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Stelinmatvic Industries Limited
Greenacre, Shoreditch, Taunton
Somerset TA3 7BL
Tel: 01823 275 975
28th ROUND OF UK OFFSHORE LICENSING
RELINQUISHMENT REPORT
FOR
LICENCE P2249
Block 47/5f
April 2017
SLMV
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LOCATION:
Licence P2249 part-block 47/5f lies adjacent to the Hyde gas field in the U.K.
Southern North Sea.
Block 47/5f lies north of the Hyde gas field and south of the Outer Silverpit Fault.
The Hyde and West Sole gas field share a common structure with a thick
Rotliegendes sandstone reservoir. Although the sandstone is continuous the
structure has been compartmentalised by slip-strike faults. A promote licence was
obtained in the 28th Round to determine whether there was down dip potential
beyond another transcurrent dislocation.
Fig. 1 Location of Block47/5f
Stelinmatvic
Block 47/5f
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SEISMIC and WELL CONTROL:
There are three overlapping 3D datasets covering most but not all of 47/5f.
(Fig.2) Loaded into a kingdom project revealed significant variations in data
quality and difficulty in any attempt to merge the separate surveys.
Published well data from the West Sole and Hyde fields was supplemented by
47/5-1, 2, 3 and traded data in blocks 48/1 & 2 all within the Sole Pit basin. These
demonstrated the basin-ward facies variations of the Lower Leman Sandstone
that control commercial prospectivity (Fig.3).
Fig. 2 3D data
sets loaded to
kingdom project
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ROTLIEGENDES (Lower Leman Sandstone) RESERVOIR:
The classic four depositional facies – aeolian, sheet sands, fluvial and sabkha are
present in the West Sole and Hyde gas fields (BPs Winter & King, Abbotts 25
Year Commemorative Volume 1991). Northward deterioration of the reservoiSr
into 47/5f is apparent in the well correlation across the gas fields.
SOURCE ROCKS:
The source of natural gas in the surrounding fields is the Upper Westphalian
“Coal Measures”. This ubiquitous source ‘cooked’ as the Sole Pit depositional
basin deepened through the Triassic and Jurassic. Gas migration occurred during
the regional inversion of the basin in mid Tertiary times as the 47/5f – Hyde –
West Sole anticline was created.
Fig.3 Lwr Leman
Sandstone facies
distribution
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SEAL:
Zechstein evaporites consistently cover the Lower Leman Sandstone Formation
and provide both an effective top seal and, in most cases, lateral seals at the
faulted edges of traps.
However, potential hydrocarbon indicators (HCIs) were observed within the
Zechstein, at Deckanhydrite/Plattendolomite level (Fig.4). These are associated
with Tertiary age faults, both normal and transcurrent, that offset the reservoir
and allowed leakage.
STRUCTURAL POTENTIAL:
The Carnelian Prospect (Fig. 5) is the only Rotliegendes structure on 47/5f. It is
a continuation of the Hyde–West Sole anticline with gentle dip to the northwest.
The overburden shows little variation such that the Time and Depth structure are
essential identical. The faulted southwest edge is the weak point. Here the fault
scissors upwards, causing the Carnelian structure to lie in a hanging wall.
Although the Zechstein halites remain thick and unbroken, the risk to effective
closure is strong. Third parties reviewing the data were dissuaded.
Figure 10
Plattendolomite
Bright Spot (HCI)
Fig.4 Possible
Gas leakage into
Plattendolomite
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REASON FOR RELINQUISHMENT:
The Promote period for licence P2249 was during the nadir of exploration in the
UK North Sea. Major companies were downsizing both staff and budgets.
Stelinmatvic were only able to attract the interest of smaller companies, none of
which had funds to support a firm drilling commitment.
Note: Transform Faults
offsetting the West Sole –
Hyde – Carnelian anticline.
Note: Yellow area
on SW side of
Carnelian is higher
than the Prospect.
Leakage could occur
in this direction.
Block 47/5f
Fig. 5 Carnelian Prospect north of Hyde gas field