16/2-11
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General information
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Wellbore history
GeneralWell 16/2-11 was drilled to appraise the western part of the Johan Sverdrup (formerly Avaldsnes) discovery on the Utsira High in the North Sea. The primary objective was to prove a 50 to 60 m oil column in Middle - Late Jurassic sandstones. The well would also serve as calibration for seismic interpretation and depth conversion and it would give information about any lateral variation in facies and thickness of the Johan Sverdrup reservoir.Operations and resultsAppraisal well 16/2-11 was spudded with the semisubmersible installation Bredford Dolphin to 2126 m in the Triassic Skagerrak Formation. A 9 7/8" pilot hole was drilled to 756 m to check for shallow gas. No indication of shallow gas was observed. No significant problem was encountered in the operations. The well was drilled with sea water and hi-vis pills down to 756 m and with Performadril Water Based Mud from 756 m to TD.Top reservoir, Intra-Draupne Formation sandstone, was encountered at 1890 m and Middle Jurassic sandstones, Vestland Group, was encountered at 1910 m. The reservoir was encountered at the prognosed depth and 54 m oil column in an oil-down-to situation was proven. The well also confirmed good reservoir properties, in line with the earlier Johan Sverdrup wells where the Late Jurassic reservoir was also of excellent quality with a high net to gross ratio. A peak of high gamma ray between 1889.3 m and 1890 m, indicated a 0.7 m thick Draupne shale on top of the reservoir, but this could not be confirmed by cuttings samples and adjacent sidewall cores. Oil shows were restricted to the Middle-Late Jurassic reservoir section.Five cores were cut from 1891.6 m, just below the possible Draupne shale, to 1957.78 m, ca 12 m into the Skagerrak Formation. Overall good recovery was obtained. MDT fluid samples were taken at 1895.61 m (oil), 1918.41 m (oil), 1937.02 m (oil), 1941.75 m (oil), 1951.38 m (water), and at 2059.09 m (water).The well was permanently abandoned on 29 March 2012 as an oil appraisal well.TestingA production test (DST) was run over the interval 1934.5 m to 1943.3 m in the previously untested Middle Jurassic reservoir section to investigate its flow properties. The main flow gave 476 Sm3 oil and 14500 Sm3 gas per day through a restricted 40/64 choke, with good reservoir properties indicating a laterally continuous reservoir. The GOR was 30 Sm3/Sm3, the oil density was 0.89 g/cm3, and the gas gravity was 0.768 (air = 1). The flowing temperature, recorded at depth 1908.2 m, was 79.7 deg C. -
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]760.002126.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom11891.61900.8[m ]21900.71922.3[m ]31922.31929.4[m ]41929.81951.4[m ]51952.81954.7[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]61.3Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Oil samples at the Norwegian Offshore Directorate
Oil samples at the Norwegian Offshore Directorate Test typeBottle numberTop depth
MD [m]Bottom depth
MD [m]Fluid typeTest timeSamples availableDST1943.301934.50OIL21.03.2012 - 16:40YESMDT0.000.00OIL05.03.2012 - 00:00NO -
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 typeCONDUCTOR30216.036218.00.00LOTSURF.COND.13 3/8744.017 1/2752.01.87LOTPILOT HOLE756.09 7/8756.00.00LOTINTERM.9 5/82097.012 1/42126.01.78LOT -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.01935194316.0Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.0Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.0430 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CMR GR16482121FMI MSIP16482126HRLA PEX ECS HNGS16482107MDT GR17392061MRX XPT GR16652080MSCT GR17232090MWD - PP ARC SON139751MWD - TELE ARC SON ADN7431650MWD - TELE ECO SON18822121MWD - TELE GVR ECO SON16491886VSP GR1362115 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit138795983983146214621484149715701581158115921668174717641783179318681876188918891890191019461946 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured10651.3529.0Water Base16561.2025.0Water Base18001.2031.0Water Base21261.2834.0Water Base