7228/2-1 S
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General information
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Wellbore history
GeneralWell 7228/2-1 S is located on the western margin of the Nordkapp Basin close to the Nyslepp Fault Complex. It was designed to drill a large salt induced anticline that is bisected by a major north - south trending fault. Due to the large Triassic throw on the fault, the up-thrown and downthrown parts of the structure were thought to represent separate prospects. The downthrown prospect seemed to have the thickest accumulation of Triassic Anisian/Early Ladinian deposits, and was the primary objective of the well. Secondary objectives were other Middle/Upper Triassic and Jurassic sandstones. To be able to meet all obligations and at the same time test the primary objective without leaving significant potential up-dip, the well path was planned deviated at approximately 30 degrees in a northeasterly direction along seismic line MN89-603. Several reflectors in the interval 397 m to 593 m were thought to represent sand layers with possible shallow gas. The strongest amplitude anomaly was at 435 m.Operations and resultsWildcat well 7228/2-1 S was spudded with the semi-submersible rig Ross Rig 21 August 1989 and drilled to TD at 4300 m in the Early Triassic Havert Formation. The well was deviated from 1475 m. At 2902 m the bottom hole assembly was lost in the hole, and the well had to be sidetracked from 2700 m. The well was drilled with seawater and hi-vis pills down to 1013 m, with KCl / polymer from 1013 m to 2206 m, with lignosulphonate from 2206 m to 3663 m, and with KCl / polymer from 3663 m to TD. No shallow gas was encountered in the well.Reservoir quality sands were found in the Jurassic and uppermost Triassic Stø, Nordmela, Tubåen, Fruholmen, and Snadd formations. Of these the Nordmela and Tubåen sands had the best properties. The Nordmela has 32.6 m of net sand but it is silty in places. Average porosity is 17% but Vsh is relatively high at 27 %. Porosity in clean sand is greater than 20 %. The Tubåen Formation has 45 m of net sand, which varies in reservoir quality from fair to excellent. The top of the sand is silty or shaly but clean high porosity sands are found at the base. Core 3 from 1384 m to 1388 m (drillers depth) has an average measured porosity of 22 %. These sands have the best reservoir quality in the entire well. Average porosity for the Tubåen is 19 %. Klinkenberg corrected permeabilities from core data are mostly between 1.5 and 2.5 Darcies. With the good porosity and permeability the sand has excellent flow potential. The sandstones of the primary objective (Kobbe Formation) were poorly developed and of poor quality.Hydrocarbon shows in the Stø and Nordmela formations are seen in both the Core 2 and petrophysical evaluation. The shows in the petrophysical evaluation decrease as the sand quality improves. As such, both the log and core analysis shows that the oil in core 2 is probably residual. Only occasional patchy traces of residual oil were recorded below 1342 m in the Tubåen, Fruholmen and Snadd formations. Gas levels never exceeded 6 % in this section and consisted predominantly of C1 with some C2 and C3. On penetrating a friable fine grained sandstone at 3401 m (drilled depth), in the Kobbe Formation total gas rose to a maximum of 24.1% at 3423 m. The gas was composed of 190159 ppm C1, 10364 ppm C2, 2200 ppm C3, 1192 ppm IC4 and 1040 ppm NC4. No shows were seen in these samples and gas levels decreased to an average of 4.5 % below 3430 m, composed mainly of C1 with subordinate amounts of C2 and C3.From organic geochemical analyses there appears to be a mixture of condensate and residual oil present in the Stø, Nordmela and upper Tubåen Formations. These residual oils are severely biodegraded. The Hekkingen Formation is the most significant source rock interval with TOC in the range 1 % to 8 % and type II kerogen, however also Snadd and Kobbe formations contain significant source intervals with both gas- and oil-prone kerogen.Five conventional cores were cut on the well with good recovery in each case. Cores number 1 and 4, cut in the Late Jurassic Hekkingen and Middle Triassic Snadd Formations respectively, consisted of claystones and were taken for source and cap rock studies. Core 1 was consumed in these analyses and is no longer available from the NPD. Core 2 was cut in sandstones of the Middle Jurassic Stø Formation. The third core was cut in sandstones of the Early Jurassic Tubåen Formation and the fifth core in siltstones of the Early Triassic Havert Formation. The core-to-log shifts were significant: +3.0 m for core 1, +3.4 m for core 2, +3.8 m for core 3,+6.0 m for core 4, and +9.8 m for core 5.RFT measurements indicate moderate to good permeabilities in the Realgrunnen Group and the uppermost Snadd Formation. A segregated sample was taken from the Nordmela Formation at 1310 m but later analysis showed it to consist of mud filtrate. A total of 334 sidewall cores were attempted whereof 238 were recovered.Well 7228/2-1 S was permanently abandoned on 20 December 1989 as dry with shows.TestingNo drill stem test was performed -
Cuttings at the Norwegian Offshore Directorate
Cuttings at the Norwegian Offshore Directorate Cuttings available for sampling?YESCuttings at the Norwegian Offshore Directorate Cutting sample, top depth [m]Cutting samples, bottom depth [m]1080.004300.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom21286.31295.5[m ]31384.01387.5[m ]42315.02320.8[m ]54189.04198.3[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]27.8Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
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Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory480.5[m]SWCRRI500.0[m]SWCRRI500.0[m]DCMOBIL540.0[m]SWCRRI560.0[m]SWCRRI580.0[m]SWCRRI600.0[m]SWCRRI608.5[m]SWCRRI620.5[m]SWCRRI630.0[m]SWCRRI640.0[m]SWCRRI660.0[m]SWCRRI680.0[m]SWCRRI700.0[m]SWCRRI707.0[m]SWCRRI720.0[m]SWCRRI740.0[m]SWCRRI760.0[m]SWCRRI780.0[m]SWCRRI800.0[m]SWCRRI820.0[m]SWCRRI820.0[m]DCMOBIL840.0[m]SWCRRI860.0[m]SWCRRI880.0[m]SWCRRI900.0[m]SWCRRI920.0[m]SWCRRI940.0[m]SWCRRI960.0[m]SWCRRI980.0[m]SWCRRI1000.0[m]SWCRRI1005.0[m]SWCRRI1018.0[m]DCRRI1025.0[m]SWCRRI1030.0[m]DCRRI1040.0[m]SWCRRI1050.0[m]SWCRRI1060.0[m]DCRRI1075.0[m]SWCRRI1095.0[m]SWCRRI1095.0[m]DCMOBIL1105.0[m]SWCRRI1115.0[m]SWCRRI1125.0[m]SWCRRI1135.0[m]DCRRI1145.0[m]SWCRRI1166.5[m]SWCRRI1166.5[m]DCMOBIL1171.0[m]DCRRI1172.2[m]DCMOBIL1174.2[m]DCMOBIL1180.0[m]DCRRI1182.5[m]SWCRRI1189.0[m]DCRRI1195.0[m]DCRRI1198.0[m]DCRRI1204.0[m]DCRRI1205.0[m]SWCRRI1210.0[m]SWCRRI1216.0[m]DCRRI1225.0[m]SWCRRI1225.0[m]DCMOBIL1240.0[m]DCRRI1248.5[m]SWCRRI1255.0[m]SWCRRI1264.0[m]DCRRI1275.0[m]SWCRRI1275.0[m]DCMOBIL1279.0[m]DCRRI1286.3[m]CRRI1287.7[m]CRRI1289.0[m]CRRI1289.0[m]CICHRON1294.0[m]CRRI1295.5[m]CRRI1300.0[m]SWCRRI1316.5[m]SWCRRI1324.0[m]DCRRI1339.0[m]DCRRI1347.0[m]SWCRRI1367.0[m]SWCRRI1375.5[m]SWCRRI1378.0[m]SWCRRI1378.0[m]DCMOBIL1381.0[m]DCRRI1384.0[m]CRRI1384.5[m]COD1385.0[m]CRRI1386.3[m]COD1387.5[m]CRRI1396.0[m]DCRRI1405.0[m]SWCRRI1405.0[m]CUIB1411.0[m]DCRRI1419.0[m]SWCRRI1419.0[m]DCMOBIL1426.0[m]CUIB1436.5[m]CRRI1438.0[m]CUIB1459.0[m]CUIB1464.0[m]SWCRRI1477.0[m]DCRRI1489.5[m]COD1491.5[m]COD1493.5[m]COD1494.0[m]SWCRRI1494.0[m]DCMOBIL1495.5[m]COD1498.1[m]COD1512.0[m]SWCRRI1522.0[m]CUIB1533.0[m]SWCRRI1543.0[m]CUIB1549.0[m]DCRRI1570.0[m]SWCRRI1592.0[m]SWCRRI1592.0[m]DCMOBIL1603.0[m]DCRRI1619.0[m]SWCRRI1640.0[m]SWCRRI1657.0[m]DCRRI1672.0[m]SWCRRI1672.0[m]DCMOBIL1693.0[m]DCRRI1704.0[m]SWCRRI1729.0[m]DCRRI1735.5[m]SWCRRI1735.5[m]DCMOBIL1753.0[m]DCRRI1766.5[m]SWCRRI1772.0[m]SWCRRI1790.0[m]SWCRRI1790.0[m]DCMOBIL1801.0[m]DCRRI1811.0[m]SWCRRI1832.5[m]SWCRRI1832.5[m]DCMOBIL1852.0[m]SWCRRI1873.0[m]DCRRI1883.0[m]SWCRRI1883.0[m]DCMOBIL1891.0[m]DCRRI1911.0[m]SWCRRI1921.0[m]SWCRRI1930.0[m]SWCRRI1945.0[m]DCRRI1963.0[m]SWCRRI1963.0[m]DCMOBIL1975.0[m]SWCRRI1981.0[m]DCRRI1999.0[m]DCRRI2003.0[m]SWCRRI2030.0[m]SWCRRI2030.0[m]DCMOBIL2042.0[m]SWCRRI2059.0[m]DCRRI2072.0[m]SWCRRI2093.0[m]SWCRRI2093.0[m]DCMOBIL2103.0[m]SWCRRI2122.0[m]DCMOBIL2125.0[m]DCRRI2138.0[m]SWCRRI2150.0[m]SWCRRI2161.5[m]SWCRRI2161.5[m]DCMOBIL2176.0[m]DCRRI2187.5[m]SWCRRI2194.0[m]DCRRI2195.0[m]SWCRRI2215.0[m]DCRRI2238.0[m]SWCRRI2238.0[m]DCMOBIL2245.1[m]SWCRRI2250.0[m]SWCRRI2276.0[m]SWCRRI2287.0[m]DCRRI2305.0[m]DCRRI2316.0[m]DCMOBIL2316.9[m]CICHRON2325.0[m]SWCRRI2346.5[m]SWCRRI2362.0[m]DCRRI2387.7[m]SWCRRI2402.0[m]SWCRRI2416.0[m]DCRRI2434.0[m]DCRRI2443.7[m]SWCRRI2443.7[m]DCMOBIL2477.5[m]SWCRRI2488.0[m]DCRRI2498.0[m]SWCRRI2524.0[m]DCRRI2542.0[m]DCRRI2560.0[m]DCRRI2566.1[m]CMOBIL2572.0[m]SWCRRI2594.5[m]SWCRRI2622.1[m]SWCRRI2632.0[m]DCRRI2656.5[m]SWCRRI2668.0[m]DCRRI2686.0[m]DCRRI2688.1[m]CMOBIL2704.0[m]SWCRRI2717.5[m]SWCRRI2748.5[m]SWCRRI2758.0[m]DCRRI2774.0[m]SWCRRI2794.0[m]DCRRI2810.5[m]SWCMOBIL2810.5[m]SWCRRI2823.0[m]SWCRRI2848.0[m]DCRRI2861.5[m]SWCRRI2888.1[m]SWCRRI2888.1[m]CMOBIL2902.0[m]DCRRI2920.0[m]DCRRI2944.0[m]SWCRRI2956.0[m]DCRRI2971.0[m]SWCRRI2995.3[m]SWCRRI2995.3[m]CMOBIL3010.0[m]DCRRI3019.0[m]SWCRRI3028.0[m]DCRRI3038.5[m]SWCRRI3064.0[m]DCRRI3077.0[m]SWCRRI3082.0[m]DCRRI3100.0[m]DCRRI3121.0[m]DCRRI3121.0[m]DCMOBIL3130.0[m]SWCRRI3142.5[m]SWCRRI3164.5[m]SWCRRI3172.0[m]DCRRI3184.4[m]SWCRRI3205.0[m]DCRRI3226.0[m]DCRRI3232.0[m]DCRRI3234.0[m]SWCRRI3259.0[m]DCRRI3280.0[m]DCRRI3296.5[m]SWCRRI3296.5[m]SWCMOBIL3318.0[m]SWCRRI3334.0[m]DCRRI3349.0[m]DCRRI3370.0[m]DCRRI3388.0[m]DCRRI3397.0[m]SWCRRI3406.0[m]DCRRI3421.1[m]SWCRRI3442.0[m]DCRRI3460.0[m]DCRRI3473.0[m]SWCRRI3478.0[m]DCRRI3496.0[m]DCRRI3506.0[m]SWCRRI3506.0[m]DCMOBIL3514.0[m]DCRRI3523.5[m]SWCRRI3529.0[m]DCRRI3535.0[m]DCRRI3543.0[m]SWCRRI3563.0[m]SWCRRI3584.0[m]SWCRRI3591.5[m]SWCRRI3598.0[m]DCRRI3602.0[m]SWCRRI3625.1[m]SWCRRI3625.1[m]CMOBIL3684.0[m]SWCRRI3714.0[m]SWCRRI3725.0[m]SWCRRI3752.0[m]SWCRRI3766.5[m]SWCRRI3817.0[m]SWCRRI3828.0[m]SWCRRI3846.0[m]SWCRRI3865.0[m]SWCRRI3904.0[m]SWCRRI3919.0[m]DCRRI3928.0[m]SWCRRI3940.0[m]SWCRRI3952.0[m]DCRRI3965.0[m]SWCRRI3965.0[m]DCMOBIL3974.0[m]SWCRRI3997.0[m]DCRRI4007.5[m]SWCRRI4012.0[m]DCRRI4028.0[m]SWCRRI4033.0[m]DCRRI4043.0[m]SWCRRI4066.0[m]DCRRI4069.0[m]SWCRRI4080.0[m]SWCRRI4104.0[m]SWCRRI4129.0[m]SWCRRI4155.0[m]SWCRRI4171.0[m]SWCRRI4188.0[m]DCRRI4191.0[m]CICHRON4194.0[m]SWCRRI4196.0[m]CICHRON4215.0[m]SWCRRI4226.0[m]SWCRRI4242.0[m]SWCRRI4268.0[m]SWCRRI4300.0[m]SWCRRI -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit3733731110116812361275127513001345140415232438243835743984 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.77 -
Geochemical information
Geochemical information Document nameDocument formatDocument size [MB]pdf3.06 -
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 nameDocument formatDocument size [MB]pdf48.46 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CST GR4801000CST GR10052187CST GR10052150CST GR21953625CST GR22503543CST GR35633602CST GR36794300CST GR37184300DIL BHC GR SP3733632DIL BHC GR SP17504124DIL BHC GR SP36364310FMS GR36373670FMS GR AMS36364311LDL CNL GR CAL AMS9974309MWD - GR RES DIR3734300RFT HP GR AMS12901922RFT HP GR AMS13100RFT HP GR AMS38853892SHDT GR AMS9973635VSP5002510VSP11004310 -
Casing and leak–off tests
Casing and leak–off tests Casing typeCasing diam.
[inch]Casing depth
[m]Hole diam.
[inch]Hole depth
[m]LOT/FIT mud eqv.
[g/cm3]Formation test typeCONDUCTOR30473.036476.00.00LOTSURF.COND.20997.0261013.01.36LOTINTERM.13 3/82186.017 1/22206.01.58LOTINTERM.9 5/83633.012 1/43663.01.86LOTOPEN HOLE4300.08 1/24300.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured6591.38WATER BASED01.09.198910051.03WATER BASED01.09.198911721.2016.018.0WATER BASED05.09.198912371.0216.018.0WATER BASED05.09.198912961.2013.018.0WATER BASED06.09.198913631.2012.017.0WATER BASED07.09.198913631.2012.016.0WATER BASED08.09.198913631.2013.016.0WATER BASED11.09.198913631.2013.015.0WATER BASED11.09.198913631.2019.029.0WATER BASED11.09.198913841.2219.025.0WATER BASED12.09.198913841.2760.035.0WATER BASED13.09.198915381.2722.040.0WATER BASED18.09.198915761.2719.035.0WATER BASED18.09.198916671.2720.034.0WATER BASED18.09.198917831.2721.037.0WATER BASED20.09.198918471.2717.033.0WATER BASED20.09.198918901.2718.028.0WATER BASED21.09.198919351.2718.029.0WATER BASED22.09.198919901.2718.030.0WATER BASED25.09.198919991.2617.028.0WATER BASED25.09.198920341.2618.027.0WATER BASED25.09.198920591.2518.031.0WATER BASED26.09.198920841.2518.031.0WATER BASED27.09.198921141.2517.031.0WATER BASED28.09.198921351.2516.030.0WATER BASED29.09.198922061.2616.028.0WATER BASED03.10.198922061.1815.018.0WATER BASED04.10.198922061.1816.014.0WATER BASED05.10.198922061.1815.016.0WATER BASED06.10.198922371.1518.025.0WATER BASED09.10.198922581.1819.022.0WATER BASED09.10.198923121.1821.026.0WATER BASED10.10.198923211.1818.022.0WATER BASED11.10.198924391.1917.021.0WATER BASED12.10.198924611.1912.019.0WATER BASED13.10.198924611.1912.019.0WATER BASED13.10.198924881.2013.019.0WATER BASED16.10.198925361.2013.019.0WATER BASED16.10.198926221.2014.020.0WATER BASED16.10.198927011.2015.015.0WATER BASED27.10.198927061.2011.014.0WATER BASED17.10.198927171.2017.015.0WATER BASED30.10.198927491.2016.018.0WATER BASED30.10.198928001.2017.019.0WATER BASED18.10.198928161.2015.013.0WATER BASED19.10.198928451.2016.018.0WATER BASED30.10.198928901.2017.017.0WATER BASED31.10.198929021.2014.015.0WATER BASED23.10.198929021.2015.015.0WATER BASED23.10.198929021.2014.015.0WATER BASED23.10.198929021.2015.015.0WATER BASED23.10.198929021.2016.015.0WATER BASED24.10.198929531.2014.015.0WATER BASED01.11.198930261.2012.016.0WATER BASED02.11.198930701.2012.015.0WATER BASED03.11.198931001.2015.017.0WATER BASED06.11.198931501.2014.016.0WATER BASED06.11.198931651.2014.016.0WATER BASED06.11.198932061.2015.017.0WATER BASED07.11.198932771.2015.015.0WATER BASED08.11.198933541.2416.018.0WATER BASED09.11.198933591.2419.019.0WATER BASED10.11.198934191.2415.018.0WATER BASED13.11.198934741.3216.018.0WATER BASED13.11.198934741.3216.018.0WATER BASED13.11.198935151.3215.017.0WATER BASED14.11.198935871.3415.018.0WATER BASED15.11.198936021.3315.016.0WATER BASED16.11.198936051.3315.018.0WATER BASED17.11.198936051.3314.017.0WATER BASED20.11.198936111.3815.015.0WATER BASED20.11.198936171.3813.017.0WATER BASED20.11.198936541.3815.017.0WATER BASED21.11.198936631.3916.019.0WATER BASED22.11.198936631.4417.019.0WATER BASED23.11.198936631.4418.022.0WATER BASED24.11.198936631.4419.018.0WATER BASED27.11.198936631.4418.019.0WATER BASED27.11.198936631.4416.019.0WATER BASED28.11.198936631.4416.018.0WATER BASED29.11.198936631.4418.016.0WATER BASED30.11.198936631.4416.018.0WATER BASED27.11.198936711.4420.015.0WATER BASED01.12.198936971.4415.020.0WATER BASED04.12.198938601.4417.013.0WATER BASED04.12.198939641.4416.013.0WATER BASED04.12.198940021.4520.014.0WATER BASED05.12.198941311.4422.013.0WATER BASED06.12.198941891.4623.015.0WATER BASED08.12.198941991.4623.114.0WATER BASED08.12.198942801.4626.013.0WATER BASED11.12.198943001.4625.014.0WATER BASED11.12.198943001.4626.019.0WATER BASED15.12.1989 -
Thin sections at the Norwegian Offshore Directorate
Thin sections at the Norwegian Offshore Directorate DepthUnit1286.75[m ]1288.50[m ]1292.50[m ]1385.25[m ]1387.00[m ] -
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 nameDocument formatDocument size [MB]pdf0.22