35/11-3 S
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General information
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Wellbore history
GeneralWell 35/11-3 S was drilled on a location ca 20 km north-north-east of the Troll Field, and was designed to test multiple deltaic sands in the Middle Jurassic Brent Group. Early Eocene turbidites and Paleocene channel fill deposits were secondary objectives. Reservoir sands were expected in the Tarbert, Ness, Etive and Oseberg Formations. These were hydrocarbon bearing in the 35/11-2 well. The seismic anomaly at Middle Jurassic level was mapped with a 30.4 km3 closure, and the expected gross thickness was 220 m. The site survey showed no strong indications of shallow gas. It was, however, thought possible that sands in the intervals 479 - 497 m, and 573 - 634 m might be gas charged.Operations and resultsWildcat well 35/11-3 S was spudded with the semi-submersible installation Dyvi Stena on 27 June 1989 and drilled to TD at 4040 m in the Early Jurassic Statfjord Formation. The well was drilled deviated below 2100 m. Drilling proceeded without significant problems. However, the FMT sampling program for the Jurassic was curtailed when hole conditions deteriorated, and both the FMT tool and drill pipe became stuck during the final logging operation. The well was drilled with seawater and hi-vis pills down to 1010 m and with KCl/polymer mud from 1010 m to TD. No shallow gas was encountered.No reservoir rocks were encountered in the Lower Eocene succession, but good sands were present in the Paleocene (Intra Lista sand). Top Draupne Formation shales came in at 2821 m. Then came the Sognefjord Formation at 3081 m and the Heather Formation at 3096 m. The well penetrated the Brent Group at 3431 m, 236 m deep to prognosis. Good quality sands were found in the Brent Group, but not as good as in the 35/11-2 well.Gas levels throughout the Tertiary and Late Cretaceous were low. Oil shows with abundant free oil in the mud system were observed in limestones of the Early Cretaceous Rødby and Mime Formations and in sandstones of the Late Jurassic Sognefjord Formation. The sandstone units within the Middle Jurassic Brent Group were water wet with residual hydrocarbon shows. Petrophysical evaluation did not indicate hydrocarbons in the Cromer Knoll Group but did so in the Sognefjord Formation and, possibly, in the Brent Group. The evaluation and shows however, did not indicate significant hydrocarbons and did not warrant a test in any of the zones.Excellent, highly oil prone, source rock was found in the Draupne Formation and good source rock was found in the Heather Formation. Both are capable of producing large quantities of petroleum, given sufficient maturity. In well position the Draupne Formation is early mature for petroleum generation, but probably has not expelled any hydrocarbons yet. The Heather Formation appears early to middle mature and may have expelled significant oil quantities in the lower section. Maturity indicators show a dramatic increase in thermal maturity at the base of the Draupne Formation. A similar break is indicated in today temperature gradient in the wire line BHT data.Three conventional cores were cut: in the Intra Lista Sand, in the Sognefjord Formation, and in the Tarbert/Ness Formations of the Brent Group. FMT formation pressures were obtained in the Late Jurassic Sognefjord Formation and in the Brent and Dunlin Groups of the Middle and Early Jurassic. The valid pressure points showed a water gradient. Additionally, formation fluid samples were attempted in the Sognefjord Formation, but recovered only mud filtrate due to seal failures.The well was permanently abandoned on 9 September 1989 as a dry hole with oil 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]1020.004040.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom11987.01996.0[m ]23082.03086.0[m ]33446.03472.8[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]39.8Cores 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 typeLaboratory1020.0[m]DCRRI1050.0[m]SWCRRI1080.0[m]DCRRI1120.0[m]DCRRI1150.0[m]SWCRRI1180.0[m]DCRRI1220.0[m]DCRRI1280.0[m]DCRRI1320.0[m]DCRRI1350.0[m]SWCRRI1380.0[m]DCRRI1400.0[m]DCRRI1421.0[m]DCRRI1439.0[m]DCRRI1450.0[m]SWCRRI1469.0[m]DCRRI1481.0[m]DCRRI1511.0[m]SWCRRI1529.0[m]DCRRI1537.0[m]SWCRRI1550.0[m]DCRRI1610.0[m]DCRRI1619.0[m]DCRRI1620.0[m]DCRRI1650.0[m]SWCRRI1661.0[m]DCRRI1671.0[m]DCRRI1679.0[m]DCRRI1709.0[m]DCRRI1739.0[m]DCRRI1750.0[m]SWCRRI1775.0[m]SWCRRI1790.0[m]SWCRRI1799.0[m]DCRRI1811.0[m]DCRRI1825.0[m]SWCRRI1850.0[m]SWCRRI1910.0[m]SWCRRI2005.0[m]SWCRRI2009.0[m]DCRRI2051.0[m]DCRRI2550.0[m]SWCRRI2650.0[m]SWCRRI2690.0[m]SWCRRI2728.0[m]SWCRRI2800.0[m]DCRRI2805.0[m]DCRRI2815.0[m]DCRRI2820.0[m]DCRRI2840.0[m]DCRRI2880.0[m]SWCRRI2890.0[m]SWCRRI2910.0[m]SWCRRI2960.0[m]DCRRI3000.0[m]SWCRRI3025.0[m]DCRRI3030.0[m]DCRRI3040.0[m]DCRRI3070.0[m]SWCRRI3080.0[m]SWCRRI3082.0[m]CRRI3082.4[m]CRRI3082.7[m]CRRI3082.8[m]CHYDRO3083.4[m]CHYDRO3084.0[m]CRRI3084.4[m]CRRI3085.7[m]CRRI3100.0[m]SWCRRI3110.0[m]SWCRRI3120.0[m]SWCRRI3140.0[m]SWCRRI3170.0[m]DCRRI3180.0[m]SWCRRI3200.0[m]SWCRRI3220.0[m]SWCRRI3230.0[m]DCRRI3240.0[m]SWCRRI3260.0[m]SWCRRI3280.0[m]SWCRRI3290.0[m]DCRRI3300.0[m]SWCRRI3310.0[m]DCRRI3320.0[m]SWCRRI3360.0[m]SWCRRI3380.0[m]SWCRRI3400.0[m]SWCRRI3410.0[m]DCRRI3420.0[m]SWCRRI3430.0[m]DCRRI3443.5[m]SWCRRI3446.5[m]CRRI3454.6[m]CRRI3458.6[m]CRRI3462.6[m]CRRI3467.7[m]CRRI3472.7[m]CRRI3477.0[m]SWCRRI3494.0[m]SWCRRI3505.5[m]SWCRRI3522.0[m]SWCRRI3589.0[m]SWCRRI3609.0[m]SWCRRI3640.0[m]DCRRI3650.0[m]DCRRI3660.0[m]DCRRI3670.0[m]DCRRI3710.0[m]DCRRI3730.0[m]DCRRI3760.0[m]DCRRI3790.0[m]DCRRI3830.0[m]DCRRI3850.0[m]DCRRI3900.0[m]DCRRI3920.0[m]DCRRI4000.0[m]DCRRI -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit38378986617281728178618711905199720422063271627162747280328212821308130963431343134703528353835733640364036933764379438953930 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.53 -
Geochemical information
Geochemical information Document nameDocument formatDocument size [MB]pdf2.95 -
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]pdf41.29 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]ACBL VDL GR8753038ACBL VDR GR16102175COREGUN GR10502028COREGUN GR16901975COREGUN GR21003110COREGUN GR21003110COREGUN GR31203745DIFL AC GR9984042DIPLOG GR9982034DIPLOG GR31163700FMT GR27173095FMT GR34533497FMT GR34693695MWD - GR RES DIR4994040VSP17803870ZDEN CNL GR CAL9984041 -
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 typeCONDUCTOR30498.036499.00.00LOTINTERM.201000.0261013.01.42LOTINTERM.13 3/82040.017 1/22057.01.70LOTINTERM.9 5/83111.012 1/43115.01.91LOTOPEN HOLE4040.08 1/24040.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured4001.03WATER BASED30.06.19894991.03WATER BASED03.07.19896921.03WATER BASED04.07.198910101.03WATER BASED04.07.198910101.03WATER BASED04.07.198910101.03WATER BASED10.07.198910101.03WATER BASED04.07.198910101.03WATER BASED10.07.198912851.2017.021.0WATER BASED18.07.198915541.0221.020.0WATER BASED18.07.198917611.2021.020.0WATER BASED18.07.198917761.2016.020.0WATER BASED18.07.198919871.2017.021.0WATER BASED18.07.198919961.2016.021.0WATER BASED18.07.198920391.2716.019.0WATER BASED18.07.198920571.2714.016.0WATER BASED18.07.198920571.2714.016.0WATER BASED18.07.198920701.0315.024.0WATER BASED24.07.198921201.3021.021.0WATER BASED25.07.198922241.3024.026.0WATER BASED26.07.198922781.3020.024.0WATER BASED28.07.198923661.2618.022.0WATER BASED31.07.198924671.2618.026.0WATER BASED31.07.198925311.2616.023.0WATER BASED01.08.198926221.2616.018.0WATER BASED01.08.198927011.2617.022.0WATER BASED02.08.198927261.2616.018.0WATER BASED03.08.198927751.2615.018.0WATER BASED07.08.198930391.2617.018.0WATER BASED07.08.198930821.3818.020.0WATER BASED07.08.198930961.3818.023.0WATER BASED08.08.198931151.3817.019.0WATER BASED08.08.198932041.6228.018.0WATER BASED17.08.198933331.6222.016.0WATER BASED22.08.198933521.6221.017.0WATER BASED22.08.198934461.6223.016.0WATER BASED22.08.198936731.5824.015.0WATER BASED24.08.198936731.5825.017.0WATER BASED28.08.198936731.5824.015.0WATER BASED24.08.198938911.5825.017.0WATER BASED28.08.198939101.5832.023.0WATER BASED28.08.198939291.5825.018.0WATER BASED28.08.198940401.4021.017.0WATER BASED04.09.198940401.5832.024.0WATER BASED31.08.198940401.4935.015.0WATER BASED04.09.198940401.4020.019.0WATER BASED05.09.1989 -
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]pdf0.23