2/7-29
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General information
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Wellbore history
GeneralWell 2/7-29 was the second commitment well on licence PL 145. The primary objective was to establish the presence, quality and fluid content of Jurassic sandstones in Prospects JU2 and JU7 via cores and wire line logs and to evaluate their productivity and fluid properties if hydrocarbon bearing. The pre-Cretaceous was to be accurately dated via biostratigraphy. The secondary objective was to verify the presence, quality and fluid content of Permian sandstones in Prospect P2, and if possible to test the margin of the Jurassic JU2-B Prospect located stratigraphically between JU2 and JU7.Operations and resultsExploration well 2/7-29 was spudded with the jack-up installation "Maersk Guardian" on 18 September 1993 and drilled to TD at 4900 m in mudstones of the Permian Rotliegend Group. A 9 7/8"pilot hole was drilled to 310 m before opening to 36" to evaluate possible shallow gas. No shallow gas was observed and the 30" casing was set at 302 m. A further 9 7/8" pilot hole was drilled to 1155 m before opening to 26" and the 20" casing set at 1146 m. The well was drilled with seawater and hi-vis sweeps down to 310 m, with bentonite mud from 310 m to 1153 m, and with synthetic oil (ester) based "AQUAMUL B II EBM" mud from 1153 m to TD.Hydrocarbons were encountered in 129m of gross (49m net) sandstone in the JU2 prospect (Eldfisk Fm.), the shallower of the Jurassic prospects. Log evaluation established an Oil-Down-To at 4530 m TVDSS. Mean porosities of 12% and permeability in the range 0.01 to 80 mD were measured from core and log data over the pay zone. The mean reserves for the discovery are estimated at 9.3mmbbl (1.48mmcum). Two sand intervals of 12.5 and 19m gross thickness were encountered in the JU7 target. The upper interval contained hydrocarbons. A gross sandstone thickness of 46m was encountered in the Early Permian, although no hydrocarbons were present.A total of seven cores were cut, five in the Jurassic JU2 sandstone (Eldfisk Fm.), one in the Jurassic JU7 sandstone (Eldfisk Fm.) and one in the Permian P2 Rotliegend sandstone. JU2 was cored from 4474 to 4549 m and had moderate to good shows to 4539 m. However, two logging runs with the Schlumberger MDT tool showed the JU2 formation to be generally tight.JU7 was cored from 4684 to 4703 m and was found to grade to siltstone below 4688 m. Minor shows were present in the sandstone above this depth but from the MDT runs the formation was found to be tight. The Permian P2 Rotliegend sandstone was cored from 4853 m to 4872 m but did not contain hydrocarbons. This formation also proved tight from the second MDT logging run. Two PVT samples and a one-gallon dead-oil sample were obtained in JU2. The one-gallon sample proved to be oil when emptied at well site.The well was permanently abandoned as an oil discovery on 6 January 1994.TestingNo drill stem test was performed. -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom14474.04483.6[m ]24483.64501.3[m ]34501.34519.0[m ]44519.04538.0[m ]54538.04548.8[m ]64684.14703.3[m ]74853.04872.0[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]113.0Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
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Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit11416132999299930153069311231383138319036814092410742254225422843294363436343914473460246584664469847564789478948004853 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.43 -
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]pdf34.83 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CST GR42254371DIL AS CAL GR31264371DIL AS GR713133DIL MSFL GR43634906DSI LDL CNL GR43634892MDT GR44914688MDT GR44914868MWD114308MWD3093130MWD33083483MWD - LWD CDR114310MWD - LWD CDR3091154MWD - LWD CDR31403308MWD - LWD CDR34834900OBDT GR43634907VSP11604880 -
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 typeCONDUCTOR30302.036310.00.00LOTSURF.COND.201146.0261155.00.00LOTINTERM.13 3/83124.017 1/23130.00.00LOTINTERM.9 7/84356.012 1/44366.00.00LOTOPEN HOLE4900.08 3/84900.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured3011.05WATER BASED3081.08WATER BASED5541.118.0WATER BASED9491.8120.0WATER BASED11481.155.0WATER BASED11531.175.0OIL BASED20281.6049.0OIL BASED22591.5948.0OIL BASED24981.6048.0OIL BASED27051.5946.0OIL BASED28121.6047.0OIL BASED30131.8122.0WATER BASED31300.00OIL BASED31381.6251.0OIL BASED33081.6144.0OIL BASED34571.6243.0OIL BASED34831.6245.0OIL BASED37381.6250.0OIL BASED38431.6250.0OIL BASED39011.6246.0OIL BASED40091.6247.0OIL BASED42241.6248.0OIL BASED42741.8124.0WATER BASED42911.8161.0OIL BASED43521.8156.0OIL BASED43661.8161.0OIL BASED43661.8250.0OIL BASED43661.8253.0OIL BASED43871.8267.0OIL BASED43951.8767.0OIL BASED45011.8760.0OIL BASED45191.8759.0OIL BASED45741.8759.0OIL BASED45991.8761.0OIL BASED46841.8768.0OIL BASED47031.8762.0OIL BASED49001.9067.0OIL BASED -
Thin sections at the Norwegian Offshore Directorate
Thin sections at the Norwegian Offshore Directorate DepthUnit4544.00[m ]4540.65[m ]4532.00[m ]4529.65[m ]4523.30[m ]4517.65[m ]4514.00[m ]4508.85[m ]4506.00[m ]4504.05[m ]4500.80[m ]4493.35[m ]4490.70[m ]4487.85[m ]4482.65[m ]4477.65[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