30/6-9
Export: PDF
-
General information
-
Wellbore history
GeneralWell 30/6-9 was drilled on the Gamma structure on the Oseberg Field in the northern North Sea. The Gamma structure lies on the west side of the Alpha structure and is separated from it by a large northwest-southeast fault. The primary objectives of well 30/6-9 were to test hydrocarbon accumulations in the Brent Group and find additional hydrocarbon accumulations within the Early Jurassic. This was the first well located on the Gamma structure. Planned depth for the well was ca 3360 m or 75 m into the Triassic Lunde Formation.Operations and resultsWildcat well 30/6-9 was spudded with the semi-submersible installation Nortrym on 28 August 1982 and drilled to TD at 3476 m in the Late Triassic Lunde Formation. No significant problems occurred while drilling the well. The well was drilled with seawater, bentonite and hi-vis pills down to 975 m, with KCl/polymer mud from 975 m to 2750 m, and with lignite/lignosulphonate/freshwater mud from 2750 m to TDWeak to strong shows were reported mainly in soft limestone stringers in the lowermost part of the Lista Formation in the Late Paleocene, in the Danian, and through the Maastrichtian. Further shows above the Brent Group were reported in cuttings in limestones from 2410 to 2422.5 m, just above the Late Jurassic unconformity.The main target, Brent Group was penetrated from 2458 to 2620 m. It was hydrocarbon bearing over the entire interval with the gas/oil contact calculated from FMT pressure recordings at ca 2520 m. This is the same, as the GOC on the Alpha structure. No oil/water contact was encountered. The net pay in the Brent Group is calculated to be 98 m giving a net/gross ratio of 0.60. The average porosity is 22.7% with an average water saturation of 20%. Below the Brent Group weak shows were reported from 2622 to 2630 m in the Drake Formation and in thin sandstone and siltstone stringers at 3000 to 3046 m in the Early Jurassic Amundsen Formation. The Early Jurassic Statfjord Group was found to be water bearing.Ten cores were cut from 2462 m to 2624.5 m in the Ness, Etive, and Drake formations. FMT fluid samples were taken in the Bent Group at 2461.5 m (gas and mud filtrate), 2489.5 m(2 3/4 gal chamber empty), 2543 m (gas, oil and mud filtrate), 2567 m (gas, oil and trace mud filtrate), and at 2617.5 m (gas, oil and mud filtrate) .The well was suspended on 16 December 1982 as an oil and gas discovery.TestingFive DST's were performed in this well, two in the gas zone and three in the oil zone.DST No 1 (2612.5 - 2615.5 m) at the base of the Etive Formation tested 528.7 Sm3/day of oil and 58581 Sm3 /day of gas through a 32/64" choke. GOR was 110 Sm3/Sm3. Oil gravity was 33.2 deg API and gas gravity was 0.679 (air = l). Maximum temperature recorded at reference depth 2594.3 m was 103.1 deg C.DST No 2 (2554 - 2559 m) at the very top of the Etive Formation tested 554 Sm3 oil /day and 65656 Sm3 gas /day through a 32/64" choke. GOR was 118 Sm3/Sm3. Oil gravity was 33.5 deg API and gas gravity was 0.678 (air = 1). Maximum temperature recorded at reference depth 2553 m was 100 deg C. This test was interrupted by technical problems during sampling. A re-test over the same interval (DST No 2A) was done to complete the test programme.DST No 3 (2537.3 - 2540 m and 2542.5 - 2547 m) in the lower Ness Formation tested 429 Sm3oil and 52072 Sm3 associated gas /day) through a 30/64" choke. GOR was 121 Sm3/Sm3. Oil gravity was 34 deg API and gas gravity was 0.675 (air = 1). Maximum temperature recorded at reference depth 2519.7 m was 99.8 deg C.DST No 4 (2498 - 2501 m) in the middle Ness Formation gas zone tested 200 Sm3 condensate and 624400 Sm3 gas /day through a 40/54" choke. Gas/Condensate Ratio was 3210 Sm3/Sm3. Condensate gravity was 54.8 deg API and gas gravity was 0.662 (air = 1). Maximum temperature recorded at reference depth 2485.8 m was 98.2 deg C.DST No 5 (2460 - 2463 m) at the top of the Ness Formation tested 189 Sm3 condensate and 673500 Sm3 gas /day through a 40/64" choke. GCR was 3560 Sm3/Sm3. Oil gravity was 60.2 deg API and gas gravity was 0.670 (air =1). Maximum temperature recorded at reference depth 2453.2 m was 97.8 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]210.003475.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom12462.02480.0[m ]22480.02498.5[m ]32498.52516.0[m ]42516.52532.8[m ]52533.02534.0[m ]62535.02552.8[m ]72553.02571.0[m ]82571.02589.0[m ]92589.02607.0[m ]102607.02624.2[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]160.3Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
-
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 availableDSTDST52460.002463.0010.12.1982 - 00:00YES -
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 typeCONDUCTOR30218.536219.50.00LOTSURF.COND.20960.026975.01.66LOTINTERM.13 3/82384.017 1/22400.01.81LOTINTERM.9 5/82738.012 1/42750.00.00LOTOPEN HOLE3476.08 3/83476.00.00LOT -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.02612261512.72.02554255912.73.02537254711.94.02498250115.85.02460246315.8Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.01032.01003.01004.0985.098Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.0529590000.8590.6791102.0554660000.8570.6781183.0429520000.8060.6751214.02006430000.7590.66232145.01896740000.7380.6703563 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]AC23682745CBL VDL23032725CCL GR23502748CDL CNL GR9302397CDL CNL GR25813473CDL CNL SP GR23782646CST13202397CST24002750CST27493461DIFL BHC CBL VDL27133474DIFL BHC FR1302748DLL MSFL GR23702748FMT24142617FMT24572457FMT24592567FMT24612461FMT24892489FMT24892489FMT25332543FMT25672567FMT25672567FMT26062618FMT30493457HRD19203465SP23782641VELOCITY2981316VELOCITY16353407 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit1326518622001200120732175226522792423242324582458255426202620282128782964304630463226333433893389 -
Geochemical information
-
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]pdf22.89 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured1451.3212.010.0WATER BASED14.05.199022821.3211.014.0WATER BASED10.05.1990 -
Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory2444.5[m]SWCRRI2456.5[m]SWCRRI2471.0[m]CRRI2483.0[m]CRRI2501.0[m]CRRI2507.0[m]CRRI2518.5[m]CRRI2529.5[m]CRRI2542.5[m]CRRI2547.5[m]CRRI2552.5[m]CRRI2612.0[m]CRRI2621.0[m]CRRI2624.0[m]CRRI2629.5[m]SWCRRI2662.5[m]SWCRRI2676.0[m]SWCRRI2701.5[m]SWCRRI2711.0[m]SWCRRI2727.0[m]SWCRRI2740.0[m]SWCRRI2755.0[m]SWCRRI2775.0[m]SWCRRI2795.0[m]SWCRRI2854.0[m]SWCRRI2879.5[m]SWCRRI2901.0[m]SWCRRI2923.0[m]SWCRRI2962.5[m]SWCRRI3008.0[m]SWCRRI3042.0[m]SWCRRI3105.5[m]SWCRRI