25/12-1
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Generell informasjon
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Brønnhistorie
Well 25/12-1 is located on the Patch Bank Ridge between the Utsira High and the Stord Basin in the North Sea. The well was designed to test Paleocene sand and late Cretaceous chalk prospects (found oil bearing in the adjacent Esso blocks). Additional objectives were the Mesozoic and possibly older sands, which formed part of a monocline, east dipping subcrop below this structure. The well was programmed to investigate the entire sedimentary sequence down to igneous/metamorphic basement, interpreted to occur at approximately 2743 m.Operations and resultsWildcat well 25/12-1 was spudded with the semi-submersible installation SEDCO 135 G on 3 October 1973 and drilled to TD at 2865 m in rocks of possible Devonian age. The spud was delayed due to rig repairs in Hamburg. This resulted in the well being drilled during the worst of the winter weather. Due to adverse weather and bad anchoring conditions, 14.5 days were spent anchoring the rig. A total of 19.7 days was lost directly due to weather during drilling and abandoning. A further 8.7 days were lost repairing underwater equipment, much of which was also due to weather damage. The well was drilled with seawater and bentonite down to 463 m and with a seawater / lignosulphonate mud from 463 m to TD.The Oligocene-Eocene sands of the Hordaland Group were water bearing and the Paleocene sands absent. The Chalk section (Tor and Hod formations) showed poor reservoir characteristics and was also water bearing. Below the Late Jurassic shale sequence sands and conglomerates of Middle Jurassic age and older were penetrated. The sands were penetrated in a down dip position on a monoclinal structure rising towards block 25/11. Middle Jurassic (Vestland Group) sands were encountered at 2244 m with porosity up to 30 %, averaging 18 %. Conglomerates were encountered at 2425 m and extended down to 2671 m. From this point down to TD at 2865 m the well drilled a thick water bearing sand sequence. This possible Devonian sandstone ranged in porosity from 17 % - 23 % with an average of 20 %. No hydrocarbon indications were present in the well, with the exception of characteristic gas indications in the Late Jurassic Draupne Formation source rock interval, which at this location was found to be immature. In view of the discouraging results obtained thus far, together with the fact that no seismic configuration was mappable below this depth, it was decided to abandon the well without having reached igneous rock. One core was cut in the ?Devonian conglomerate from 2450 m to 2456 m. No fluid sample was takenThe well was permanently abandoned as dry on 23 November 1973.TestingNo drill stem test was performed -
Borekaks i Sokkeldirektoratet
Borekaks i Sokkeldirektoratet Borekaks tilgjengelig for prøvetaking?YESBorekaks i Sokkeldirektoratet Borekaksprøve, topp dybde [m]Borekaksprøve, bunn dybde [m]262.132865.12 -
Borekjerner i Sokkeldirektoratet
Borekjerner i Sokkeldirektoratet Kjerneprøve nummerKjerneprøve - topp dybdeKjerneprøve - bunn dybdeKjerneprøve dybde - enhet18037.18055.4[ft ]Borekjerner i Sokkeldirektoratet Total kjerneprøve lengde [m]5.6Borekjerner i Sokkeldirektoratet Kjerner tilgjengelig for prøvetaking?YES -
Palynologiske preparater i Sokkeldirektoratet
Palynologiske preparater i Sokkeldirektoratet Prøve dybdeDybde enhetPrøve typeLaboratorie6800.0[ft]DC6850.0[ft]DC6910.0[ft]DC6960.0[ft]DC7010.0[ft]DC7040.0[ft]DC7080.0[ft]DC7110.0[ft]DC7180.0[ft]C7200.0[ft]DC7210.0[ft]DC7260.0[ft]DC7310.0[ft]DC7340.0[ft]DC7360.0[ft]DC7410.0[ft]DC7440.0[ft]DC7460.0[ft]DC7510.0[ft]DC7540.0[ft]DC7550.0[ft]DC7550.0[ft]C7580.0[ft]DC7630.0[ft]DC7630.0[ft]C7650.0[ft]DC7680.0[ft]DC7680.0[ft]C7710.0[ft]DC7720.0[ft]DCAPT7730.0[ft]DC7750.0[ft]DCAPT7760.0[ft]DC7760.0[ft]C7780.0[ft]DCAPT7810.0[ft]DC7820.0[ft]DCAPT7830.0[ft]DC7850.0[ft]DCAPT7860.0[ft]C7860.0[ft]DC7880.0[ft]DCAPT7900.0[ft]DCAPT7910.0[ft]DC7920.0[ft]DCAPT7920.0[ft]DCAPT7930.0[ft]DCAPT7940.0[ft]DC7950.0[ft]DCAPT7960.0[ft]DC7990.0[ft]DC8010.0[ft]DC8060.0[ft]C -
Litostratigrafi
Litostratigrafi Topp Dyb [mMD RKB]Litostrat. enhet169902145714571500156715971597170719082187218722442425 -
Spleisede logger
Spleisede logger Dokument navnDokument formatDokumentstørrelse [MB]pdf0.34 -
Geokjemisk informasjon
Geokjemisk informasjon Dokument navnDokument formatDokumentstørrelse [MB]pdf0.41pdf3.06 -
Dokumenter – eldre Sokkeldirektoratets WDSS rapporter og andre relaterte dokumenter
Dokumenter – eldre Sokkeldirektoratets WDSS rapporter og andre relaterte dokumenter Dokument navnDokument formatDokumentstørrelse [MB]pdf0.29 -
Dokumenter – rapportert av utvinningstillatelsen (frigitt ihht til regelverk)
Dokumenter – rapportert av utvinningstillatelsen (frigitt ihht til regelverk) Dokument navnDokument formatDokumentstørrelse [MB]pdf0.36pdf1.81pdf3.06 -
Logger
Logger Type loggTopp dyp for logg [m]Bunn dyp for logg [m]BHC GR136456BHC GR13572864CNL FDC13572864CST19962850HDT13572864IES4562864VSP1832864 -
Foringsrør og formasjonsstyrketester
Foringsrør og formasjonsstyrketester Type utforingUtforing diam.
[tommer]Utforing dybde
[m]Brønnbane diam.
[tommer]Brønnbane dyp
[m]LOT/FIT slam eqv.
[g/cm3]Type formasjonstestCONDUCTOR30244.036250.00.00LOTSURF.COND.20456.026460.00.00LOTINTERM.13 3/81356.017 1/21360.00.00LOTINTERM.9 5/81978.012 1/41980.00.00LOTOPEN HOLE2865.08 1/22865.00.00LOT -
Boreslam
Boreslam Dybde MD [m]Egenvekt, slam [g/cm3]Viskositet, slam [mPa.s]Flytegrense [Pa]Type slamDato, måling3751.1075.0spud mud7711.1043.0spud mud12081.1540.0spud mud24721.2553.0mixed mud28641.2452.0mixed mud