Permeability Enhancement at Habanero EGS Projectiea-gia.org/.../10/Geodynamics-01309-IEA-GIA-Habanero-Stimulation.pdf · Habanero fault within seismic cloud View from the north showing

Permeability Enhancement at

Habanero EGS Project

PROGRESS UPDATE FOR IEA-GIA

SEPTEMBER 2013

Robert Hogarth

Habanero Wells

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Habanero Project Update

• Granite temperature of 241°C at 4,130m depth;

consistent with earlier well results

• Open flow tests achieved rates of ~38 kg/s

• Indications of >40 kg/s � Much higher than

previous wells flow tests of 25-30 kg/s

• Pilot Plant commissioned April 30; results meeting

or exceeding expectations in all key areas

• Circulating 17.6 kg/s in closed-loop (10 Sep 2013)

• Flowing temperature of 211°C and increasing

• Power station generating power to run brine pump,

auxiliaries and camp – excess capacity, but no load

available

Over the past 12 months Geodynamics has achieved

significant progress in its Habanero EGS Project

culminating in the commissioning of the 1 MWe Pilot

Plant in April.

Habanero 4 seismicity

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Plan view with

Habanero 1 at 0,0

Colour indicates time

of event;

Size indicates event

magnitude;

Seismicity from earlier

stimulations shown as

grey dots

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Habanero fault within seismic cloud

View from the north showing seismic cloud, top granite and wells

Habanero reservoir is an overthrust fault, dipping ~10° to the west

Truncated to the east by a reverse boundary fault

Stimulations of Habanero Producers

• Habanero 3 (drilled into seismic cloud from H01)–Short (local) stimulation with 2.2 ML water (no additives)

–Generated 475 seismic events around the well

–Productivity tripled post-stimulation

– k.h improved from ~1 D.m to ~3 D.m and skin reduced

• Habanero 4 (drilled into seismic cloud from H01)–Short (local) stimulation with 2.5 ML water (no additives)

–Generated 1,900+ seismic events around the well

–Productivity doubled post-stimulation

– k.h improved from ~5 D.m to ~10 D.m and skin reduced to zero

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Habanero Productivity Enhancement

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Stimulations of Habanero Injectors

• Habanero 1–Two massive stimulations with total 37 ML water (some NaCl for weight)

–Generated 40,000+ seismic events extending up to 1,950 m from well

– Injectivity remained low throughout at ~ 1 kg/s/MPa

–Steady improvement with continued injection in closed-loop mode

–Most likely explanation is mud damage in fault zone

• Habanero 4–One short and one massive stimulation with total 36 ML water

– Injectivity ~ 4.5 kg/s/MPa which is 3 times the best achieved at H01

–Generated 27,000+ seismic events extending up to 1,550 m from well

–Shows benefit of managing bottom hole pressure during drilling to avoid

mud losses into fractures/faults

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Habanero Injectivity Enhancement

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Lessons learned at Habanero

• Habanero reservoir is a fault which is critically stressed and prone to

slip, triggered by stimulation

• The fault was already hydraulically conductive, water saturated,

overpressured, and critically stressed when H01 was drilled

• Mud losses into the fault system were extremely damaging and must

be avoided

• Small volume (local) stimulations have delivered significant

productivity improvements

• Large volume (extended) stimulations have created a seismic cloud

of ~ 4 km2 area

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