30/6-20
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General information
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Wellbore history
GeneralWell 30/6-20 was drilled on the Lambda structure west of the Oseberg Field in the North Sea. Lambda, Alpha North, Theta and Theta South are all rotated fault blocks with the Jurassic sequence dipping towards the east-northwest. The primary objective was to prove hydrocarbons in the Statfjord Group up-dip of well 30/6-16 Theta. The Statfjord Group is truncated by the base Cretaceous Unconformity to the west, and by faults to the south and east. Planned TD was ca 40 m into the Triassic Hegre Group, at a depth of ca 3025 m RKB.Operations and resultsWildcat well 30/6-20 was spudded with the semi-submersible installation Treasure Scout on 10 March 1986 and drilled to TD at 3046 m in the Early Jurassic Statfjord Group. A pilot hole was drilled from 222 m to 620 m due to a shallow gas warning at 363 m. A thin sand with shallow gas was penetrated at this depth without creating any problem. Drilling proceeded without significant problems, but was delayed ca 8 days by bad weather. The well was drilled with sea water and viscous pills down to 620 m and with KCl/polymer mud from 620 m to TD.The Cook Formation came in at 2747 m, and Statfjord Group at 2937 m. The seismic reflector that was interpreted as top Statfjord Group proved to be top Cook Formation. This implies that the fault bounding to the east has a larger throw than first assumed. Both Cook Formation and Statfjord Group were found water bearing, but with some oil shows in the Cook Formation. RFT data indicated pressure communication between Cook and Statfjord. The first oil show in the well was described on claystone at 1990 m in the Balder Formation. Oil shows in thin limestones and claystones were seen also in the Shetland Group.No cores were cut and no wire line fluid samples were taken.The well was permanently abandoned on 13 April 1986 as a well 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]630.003045.00 -
Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory2267.0[m]SWCR.R.I2370.0[m]SWCR.R.I2435.0[m]SWCR.R.I2443.0[m]SWCR.R.I2645.0[m]SWCR.R.I2673.0[m]SWCR.R.I2687.0[m]SWCR.R.I2695.0[m]SWCR.R.I2715.0[m]SWCR.R.I2740.0[m]SWCR.R.I2932.0[m]SWCR.R.I2977.0[m]SWCR.R.I3037.0[m]SWCR.R.I -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit134705922198419842068215022672284266526732673274727922937 -
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]pdf1.86pdf2.79 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CBL VDL300770CST22673037DIL LSS GR6051597DIL LSS GR16113045DLWD2213044LDL CAL GR6051597LDL CNL CAL GR16113038RFT27653022SHDT22203036VSP9283040 -
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 typeCONDUCTOR30222.036500.00.00LOTSURF.COND.20603.026623.00.00LOTINTERM.13 3/81611.017 1/22266.02.25LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured1391.03WATER BASED14.04.19861931.03WATER BASED10.03.19862221.03WATER BASED11.03.19865001.03WATER BASED12.03.19866201.03WATER BASED17.03.19866201.1519.013.0WATER BASED21.03.19866201.03WATER BASED13.03.19866201.03WATER BASED16.03.19866201.15WATER BASED18.03.19866231.1518.013.0WATER BASED21.03.19866231.1518.013.0WATER BASED24.03.19866231.1522.016.0WATER BASED24.03.19866231.1518.014.0WATER BASED24.03.198611601.1519.015.0WATER BASED26.03.198613961.2020.015.0WATER BASED01.04.198615331.39WATER BASED14.04.198616061.2020.017.0WATER BASED25.03.198616061.2320.023.0WATER BASED25.03.198616291.2518.021.0WATER BASED25.03.198616291.2518.019.0WATER BASED25.03.198617901.3822.015.0WATER BASED25.03.198620081.3823.015.0WATER BASED25.03.198622661.3823.010.0WATER BASED02.04.198623361.3824.010.0WATER BASED03.04.198624931.3931.015.0WATER BASED04.04.198625941.3821.011.0WATER BASED07.04.198627021.3828.011.0WATER BASED07.04.198628371.3928.010.0WATER BASED07.04.198629581.3930.011.0WATER BASED08.04.198630461.3930.011.0WATER BASED10.04.198630461.3926.010.0WATER BASED11.04.198630461.3927.011.0WATER BASED10.04.1986 -
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