Generell informasjon Brønnbane navn Type Formål Status Pressemelding Faktakart i nytt vindu Hovedområde Felt Funn 33/12-8 S EXPLORATION WILDCAT P&A lenke lenke NORTH SEA GULLFAKS SØR Brønn navn 33/12-8 Seismisk lokalisering Boret i utvinningstillatelse 152 Boreoperatør Boretillatelse 1031-L Boreinnretning Bore dager 32 33/12-8 S SKINFAKS Statoil ASA (old) BORGLAND DOLPHIN Borestart 26.03.2002 Boreslutt 26.04.2002 Frigitt dato 26.04.2004 Publiseringsdato 18.05.2004 Opprinnelig formål Gjenåpnet Innhold Funnbrønnbane WILDCAT NO OIL/GAS 1. nivå med hydrokarboner, alder MIDDLE JURASSIC 1. nivå med hydrokarboner, formasjon BRENT GP 2. nivå med hydrokarboner, alder EARLY JURASSIC 2. nivå med hydrokarboner, formasjon Avstand, boredekk - midlere havflate Vanndybde ved midlere havflate STATFJORD GP 31.0 137.0 Totalt målt dybde (MD) [m RKB] 3750.0 Totalt vertikalt dybde (TVD) [m RKB] Temperatur ved bunn av brønnbanen [ C] Eldste penetrerte alder 3380.7 124 EARLY JURASSIC Side 1 av 5
Eldste penetrerte formasjon STATFJORD GP Geodetisk datum ED50 NS grader 61 4' 38.44'' N ØV grader 1 57' 56.22'' E NS UTM 6772004.04 ØV UTM 444189.40 UTM sone 31 NPDID for brønnbanen 4493 Brønnhistorie Side 2 av 5
General Well 33/12-8 S is situated in the Tampen Spur area and the structure is a rotated fault block on the southern part of the Beta Ridge. The purpose of the wildcat well 33/12-8 S was to evaluate the potential for hydrocarbons in the "Dole" prospect (Skinfaks segment N3) of the Middle Jurassic Brent Group and the Early Jurassic Statfjord Group. A secondary objective was to identify the hydrocarbon contact in the Brent Group. A sidetrack from 13 3/8" shoe into the N2-segment ("Ole") was considered in case of a positive hydrocarbon finding in the Middle Jurassic Brent Group. Operations and results Wildcat well 33/12-8 S was spudded on 26 March 2002 with the semi-submersible installation Borgland Dolphin and drilled to TD at 3750 m (3380.7 m TVD RKB) in the Statfjord Formation, Eriksson Member. The well was drilled with CMC/seawater above 26" hole/20" casing. The 17 1/2" section was drilled with Glydril MC, a water-based KCl mud with glycol additive. Versavert OBM was used below the13 3/8" casing at 2066 m. The drilling progress was slow in the uppermost 36" section because of cuttings falling into the hole. In the following 26" section boulders were encountered around 478 m and 489 m and followed up with backreaming. Prognosed sand with potential shallow gas was encountered at 450 m. Gamma ray and resistivity showed water filled sand. Further drilling in the 17 1/2" and 8 1/2" section went well, with exception of the Shetland Group, which was significantly slower to drill due to marl/calcareous claystone. The well proved an approximately 81 m TVD thick hydrocarbon column in Tarbert and Upper Ness Formations. The discovery was oil with a gas cap. Lower part of Ness Formation and Etive Formation was water filled. A five meters column with oil (TVD) was in addition encountered in the Statfjord Formation. The stratigraphic column in the N3 segment was found 30-50 m deeper than originally mapped. The oil-water contact in Ness came in as prognosed in depth, but shallow compared to the relative shift of the structure. Ten fluid samples were collected in the Brent Group. Oil was found in the samples from depth 2914 m. Gas/condensate was found in the rest of the samples at depths 2864, 2845, 2815.5, and 2830 m. The oil samples were contaminated by 2.8-3.3 percent, and the gas/condensate samples suffered 9 to 40 percent contamination. No coring was performed in the well. Pressure testing showed that the hydrocarbon filled part of the upper Brent reservoir (N3) is depleted with 20-30 Bars. The pressure at top of the prognosed reservoir (2625 m TVD MSL) is estimated to be 359 Bar based on MDT-pressure tests in the drilled part of the reservoir, corresponding to 1.39 g/cm3 EMW. No pressure tests were taken in the Statfjord Formation. After displacing the well from oilbased mud to treated seawater the well was permanently plugged and abandoned as an oil and gas discovery on 26 of April 2002. Testing No drill stem test was performed Borekaks i OD Borekaksprøve, topp dybde Borekaksprøve, bunn dybde 750.00 3750.00 Borekaksprøve tilgjengelig Side 3 av 5
Oljeprøver i OD Test type Flaske nummer Topp MD Bunn MD Væske type Test tidspunkt Prøver tilgjengelig DST 2914.00 0.00 OIL 21.04.2002-00:00 Litostratigrafi Top depth Lithostrat. unit 168 NORDLAND GP 906 UTSIRA FM 931 HORDALAND GP 1807 ROGALAND GP 1807 BALDER FM 1885 LISTA FM 2030 SHETLAND GP 2636 VIKING GP 2636 DRAUPNE FM 2640 HEATHER FM 2814 BRENT GP 2814 TARBERT FM 2906 NESS FM 3075 ETIVE FM 3098 RANNOCH FM 3155 BROOM FM 3167 DUNLIN GP 3167 DRAKE FM 3285 COOK FM 3429 BURTON FM 3476 AMUNDSEN FM 3647 STATFJORD GP 3647 NANSEN FM 3731 EIRIKSSON FM Spleisede logger Side 4 av 5
Dokument navn Dokument format Dokument størrelse [KB] 4493 pdf 0.32 Logger Type logg Topp Bunn for for logg logg DSI 2050 3100 DSI 2068 2811 MDT 2815 3570 MWD - LWD CDR 232 2077 MWD - LWD DIR 168 232 MWD - LWD V675R 2077 3750 PEX AITH 2050 3750 PEX AITH 2068 2811 Foringinsrør og formasjonsstyrketester Type utforing Utforing diam. [tommer] Utforing dybde Brønnbane diam. [tommer] Brønnbane Slam egenvekt ekvivalent [g/cm3] Type formasjonstest CONDUCTOR 30 227.0 36 230.0 0.00 LOT SURF.COND. 20 737.0 26 740.0 1.75 LOT INTERM. 9 5/8 2066.0 12 1/4 2077.0 1.74 LOT OPEN HOLE 3750.0 8 1/2 3750.0 0.00 LOT Boreslam Dybde Egenvekt, Viskositet, Flytegrense Type slam MD slam [g/cm3] slam [mpa.s] [Pa] 1479 1.35 22.0 GLYDRIL MC 2047 1.41 19.0 GLYDRIL MC 2077 1.45 22.0 GLYDRIL MC 2100 1.64 65.0 VERSAVERT 2637 1.62 49.0 VERSAVERT 2656 1.62 47.0 VERSAVERT Dato, måling Side 5 av 5