2/4-16
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Generell informasjon
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Brønnhistorie
GeneralWell 2/4-16 was drilled on the eastern margin of the Feda Graben North of the Albuskjell and Ekofisk Fields in the North Sea. Geologically the area consists of three sub-platforms. These are separated by large NW-SE striking normal faults down-faulted to the southwest and stepping down to the Feda Graben in the southern part of the block. The 2/4-16 well is located in the centre of the licence area on the same down faulted segment as the blowout wells 2/4-13, -14 and -15. Shallow gas was predicted from seismic anomalies at 10 different levels, and several precautions and actions were carried out to be able to handle potential gas-charged shallow gas.The main objective for the well was to test the Late Jurassic, expected to contain a thick sand resting unconformable on the Middle Jurassic. This objective was the basis also for the 2/4-14 well. A secondary objective for the well was to penetrate the Middle Jurassic and 150 m into the Triassic sequence to test for possible hydrocarbon bearing sandstones sequences.Operations and resultsWildcat well was spudded with the semi-submersible installation Treasure Saga on 7 May 1991 and drilled to TD at 4996 m in the Middle Jurassic Bryne Formation. Shallow gas was detected at 522, 606, 628 and 675 m during drilling of 9 7/8" pilot hole. While drilling through very hard chalk rocks in the 12,6" section severe problems with the drilling equipment was experienced. The hard rocks also caused 8.5 days of delay due to ten washouts and fishing jobs. In addition the vibration together with high temperature caused twelve failures to the MWD tools, and also problems related to equipment deliveries. When drilling down to 4996 m the top drive saver sub had to be changed out due to a washout. During change of saver sub, the well started flowing uncontrolled up through the drill string, and the drill pipe was cut with the shear ram. Fifty-eight days were spent from shearing the pipe until temporary abandoning the well was decided. The well was drilled with spud mud down to 424 m, with gel mud from 424 m to 951 m, with KCl mud from 951 m to 4726 m, with a reduced ph water based mud from 4726 m to 4910 m, and with HI TEMP Polymer mud from 4910 m to TD.A detailed study of the logs indicated no gas in the sand beds at 497 m and 832 m. Gas peaks were observed only on the MWD in the following thin sand beds from: 520.8 - 521.5 m, 604.5 - 606.2 m, 625 - 626 m and 675.5 - 676.1 m. This was later verified on the wire line logs, with a 3 m depth shift. This was interpreted as "original" gas, as similar observations were experienced at similar depths (520, 605 and 625 m in wells 2/4-13, 14 and 15).There were no hydrocarbon indications from the logs in the well. The only indications from sidewall cores were some very weak shows in 3140 to 3155 m in the Balder Formation. Post-well organic geochemical analyses also reported migrant hydrocarbons in the interval 4638 to 4737 m in the Cromer Knoll Group.The 2/4-16 well consisted of a 3341 m thick Cenozoic sequence. The Late Miocene to Pliocene Nordland Group was mainly composed of sand and clay down to 900 m. The rest of the Nordland Group and the Hordaland Group was dominated by claystones with thin beds of sandstone and limestone. The Late Paleocene Rogaland Group at 3140 m consisted of the characteristic tuffaceous claystone in the upper part. The middle part was dominated by claystone with traces of limestone/dolomite becoming claystone interbedded with limestone and marl downwards. The 1321 m thick chalk sequence of the Shetland Group rested unconformable on claystone and marl of the Early Cretaceous Cromer Knoll Group. The 140 m thick Tyne Group was dominated by claystones and siltstones with thin beds of limestone/dolomite. The final section above TD was 119 m of Vestland Group siltstones and shales with minor sand and coal beds.No conventional cores were cut and no wire line fluid samples taken. A total of 371 sidewall cores were attempted, of which 147 were recovered.Due to the gas kick at 4996 m the well was terminated without having reached the Triassic target. The well was suspended on 4 November as a dry well with shows.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]430.004996.00 -
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 formasjonstestCONDUCTOR30167.036170.00.00LOTINTERM.24410.030424.01.44LOTINTERM.18 5/8937.024951.01.85LOTINTERM.142897.017 1/22912.01.93LOTINTERM.10 3/44632.012 1/24650.02.20LOTINTERM.7 5/84892.09 1/24910.02.35LOTOPEN HOLE4963.064996.00.00LOT -
Logger
Logger Type loggTopp dyp for logg [m]Bunn dyp for logg [m]CBL28904650CBL VDL GR28904650CST GR28904650CST GR46344910DIL LSS MSFL GR SP409948DIS MSDL LSS GR AMS46344910DLL LSS MSFL GR SP9362899DLL LSS MSFL GR SP28904650LDL CNL GR409948LDL CNL GR AMS28904650LDL CNL GR AMS46344910LDL GR CAL9362899MSCT46344910MWD - GR RES DIR TEMP1704910RFT409948RFT GR TLC AMS46344910SHDT GR AMS28904650SHDT GR AMS46344910VELOCITY10004630 -
Litostratigrafi
Litostratigrafi Topp Dyb [mMD RKB]Litostrat. enhet94833914179831403140315531893238325432923317331734353920457545984638463846784714473747374770482848774877 -
Spleisede logger
Spleisede logger Dokument navnDokument formatDokumentstørrelse [MB]pdf0.82 -
Geokjemisk informasjon
Geokjemisk informasjon Dokument navnDokument formatDokumentstørrelse [MB]pdf2.89 -
Dokumenter – rapportert av utvinningstillatelsen (frigitt ihht til regelverk)
Dokumenter – rapportert av utvinningstillatelsen (frigitt ihht til regelverk) Dokument navnDokument formatDokumentstørrelse [MB]pdf40.57 -
Dokumenter – eldre Sokkeldirektoratets WDSS rapporter og andre relaterte dokumenter
Dokumenter – eldre Sokkeldirektoratets WDSS rapporter og andre relaterte dokumenter Dokument navnDokument formatDokumentstørrelse [MB]pdf1.02pdf0.27 -
Boreslam
Boreslam Dybde MD [m]Egenvekt, slam [g/cm3]Viskositet, slam [mPa.s]Flytegrense [Pa]Type slamDato, måling4241.05WATER BASED4311.2711.0WATER BASED7701.274.0WATER BASED9511.2514.0WATER BASED9681.3931.0WATER BASED13301.6033.0WATER BASED13351.6031.0WATER BASED14271.7039.0WATER BASED17031.7263.0WATER BASED19911.7249.0WATER BASED21641.7266.0WATER BASED22121.7247.0WATER BASED24881.7252.0WATER BASED26741.7247.0WATER BASED28971.7037.0WATER BASED29121.7251.0WATER BASED29271.7240.0WATER BASED29331.7244.0WATER BASED40891.6723.0WATER BASED41271.6725.0WATER BASED41551.6725.0WATER BASED41881.6722.0WATER BASED42051.6724.0WATER BASED42881.6722.0WATER BASED43051.6723.0WATER BASED43541.6724.0WATER BASED44271.6725.0WATER BASED44281.6725.0WATER BASED44411.6725.0WATER BASED44731.6725.0WATER BASED44911.7233.0WATER BASED45121.7535.0WATER BASED45471.7528.0WATER BASED45831.7527.0WATER BASED45941.8029.0WATER BASED46322.1219.0WATER BASED46501.8529.0WATER BASED46552.0028.0WATER BASED46972.0231.0WATER BASED47262.0625.0WATER BASED47272.0626.0WATER BASED47422.1025.0WATER BASED47542.1228.0WATER BASED47712.1223.0WATER BASED48032.1224.0WATER BASED48382.1222.0WATER BASED48932.1224.0WATER BASED49102.1221.0WATER BASED49142.1218.0WATER BASED49172.1218.0WATER BASED49242.2048.0WATER BASED49352.2033.0WATER BASED49512.1229.0WATER BASED49962.2033.0WATER BASED -
Palynologiske preparater i Sokkeldirektoratet
Palynologiske preparater i Sokkeldirektoratet Prøve dybdeDybde enhetPrøve typeLaboratorie2110.0[m]DCRRI2130.0[m]DCRRI2150.0[m]DCRRI2170.0[m]DCRRI2190.0[m]DCRRI2210.0[m]DCRRI2230.0[m]DCRRI2250.0[m]DCRRI2270.0[m]DCRRI2290.0[m]DCRRI2310.0[m]DCRRI2330.0[m]DCRRI2350.0[m]DCRRI2370.0[m]DCRRI2390.0[m]DCRRI2410.0[m]DCRRI2430.0[m]DCRRI2450.0[m]DCRRI2470.0[m]DCRRI2490.0[m]DCRRI2510.0[m]DCRRI2530.0[m]DCRRI2550.0[m]DCRRI2570.0[m]DCRRI2590.0[m]DCRRI2610.0[m]DCRRI2630.0[m]DCRRI2650.0[m]DCRRI2670.0[m]DCRRI2690.0[m]DCRRI2710.0[m]DCRRI2730.0[m]DCRRI2750.0[m]DCRRI2770.0[m]DCRRI2790.0[m]DCRRI2810.0[m]DCRRI2830.0[m]DCRRI2850.0[m]DCRRI2870.0[m]DCRRI2890.0[m]DCRRI2910.0[m]DCRRI2930.0[m]DCRRI2950.0[m]DCRRI2970.0[m]DCRRI2990.0[m]DCRRI3010.0[m]DCRRI3030.0[m]DCRRI3050.0[m]DCRRI3070.0[m]DCRRI3090.0[m]DCRRI3110.0[m]DCRRI3130.0[m]DCRRI3150.0[m]DCRRI3170.0[m]DCRRI3190.0[m]DCRRI3210.0[m]DCRRI3230.0[m]DCRRI3240.0[m]DCRRI3250.0[m]DCRRI3270.0[m]DCRRI3290.0[m]DCRRI3310.0[m]DCRRI3330.0[m]DCRRI3350.0[m]DCRRI3370.0[m]DCRRI3390.0[m]DCRRI3410.0[m]DCRRI3430.0[m]DCRRI4600.0[m]DCRRI4610.0[m]DCRRI4620.0[m]DCRRI4630.0[m]DCRRI4640.0[m]DCRRI4650.0[m]DCRRI4660.0[m]DCRRI4670.0[m]DCRRI4680.0[m]DCRRI4690.0[m]DCRRI4700.0[m]DCRRI4710.0[m]DCRRI4720.0[m]DCRRI4737.0[m]DCRRI