GRID FM

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• General information

  General information

  Attribute	Value
  Lithostrat. unit The lithostratigraphic unit's official name.	GRID FM
  NPDID lithostrat. unit Norwegian Offshore Directorate's unique id for lithostratigraphic units.	53
  Level Indicates the lithostratigraphic unit's level. Legal values: GROUP, FORMATION, MEMBER.	FORMATION
  Lithostrat. unit, parent The parent lithostratigraphic unit's official name. See also level. Will be empty if Level = GROUP.	HORDALAND GP

• Level below

  Level below

  Lithostrat. unit

• Description

  Grid Formation
  
  Name

  Named after a female giant in Norse mythology, who was one of the wives of Odin.

  Well type section

  Norwegian well 15/3-3 from 1840 m to 1470 m, coordinates N 58°52'31.25", E 01°46'46.24" (Fig 5.64) . No cores.

  Well reference sections

  Norwegian well 24/12-1 from 1660 m to 1502 m, coordinates N 59°02'29.80", E 01°52'57.93" (Fig 5.61) . No cores. Norwegian well 24/12-2 from 1397 m to 1282 m, coordinates N 59°12'00.75", E 01°52'53.34" (Fig 5.65) . No cores.

  Thickness

  In wells 24/12-1 and 24/12-2 it is 158 m and 115 m, respectively.

  Lithology

  The formation consists of sandstones with interbeds of claystone and siltstone. The sandstones often have a massive, "blocky", appearance as illustrated by type well 15/3-3 (Fig 5.64) . Individual sandstone beds show little, or no evidence of fining-upwards or coarsening- upwards. The sandstones are very fine to fine, sometimes medium to coarse. Sorting is generally moderate to good. Traces of mica, pyrite, glauconite and fossil fragments are common. A higher argillaceous content is found in distal areas. Well 24/12-1 illustrates the interfingering of thicker claystone units of the Hordaland Group with the Grid Formation (Fig 5.61) . Further subdivision may be possible in the future (see Remarks).

  Basal stratotype

  The lower boundary shows a decrease in gamma-ray response and an increase in velocity from the Hordaland Group into the sandstones of the Grid Formation (Fig 5.64) .

  Characteristics of the upper boundary

  The upper boundary is characterised by an increase in gamma-ray readings and a decrease in velocity from the sandstones of the Grid Formation into the clay-stones of the Hordaland Group (Fig 5.64) .

  Distribution

  The sandstones were probably derived from the East Shetland Platform and the formation is recognised in the Viking Graben area between 58°30'N and approximately 60°30'N (Fig 5.66) . A depocentre lies in Norwegian block 15/3 where the formation reaches a thickness of nearly 400 m. It thins eastwards and is not penetrated by wells on the Utsira High. It has been identified in some wells in the Oseberg area. In the Viking Graben north of 61° N, several sandstone bodies occur in the Hordaland Group at the same level, but it is uncertain whether they belong to the Grid Formation.

  Age

  Middle to Late Eocene, but wells 25/6-1 and 24/12-2 have given an Early Oligocene age.

  Depositional environment

  The formation is thought to have been deposited in an open marine environment during a regressive period. An eustatic fall in sea level in the Late Eocene is indicated by Haq et al. (1987).

  Remarks

  The formation comprises a series of sand bodies which interfinger with claystones. There is a considerable increase in thickness from less than 200 m north of 59° N (e.g. wells 24/12-1 and 24/12-2 ) to nearly 400 m south of 59° N (e.g. well 15/3-3 ). This is not due to a general increase in thickness, but rather to sand deposition having started earlier in the south. This could give grounds for erecting two formal units, a lower one confined to the area south of 59° N and probably of Middle Eocene age, and an upper one. In some areas the lower unit is separated from the upper one by a sequence of claystones which is referred to informally as the Belton member in the UK sector. However, lithological uniformity renders such subdivision impractical at present.

  Source

  • Isaksen, D. and Tonstad, K. (eds.) 1989: A revised Cretaceous and Tertiary lithostratigraphic nomenclature for the Norwegian North Sea. NPD-Bulletin No. 5, 59 pp.

• Wellbores penetrating

  Wellbores penetrating

  Wellbore name	Wellbore completion date	Top depth [m]	Bottom depth [m]
  15/2-1	24.02.1982	1428	1824
  15/3-1 S	06.07.1975	1460	2147
  15/3-2	24.01.1977	1402	1617
  15/3-2	24.01.1977	1752	1775
  15/3-2 R	27.11.1977	1402	1617
  15/3-2 R	27.11.1977	1752	1775
  15/3-3	09.08.1979	1470	2176
  15/3-4	30.03.1982	1635	2258
  15/3-5	13.05.1984	1596	2236
  15/3-6	05.01.1999	1560	1850
  15/3-6	05.01.1999	1978	2015
  15/3-7	01.09.2001	1476	1850
  15/3-8	11.04.2006	1448	1792
  15/3-9	13.08.2010	1521	2209
  15/3-11	09.08.2018	1639	2252
  15/3-12 S	20.01.2020	1726	2254
  15/5-3	07.12.1980	1774	2055
  15/5-5	05.10.1995	1479	1807
  15/5-6	16.07.1997	1539	1839
  15/5-7	07.09.2008	1732	2110
  15/5-7 A	13.10.2008	1732	2110
  15/6-2 R	01.08.1974	1746	2112
  15/6-3	19.12.1974	1792	2142
  15/6-4	16.08.1976	1718	2174
  15/6-5	29.11.1977	1891	2239
  15/6-6	09.06.1982	1917	1971
  15/6-7	08.06.1993	1836	2108
  15/6-8 A	18.04.1997	1811	2086
  15/6-8 S	05.04.1997	1811	2037
  15/6-9 A	13.06.2007	1857	2020
  15/6-9 B	23.07.2007	1857	2020
  15/6-9 S	27.05.2007	1857	2020
  15/6-10	06.04.2009	1746	2059
  15/6-11 A	13.03.2011	1748	2109
  15/6-11 S	19.12.2010	1748	2110
  15/6-12	09.02.2011	1715	2191
  15/6-13	15.05.2015	1725	1988
  15/6-13 A	03.06.2015	1725	1988
  15/6-13 B	29.06.2015	1725	1988
  15/6-15	02.06.2019	1812	2035
  15/6-16 S	28.06.2019	1635	1979
  15/8-1	07.01.1982	1926	2225
  15/8-2	21.10.2011	1898	2312
  15/9-1	30.05.1977	1808	2131
  15/9-10	07.11.1981	2049	2079
  15/9-19 A	09.11.1997	2778	2802
  15/9-19 B	02.02.1998	2782	2832
  15/9-19 S	31.01.1993	3008	3240
  15/9-19 SR	29.04.1993	3008	3240
  15/9-19 SR2	25.07.1997	3011	3243
  15/9-21 S	23.05.1998	2447	2481
  15/9-22	13.03.2006	1975	2236
  15/12-1	06.09.1975	2256	2277
  15/12-3	22.12.1980	2076	2106
  15/12-11 S	19.05.1997	2270	2309
  15/12-18 S	07.11.2007	2250	2274
  15/12-23	29.05.2010	1212	1283
  15/12-23 A	18.07.2010	1212	1279
  16/1-1	10.12.1967	1854	1942
  16/1-2	07.08.1976	1660	1730
  16/1-3	27.09.1982	1610	1760
  16/1-3	27.09.1982	1834	1893
  16/1-4	13.04.1993	1539	1556
  16/1-4	13.04.1993	1584	1626
  16/1-5	21.11.1998	1617	1733
  16/1-5 A	06.12.1998	1652	1798
  16/1-6 A	21.06.2003	1530	1553
  16/1-6 A	21.06.2003	1629	1638
  16/1-6 A	21.06.2003	1742	1757
  16/1-6 S	07.06.2003	1490	1550
  16/1-6 S	07.06.2003	1597	1602
  16/1-6 S	07.06.2003	1672	1685
  16/1-7	28.05.2004	1631	1723
  16/1-7	28.05.2004	1782	1820
  16/1-7	28.05.2004	1862	1922
  16/1-8	13.11.2007	1556	1713
  16/1-8 R	10.10.2009	1556	1713
  16/1-9	22.04.2008	1598	1632
  16/1-9	22.04.2008	1693	1793
  16/1-10	05.02.2009	1494	1734
  16/1-11	26.04.2010	1609	1738
  16/1-11 A	09.05.2010	1609	1738
  16/1-12	08.09.2009	1633	1661
  16/1-13	21.01.2010	1467	1764
  16/1-14	30.11.2010	1607	1798
  16/1-15	05.04.2011	1553	1642
  16/1-15 A	13.05.2011	1598	1729
  16/1-16	07.12.2012	1633	1731
  16/1-16 A	01.01.2013	1633	1731
  16/1-18	14.05.2014	1588	1646
  16/1-19 S	25.10.2013	1501	1727
  16/1-20 A	21.10.2013	1772	1937
  16/1-21 A	20.04.2015	1811	2094
  16/1-21 S	03.03.2015	1664	1730
  16/1-21 S	03.03.2015	1759	1808
  16/1-22 A	04.06.2015	1623	1835
  16/1-22 B	14.06.2015	1621	1826
  16/1-22 S	27.05.2015	1627	2084
  16/1-23 S	25.08.2015	1621	1750
  16/1-24	16.03.2015	1666	1747
  16/1-25 S	26.12.2015	1704	1788
  16/1-26 A	24.04.2016	2368	2560
  16/1-26 S	14.04.2016	2368	2560
  16/1-27	11.04.2017	1562	1836
  16/1-28 S	23.08.2018	1626	1704
  16/1-29 S	03.06.2018	1419	1561
  16/1-30 A	19.07.2019	1440	1550
  16/1-30 S	01.07.2019	1442	1453
  16/1-31 S	10.05.2019	1604	1649
  16/1-33 S	05.08.2020	1599	1695
  16/1-34 A	15.09.2021	1692	1743
  16/1-34 S	31.07.2021	1693	1786
  16/1-35 S	28.02.2023	1676	1827
  16/2-3	28.09.2007	1251	1267
  16/2-4	15.12.2007	1243	1325
  16/2-5	13.05.2009	1192	1242
  16/2-5	13.05.2009	1287	1305
  16/2-9 S	24.09.2011	1197	1241
  16/2-20 A	16.02.2014	1690	1729
  16/4-2	29.07.1990	1913	2001
  16/4-3	24.12.2000	1823	1880
  16/4-4	23.03.2007	1897	1925
  16/4-7	21.08.2013	1859	1893
  16/4-9 S	16.08.2015	1663	1670
  16/4-9 S	16.08.2015	1705	1708
  16/4-10	07.03.2016	1880	2059
  16/4-12	08.10.2021	1665	1716
  16/4-13 S	10.04.2021	1702	1759
  16/7-10	13.09.2011	1951	2002
  24/6-1	25.08.1985	1263	1295
  24/6-2	08.07.1998	1183	1279
  24/6-4	02.06.2003	1148	1301
  24/9-1	03.07.1976	1131	1264
  24/9-1	03.07.1976	1358	1420
  24/9-3	15.04.1981	1201	1400
  24/9-4	17.06.1991	1067	1243
  24/9-4	17.06.1991	1332	1371
  24/9-5	26.01.1994	1203	1255
  24/9-5	26.01.1994	1294	1309
  24/9-6	07.03.1994	1158	1271
  24/9-6	07.03.1994	1323	1350
  24/9-7	25.03.2004	1149	1268
  24/9-7	25.03.2004	1305	1329
  24/9-7 A	29.03.2004	1149	1268
  24/9-7 A	29.03.2004	1305	1329
  24/9-7 B	02.04.2004	1151	1293
  24/9-7 B	02.04.2004	1327	1342
  24/9-7 C	11.04.2004	1152	1320
  24/9-7 C	11.04.2004	1371	1379
  24/9-7 C	11.04.2004	1407	1432
  24/9-8	04.09.2007	1230	1422
  24/9-9 A	15.10.2009	1124	1420
  24/9-9 B	25.10.2009	1121	1472
  24/9-9 S	07.10.2009	1117	1382
  24/9-10 A	20.02.2011	1248	2514
  24/9-10 S	02.02.2011	1248	2063
  24/9-11 S	13.06.2017	1093	1295
  24/9-12 A	25.02.2018	1120	1316
  24/9-12 S	08.02.2018	1120	1316
  24/9-13	16.07.2019	1104	1325
  24/9-13 A	29.07.2019	1104	1462
  24/9-14 A	13.03.2019	1128	1441
  24/9-14 S	22.02.2019	1028	1441
  24/9-15 A	24.04.2019	1318	1737
  24/9-15 S	18.04.2019	1318	1737
  24/12-1	09.04.1978	1502	1660
  24/12-1 R	14.08.1978	1502	1660
  24/12-2	21.01.1982	1282	1397
  24/12-3 S	29.07.1996	1373	1648
  24/12-4	14.09.2001	1211	1415
  24/12-5 S	21.12.2007	1316	1540
  24/12-6 S	20.12.2010	1356	1682
  25/1-11 A	14.05.2010	1509	1519
  25/1-11 R	26.04.2010	1479	1486
  25/2-1	21.09.1973	1424	1442
  25/2-4	20.10.1975	1213	1250
  25/2-6	15.11.1977	1403	1491
  25/2-8	01.08.1984	1015	1125
  25/2-10 S	19.03.1986	1732	1740
  25/2-10 SR	22.09.1987	1736	1744
  25/2-12	12.11.1988	1210	1255
  25/2-12	12.11.1988	1427	1440
  25/2-12 A	06.04.1989	1210	1255
  25/2-12 A	06.04.1989	1427	2042
  25/2-14	30.03.1991	1348	1425
  25/4-1	09.12.1972	1317	1330
  25/4-2	06.12.1973	1125	1200
  25/4-3	22.11.1974	1285	1363
  25/4-5	26.03.1981	1343	1372
  25/4-5	26.03.1981	993	1090
  25/4-6 S	24.08.1991	1272	1362
  25/4-6 SR	14.09.2003	1281	1371
  25/4-7	17.04.2003	1216	1320
  25/4-8	22.06.2003	1219	1305
  25/4-10 A	28.11.2009	1274	1387
  25/4-10 S	10.11.2009	1331	1527
  25/4-13 A	09.10.2018	1284	1325
  25/4-13 S	28.09.2018	1229	1328
  25/5-1	01.08.1987	1287	1345
  25/5-1 A	16.09.1987	1287	1345
  25/5-2	04.07.1989	1388	1448
  25/5-3	26.03.1990	1357	1373
  25/5-4	07.03.1991	1357	1387
  25/5-5	23.11.1995	1420	1433
  25/5-7	23.10.2010	1243	1314
  25/5-7	23.10.2010	1314	1407
  25/5-9	25.02.2014	1293	2036
  25/6-1	03.02.1986	1373	1395
  25/6-2	29.05.1992	1640	1682
  25/6-6 S	22.04.2019	1700	1711
  25/7-3	28.08.1995	1236	1299
  25/7-5	30.08.1997	1184	1324
  25/7-6	14.10.2000	1203	1305
  25/8-4	11.08.1992	1385	1390
  25/8-5 S	22.09.1994	1247	1303
  25/8-5 SR	03.08.1997	1247	1303
  25/8-6	27.06.1995	1185	1310
  25/8-7	12.08.1995	1484	1504
  25/8-8 A	11.10.1995	1291	1310
  25/8-8 B	24.10.1995	1313	1336
  25/8-8 S	24.09.1995	1318	1333
  25/8-9	28.01.1997	1301	1345
  25/8-9 A	14.02.1997	1292	1355
  25/8-11	02.12.1997	1129	1138
  25/8-12 A	19.06.1999	1155	1166
  25/8-12 S	09.06.1999	1150	1159
  25/8-16 A	23.05.2009	1227	1948
  25/8-16 S	13.05.2009	1224	1973
  25/8-17	29.10.2009	1224	1322
  25/8-17 A	15.11.2009	1221	1320
  25/8-19 A	19.03.2020	1123	1153
  25/8-19 S	30.12.2019	1128	1154
  25/8-20 B	28.05.2021	1185	1215
  25/8-20 C	13.06.2021	1190	1277
  25/8-20 S	10.05.2021	1197	1226
  25/8-21 S	20.06.2021	1021	1065
  25/9-3	20.09.2009	1286	1303
  25/9-4	27.02.2014	1322	1336
  25/9-4	27.02.2014	1575	1606
  25/10-3	13.09.1970	1401	1410
  25/10-4	18.01.1981	1418	1487
  25/10-4 R	13.06.1981	1418	1487
  25/10-5	17.07.1981	1399	1443
  25/10-6 S	22.03.1996	1456	1472
  25/10-6 S	22.03.1996	1491	1530
  25/10-7 S	08.06.1996	1526	1538
  25/10-7 S	08.06.1996	1553	1632
  25/10-8	07.04.1997	1551	1613
  25/10-8 A	27.04.1997	1737	1810
  25/10-9	27.07.2009	1504	1593
  25/10-10	02.04.2010	1505	1518
  25/10-11	10.08.2011	1487	2136
  25/10-12 S	18.01.2015	1597	1612
  25/10-13 S	19.06.2015	1452	1470
  25/10-14 S	17.01.2016	1540	1896
  25/10-15 S	02.08.2016	1564	1635
  25/10-16 A	09.08.2018	2221	2472
  25/10-16 B	18.08.2018	2221	2472
  25/10-16 C	26.08.2018	2221	2472
  25/10-16 S	30.07.2018	1602	1802
  25/10-17 S	10.02.2023	1632	1751
  25/11-6	01.10.1978	1462	1471
  25/11-11	18.03.1981	1218	1245
  25/11-13	29.05.1981	1442	1452
  25/11-15	25.12.1991	1491	1506
  25/11-16	24.07.1992	1521	1562
  25/11-18	24.10.1994	1437	1464
  25/11-24	29.03.2007	1530	1534
  25/11-25 A	10.03.2008	1637	1665
  25/11-25 S	15.02.2008	1648	1656
  25/11-28	25.09.2015	1520	1648
  25/11-29 S	13.05.2019	1588	1601
  26/4-1	17.07.1987	1682	1733
  29/3-1	15.09.1986	1580	1598
  29/6-1	09.05.1982	1320	1520
  29/9-1	24.02.1984	1303	1399
  30/2-4 S	09.08.2008	1595	1717
  30/3-1	07.09.1979	1661	1682
  30/3-1 R	26.04.1982	1635	1679
  30/3-4	12.06.1985	1350	1361
  30/3-4	12.06.1985	1453	1518
  30/3-4 R	18.11.2001	1352	1363
  30/3-4 R	18.11.2001	1455	1520
  30/3-9	01.07.2000	1613	1641
  30/3-10 S	29.04.2009	1650	1690
  30/3-11 S	09.09.2022	1353	1627
  30/4-1	14.05.1979	1648	1700
  30/5-1	29.07.1972	1704	1763
  30/5-2	21.12.1996	1487	1632
  30/6-28 S	29.03.2012	1342	1448
  30/7-3	25.10.1976	1994	2018
  30/7-3	25.10.1976	2062	2099
  30/7-7	01.07.1979	2126	2130
  30/8-1 S	01.03.1995	1417	1498
  30/8-1 SR	01.03.1996	1417	1498
  30/8-2	14.01.1996	1485	1757
  30/8-3	05.01.1998	1538	1558
  30/9-12	09.05.1991	1350	1380
  30/9-12 A	04.06.1991	1353	1385
  30/9-12 AR	11.07.2002	1357	1389
  30/9-13 S	11.10.1991	1160	1417
  30/9-13 S	11.10.1991	1515	1535
  30/9-13 S	11.10.1991	1684	1703
  30/9-13 SR	17.07.2002	1164	1421
  30/9-13 SR	17.07.2002	1519	1539
  30/9-13 SR	17.07.2002	1688	1707
  30/9-14	14.05.1993	1443	1478
  30/9-14	14.05.1993	1538	1571
  30/9-18	11.04.1995	1417	1522
  30/9-19	22.10.1998	1257	1380
  30/9-19 A	21.12.1998	1257	2119
  30/9-20 S	11.02.2002	1579	1613
  30/9-21 A	15.06.2008	1687	1758
  30/9-21 S	30.04.2008	1656	1727
  30/9-24	17.10.2009	1345	1559
  30/9-25	20.09.2013	1439	2069
  30/11-1	14.03.1975	1465	1953
  30/11-5	09.01.1997	1750	1757
  30/11-5	09.01.1997	1785	1850
  30/11-9 A	08.01.2014	1429	1481
  30/11-9 S	13.11.2013	1443	1480
  30/11-10	26.12.2014	1755	1837
  30/11-11 A	07.04.2016	1532	1634
  30/11-11 S	19.03.2016	1530	1583
  30/11-12 A	20.05.2016	1459	1462
  30/11-12 S	04.05.2016	1464	1467
  30/11-13	06.06.2016	1458	1475
  30/11-14	06.07.2016	1335	1479
  30/11-14 B	23.07.2016	1335	1479
  33/9-22 S	17.09.2017	1352	1373
  34/2-5 S	31.03.2018	1553	1573
  34/7-27	07.10.1998	1258	1294
  35/3-7 S	01.10.2009	909	1038
  35/7-1 S	15.08.2011	1514	1780
  35/8-5 S	20.07.2003	854	1100
  35/8-6 A	14.05.2016	1247	1442
  35/8-6 S	22.04.2016	1247	1442
  35/9-5	07.02.2010	670	860
  35/9-6 S	07.12.2010	790	989
  35/9-7	14.04.2012	1081	1108
  35/9-8	11.04.2013	1074	1108
  35/9-10 A	16.01.2014	1095	1112
  35/9-10 S	26.11.2013	1102	1181
  35/9-11 A	21.05.2014	834	965
  35/9-11 S	15.04.2014	834	965
  35/9-12 S	26.12.2014	854	1000
  35/10-1	16.01.1992	1203	1252
  35/10-2	22.08.1996	1258	1874
  35/10-3	14.07.1999	1247	1269
  35/12-6 A	30.06.2018	895	950
  6204/10-1	23.11.1995	685	710

• Wellbores with cores

  Wellbores with cores

  Wellbore name	Wellbore completion date	Core length [m]
  15/3-4	30.03.1982	5
  16/1-1	10.12.1967	10
  16/1-4	13.04.1993	25
  16/1-23 S	25.08.2015	9
  16/4-2	29.07.1990	6