Factpages Norwegian Offshore Directorate
Factpages Norwegian Offshore Directorate
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16.07.2024 - 01:28
Time of last synchronization with Norwegian Offshore Directorate's internal systems

25/8-11

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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.
    25/8-11
    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.
    NORTH 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.
    25/8-11
    Seismic location
    Position of spud location on seismic survey lines. SP: shotpoint.
    ES9403 3D- INLINE 3824 & X-LINE 2313
    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.
    Esso Exploration and Production Norway 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.
    909-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.
    48
    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,
    16.10.1997
    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.
    02.12.1997
    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.
    02.12.1999
    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.
    18.12.2002
    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.
    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.
    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.
    PALEOCENE
    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.
    HERMOD FM
    2nd level with HC, age
    Age of lithostratigraphic unit, 2nd level, where hydrocarbons were encountered. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EOCENE.
    EARLY JURASSIC
    2nd level with HC, formation
    Name of lithostartigraphic unit, 2nd 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.
    STATFJORD GP
    Kelly bushing elevation [m]
    Elevation of the rotary kelly bushing (RKB) above mean sea level.
    18.0
    Water depth [m]
    Depth in metres betweem mean sea level and sea floor.
    128.0
    Total depth (MD) [m RKB]
    Total measured length of wellbore from kelly bushing to total depth (driller's depth).
    1994.0
    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).
    1994.0
    Maximum inclination [°]
    Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
    2.97
    Bottom hole temperature [°C]
    Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.
    82
    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.
    59° 18' 7'' N
    EW degrees
    Geographic coordinate of the wellhead, east-west degrees.
    2° 26' 51'' E
    NS UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, north-south.
    6573957.14
    EW UTM [m]
    Universal Transverse Mercator coordinate of the wellhead, east-west.
    468534.61
    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.
    3209
  • Wellbore history

    General
    The 25/8-11 well was drilled in PL 027 with Esso as the operator and sole licensee. The well was drilled in the Ringhorn prospect, which is located approximately 14 km North of Balder. The primary target was the Paleocene Hermod Formation sandstones. Jurassic sandstones constituted a secondary target.
    Operations and results
    Wildcat well 25/8-11 was spudded with the semi-submersible drilling rig "West Alpha" on 16 October 1997 and drilled to a total depth of 1994 m in Early Jurassic sediments of the Statfjord Formation. The well was drilled with spud mud down to 1001 m and oil-based mud from 1001 m to TD. Hydrocarbons were encountered in both targets. Top Hermod sandstones were found at 1765 m. The Paleocene OWC (from wire line log) was found at 1775 m. The Paleocene reservoir properties were close to those of the Balder reservoirs and it was not the plan to test this reservoir. The top of the Jurassic reservoir (Top Statfjord Formation) came in at 1891 m. The Jurassic OWC (from wire line log) was found at 1935 m. The discovery in the Jurassic was the first of it's kind in this area and it was therefore decided to test this part of the Ringhorn Discovery. One core was cut in the interval 1763 m to 1790 m from lowermost Sele Formation and through half of the Hermod Formation. Two MDT samples were taken in the Statfjord Formation: one oil sample from 1919 m and one water sample from 1938 m. After production testing the well was suspended as an oil discovery on 2 December 1997.
    Testing
    A DST was performed in the interval 1892.5 m to 1909.5 m in thin sands of the Upper Statfjord Formation. The well produced 517 Sm3 oil per day and with a GOR of 42 Sm3/Sm3 on a 40/64th inch choke. Only surface samples were collected. Initial reservoir conditions at 1882 m were found to be 18.74 Mpa and 78 deg C. The plan was to continue with the test by perforating a lower sand interval and do a commingled test of both sand intervals. Due to bad weather this was delayed and when the weather improved technical problems lead to suspension of the test without any data obtained from the lower interval.
  • 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]
    1030.00
    1994.50
  • 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
    1763.0
    1789.7
    [m ]
    Cores at the Norwegian Offshore Directorate
    Total core sample length [m]
    26.7
    Cores at the Norwegian Offshore Directorate
    Cores available for sampling?
    YES
  • Core photos

    Core photos
    Core photo at depth: 1763-1768m
    Core photo at depth: 1768-1773m
    Core photo at depth: 1773-1778m
    Core photo at depth: 1778-1783m
    Core photo at depth: 1783-1788m
    1763-1768m
    1768-1773m
    1773-1778m
    1778-1783m
    1783-1788m
    Core photo at depth: 1788-1790m
    Core photo at depth:  
    Core photo at depth:  
    Core photo at depth:  
    Core photo at depth:  
    1788-1790m
  • Palynological slides at the Norwegian Offshore Directorate

    Palynological slides at the Norwegian Offshore Directorate
    Sample depth
    Depth unit
    Sample type
    Laboratory
    1030.0
    [m]
    DC
    CGG
    1060.0
    [m]
    DC
    CGG
    1120.0
    [m]
    DC
    CGG
    1140.0
    [m]
    DC
    CGG
    1150.0
    [m]
    DC
    CGG
    1180.0
    [m]
    DC
    CGG
    1220.0
    [m]
    DC
    CGG
    1260.0
    [m]
    DC
    CGG
    1280.0
    [m]
    DC
    CGG
    1290.0
    [m]
    DC
    CGG
    1300.0
    [m]
    DC
    CGG
    1310.0
    [m]
    DC
    CGG
    1320.0
    [m]
    DC
    CGG
    1330.0
    [m]
    DC
    CGG
    1340.0
    [m]
    DC
    CGG
    1350.0
    [m]
    DC
    CGG
    1460.0
    [m]
    DC
    CGG
    1580.0
    [m]
    DC
    CGG
    1670.0
    [m]
    DC
    CGG
    1680.0
    [m]
    DC
    CGG
    1745.0
    [m]
    DC
    CGG
    1750.0
    [m]
    DC
    CGG
    1770.6
    [m]
    C
    CGG
    1773.3
    [m]
    C
    CGG
    1778.2
    [m]
    C
    CGG
    1786.0
    [m]
    C
    CGG
    1810.0
    [m]
    DC
    CGG
    1820.0
    [m]
    DC
    CGG
    1830.0
    [m]
    DC
    CGG
    1850.0
    [m]
    DC
    CGG
    1870.0
    [m]
    DC
    CGG
    1900.0
    [m]
    DC
    RRI
    1920.0
    [m]
    DC
    RRI
    1970.0
    [m]
    DC
    RRI
  • 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
    DST 1
    1910.00
    1893.00
    15.11.1997 - 00:00
    YES
  • Lithostratigraphy

  • Composite logs

    Composite logs
    Document name
    Document format
    Document size [MB]
    pdf
    0.32
  • 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
    49.47
  • Drill stem tests (DST)

    Drill stem tests (DST)
    Test number
    From depth MD
    [m]
    To depth MD
    [m]
    Choke size
    [mm]
    1.0
    1893
    1910
    16.0
    Drill stem tests (DST)
    Test number
    Final shut-in pressure
    [MPa]
    Final flow pressure
    [MPa]
    Bottom hole pressure
    [MPa]
    Downhole temperature
    [°C]
    1.0
    78
    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
    520
    23000
    44
  • Logs

    Logs
    Log type
    Log top depth [m]
    Log bottom depth [m]
    AIT UBI DSI
    992
    1986
    CMR IPL
    1671
    1990
    LDL CNL GR
    1578
    1995
    MDT
    1766
    1981
    MWD - DIR
    920
    998
    MWD - GR RES DIR
    219
    1001
    MWD - GR RES DIR
    1024
    1994
    SWC
    1678
    1985
    VSP
    350
    1990
  • 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
    220.0
    36
    221.0
    0.00
    LOT
    INTERM.
    13 3/8
    998.0
    17 1/2
    1008.0
    0.00
    LOT
    OPEN HOLE
    1994.0
    8 1/2
    1994.0
    0.00
    LOT
  • Drilling mud

    Drilling mud
    Depth MD [m]
    Mud weight [g/cm3]
    Visc. [mPa.s]
    Yield point [Pa]
    Mud type
    Date measured
    1001
    1.32
    24.0
    OIL BASED
    1024
    1.32
    26.0
    OIL BASED
    1471
    1.32
    20.0
    OIL BASED
    1565
    1.32
    25.0
    OIL BASED
    1790
    1.33
    26.0
    OIL BASED
    1994
    1.13
    DUMMY
    1994
    1.32
    26.0
    OIL 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
    0.19