30/9-B-18
Export: PDF
-
General information
-
Wellbore history
GeneralWell 30/9-B-18 was drilled as a development well on the 30/9-1 Oseberg Discovery in the North Sea. It was drilled as a penetration well prior to the horizontal well 30/9-B-18 A. The objective was to accurately locate the oil/water contact in the Oseberg Formation and to give structural information and exact target depth for the horizontal section of the production well 30/9-B-18 A.The NSO-1 geochemical standard oil was produced from 30/9-B-18 A.Operations and resultsDevelopment well 30/9-B-18 was spudded on 10 June 1992. It was drilled from the Oseberg B platform to TD at 3980 m (2814 m TVD) m in the Early Jurassic Drake Formation. The target of the well was on the Oseberg Alpha Structure approximately 2.5 km south-east of the Oseberg B platform. Serious hole cleaning problems were evident throughout the 12 1/4" section, causing a sidetrack from 1448 m. The well was drilled with spud mud down to 1155 m, with ANCO 2000 mud from 1155 to 3342 m, and with oil based Safemul mud from 3342 m to TD.The well drilled through a 121 metres vertical section of the Brent Group, which is 10 metres more than prognosed, and the oil-water contact was established at 3878 m MD (2767 m TVD). Good shows were observed on the cores from the Oseberg Formation, otherwise no shows descriptions were reported from the well. RFT pressure points proved an 11 bar depleted oil gradient compared to the initial Oseberg-Rannoch-Etive gradient in the Alpha structure.Two cores were cut in succession from 3859 to 3903 m in the Oseberg Formation. The core-log depth shift is +2 m for both cores. The RFT was run on wireline to record pressure points in the Brent Group. No fluid sample was taken.The well is classified as observation well and was plugged on 25 September 1992.TestingNo drill stem test was performed. -
Cores at the Norwegian Offshore Directorate
Cores at the Norwegian Offshore Directorate Core sample numberCore sample - top depthCore sample - bottom depthCore sample depth - uom13859.03891.3[m ]23893.03903.2[m ]Cores at the Norwegian Offshore Directorate Total core sample length [m]42.5Cores at the Norwegian Offshore Directorate Cores available for sampling?YES -
Logs
Logs Log typeLog top depth [m]Log bottom depth [m]GCT1673275MWD - DG2831162MWD - DPR DG11623980PI LSS LDL CNL GR33383960RFT HP GR36883934VDL GR27003338VSP2503960 -
Lithostratigraphy
Lithostratigraphy Top depth [mMD RKB]Lithostrat. unit167167707886261426142735286830453062306232583258330936833683369538183825383139413941 -
Drilling mud
Drilling mud Depth MD [m]Mud weight [g/cm3]Visc. [mPa.s]Yield point [Pa]Mud typeDate measured2251.2319.08.5WATER BASED10.08.199211001.2530.016.5WATER BASED31.08.199211551.2518.08.5WATER BASED11.08.199211551.2528.021.0WATER BASED11.08.199211681.2515.016.5WATER BASED31.08.199212001.2511.014.5WATER BASED31.08.199214481.2530.026.0WATER BASED31.08.199216751.2631.028.5WATER BASED01.09.199217341.4837.021.5WATER BASED11.08.199217851.5448.022.0WATER BASED12.08.199218801.4641.033.0WATER BASED02.09.199218931.5040.031.5WATER BASED03.09.199219911.5550.029.0WATER BASED09.09.199223531.5438.018.5WATER BASED11.08.199223571.5443.030.5WATER BASED04.09.199224751.5442.029.0WATER BASED07.09.199225621.5439.023.5WATER BASED14.08.199226531.5568.035.5WATER BASED17.08.199226571.5441.026.5WATER BASED07.09.199227881.5444.031.0WATER BASED07.09.199230621.5445.025.5WATER BASED17.08.199231131.5446.022.0WATER BASED17.08.199231131.5558.031.0WATER BASED17.08.199231751.2044.010.5OIL BASED28.09.199231761.5552.027.5WATER BASED18.08.199232151.5443.026.0WATER BASED08.09.199232601.2044.010.5OIL BASED28.09.199232781.5554.030.0WATER BASED19.08.199233041.5547.020.0WATER BASED24.08.199233421.5447.021.5WATER BASED10.09.199233421.5429.07.0OIL BASED15.09.199234891.2034.07.5OIL BASED16.09.199234921.2040.07.5OIL BASED28.09.199236421.2037.07.5OIL BASED17.09.199237351.2036.07.0OIL BASED18.09.199238571.2135.09.0OIL BASED21.09.199238841.2131.06.5OIL BASED21.09.199238851.2036.06.5OIL BASED21.09.199239701.2039.07.0OIL BASED22.09.199239801.2132.07.5OIL BASED23.09.199239801.2038.08.5OIL BASED24.09.1992