Factpages Norwegian petroleum directorate
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31/5-7

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  • General information

    General information
    Attribute Value
    Wellbore name
    Official name of wellbore based on NPD guidelines for designation of wells and wellbores.
    31/5-7
    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-CCS
    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 NPD.
    INJECTING: It was injected to the wellbore at the time of the operators last monthly report to the NPD.
    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.
    PLUGGED
    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 NPD 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
    Well name
    Official name of the parent well for the wellbore based on NPD guidelines for designation of wells and wellbores.
    31/5-7
    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.
    Equinor Energy AS
    Drill permit
    The drilling permit number together with the version of the drilling permit as stated in the drilling permit granted by the NPD.
    1799-L
    Drilling facility
    NPD's name of the facility which the wellbore was drilled from.
    Drilling days
    Number of days from spud to completed. The first and last days of the operation is included in the count. Days where the drilling operations has been suspende, is not included. Days used for predrilling is not included. These are made available where applicable.
    97
    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,
    02.12.2019
    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.
    06.03.2020
    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.
    06.03.2020
    Plugged date
    Date when plugging operations was finished, as reported by the operator to the NPD through DDRS (Daily Drilling Reporting System).
    17.08.2022
    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.
    10.01.2022
    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-CCS
    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.
    WATER
    Discovery wellbore
    Indicator which telles if the wellbore made a new discovery. Legal values: YES, NO.
    NO
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    31.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    307.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    2915.0
    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).
    2914.9
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    1.7
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    115
    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.
    STATFJORD GP
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    60° 34' 35.13'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    3° 26' 36.12'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6715849.31
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    524299.59
    UTM zone
    Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.
    31
    NPDID wellbore
    NPD's unique id for the wellbore.
    8951
  • Wellbore history

    General
    Well 31/5-7 was drilled to test the Northern Light Carbon Capture and Storage (CCS) prospect between the Troll and Brage fields on the Horda Platform in the North Sea. The well is the first CCS well on the Norwegian Continental Shelf. The overall objective of the well was to investigate whether reservoir rocks in the Early Jurassic are suitable for storage of carbon dioxide (CO2). Specific aims were:
    · Confirm the ability to inject a minimum of 0.8 Mt/yr CO2.
    · Confirm Johansen and Cook Formations sandstones presence and with a sufficient reservoir quality for large scale injection purpose
    · Confirm Drake Formation sealing potential.
    · Additional well objectives were to collect data to meet requirements on overburden management and implementation of data into geomechanical models and leakage risk assessment.
    Operations and results
    Wildcat well 31/5-7 was spudded with the semi-submersible installation West Hercules on 2 December 2019 and drilled to TD at 2915 m in the Early Jurassic (Hettangian age) Statfjord Group. Drilling operations proceeded without significant problems, but during drill stem testing issues with the Electrical Submersible pump (ESP) and further difficulties with landing the DST string caused 19 days of NPT. The well was drilled with seawater and hi-vis pills down to 931 m and with Glydril water-based mud 931 m to TD.
    The lower Drake Formation shale thickness is 75 m, and an extended leak-off test (XLOT) confirmed the sealing potential for the future CO2 injection. The underlying injection and storage units, Johansen, and Cook Formations, consist of high-quality sandstones with a total thickness of 173 m. Formation pressure data acquired on wire line show that the rocks over and under the Drake shale cap rock are not in communication and the pressure gradients indicate water in all Viking and Brent Group sands.
    No hydrocarbon indications were seen on the logs and no shows were seen on the cuttings and the gas levels were very low, below 1 % with gas peaks up to 2.3 %, throughout the upper part of the well. The gas levels were very low throughout the 8 1/2" section as well, between 0.2 and 1 %, without any significant gas peaks. No HC odour or stain was observed in the cores, very weak spotted dull yellow residual fluorescence was seen in core chips between 2907 m and 2765 m, most likely mineral fluorescence.
    Four cores were cut in the well. Core 1 was cut from 2592 to 2596 m (79.5% recovery) in the Drake Formation cap rock. Core 2 was cut from 2643 to 2697 m (98.9% recovery) in the Cook Formation sandstones. Cores 3 and 4 were cut from 2709 to 2783 m (95.4 and 94.2 % recovery, respectively) in the Johansen Formation sandstones. MDT fluid samples were taken at 2686.3 m in the Cook Formation and at 2743.5 m in the Johansen Formation. Analyses of water samples from both MDT and DST are available on DISKOS.
    Due to the planned later drilling of a side-track and further plans for CO2 injection, a template was pre-installed at location. The well was suspended on 6 March 2020 as a dry well.
    Testing
    One drill stem test was performed from the interval 2697.5 to 2805 m in the Johansen Formation. A clean-up period of 12 hours was performed to clean the well and to find optimum surface setting for the following main flow. Both choke and ESP were increased in steps. The main flow period was 36 hours on a fixed 44/64” choke size. A corrected water flow rate of approximately 1000 m³/day was achieved. The corrected gas flow rate was around 600 m3/day. No barriers were observed during the test and the observation radius is calculated to between 2200 m to 3200 m. The temperature measured at the gauge depth at the end of the main flow has been extrapolated using Olga flow simulation software down to the top of the probably best producing interval assessed on logs. This gives a temperature of 110 °C at 2770 m. An extensive program for sampling of formation water was carried out.
  • Cuttings at the NPD

    Cuttings at the NPD
    Cuttings available for sampling?
    YES
    Cuttings at the NPD
    Cutting sample, top depth [m]
    Cutting samples, bottom depth [m]
    940.00
    2878.00
  • Cores at the NPD

    Cores at the NPD
    Core sample number
    Core sample - top depth
    Core sample - bottom depth
    Core sample depth - uom
    2
    2643.0
    2696.4
    [m ]
    3
    2709.0
    2744.3
    [m ]
    4
    2747.0
    2780.9
    [m ]
    Cores at the NPD
    Total core sample length [m]
    122.6
    Cores at the NPD
    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
    407.0
    36
    411.0
    0.00
    SURF.COND.
    20
    925.0
    26
    931.0
    1.54
    LOT
    INTERM.
    13 5/8
    1897.0
    17 1/2
    1906.0
    1.57
    LOT
    LINER
    9 5/8
    2583.0
    12 1/4
    2584.0
    1.54
    LOT
    OPEN HOLE
    2915.0
    8 1/2
    2915.0
    0.00
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    HRLA PEX
    1897
    2585
    MWD - ARC TS
    411
    931
    MWD - ARC TS
    931
    1906
    MWD - GVR ARC TS
    2584
    2915
    MWD - PD ARC TS
    931
    1906
    MWD - PD ECS TS SS
    411
    944
    MWD - PD OB ARC TS
    1906
    2584
    MWD - TELE
    338
    411
    PEX MSIP
    931
    959
    XPT MSIP FMI
    925
    2585
  • Lithostratigraphy