6406/2-4 SR
Export: 
PDF
PDF-
General information
-
Wellbore history
GeneralAppraisal well 6406/2-4 S was drilled on the southern part of the Lavrans structure in the eastern part of block 6406/2, south of the Sørbukk Field and west of the Trestakk Field on Haltenbanken. The Lavrans structure is a rotated fault block west of the Trestakk Fault on the Halten Terrace. The purpose of the well was to appraise the southward extension of hydrocarbons in the Garn, Ile and Tofte Formations in the Lavrans structure, and to test separate closures in the Tilje and Åre formations. In addition, the well was planned to test the productivity improvement achievable by hydraulic stimulation. The well should also penetrate two sandy zones of Turonian (Lysing Formation) and Cenomanian/Albian age (Intra Lange sandstone).Operations and resultsThe deviated appraisal well 6406/2-4 S was spudded 18 January1997 with the semi-submersible installation "Deepsea Bergen". It was drilled to 4546 m (4457 m TVD) in the Melke Formation. Mainly because of the weather conditions (41 days of WOW and weather-related problems) drilling of 6406/2-4 S was significantly delayed. Due to environmental restrictions in the area the well had to be suspended on April 5 1997 before the well targets had been reached. Well 6406/2-4 S R was re-entered 12 November at depth 4534 m (4446 m TVD), below the 9 5/8" casing shoe in the initial well, and drilled to final TD at 5080 m (4969 m TVD) in Early Jurassic Åre Formation sediments. The well bores were drilled with KCl mud / spud mud down to 1110 m, with KCl mud and "ANCO 208" glycol from 1110 m to 2260 m, and with oil based "ANCOVERT" mud from 2260 m to final TD.Down to Base Cretaceous Unconformity the stratigraphy was as expected, the prognosis matched the experienced stratigraphy well. Below ECU, 154 meters of Upper Jurassic shales were penetrated before the drilling had to be stopped. Prognosed thickness of the Upper Jurassic shales was 44 m TVD. High total gas was observed when drilling through the Cretaceous sandy intervals, the Lysing and Lange Formations, but shows were not described in the cuttings.Well 6406/2-4 S R proved gas/condensate bearing sandstones in the Garn, Tofte and Tilje formations in hydrocarbon-down-to situations. The well penetrated a large fault within the Garn Formation, so that the Ile Formation along with parts of the Garn, most of the Not, the entire Upper Ror and the upper part of the Tofte Formation were faulted out. This fault came on depth as prognosed, but it had considerably larger throw than expected. In addition to this large fault, two smaller faults were penetrated in the Tilje Formation. The quality of the reservoir formations was somewhat lower than expected due to the tectonic influence. In the Tofte Formation, the proximity to the fault has reduced reservoir quality due to fractures and higher degree of cementation. In the Tilje Formation, the best-developed reservoir zones were either fractured or faulted out. The Garn Formation was intensively brecciated and fractured. Disregarding the faults, thickness of the formations approximates those of the neighbouring wells on Lavrans. The Åre Formation gave some gas readings during drilling but was regarded to be without hydrocarbons. No cores were cut and no wire line samples taken in well bore 6406/2-4 S. In the re-entry a total of ten conventional cores with a total length of 325.1 m were drilled, of which 322.8 m (99.3 %) were recovered. The cores were cut in the Middle Jurassic.A total of seven fluid samples were acquired in 6406/2-4 S R. Two hydrocarbon samples were taken in the Tofte Formation at 4701 m, four hydrocarbon samples were taken in the Tilje Formation at 4945.2 m and 4881.0 m, and one water sample was acquired in the Tilje Formation at 4835 m. The mud contamination from base oil in the MDT hydrocarbon samples were analysed to be from 25 to 71 % by weight. Well 6406/2-4 S R was permanently abandoned on 15 February 1999 as a gas and condensate appraisal well.TestingThe Tilje (4874 m - 4904 m) and Tofte (4684 m - 4704 m) formations were production tested. Test 1 in the Tilje Formation produced 237000 m3 gas/day and 93 m3 condensate/day through a 9.53 mm choke. Test 2 in the Tofte Formation produced 42855 m3 gas/day and 18.1 m3 condensate/day through a 7.94 mm choke. The flow capacity of the test was severely influenced by fractures. -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom14615.04619.4[m ]24620.04627.9[m ]34692.04719.0[m ]44762.04818.2[m ]54818.54838.2[m ]64838.54857.2[m ]74857.24898.4[m ]84898.54936.1[m ]94939.14992.2[m ]104992.25046.5[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]320.0Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Core photos
Core photos 
4615-4619m4620-4625m4625-4694m4694-4699m4699-4704m
4704-4709m4709-4714m4714-4719m4762-4767m4767-4772m
4772-4777m4777-4782m4782-4787m4787-4792m4792-4797m
4797-4802m3802-4807m4807-4812m4812-4817m4817-4821m
3821-4826m4826-4831m4831-4836m4836-4840m4840-4845m
4845-4850m4850-4855m4855-4859m4859-4864m4864-4869m
4869-4874m4874-4879m4879-4884m4884-4889m4889-4894m
4894-4898m4898-4903m4903-4908m4908-4913m4913-4918m
4918-4923m4923-4928m4928-4933m4933-4937m4937-4942m
4942-4947m4947-4952m4952-4957m4957-4962m4962-4967m
4967-4872m4972-4977m4977-4982m4982-4987m4987-4992m
4992-4996m4996-5001m5001-5006m5006-5011m5011-5016m
5016-5021m5021-5026m5026-5031m5031-5036m5036-5041m
5041-5046m5046-5047m -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit29629615761946194624622462252825892589272529133485348535023565362343724388438844064612461246674671467147554950 -
Composite logs
Composite logs Document nameDocument formatDocument size [MB]pdf0.45 -
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].pdf32.80 -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.0490548749.52.0470446847.9Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.044.00031.00052.0002.050.00012.00051.000Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.0932370000.7730.78029252.018428550.7890.7432300 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]AIT IPLT45345081CMR ECS HNGS45345060MDT46195008MDT46434988MDT49454945MSCT46104764MWD - GR RES DIR45345080UBI DSI45345060VSP44005080 -
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 typeINTERM.9 5/84534.012 1/44534.01.87LOTLINER75080.08 1/25080.00.00LOT -
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]pdf0.28
