2/9-4
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General information
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Wellbore history
GeneralThe 2/9-4 Trane well is located on the Piggvar Terrace in the Norwegian Sector of the Danish-Norwegian Basin inthe North Sea. The target prospect was seen as a continuation of the recent Danish sector Hejre discovery structural trend and reservoir/trap system and the sole objective of the well was to explore the hydrocarbon potential of the Jurassic J62 Heno Formation (Gert Member Sandstone) prospect. The 2/9-4 well location was planned to be approximately 10 km from the Danish sector Hejre-2 well location. The Trane well was planned as a near-vertical HPHT well with a prognosed TD at 5512 m or when sufficient rat hole was drilled below the base of the Karl Volcanics to allow testing in the discovery case and full coverage logging in the wet case.Operations and resultsWildcat well 2/9-4 was spudded with the jack-up installation Mærsk Galant on 20 March 2008 and drilled to TD at 5500 m in volcanic rocks within the Permian Rotliegend Group. An apparent influx into the wellbore was observed while drilling at 5056 m with 16.9ppg MW and required an increase in MW to 17.0 ppg to allow drilling to continue. The ECD immediately prior to this "influx" had been 17.2 ppg and the influx was thought to have been caused by gas expansion near surface after drilling into a gas pocket trapped beneath a thin dolomitic limestone stringer. A flow check at 5116 m due to high drilled gas levels in the mud showed the well was flowing at 14bbl/hr with a MW of 17.4ppg. The well required 17.7 ppg MW to return to a static condition. The Pore Pressure through this section was significantly higher than the pre-drill estimate and appeared to indicate that the Trane structure represented an isolated block with a different structural and pressure history to the adjacent Hejre structure. Losses of 26 bbl/hr were noted at 5475 m and were cured after pumping and soaking 2 LCM pills. Drilling continued to TD without further incident. The well was drilled with sea water and hi-vis pills down to 203 m, with spud mud from 203 m to 1007 m, with Glydril mud from 1007 m to 2495 m, with Paratherm oil based mud from 2495 m to 2715.5 m, and with WARP oil based mud from 2715.5 m to TD.No reservoir quality sands were developed at any level below Miocene level. The Gert Member Sandstone objective was absent. The oil-based muds used as the drilling fluids for the entire well below the 20" shoe at 1002.1 m, madeshows identification difficult. No shows that could be distinguished from the OBM were observed.Wire line logging runs gave a bottom hole maximum temperature of 156 deg C with Horner plot corrections suggesting a maximum static down hole temperature at TD of 158 deg C.No cores were cut and no wire line fluid samples were taken.The well was permanently abandoned on 4 July 2008 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]200.005500.00 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit115161630933093310531543204321832183336385840824082417542594323469846985450 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]DSL ORIT XMAC HDIL CN ZDL1155493GR VSP8005485MWD LWD - DGR10072510MWD LWD - EWR PWD25004715MWD LWD - GR EWR PWD47155500MWD LWD - PWD1151007 -
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 typeCONDUCTOR30195.036203.00.00LOTSURF.COND.201002.0261007.01.74LOTINTERM.13 5/82499.017 1/22510.01.89LOTINTERM.9 7/84710.012 1/44715.02.19LOTOPEN HOLE5500.08 1/25500.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured3001.164.0water based5001.147.0water based5961.136.0water based8951.185.0water based10051.146.0water based10071.6032.0water based10071.136.0water based12251.6031.0water based17421.6032.0water based22521.6038.0water based25101.6234.0water based29221.6540.0oil based32521.6538.0oil based35401.6535.0oil based36501.6537.0oil based37301.6533.0oil based38191.6535.0oil based39411.6537.0oil based39941.6535.0oil based40451.7439.0oil based40761.7438.0oil based41391.7435.0oil based41871.7439.0oil based42231.7440.0oil based43461.7438.0oil based44701.7444.0oil based45681.7446.0oil based46351.7443.0oil based46851.7442.0oil based47162.0047.0oil based47162.0045.0oil based47161.7443.0oil based47161.7442.0oil based47502.0043.0oil based48112.0042.0oil based48782.0039.0oil based49462.0041.0oil based49880.2045.0oil based50262.0048.0oil based50342.0045.0oil based50562.0345.0oil based51172.1052.0oil based51842.1261.0oil based52232.1261.0oil based52972.1258.0oil based53432.1263.0oil based53842.1266.0oil based55002.1258.0oil based