925
    CDL DNL GR CAL
    1677
    2154
    COREGUN
    875
    1615
    COREGUN
    1712
    2150
    DIFL BHC AC CDL GR SP CAL
    654
    1628
    DIFL BHC AC GR SP CAL
    345
    675
    DIFL BHC AC GR SP CAL
    1600
    2155
    DLL MLL GR
    1870
    2004
    FMT
    1882
    2068
    FMT
    1899
    1899
    FMT
    1899
    1899
    HR DIP
    1677
    2154
    MWD - GR RES
    428
    674
    RLL - GR RES
    1680
    2028
    VSP
    405
    2140
  • 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
    422.0
    36
    426.0
    0.00
    LOT
    SURF.COND.
    20
    654.0
    26
    675.0
    1.74
    LOT
    INTERM.
    13 3/8
    1680.0
    17 1/2
    1698.0
    1.53
    LOT
    INTERM.
    9 5/8
    2156.0
    12 1/4
    2156.0
    0.00
    LOT
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    425
    1.08
    WATER BASED
    678
    1.10
    1100.0
    WATER BASED
    795
    1.11
    1500.0
    WATER BASED
    1296
    1.14
    21.0
    WATER BASED
    1680
    1.20
    2000.0
    WATER BASED
    1850
    1.26
    1500.0
    WATER BASED
    1939
    1.25
    1800.0
    WATER BASED
    2114
    1.26
    1800.0
    WATER BASED
    2156
    1.25
    1800.0
    WATER BASED
  • 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
    0.25