31/5-5
Export: PDF
-
General information
-
Wellbore history
GeneralThe well was drilled as part of the appraisal programme initiated for the southern part of the Troll West Gas province (TWGP-S). The objectives of the well were to provide geological, geophysical and petrophysical data for evaluation of the potential for a group of oil producers in TWGP-S; and to provide data on the Fensfjord and Krossfjord Formations to improve aquifer modelling. The well was further planned for later re-entry, either for sidetracking and completion as a horizontal producer, or for vertical recompletion for Sognefjord Formation reservoir monitoring.Operations and resultsWell 31/5-5 was spudded with the semi-submersible installation West Delta on 30 December 1992 and drilled to a total depth at 1930 m in the Middle Jurassic Krossfjord Formation. The well was drilled with spud mud to 940 m and with KCl/brine from 940 m to TD.The Sognefjord Formation was encountered from 1572 m to 1725 m, and was hydrocarbon bearing. Strong oil shows were recorded from 1573 m to1587.5 m, weaker oil shows were recorded below this depth down to 1650 m. The gas-oil contact was identified at 1573.5, and the oil-water contact was identified at 1585.5 m. From FMT pressure tests a gas gradient of 0.152 g/cc, an oil gradient of 0.825 g/cc, and a water gradient of 1.02 g/cc was defined. Twelve conventional cores were cut. The first ten were from 1555 m in the top of the Sognefjord Formation to1726 m, one meter into the Fensfjord Formation. Cores 11 and 12 were cut from 1835 m in the Fensfjord Formation to 1888 m in the Krossfjord Formation. FMT fluid samples were taken at 1583 m (two samples, both contained oil and gas), 1576.5 m (oil and gas), and at 1571 m (gas).The well was temporarily plugged at 1450 m and 450 m using two 9 5/8" Baker type N1 bridge plugs and suspended as an oil and gas appraisal well on 11 February 1993.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]950.001930.00 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom11555.01571.5[m ]21571.51583.0[m ]31585.51601.0[m ]41603.51622.0[m ]51622.71640.0[m ]61640.01658.0[m ]71658.01674.7[m ]81675.01693.0[m ]91693.01710.5[m ]101710.51736.0[m ]111835.01860.0[m ]121861.01888.9[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]227.9Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
-
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 typeCONDUCTOR30432.036432.00.00LOTINTERM.18 5/8926.024940.01.58LOTINTERM.9 5/81515.012 1/41530.01.54LOTOPEN HOLE1930.08 1/21930.00.00LOT -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]ACL SDL GR347910ACL SDL GR8701412ACL SDL GR13501500CST GR15831925DCBIL HDIP GR15371923DLL MLL AC ZDL CN SP GR14611927FMT VPC FQPG GR15371923FMT VPC FQPG GR15721572FMT VPC FQPG GR15771577FMT VPC FQPG GR15831583MAC SL14741928MWD - GR DPR DIR15601930MWD - GR RES DIR3471555VSP9601920 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit34874112951295137514041529155415721572166017251855 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.26 -
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]pdf16.77 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured4001.347.0WATER BASED4561.349.0WATER BASED9401.20WATER BASED12551.347.0WATER BASED14661.3411.0WATER BASED15301.3422.0WATER BASED15711.1723.0WATER BASED16401.1719.0WATER BASED17371.1719.0WATER BASED19301.17WATER BASED