6305/8-2
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General information
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Wellbore history
GeneralWell 6305/8-2 was drilled to appraise the southern part of the Ormen Lange Field in the Sothern Norwegian Sea. The objective of well 6305/8-2 was to delineate the field to the south, as it was unclear whether the area was optimally drained or not by existing production wells.Operations and resultsAppraisal well 6305/8-2 was spudded with the semi-submersible installation Transocean Barents on 24 September 2014 and drilled to TD at 3078 m in the Late Cretaceous Springar Formation. No significant problem was encountered in the operations. The well was drilled with seawater and bentonite sweeps down to 1499 m, with KCl/polymer/glycol mud from 1499 m to 2897 m, and with Innovert NS oil based mud from 2897 m to TD.Top of the Egga Informal Formation Reservoir was encountered at 2906.5 m 23.5 m deeper than prognosed. Below Egga from 3005 to 3015 m an undifferentiated unit was penetrated before entering the Maastrichtian age Jorsalfare Formation. The Egga contained a 28-metre gas column down to a current GDT at 2936.0 m, and an underlying water zone with very good reservoir quality. The water zone in the lower part of Egga has extreme core permeabilities in the several Darcy range, often exceeding five Darcy. Below the GDT, the interpretation indicated a swept zone down to ca 2950 m followed by a residual gas zone down to ca 2969 m. All sands are fully water bearing below this depth. Both the undifferentiated unit and the Jorsalfare Formation were aquiferous with very good and poor to very good reservoir quality, respectively. The water zone is 70 metres in total. Wireline pressure measurements show depletion due to production in the D-template area. Pressure depletion relative to the closest exploration well 6305/7-1 vary from a high of 88.5 bar to a low of 7.4 bar.Four consecutive cores were cut from 2898 to 3006.5 m, from the shale unit above the reservoir and down through the whole of Egga. MDT water samples were taken at 2991.7 m in Egga and at 3012 m in the underlying undifferentiated unit.The well was permanently abandoned on 21 November 2014 as a gas appraisal 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]1500.003078.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom12910.02924.4[m ]22924.42952.2[m ]32952.22978.0[m ]42978.03005.8[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]95.8Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit656656146516141614252725272680289129073005301530153047 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]DEN SON CAL GR7312897GR RES DEN NMR SPEC GR28303080MDT MFRAC29043046MFRAC29042975MFRAC29202960MIC RES SON CBL VDL25763081MWD - DI655737MWD - GR RES PWD DI7242000MWD - GR RES PWD DI17942897MWD - GR RES PWD SON NEU DEN DI28963068MWD - PWD DI28893077VSP GR6551980VSP GR16752879VSP GR17902897VSP GR27113062 -
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 typeCONDUCTOR36734.142737.70.00SURF.COND.201492.4261496.61.25LOTPROD.13 5/81996.417 1/22001.01.35LOTLINER9 5/82896.512 1/42897.01.21LOTOPEN HOLE3078.08 1/23078.00.00 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured6551.03Seawater14801.25KCl / NaCl /Glycol polymer mud14801.30P&D Mud14981.30KCl/Polymer Displacement14991.25KCl / NaCl /Glycol polymer mud17141.28KCl / NaCl /Glycol polymer mud18631.32KCl / NaCl /Glycol polymer mud20011.35KCl / NaCl /Glycol polymer mud20291.41KCl / NaCl /Glycol polymer mud28971.20INNOVERT NS OBM28971.41KCl / NaCl /Glycol polymer mud29251.20INNOVERT NS OBM30781.35Bentonite mud30781.35Polymer Mud / Glycol30781.22INNOVERT NS OBM30781.22INNOVERT NS OBM