Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
sodir.no    Norsk
sodir.no          Norsk
09.12.2025 - 01:23
Time of last synchronization with Norwegian Offshore Directorate's internal systems

31/5-7

Export: PDF icon PDF

  • General information
    General information
    Attribute Value
    Wellbore name
    31/5-7
    Type
    EXPLORATION
    Purpose
    WILDCAT-CCS
    Status
    PLUGGED
    Press release
    Multilateral
    NO
    Factmaps in new window
    Main area
    NORTH SEA
    Well name
    31/5-7
    Exploitation licence at wellhead
    Exploitation licence for drilling target
    Drilling operator
    Northern Lights JV DA
    Drill permit
    1799-L
    Drilling facility
    Production facility
    31/5-7 EOS
    Drilling days
    97
    Entered date
    02.12.2019
    Completed date
    06.03.2020
    Release date
    06.03.2020
    Plugged date
    30.09.2022
    Publication date
    10.01.2022
    Purpose - planned
    WILDCAT-CCS
    Content
    WATER
    Discovery wellbore
    NO
    Kelly bushing elevation [m]
    31.0
    Water depth [m]
    307.0
    Total depth (MD) [m RKB]
    2915.0
    Final vertical depth (TVD) [m RKB]
    2914.9
    Maximum inclination [°]
    1.7
    Bottom hole temperature [°C]
    115
    Oldest penetrated age
    EARLY JURASSIC
    Oldest penetrated formation
    STATFJORD GP
    Geodetic datum
    ED50
    NS degrees
    60° 34' 35.13'' N
    EW degrees
    3° 26' 36.12'' E
    NS UTM [m]
    6715849.31
    EW UTM [m]
    524299.59
    UTM zone
    31
    NPDID 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 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]
    940.00
    2878.00

  • 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
    2
    2643.0
    2696.4
    [m ]
    3
    2709.0
    2744.3
    [m ]
    4
    2747.0
    2780.9
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    122.6
    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
    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

  • Drill stem tests (DST)
    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    2698
    2805
    17.4
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    110
    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
    600

  • 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