6507/7-6
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General information
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Wellbore history
Well 6507/7 6 is an appraisal well on the crest of the Heidrun field structure on Haltenbanken off shore Mid Norway. The structure is a fault wedge. The main objectives of the well were to establish the Ti1je gas/oil contact, to define Tilje and Åre oil properties, and to investigate the Åre oil/water contact. In addition, the well was expected to prove Fangst erosion and established lateral continuity of Tilje reservoir properties.Operations and resultsAppraisal well 6507/7 6 was spudded with the semi-submersible installation Nortrym on 23 July 1986 and drilled to TD at 2525 m in Early Jurassic sediments of the Åre Formation. At 419 m the drill string torqued up and spun out five joints below the kelly, dropping the string to the seabed. The well was re-spudded after being moved approximately 8 m, and this time drilling proceeded without significant problems. The well was drilled with seawater and pre-hydrated gel sweeps down to 1030 m and with KCl/polymer mud from 1030 m to TD.Oil shows were recorded in 3 m thick sandstone at 2096 m in the Cretaceous. A marked unconformity separates the Middle Jurassic from the overlying Late Cretaceous sequence. The total hiatus was from Aalenian-Bajocian to Campanian-Santonian. Top Middle Jurassic Fangst Group, Ile Formation was encountered at 2144.5 m and was gas bearing. From good quality RFT pressure data, cores, and electric logs a gas/oil contact was established at 2339 m in the Tilje Formation and the oil/water contact at 2440 m in the Åre Formation. Shows continued down to 2445. Below this depth no shows were reported.A total of 191 m core was recovered from the well. Two cores were cut from the Early Cretaceous through the Fangst Group and into the top Båt Group (2129 - 2185 m), and eight cores were cut from the gas zone in the lower part of the Tilje Formation, through the OWC and into the Åre Formation (2305 - 2462 m). One RFT run was made in the 12 1/4" hole. A water sample was attempted at 2457m without any recovery. The gas gradient was 0.073 psi/ft (0.169 g/cc). Two oil gradients were found. To 2390 m the gradient was 0.327 psi/ft (0.754 g/cc). Passing through the upper Åre Formation siltstone/claystone bed a pressure increase was encountered and the oil column down to the oil/water contact exhibited a higher oil gradient of 0.362 psi/ft (0.834 g/cc). The water gradient was 0.446 psi/ft (1.028 g/cc).The well was permanently abandoned on 6 September 1986 as a gas and oil appraisal.TestingTwo DST's were performed in this well.DST 1 tested the combined intervals 2411.5 ? 2415 and 2421 ? 2424 m in the Åre Formation. Maximum flow was 782 Sm3 oil and 46100 Sm3 gas /day through a 90.5/64" choke. The GOR was 59 Sm3/Sm3, the oil gravity was 23 deg API, and the gas gravity was 0.627 with 3 % CO2 and no detectable H2S.DST 2 tested the interval 2348.5 ? 2365 m in the Tilje Formation. The well flowed at maximum rates 628 Sm3 oil and 61450 Sm3 gas /day through a 132/64" choke. The GOR was 98 Sm3/Sm3, the oil gravity was 27 deg API, and the gas gravity was 0.614 with 1.7 % CO2 and no detectable H2S. Large amounts of sand were also produced in DST 2, leading to a pre-mature end of the flow period. The recorded down-hole temperatures were 83.3 and 78.9 deg C in DST 1 and DST 2 respectively. -
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]1040.002524.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom12129.02156.7[m ]22157.92184.4[m ]32305.02306.6[m ]42315.02341.9[m ]52344.02363.3[m ]62364.52390.4[m ]72392.52404.7[m ]82405.02419.8[m ]92424.02441.0[m ]102442.02460.3[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]190.2Cores 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 availableDSTDST12411.502424.0024.08.1986 - 00:00YESDSTDST22348.502365.0030.08.1984 - 00:00YESDSTTEST20.000.0030.08.1986 - 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 typeCONDUCTOR30473.036474.00.00LOTSURF.COND.201024.0261030.01.52LOTINTERM.13 3/82080.017 1/22087.01.66LOTINTERM.9 5/82510.012 1/42525.00.00LOT -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.02424241235.92.02349236552.4Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.04.00024.0002.02.00022.000Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.0782461000.9180.617592.0628614500.8950.61798 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CBL VDL GR CCL4962045CBL VDL GR CCL17002478DIL SLS GR SP20792524DLL MSFL GR20792521LDL CNL NGL20792525MSD20852523MWD - GR RES DIR4722525RFT HP21492504RFT SG21492504SHDT FAST CHANNELS20792524SHDT GEOMETRY20792524VSP SAT18002475 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit37537514951852185219351935196720162145215921902369 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.26 -
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]pdf1.56pdf11.24pdf7.86 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured4191.03WATERBASED23.07.198610301.1420.012.9WATERBASED31.07.198613031.1617.08.6WATERBASED04.08.198617691.3824.09.1WATERBASED04.08.198618361.3930.09.6WATERBASED04.08.198620501.4227.08.1WATERBASED05.08.198620801.26WATERBASED08.08.198620871.4428.08.6WATERBASED06.08.198620870.0028.08.6WATERBASED07.08.198623051.27WATERBASED11.08.198623050.00WATERBASED12.08.198625251.26WATERBASED18.08.198625250.00WATERBASED21.08.198625250.00WATERBASED19.08.1986 -
Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory2129.0[m]COD2130.1[m]COD2131.2[m]COD2133.4[m]COD2134.5[m]COD2135.5[m]COD2136.4[m]COD2137.4[m]COD2138.5[m]COD2139.6[m]COD2140.5[m]COD2141.5[m]COD2142.5[m]COD2142.9[m]COD2143.6[m]COD2144.5[m]COD2145.5[m]COD2148.8[m]COD2156.5[m]COD2171.8[m]COD2175.7[m]COD2180.9[m]COD