25/1-3
Export: PDF
-
General information
-
Wellbore history
GeneralWell 25/1-3 was drilled to appraise the eastward extension of the 25/1-1 Frigg Discovery on the Frigg Ridge in the North Sea. The primary objective was to test the Eocene sandstones that were gas bearing in well 25/1-1.Operations and resultsAppraisal well 25/1-3 was spudded with the semi-submersible installation Pentagone 81 on 14 November 1971 and drilled to TD at 2872 m in the Late Cretaceous Shetland Group. The well was drilled with seawater down to 405 m and with a seawater/LFC mud from 405 m to TD.The target Eocene sandstones (Frigg Formation) was penetrated at 1952 m. The gross thickness was 217 m and the N/G was 0.82 with porosities ranging from 28 to 33%. It was gas bearing down to the GOC at 1973 m and oil bearing down to the OWC at 1982.5 m. Good oil shows on cores were recorded throughout the hydrocarbon-bearing reservoir. Weaker oil shows on cores were described ("fluo but salty taste") below the OWC.Three cores were cut from 1951 to 2005 m in the Frigg reservoir. Total recovery for these three cores was 42.25 m (78.2% recovery). A fourth core was cut from 2563 to 2568 m with 50% recovery. FIT fluid samples were attempted at 2550.5 m and 2576.3 m but only mud and filtrate was recovered.The well was permanently abandoned on 27 January 1972 as an oil and gas appraisal wellTestingSix drill stem tests were conducted.DST 1, 2 and 3 tested the interval 1985 to 1987 m. All three tests produced water.DST 4 and 5 tested the interval 1978 to 1980 m. DST 4 produced 21.5 Sm3 oil/day and DST 5 produced 70 Sm3 oil/day. The maximum temperature in these tests was reported to be 63 °C.DST 6 tested the interval 1976 to 1980 m and produced in the final flow; through a 24/64" choke an average of 14400 Sm3 gas and 136 Sm3 oil /day. The corresponding GOR is 106 Sm3/Sm3. -
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]420.002870.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom11951.01965.3[m ]21969.01982.9[m ]31991.12005.0[m ]42563.02565.5[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]44.6Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
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 typeCONDUCTOR30165.036165.00.00INTERM.13 3/8405.017 1/2415.00.00SURF.COND.9 5/81880.012 1/41886.00.00LINER72036.08 1/22872.00.00 -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.0198519870.02.0198519870.03.0198519870.04.0197819800.05.0197819800.06.0197619800.0Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.02.03.04.05.06.0Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.02.03.04.0215.0706.084110 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]BHC1502869CBL15002011CDM AP18832873DL18822869FDC18822874IES4072869ML MLL18832872SNP18822874SRS4072873 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit12983519522244224422722289249227112734 -
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]pdf1.43pdf0.51 -
Palynological slides at the Norwegian Offshore Directorate
Palynological slides at the Norwegian Offshore Directorate Sample depthDepth unitSample typeLaboratory1775.0[m]DC1795.0[m]DC1815.0[m]DC1835.0[m]DC1855.0[m]DC1875.0[m]DC1895.0[m]DC1925.0[m]DC1930.0[m]DC1935.0[m]DC1945.0[m]DC2025.0[m]DC2045.0[m]DC2065.0[m]DC2085.0[m]DC2105.0[m]DC2125.0[m]DC2145.0[m]DC2160.0[m]DC2180.0[m]DC2200.0[m]DC2220.0[m]DC2245.0[m]DC2265.0[m]DC2285.0[m]DC2305.0[m]DC2325.0[m]DC2345.0[m]DC2365.0[m]DC2385.0[m]DC2405.0[m]DC2425.0[m]DC2448.0[m]DC2476.0[m]DC2496.0[m]DC2516.0[m]DC2536.0[m]DC2552.0[m]DC2564.0[m]CIGS