500µm edited version of conference ppt

500µm

Edited version of conference ppt

STUDY DATABASE: Rock-Based Reservoir Geology

� New cyclostratigraphic correlation of all wells incorporating legacy

biostratigraphy data - providing a regional rock-based correlative framework

� New digital description & photography of all cores (~560 metres of core) providing high resolution (1:20 scale) colour graphical plots and exportable

lith/grain-size data

� New core & cuttings thin section petrography (15 key wells) combined with

legacy data. Also selected SEM/XRD analyseslegacy data. Also selected SEM/XRD analyses

� Rock type characterization of cuttings, providing analogue petrophysical data

in uncored intervals

� Construction of digital sedimentological logs (SEDlogs) for full drilled

succession in all wells – including interpreted depositional environments

� New SEAL rock analysis of representative seal horizons in 11 key wells

� ArcGIS database showing GDE maps for all sequences (Carboniferous to Late

Tertiary) – providing useful calibration and constraint of seismic-based

geological models in undrilled areas.


Seismic Line PW93-311 across the

northern boundary of Finnian’s Spur

SENW

REGIONAL CONTEXT

Integration of well data with structural framework

Basement-up reservoir description in all

wells (using cores, SWCs, cuttings tied to downhole logs)

METHODOLOGY: Fundamental Geology

New Correlative Framework (legacy

biostrat + new cyclostratigraphy)

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100

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0.000.100.200.300.400.500.600.700.800.901.00

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A/H

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Mercury Saturation, fraction of pore space

MERCURY INJECTION

ArcGIS GDE maps for each

mappable sequenceDigital entire

well SEDlogsSeal Rock Analysis

Digital Core Logs

New Digital

Core Photos

New & Legacy Petrography

Legacy

PetrophysicsEdited version of conference ppt

• Graphical full colour

displays at variable scales (1:20 plots in

thin-bedded

reservoirs)

• Lith and grain-size data in ascii format

for importing into

SEDIMENTOLOGY: New Digital Core Logs

for importing into

seismic/log software

• Integrated

stratigraphic surfaces/sequences

• Integrated poro-perm

• Facies codes and

colour-coded depositional

environments

Legacy core descriptions in hand-

drawn B/W paper formats, usually

1:40 or 1:50 scale (scanned images).

Difficult to extract grain-size,

lithology & depositional environment

data from these plots.New fully digital core descriptions allow full integration with

other geological well data sets & also permit detailed

representation of important mineralogical variations (e.g. formation damage-prone pyritic zones)


• Graphical full colour displays of full

drilled succession – bitmap and PDF formats (constructed by integration of

core, SWC & cuttings data with

downhole logs).

• Lith and grain-size data - exportable in ascii format for integration with

log/seismic models

SEDlogs for full drilled succession in each well

TE

RT

IAR

Y

Lithology &

grain-size

Bounding

surfaces

log/seismic models

• Integrated stratigraphy including colour

coded StratPacs and major bounding

surfaces

• Integrated mineralogy from cuttings

petrography

• Interpreted depositional environments

• ODM database- providing well to well

correlations & statistical lith/facies data

CR

ET

AC

EO

US

JU

RA

SS

IC

CARB

Interpreted

depositional

environments

Minerals from

SWC &

Cuttings

petrography

Core poro-

perm data


Standardized & Integrated ODM Database

CARBONIFEROUS –

� Well to well correlation panels for

each stratigraphic

package

� Thickness tables per sequenceCARBONIFEROUS –

LR JURASSIC

LOWER

CRETACEOUSUPPER

CRETACEOUS

sequence

� Lith & Depositional

Environ % Pie-charts

� Poro-perm cross-

plots coded by

Well/Sequence/Facies

HM

61%

MO

35%

S2

4%

Distribution of Lithofacies

in 35/8-1 Core 1

% Lithofacies(Core 2, example)

MJ

1%

MO/S2

9%

MS/S1

16%

S1/S1M

2%

S2

35%

S3

36%

S3G

0.77

Distribution of Lithofacies

in 35/18-1 Core 1% Lithofacies

(Core 1, example)


Black shales

Heterolithics

Medium sand

Fine sand

Shale

Access to legacy data and sample material was provided by the DCENR

Particular thanks is due to Michael Hanrahan for all his efforts in

providing well datasets and also access to the core and cuttings material.

Thanks also to Core Lab colleagues:

ALICE ROOKS, JOSEPH WHITING, LAURA STEEL,

SIMON GREENFIELD, STEPHEN POOLE, SABAT PRASETYO,

GUY COMFORT, CORNEL COSOVANU, MARTIN BARON

500µm edited version of conference ppt

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