Give whole or part of name of wellbore, licence, field, company, discovery etc. E.g. Aker, Statfjord, 24/12, ABP21014. The main content is not searched.
Official name of wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
35/11-20 A
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).
APPRAISAL
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.
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 Norwegian Offshore Directorate guidelines for designation of wells and wellbores.
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.
Wintershall Norge 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.
1633-L
Drilling facility
Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.
Number of days from wellbore entry to wellbore completion.
24
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,
14.07.2016
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.
07.08.2016
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.
07.08.2018
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.
07.08.2018
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
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.
NO
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.
LATE 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.
INTRA HEATHER FM SS
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.
373.0
Total depth (MD) [m RKB]
Total measured length of wellbore from kelly bushing to total depth (driller's depth).
3973.0
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).
3319.0
Maximum inclination [°]
Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.
56.8
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.
MIDDLE 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.
HEATHER FM
Geodetic datum
Reference system for coordinates. Example of legal values: ED50.
ED50
NS degrees
Geographic coordinate of the wellhead, north-south degrees.
61° 13' 20.29'' N
EW degrees
Geographic coordinate of the wellhead, east-west degrees.
3° 26' 25.57'' E
NS UTM [m]
Universal Transverse Mercator coordinate of the wellhead, north-south.
6787789.95
EW UTM [m]
Universal Transverse Mercator coordinate of the wellhead, east-west.
Well 35/11-20 A is a geological sidetrack to the 35/11-20 S Antares well, which discovered oil in Oxfordian age Intra-Heather Formation sandstone. The sidetrack was planned to appraise the presence of HC-filled Upper Jurassic Early-Middle Oxfordian sandstone (Orion prospect) with appropriate thickness and quality to be commercially exploited. Secondary target was to prove the presence of HC-filled Brent and Cook formations.
Operations and results
Appraisal well 35/11-20 A was kicked off from the main bore (35/11-20S) at 1815 m in the Shetland Group on 14 July 2016. It was drilled with the semi-submersible installation Borgland Dolphin. Drilling operations proceeded without significant problems, but intermediate logging of the Orion reservoir was aborted as the cable broke at surface and was lost in hole. Fishing was unsuccessful and it was decided to plug back and sidetrack to reach the secondary objective. Final TD for well 35/11-20 A became 3973 m (3319 m TVD) m in Callovian age sediments in the Heather Formation. The well was drilled with Innovert oil based mud from kick-off to TD.
35/11-20A encountered top primary target Oxfordian sandstone at 3869 m (3233 m TVD). The reservoir was 27 m TVD thick, which is thinner than in the main bore, but had much better reservoir quality, characterized by an average porosity of 18% and 64% Net-to-Gross. The top 8 m TVD were found oil bearing with a possible OWC at around 3878 m (3241 m TVD).
Two cores were cut: core 1 from 3870 to 3898.5 m and core 2 from 3898.5 m to 3973 m. Core recoveries were 99% and 100%. The MDT tool was run to collect pressures and fluid samples.The fluid sampling
confirmed that both oil & water phases are mobile, but unfortunately, all downhole fluid samples were lost down hole in the incident with the wireline cable.
Well bore 35/11-20 A plugged back and abandoned on 7 August 2016 as an oil appraisal well.
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