Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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24.11.2024 - 01:27
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2/4-20

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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.
    2/4-20
    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
    Press release
    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.
    NORTH SEA
    Well name
    Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
    2/4-20
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    Line 7832 Trace 17200 (VGCNS-05 3D)
    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.
    ConocoPhillips Skandinavia 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.
    1142-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.
    175
    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,
    22.09.2007
    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.
    14.03.2008
    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.
    14.03.2010
    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.
    14.03.2010
    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.
    DRY
    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
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    45.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    68.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    5719.0
    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).
    5673.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    3
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    197
    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 PERMIAN
    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.
    ROTLIEGEND GP
    Geodetic datum
    Reference system for coordinates. Example of legal values: ED50.
    ED50
    NS degrees
    Geographic coordinate of the wellhead, north-south degrees.
    56° 36' 43.17'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    3° 8' 40.08'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6274345.10
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    508867.61
    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.
    5556

  • Wellbore history
    General
    Well 2/4-20 was drilled in the Feda Graben ca 8 km north of the Ekofisk Field and 5 km east of the Albuskjell Field in the Central Graben of the North Sea. The purpose of the 2/4-20 North Ekofisk exploration well was to test potential reservoirs in the pre-Cretaceous High-Pressure-High-Temperature play at both Jurassic and Permian Rotliegendes levels. The 2/4-17 Tjalve Discovery drilled in 1991ca 9 km to the north-east of 2/4-20 had proved condensate in deep Oxfordian sand and traces of hydrocarbons in the Rotliegendes Group. The main targets in the well were two Jurassic potential reservoir horizons: a primary target J50 (Oxfordian) sandstone and a secondary target J40 (Callovian) sandstone. In the Permian excellent reservoir sandstones analogous to 2/4-17 were expected to consist of Rotliegendes Group strata, largely of aeolian origin. Planned TD was at 5695 m with an expected TD temperature of 195 deg C.
    Operations and results
    Wildcat well 2/4-20 was spudded with the jack-up installation Mærsk Galant on 22 November 2007 and drilled to TD at 5719 m in the Early Permian Rotliegendes Group. The 2/4-20 HPHT well was drilled within risked AFE time and cost. The well took a total of 189.1 days (including 7.9 days WOW). The R70 shallow gas reflector (Crenulate Reflector) was drilled at 645 m with 11.0 ppg mud and a gas peak of 4.4% recorded. The section was cased with a 16" liner. At 1786m, a 35 bbl kick of 13.65 ppg intensity was taken in a thin (1.5m thick) sand sitting directly on the Mid Miocene unconformity. The mud weight at the time was 13.0 ppg. The well was killed with 14.0 ppg mud using a modified driller?s method. With a maximum measured temperature at TD of 194 deg C, Horner corrected to 197 deg C, this was the hottest well on the Norwegian continental shelf to date.
    The well was drilled with seawater/hi-vis sweeps/spud mud down to 479 m, with Versatec OBM from 479 m to 2888 m, with Paratherm OBM from 2888 m to 4766 m, and with WARP OBM from 2888 m to TD. The WARP mud used in the 8 1/2" and 5 3/4" hole sections proved difficult to clean off the cuttings samples. It posed problems for biostratigraphic analyses and proved detrimental to organic geochemical analyses.
    The Late Jurassic J60 - J70 Kimmeridge Clay equivalent (Draupne Formation) seen in the 2/4-19 B well was not present in 2/4-20 having been eroded down into the Farsund Formation at crest of structure. A significant thickness of sand was penetrated at a number of stratigraphic levels. The J50 target sands were not developed in the well location. Below this however, was encountered a thick J54 Lower Ula Sandstone sequence (top 5183.5 m); well developed sands of the J40-J22 Bryne Formation (top 5340 m); and a 51m-thick (gross) sandstone/shale unit of undifferentiated Jurassic/Triassic age (top 5453 m). Below the Zechstein evaporites, a sequence of Permian Rotliegendes sandstones was drilled down to the TD of the well.
    Jurassic reservoir presence and quality was significantly greater than pre-drill estimates. Jurassic J54 net porosity-metres was seven times greater than the pre-drill P50 prediction with two, thick, stacked shoreface sequences totalling 156.5 m gross being penetrated. The J40 ? J22 fluvio-deltaic Bryne reservoir consisted of 113m gross of interbedded sands, silts and coals. Pre-drill there was estimated to be only a 20% chance of this reservoir being present. The Rotliegendes Auk Formation, penetrated at 5592.5 m, consisted of 99.5 m of an Upper Unit of very tight non-reservoir argillaceous sandstones, underlain by 35 m-thick Lower Unit of better quality sandstones down to TD.
    Shows detection was made difficult by the Versatec, Paratherm and WARP oil based mud used as drilling fluids for the entire well below 479 m. The only shows encountered were in the top of the Ekofisk Formation where faint oil shows were observed, and in the upper part of the Rotliegendes Sandstone where very weak slow white cut fluorescence was noted. White fluorescent fluid inclusions in the Rotliegendes strengthened the evidence for migrated light hydrocarbons in these strata
    No sidewall or conventional cores were cut in the well. No wire line fluid samples were taken. Pressure points were recorded with the XPT and MDT tools. I n the Rotliegendes sandstone at TD pressures were acquired with the XPT-H tool, run in this well as the first in the world. The number of good pressure points obtained were in general sparse, but showed that the Jurassic and Permian reservoirs sections were in different pressure compartments. The logging programme also included a CMR magnetic resonance run in the 8 1/2" section to explore the poroperm properties of the lower Ula Formation sandstone.
    The well was permanently abandoned on 14 March 2008 as a dry 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]
    210.00
    5719.00

  • Lithostratigraphy

  • Logs
    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    CMR GR
    5167
    5250
    MWD LWD - DGR
    479
    2888
    MWD LWD - DGR EWR PWD
    3551
    5719
    MWD LWD - DWD
    113
    479
    MWD LWD - EWR PWD AGR ALD CTN BA
    2888
    3551
    QAIT QSLT QLDT QCNT QTGC SON GR
    100
    5433
    QAST
    1441
    5715
    QLDT QCNT QTGC
    5450
    5727
    QLDT QCNT QTGC QSLT QSCS
    5300
    5560
    WAIT QSLT QTGC
    5440
    5727
    XPT QTGC
    5185
    5352
    XPT QTGC
    5694
    5723

  • 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
    195.0
    36
    201.0
    0.00
    LOT
    SURF.COND.
    20
    473.0
    26
    479.0
    1.51
    LOT
    INTERM.
    16
    1451.0
    20
    1461.0
    0.00
    LOT
    INTERM.
    13 5/8
    2883.0
    17 1/2
    2888.0
    1.87
    LOT
    INTERM.
    10 3/4
    4763.0
    12 1/4
    4766.0
    1.91
    LOT
    LINER
    7
    5565.0
    8 1/2
    5565.0
    2.25
    LOT
    OPEN HOLE
    5719.0
    5 3/4
    5719.0
    0.00
    LOT

  • Drilling mud
    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    94
    1.08
    5.0
    SPUD MUD
    128
    1.05
    6.0
    WATER BASE
    146
    1.13
    7.0
    WATER BASE
    442
    1.39
    36.0
    OIL BASE
    445
    1.57
    39.0
    OIL BASE
    670
    1.70
    35.0
    OIL BASE
    1082
    1.75
    41.0
    OIL BASE
    1204
    1.73
    43.0
    OIL BASE
    1353
    1.38
    33.0
    OIL BASE
    1402
    1.77
    51.0
    OIL BASE
    1410
    1.77
    46.0
    OIL BASE
    1448
    1.38
    33.0
    OIL BASE
    1667
    2.08
    60.0
    OIL BASE
    4746
    1.77
    42.0
    OIL BASE
    4847
    2.12
    57.0
    OIL BASE
    5002
    2.12
    59.0
    OIL BASE
    5133
    2.12
    61.0
    OIL BASE
    5440
    2.12
    61.0
    HPHT OB WARP
    5608
    2.06
    55.0
    OIL BASE
    5719
    2.08
    49.0
    OIL BASE