16/1-15
Export: PDF
-
General information
-
Wellbore history
GeneralWell 16/1-15 was drilled on the western side of the Utsira High in the North Sea. The objective was to test Jurassic/Triassic sandstones prognosed at 1925 in the Tellus prospect north of the Luno Discovery. The Luno Discovery has later been officially named the Edvard Grieg Field. The Tellus prospect was separated from Luno by a fault zone trending NW SE.Operations and resultsWildcat well 16/1-15 was spudded with the semi-submersible installation Bredford Dolphin on 22 January 2011 and drilled to TD at 2150 m, 230 m into pre-Devonian basement rock. Due to possible shallow gas sands a precautionary 9 7/8" pilot hole was drilled down to 585 m. Only water filled sands were seen. Several incidents interrupted the progress where the most serious was a failed 20" casing cement job. The other incidents were related to the BOP and a stuck wire line string. The well was drilled with seawater and sweeps down to 585 m, and with Performadril mud from 585 m to TD.The well proved an oil column of 48 metres in a thin, Intra Åsgard Formation Sandstone directly overlying weathered and porous / fractured basement. Top of fractured basement was at 1920 m. No Triassic or Jurassic sediments were identified in the well. The Intra Åsgard Formation Sandstone is a chalk arenite, 2.7m thick, with excellent reservoir properties. An oil/water contact was established at approximately 1965 m (1940 m TVD MSL). The acquired pressure, geochemistry and PVT data supports communication between the Luno and Tellus Discoveries, making the Tellus area a northern extension of the Luno Discovery.Intermittent oil shows were described on core 1 immediately above the reservoir in a thin Hod Formation limestone. Below OWC shows were described on cores down to 1976 m. Further weak shows were described on cuttings down to 1997 m.A total of 61 meter core was recovered in four cores from 1915 to 1976 m (all core depths 2.15 m deeper than logger's depth) in the Hod Formation, Intra Åsgard Formation Sandstones and Basement. The overall recovery rate was 85.2%. Fluid sampling, water and oil, was performed using an extra-large diameter MDT-probe and dual packer. Samples were taken in the oil bearing zone at 1918.99 m, 1921.47 m, 1923.81 m, 1932.96 m,1937.23 m, 1952.43 m, 1959.62 m, and 1967.04 m. A water sample was taken at 2030.52 m. The oil samples show an under saturated light oil similar to the oil found in the Luno Field. The typical GOR from the MDT samples was 125 Sm3/Sm3, the oil density was 0.72 g/cm3 and the gas gravity was 0.95 (air=1).The well was plugged back to the 20" casing shoe on 5 April 2011 and a sidetrack 16/1-15 A was prepared. Well 16/1-15 is classified as an oil appraisal.TestingTwo drill stem tests were performed.DST 1 tested the interval 1926 to 1960 m in the basement. After a slow initial production, the perforations were cleaned up and the well produced with a continuous flow to surface with an oil-rate of 105 sm3/d on a 40/64" choke and a bottom-hole pressure of 56.6 bar. No water was produced. This was the first successful full-scale production test of a reservoir consisting of cracked and porous bedrock on the Norwegian Continental Shelf.DST 2 tested the interval 1917 to 1920 m in the Intra Åsgard Formation Sandstone. The main flow produced 470 sm3/d on a 36/64" choke with a bottom-hole pressure of 179.7 bar. No water was produced. The average GOR was 90 Sm3/Sm3. The maximum temperature at reference depth 1916.9 m was 84.5 deg C. -
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]590.002150.28 -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom11915.01931.2[m ]21931.21937.1[m ]31946.01960.1[m ]41960.31976.2[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]52.1Cores 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 availableDST0.000.00YESMDT2067.800.00OIL07.05.2011 - 00:00NO -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit1367748709449441189155316421766176617781800187918891889190619131915191519171920 -
Drill stem tests (DST)
Drill stem tests (DST) Test numberFrom depth MD
[m]To depth MD
[m]Choke size
[mm]1.01926196015.82.01917192015.8Drill stem tests (DST) Test numberFinal shut-in pressure
[MPa]Final flow pressure
[MPa]Bottom hole pressure
[MPa]Downhole temperature
[°C]1.02.0Drill stem tests (DST) Test numberOil
[Sm3/day]Gas
[Sm3/day]Oil density
[g/cm3]Gas grav. rel.airGOR
[m3/m3]1.01052.0620 -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]CMR XPT EDTC18722146FMI PPC MSIP PPC ECRD LEH QT14661872FMI PPC MSIP PPC ECRD LEH QT18722149HRLA PEX ECS HNGS18722144MDT GR LEH QT18722149MRX LEH QT18722149MWD LWD - GR RES DEN NEU AC PWD5572147MWD LWD - GR RES PWD DIR131582VSP GR1362085 -
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 typeCONDUCTOR30214.036214.00.00LOTSURF.COND.20576.026585.01.70LOTPILOT HOLE585.09 7/8585.00.00LOTINTERM.9 5/81874.012 1/41880.01.91LOTLINER72148.08 1/22150.00.00LOT -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured5171.3516.0Polymer Mud5851.2927.0PERFORMADRIL5851.3030.0PERFORMADRIL5851.3030.0Performadril WBM6191.3027.0PERFORMADRIL6351.3516.0Polymer Mud18801.3541.0PERFORMADRIL19141.2029.0PERFORMADRIL19311.2027.0PERFORMADRIL19391.2026.0PERFORMADRIL19601.2026.0PERFORMADRIL19761.2027.0PERFORMADRIL21501.20sodium chloride brine21501.2029.0PERFORMADRIL -
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