OR/17/037 Appendix 3 - Stratigraphic interpretations

From Earthwise
Jump to navigation Jump to search
Hannis, S, and Gent, C. 2017. Petrophysical interpretation of selected wells near Liverpool for the UK Geoenergy Observatories project. British Geological Survey Internal Report, OR/17/037.
Table 12    Two stratigraphic interpretations for the 2 wells studied and some nearby wells. All depths in metres
Borehole Kemira 1 Ince Marshes Morley Bridge Collinge Hale Lovel's Hall
Easting (m) 347586 346211 346181 341429 347077 347964
Northing (m) 376421 376439 371455 371112 383134 384935
Well top short name and explanation Interpreter NS CW NS CW NS CW NS CW NS CW NS CW
OD level Ordnance datum 8.99 8.99 14.33 17.22 14.8 9.79 12.8
Bromsgrove Bromsgrove Sandstone Formation 39 39
Sherwood Sherwood Sandstone Group 281 281
TSZ/?KDM Kidderminster Formation, conglomerate, pebble beds. 523 523 60 30 36
MM/Bold Manchester Marls Formation,
Bold Formation
618 618 22 165 91 100
CS Collyhurst Sandstone Formation 738 738 200 56 233 268 165
UVAR Variscan unconformity 1042 1042 272 526 848 557 344
Salop Salop Formation 200 526 848 870 30 344
Halesowen Halesowen Formation 1042 1042 272 398a 700 786b 930 1012c 557 NP 400
Etruria Etruria Formation (ETM) 668 Npe 599 NP
West C Westphalian C. CW lists Pennine Upper Coal Measures Formation (PUCM) 1221 NP 331 NP 675 700g
West B Westphalian B. CW lists Pennine Middle Coal Measures Formation (PMCM) 1248 NP 548 NP 969 1172 1169d 708 NP 741 795h
West A Westphalian A. CW lists Pennine Lower Coal Measures Formation (PLCM) 1401 1079 700 582 1078 1256 745 700f 933.1
MG Millstone Grit Group (MG) 1432 944.9 1124
CRAVEN GP Craven Group 1276
TD Total depth: deepest well penetration depth 1438 1438 1577 1577
WAWK Warwickshire Group (Calculated from depths West B-UVAR) 205.6 276 443 324 151 397
PT Permian-Triassic (Calculated from depths UVAR-top of log depth) 1003.4 272 504 788 527 308

Table notes: NS = Nigel Smith (partly chronostratigraphic), CW = Colin Waters (lithostratigraphic). Blue shading indicates the top of the log, yellow indicates a fault. Table notes by CW: a Base of red beds; b At marked change in GR log & appearance of red beds; c At big change in GR & LD logs & near transition to red beds; d Similar to NS interpretation; e Salop above reddened PMCM; f In part reddened; g Top PUCM at fault at 700 m- big change in GR log; h Top PMCM taken at 795 m at Cambriense MB. Base West B would be lower.


In addition to the two stratigraphic interpretations shown in Table 12, interpretations were also available from the company composite log plots or end of well reports. These data were considered during the reinterpretation presented in Table 12. They are listed below in Table 13 and shown, together with those from Table 12, in the output plots for this study (Figure 2 and Figure 9) for ease of comparison between the alternate interpretations.

Nigel Smith’s (NS) partly chronostratigraphic interpretations were selected for use during this study. Statistical summaries of the petrophysical results were output over these formation intervals. Note that the petrophysical interpretation software (IP) requires a formation top and base to be defined, within the available data range. This means the actual tops and bases reported in the tables throughout this report may show these slightly amended formation tops and bases from the NS version reported in Table 12. The values are summarised below in Table 14.

Table 13    Stratigraphy taken from the company composite logs or end of well reports. In addition, Coal seam depths were taken from the End of Well Report, these are shown in Table 10. For explanation of the formation codes, see Table 12

Kemira 1

Ince Marshes 1

Top Base Top Base
Company-reported stratigraphy SSG 24.4 1042.4 4.3 277.4
Halesowen 277.4 397.8
UCM 1042.4 1152.1 397.8 710.2
MCM 1152.1 1274.1 710.2 944.9
LCM 1274.1 1438.0
MG 944.9 1280.2
CRAVEN GROUP 1280.2 1577.0
Table 14    Stratigraphy loaded into interpretation software for this study and depth ranges of outputs. For explanation of the formation codes, see Table 12

Kemira 1

Ince Marshes 1

Top Base Top Base
Software outputs Plot format output: 25 1448 350 1460
Las data output: 30 1445 327 1458
Actual interp data interval: 32 1433 368 1452
Formation interval in software (modified from NS, Table 12) Bromsgrove 39 281
Sherwood 281 523
TSZ_or_KDM 523 618
MM_Bold 618 738
CS 738 1042
Halesowen 1042 1221
West C 1221 1248 368 548
West B 1248 1401 548 700
West A 1401 1433 700 945
MG 945 1452