7120/12-5
Export: PDF
-
General information
-
Wellbore history
GeneralWell 7120/12-5 was drilled on the Lunde prospect next to the 7120/12-3Alke North discovery in the Hammerfest Basin of the Barents Sea. The main targets were the Stø Formation sandstones in the top of the Kapp Toscana Group, Intra Carnian sandstones of the Snadd Formation and Kobbe Formation sandstones. These formations were expected to be gas bearing.Operations and resultsWildcat well 7120/12-5 was drilled with the semi-submersible installation Polar Pioneer. Drilling started on 3 January 2010 with a 9 7/8" pilot hole 51.5 m from the main well position to check for shallow gas. No shallow gas was observed. The rig was then moved to the planned position, where it was spudded and drilling commenced to 1761 m where the initial 16" hole was abandoned owing to hole instability. A new 16" hole was sidetracked from 533 m and drilling then proceeded without significant problems to final TD at 3630 m in the Middle Triassic Kobbe Formation. The well was drilled with Seawater and hi-vis sweeps down to 510 m, with K-Format mud from 510 m to 1761 m in the primary well bore and to 1591 m in sidetrack, and with KCl/GEM/Polymer mud from 1591 m to TD.Sandstones of reservoir quality were penetrated in all three targets, but all were found to be water wet. Based on 12 valid XPT-MDT pressure points a water gradient of 0.101 bar/m was established from the Stø Formation at 2150 m to the Snadd Fm (Intra Carnian sand) at 3100 m. The Stø Formation was encountered at 2165 m, 26.5 m higher than originally prognosed. The Stø sandstones were generally very fine to fine, well sorted and poorly cemented with occasional kaolinite matrix. Top Snadd Formation was encountered at 2582 m with the secondary target Intra Carnian sandstones at 3175 to 3197.5 m, 163m deeper than prognosed. These sands were interbedded with thin siltstones and were generally fine to medium grained, well sorted, poorly cemented with moderate inferred porosity. The Kobbe Formation came in at 3572 m, 163 m deeper than prognosed. The Kobbe sandstones were interbedded with claystone and were very fine to occasionally fine, well sorted and commonly well cemented with poor inferred porosity.Shows were absent from the well apart from background mineral fluorescence. Low gas values were recorded throughout the well with the highest, short lived peak of 10.45% recorded on penetrating the Stø sandstones. After the initial peak gas values rapidly fell back to background levels below 1%.No cores were cut and no wire line fluid samples were taken.The well was permanently abandoned on 3 January 2011 as a dry well.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]510.003630.00 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit210766826826139918281963215321652165223023652407258235723572 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]GR DENS NEU SON15763164MSCT GR31773608MWD - ARC SON TELE210570MWD - DVRARC15913164MWD - PDX5 RAB6 TELE32943630MWD - PP ARC5701591MWD - RAB6 DV6MT TELE31643294VSP GR19863620XPT GR31773191XPT TLD MAIP30703634 -
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 typeCONDUCTOR30268.536268.50.00LOTSURF.COND.20503.026510.01.79LOTPILOT HOLE510.09 7/8510.00.00LOTINTERM.13 3/81576.0161591.01.66LOTINTERM.9 5/83154.012 1/43164.00.00LOTOPEN HOLE3630.08 1/23630.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured4501.3323.0KF9351.3322.0KF11061.2516.0KF13901.3620.0KF15911.3720.0KF15961.3719.0KC17611.2921.0KF18001.3721.0KC29301.391.0KC32941.5430.0KC33601.5223.0KC36301.5222.0KC -
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]pdf0.28