Shallow gas
Bright opportunities in the Dutch offshore
For questions contact info@nlog.nl or exploration@ebn.nl
Seismic data in the northern Dutch offshore shows many shallow amplitude anomalies, often indicating the presence of gas.
Miocene-Pleistocene unconsolidated sands form reservoirs (300-800 m depth), sealed by intercalating clays. Traps are generally low relief anticlines formed by underlying salt domes.
Reservoir properties
** Based on fields currently in production
• Expected ultimate recovery around 70 %
• Porosities range between 20-25 %
• Good to excellent permeability (100-500 mD)
Why explore for shallow gas?
• 8 discovered fields of which 4 are currently successfully producing.
• Production rates of 3 million Nm³/day have been achieved in the A12-FA field, making it one of the best producing gas fields in the Netherlands.
• Significant additional potential: many shallow leads identified.
-1200-1000-800-600-400
0 500m
Sand 5 Sand 6 Sand 7 Sand 3
Sand 8 Sand 4
MMU
F07-01
Main target
W Z3FUG2011A (Courtesy Spectrum) N
TWT (ms)
GR
Lead F12- Pliocene Lead
F07/F10- P-01
Licence Open acreage
Seismic data 3D coverage, seismic data in public domain
Seismic response Amplitude anomaly conformable to structure, flat-spot, push-down effect and attenuation
Structure 4-way dip closure
Thickness ~ 50 m (net-to-gross: 85 %) Porosity > 25 %
Gas saturation 60 %
GIIP 0.5 – 0.8 – 1.1 bcm (P90-P50-P10)
Licence Mainly open acreage
Seismic data 3D multiclient survey (Spectrum, 2011)
Seismic response 8 stacked amplitude anomalies of which 2 major bright spots and velocity push-down
Structure Fault-dip closure
Thickness 2 layers, 10 – 20 m each
GIIP 1.0 - 2.5 - 5 bcm (P90-P50-P10)
Information from neighbouring wells F07-01 drilled the edge of the lead – it has gas shows between 300-1000 m
Lead F12-Pliocene Lead F07/F10-P1
-700 -700 -700
-700 -700 -700
-675 -675
-675 -675 -675
-675 -675
-675
-675 -675 -675
-650 -650
-650 -650
-650 -650 -650
-625 -625
-625 -625
-625
-625 -625
-625 -625
-625 -625
-600 -600 -600 -600
-600 -600 -600
-600
-575 -575
-575 -575 -575 -575
-550 -550
-550 -550
-550 -550
-675 -725
-725
-650
-650 -650 -625
-625 -725
-725 -750
-600 -600
-700 -650
-650
-600
-600
-600 -575
-600
-600
-575
-625 -550
-625
F12-02-S1
0 500m -1200
-1000-800-600-400-200
0 500m
F12-02-S1
TWT
SW Z3WES2003A SE
GR -700
-700 -700
-700 -700 -700
-675 -675
-675 -675 -675
-675 -675
-675
-675 -675 -675
-650 -650
-650 -650
-650 -650 -650
-625 -625
-625 -625
-625
-625 -625
-625 -625
-625 -625
-600 -600 -600 -600
-600 -600 -600
-600
-575 -575
-575 -575
-575 -575
-550 -550
-550 -550
-550 -550
-675 -725
-725
-650
-650 -650 -625
-625 -725
-725 -750
-600 -600
-700 -650
-650
-600
-600
-600 -575
-600
-600
-575
-625 -550
-625
F12-02-S1
0 500m -1200
-1000-800-600-400-200
0 500m
F12-02-S1
TWT
SW Z3WES2003A SE
GR
-1200-1000-800-600-400
0 500m
Sand 5 Sand 6 Sand 7 Sand 3
Sand 8 Sand 4
MMU
F07-01
Main target
W Z3FUG2011A (Courtesy Spectrum) N
TWT (ms)
GR 100 ms
