34/10-30
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General information
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Wellbore history
GeneralWell 34/10-30 was the fifth well drilled on Gullfaks Sør. The well was the "continuation" of the junked well 34/10-28, which was plugged and abandoned at 528 m. Well 34/10-30 was drilled on the Alpha structure, and designed to test for hydrocarbon accumulations in the North East part of the structure. The main objectives were the Brent and Statfjord sandstones. The Lower Jurassic Cook sandstone, which had been water bearing in the other Gullfaks Sør wells, was considered a secondary objective, as was the penetration of the oil/water contact. Prognosed depth was 3435 m.OperationsAppraisal well 34/10-30 was spudded with the semi-submersible installation Dyvi Stena on 16 January 1986 and drilled to TD at 3785 m in the Triassic Lunde Formation. Drilling proceeded without significant problems, but 20" casing was set early due to shallow gas in the interval 332-340 m. The well was drilled with spud mud down to 232 m, with PAC/polymer mud from 232 m to 325 m, with gypsum / PAC mud from 325 m to 1898 m, with gypsum/PAC/"Borewell" mud from 1898 m to 2845 m, and with Lignite/"Borewell" mud from 2845 m to TD.A four-meter thick Brent sandstone was encountered at 2941 m. The sandstone showed a milky white to pale yellow fluorescence with a slow white streaming cut and a C1/C2 mud gas ratio that indicate a gas bearing formation. The Cook Formation was dry. The top of the Statfjord Formation was at 3120 m, approximately 100 m higher than prognosed. The formation was all filled with oil and gas and had a gas-oil contact at 3251.6 m. The Lunde Formation was reached at 3375 m. The formation was oil bearing with no defined oil-water contact. The oil/water contact was expected at 3395 m. This was not the case and drilling of a 6" section thus commenced past the prognosed depth. The oil water contact was difficult to define, but there is reason to believe it to be at approximately 3712 m. Twenty-two cores were cut in the well, 9 in the Lunde Formation, 12 in the Statfjord Formation, and one in the Dunlin Group. One segregated RFT sample was collected in the Lunde Formation at 3554.0 m. The bottom part of the well was plugged back into the 7" liner without permission from NPD. The well was tested and subsequently plugged and abandoned on 12 may 1986 as an oil and gas appraisal well.TestingThree drill stem tests were performed. DST No 1 (3460 m to 3473 m) in the Lunde Formation flowed 418 Sm3 oil /d with a GOR of 146 Sm3/Sm3 through a 12.7 mm choke, DST No 2 (3296 m to 3317 m) in the oil zone in the Statfjord Formation flowed 1161 Sm3 oil /d with a GOR of 102 Sm3/Sm3 through a 17.5 mm choke, while DST No 3 (3125 m to 3155 m) in the gas zone in the Statfjord Formation flowed 352 Sm3 oil/d and 1151000 Sm3 gas/d (GOR = 3270 Sm3/Sm3) through a 17.5 mm choke. -
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]230.003782.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom12942.42945.8[m ]23125.03146.0[m ]33146.03171.7[m ]43173.03179.5[m ]53179.53186.5[m ]63186.53199.5[m ]73199.53217.6[m ]83217.53235.6[m ]93235.53252.8[m ]103252.53270.2[m ]113270.53288.8[m ]123288.83305.2[m ]133306.03326.6[m ]143411.03429.4[m ]153429.03446.0[m ]163446.53465.0[m ]173465.03478.5[m ]183543.03561.3[m ]193561.53579.8[m ]203548.03597.5[m ]213597.53615.0[m ]223615.53633.7[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]392.2Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
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Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory2910.0[m]DCGEOCH2922.0[m]DCGEOCH2934.0[m]DCGEOCH2942.3[m]DCGEOCH2952.0[m]DCGEOCH3125.9[m]CHYDRO3133.7[m]CHYDRO3140.4[m]CHYDRO3146.8[m]CHYDRO3153.5[m]CHYDRO3158.9[m]CHYDRO3162.4[m]CHYDRO3167.9[m]CHYDRO3179.6[m]CHYDRO3185.9[m]CHYDRO3192.5[m]CHYDRO3196.9[m]CHYDRO3201.7[m]CHYDRO3204.1[m]CHYDRO3211.6[m]CHYDRO3214.4[m]CHYDRO3217.5[m]CHYDRO3228.9[m]CHYDRO3233.3[m]CHYDRO3240.7[m]CHYDRO3251.6[m]CHYDRO3255.6[m]CHYDRO3261.0[m]CHYDRO3262.5[m]CHYDRO3273.3[m]CHYDRO3283.6[m]CHYDRO3288.2[m]CHYDRO3292.1[m]CHYDRO3294.4[m]CHYDRO3297.1[m]CHYDRO3309.4[m]CHYDRO3316.7[m]CHYDRO3318.3[m]CHYDRO3320.6[m]CHYDRO3323.5[m]CHYDRO3411.4[m]CHYDRO3417.7[m]CHYDRO3420.9[m]CHYDRO3426.9[m]CHYDRO3431.7[m]CHYDRO3440.6[m]CHYDRO3448.3[m]CHYDRO3453.8[m]CHYDRO3459.7[m]CHYDRO3469.8[m]CHYDRO3472.9[m]CHYDRO3474.7[m]CHYDRO -
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 availableDSTTEST13460.003473.0015.04.1986 - 03:42YESDSTTEST23297.003318.0021.04.1986 - 20:50YESDSTTEST33125.003155.0030.04.1986 - 00:00YES -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit1589209511785178518562006291829412945294529502983312033753375 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.81 -
Geochemical information
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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]pdf36.37 -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.03460347312.72.03297331817.53.03125315517.5Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.07.60025.9001292.09.00029.2001263.043.100118Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.0418610000.8630.6941462.011501180000.8590.6621023.035211510000.7900.6583271 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CBL VDL GR1552832CBL VDL GR3001885CBL VDL GR26713500CBL VDL GR30463163CST GR18872845DLL MSFL GR28323497DLL MSFL GR35003783DLWD - GR RES DIR2363500DLWD - NMR P-K31253319DLWD - NMR P-K34113479ISF LSS MSFL GR3191405ISF LSS MSFL GR13221896ISF LSS MSFL GR18872845ISF LSS MSFL GR28323365ISF LSS MSFL GR28323499ISF LSS MSFL GR35003787ISF LSS MSFL GR35003677LDL CNL GR3191898LDL CNL GR18872846LDL CNL GR35003787LDL CNL NGS28323500RFT GR29193146RFT GR31333302RFT GR35423766SHDT GR28323483SHDT GR35003787VSP3193787 -
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 typeCONDUCTOR30231.036235.00.00LOTSURF.COND.20320.026329.01.33LOTINTERM.13 3/81886.017 1/21898.01.80LOTINTERM.9 5/82831.012 1/22845.00.00LOTLINER73785.08 1/23785.01.99LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured6341.1217.011.0WATER BASED23.01.19868981.1520.012.5WATER BASED23.01.198617181.1756.025.0WATER BASED31.01.198617761.2058.016.0WATER BASED03.02.198618871.2762.015.5WATER BASED03.02.198618981.3061.013.5WATER BASED04.02.198619051.3552.09.8WATER BASED11.02.198619281.4052.09.8WATER BASED11.02.198620431.4552.09.8WATER BASED11.02.198621001.5656.08.4WATER BASED11.02.198621511.5556.08.4WATER BASED11.02.198622041.6056.08.4WATER BASED11.02.198624761.6251.07.4WATER BASED12.02.198627501.6257.010.0WATER BASED16.02.198627701.6750.07.0WATER BASED16.02.198627771.6755.08.0WATER BASED16.02.198629441.6521.04.5WATER BASED11.03.198631331.6521.04.5WATER BASED11.03.198631461.6521.04.5WATER BASED11.03.198633651.6020.04.5WATER BASED11.03.198635001.5020.06.0WATER BASED25.03.198636751.5023.05.7WATER BASED01.04.198636931.5024.05.2WATER BASED03.04.1986 -
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]pdf0.22