34/4-2
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General information
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Wellbore history
GeneralWell 34/4-2 is located in the northern North Sea, approximately 5 km west of the Snorre Field. The purpose of the well was to test the stratigraphic sequence below the Base Cretaceous Unconformity. The primary target was the Statfjord Formation, which was known from the license 037 area to contain porous sandstones of appreciable thicknesses.The secondary target was possible Brent Group / Late Jurassic sands immediately below the Base Cretaceous unconformity. Thirdly, well 34/4-2 was a stratigraphic test of the Triassic deposits between the Statfjord Formation and the Middle to Late Triassic sequence penetrated in well 34/4-1.Operations and resultsWildcat well 34/4-2 was spudded with the semi-submersible installation Byford Dolphin on 6 March 1980 and drilled to TD at 3599 m in the Late Triassic Lunde Formation. No significant incidents occurred during operations, but the well developed as much as 20 deg deviation towards TD, giving a TVD RKB of 3571 m, 28 m less than measured depth. The well was drilled with spud mud down to 816 m, with gypsum/lignosulphonate mud from 816 m to 1975 m, and with lignosulphonate mud from 1975 m to TD.The well penetrated Tertiary, Cretaceous, Jurassic and Triassic strata as required in the work programme for License 057. More than 900 m of Triassic deposits were penetrated in order to obtain stratigraphic information. The Statfjord Formation was eroded and the reservoir characteristics here were on large negative. The exception was the upper seven meter thick Eiriksson Member with a net/gross-value of 1.00 and an average porosity of 24.3%. The underlying Raude Member had a high clay content, which reduced prospectiveness to a N/G value of 0.18 and porosities only rarely exceeding 20%. The Jurassic sequence proved to be different from the expected with Dunlin Group claystones directly underlying Barremian limestones. Hence, no Brent/Late Jurassic sands were present.No significant indications of hydrocarbons were established during the drilling of the well. Coriband processing of the Jurassic/Triassic sequences indicated a varying amount of residual hydrocarbons to be present from 2990 m, but geochemical study of these intervals showed that these readings most likely were incorrect. Oil shows were reported in limestone and sandstone stringers of the Shetland Group, giving yellow to white fluorescence, moderately fast streaming bluish white cut, occasionally crush cut. In the Jurassic to Triassic sequence, the only reported show was from a few limestone grains, in the interval 3249 - 3256 m, with golden yellow fluorescence and slow streaming, milky white cut.One core was cut from the Dunlin Group and into the Eiriksson Member. No wire line fluid samples were taken. The bottom hole temperature at TD, from Horner corrected wire line temperatures, was 120 deg C.The well was permanently abandoned on 24 May 1980 as a dry well.TestingNo production tests were performed as no significant hydrocarbon shows were encountered. -
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]480.003600.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom12595.62602.6[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]7.0Cores 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 typeLaboratory1110.0[m]DCGEOCH1140.0[m]DCGEOCH1170.0[m]DCGEOCH1200.0[m]DCGEOCH1230.0[m]DCGEOCH1260.0[m]DCGEOCH1290.0[m]DCGEOCH1320.0[m]DCGEOCH1350.0[m]DCGEOCH1380.0[m]DCGEOCH1410.0[m]DCGEOCH1440.0[m]DCGEOCH1470.0[m]DCGEOCH1500.0[m]DCGEOCH1530.0[m]DCGEOCH1560.0[m]DCGEOCH1590.0[m]DCGEOCH1620.0[m]DCGEOCH1650.0[m]DCGEOCH1670.0[m]DCGEOCH1690.0[m]DCGEOCH1720.0[m]DCGEOCH1750.0[m]DCGEOCH1780.0[m]DCGEOCH1800.0[m]DCGEOCH1810.0[m]DCGEOCH1820.0[m]DCGEOCH1850.0[m]DCGEOCH -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit34711301151165016501678180918092127256625842584259726972697 -
Geochemical information
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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]pdf13.03 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CBL VDL3402800CBL VDL3402800CST28113595FDC CNL GR19633598HDT19633597ISF BHC GR4771972ISF BHC MSFL SP GR CAL19633597RFT25993517VELOCITY3473599 -
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 typeCONDUCTOR30451.036451.00.00LOTCONDUCTOR30461.036451.00.00LOTSURF.COND.20776.026791.01.47LOTINTERM.13 3/81940.017 1/21950.01.76LOTINTERM.9 5/82785.012 1/42798.01.87LOTLINER73575.08 1/23575.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured7561.0835.0seawater19751.3868.0waterbased24051.5048.0waterbased26101.6167.0waterbased30101.6748.0waterbased36001.6354.0waterbased -
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