7/11-2
Export: PDF
-
General information
-
Wellbore history
GeneralWell 7/11-2 was drilled , ca 1.5 km from the UK Border on the eastern side of the Breiflabb Basin in the southern North Sea. The objective was to test the hydrocarbon potential in the Paleocene on the west flank of the Cod structure, and to confirm the gas and condensate discovery made by the 7/11-1 well. Well 7/11-1 tested up to 430 Sm3 condensate and 1254000 Sm3 gas /day from the Late Paleocene Forties Formation.Operations and resultsAppraisal well 7/11-2 was spudded with the semi-submersible installation Ocean Traveller on 21 July 1968 and drilled to TD at 3427 m in the Late Cretaceous Tor Formation. Tight hole was experienced when pulling out of the 17 12" hole. The hole was washed back to TD and mud weight increased to 14 ppg. Logging and casing operations could then be successfully carried out. The well was drilled with sea water down to 1219 m where the system was changed to a salt-saturated Drispac-Desco-Flosal type.The well tested gas and condensate in Paleocene sandstones (the Forties Formation).One core was taken in the Paleocene sandstone in the interval 3030.6 m to 3045 m. No wire line fluid samples were taken.The well was permanently abandoned on as a dry well.TestingThree drill stem tests were performed.DST 1 tested the interval 3166.3 m to 3192.5 m. This test produced only 3.7 m3 salt water-cut mud and mud filtrate.DST2 tested the interval 3027.3 m to 3105.9 m. This test produced 221 Sm3 gas and 469000 Sm3 gas /day through a 3/4" choke. These rates correspond to a gas/condensate ratio of 2121 Sm3/Sm3, but the GCR varied from 1251 Sm3/Sm3 on a 1/4" choke to 3111 on a 1" choke. The condensate gravity was fairly constant for all rates; 61.0 to 62.1 deg API.DST 3 tested the interval 2979.7 m to 2998 m. This test produced no formation fluid to surface. After injecting 4 m3 acid (HCl) and 1.6 m3 diesel 16.5 m3 diesel+mud flowed back from the formation.> -
Cuttings at the Norwegian Offshore Directorate
Cuttings at the Norwegian Offshore Directorate Cuttings available for sampling?NOCuttings at the Norwegian Offshore Directorate Cutting sample, top depth [m]Cutting samples, bottom depth [m]533.403427.48 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom13030.63046.2[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]15.6Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
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 typeCONDUCTOR30132.036132.00.00LOTSURF.COND.20484.026484.00.00LOTINTERM.13 3/81945.017 1/21945.00.00LOTINTERM.9 5/83203.012 1/43203.00.00LOTOPEN HOLE3427.08 1/23427.00.00LOT -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.0316731930.02.03028310719.03.0298029990.0Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.02.03.0Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.02.022146900021213.0 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CBL26683198FDC28963428GR104484HDT19463294IES19463427LL-74843296MLL28963428SGR4843427SNP28963428VSP303422 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit109154929812981299730253175322032203346 -
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]PDF20.61PDF0.59PDF1.79PDF0.51PDF19.99PDF0.09PDF0.25PDF1.73PDF5.02PDF3.43PDF3.33PDF2.22PDF12.51PDF69.81PDF0.16PDF10.14PDF4.89PDF7.07PDF0.10PDF1.38PDF1.08PDF0.15PDF0.73PDF13.78PDF1.75PDF5.01PDF2.87PDF0.31 -
Documents – Norwegian Offshore Directorate papers
Documents – Norwegian Offshore Directorate papers Document nameDocument formatDocument size [MB]pdf24.45pdf32.57pdf12.36 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured12191.0730.012.0waterbased19811.1965.030.0waterbased27441.4355.025.0waterbased29591.6355.08.0waterbased34271.5560.014.0waterbased