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High-Altitude Geothermal Operations in Chile

Cap-and-Trade for California34th Annual Meeting Highlights

High-Altitude Geothermal Operations in Chile

Cap-and-Trade for California34th Annual Meeting Highlights

G E O T H E R M A L R E S O U R C E S C O U N C I L

Bulletin

P R S R T F I R S T C L A S S U S P O S T A G E

P A I D P E R M I T # 1 6 9 8

S A C R A M E N T O , C A

Vol. 39, No. 5September/October 2010

G E O T H E R M A L R E S O U R C E S C O U N C I L


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OOver the last four years increasing interest in geothermal energy in Chile hasculminated in the recent full scale exploration drilling in the northern high altituderegions. The drilling rig selected for the highest area, Apacheta, at 4700-4800 m belongsto Estrella International Energy Services Ltd. The Apacheta project is being developed ina joint-venture called Geotrmica del Norte S.A. (GDN), with Enel holding 51%, Chileanstate oil and gas company Empresa Nacional del Petroleo SA, or ENAP, holding 46%,and state copper-mining company Corporacin Nacional del Cobre, or Codelco holdingthe remaining 3%.

The physical operation is managed through the GeoEstrella; joint venture withGeotec, a Chilean company providing local support including camp, logistics andhigh altitude operations experience. The following article discusses the preparation,mobilization and operation of a large modern automated electrical drilling rig in theseharsh environmental conditions.

32 GRC Bulletin

The Challenges ofHigh-Altitude Geothermal

Operations in Chileby Gary Pidcock,

Vice President Business Development, Estrella

Looking down on the rig from the mountains. PHOTOS PROVIDED BY E STRELLA INTERNATIONAL E NERGY S ERVICES LTD .


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September/October 2010 33

PlanningFollowing a long period

of discussions with the

Operator, an advanced AC/VFD (Alternating Current/Variable Frequency Drive)rig was speci ed andaccepted for the explorationdrilling program atApacheta. Following theaward, GeoEstrella nalizedthe full scale plan to prepareand import the rig fromthe USA and receive and

manage it at the remote highaltitude site in Chile.

Rig PreparationAlthough less than two years old, Rig

1201 was given a complete overhaul of basicequipment to ensure a trouble-free operation.Several upgrades were made to the rig prior toshipment. Major capital additions such as a TopDrive were added to improve drilling e ciency.An Iron Roughneck and a self-elevating catwalkwere ed to improve safety and reduce manual

Geothermal in Chile

Road to the high-altitude remote sit e of the Apacheta rig.

labor at high altitude. An additional powergenerator was supplemented to compensate foralmost 50% loss due to the extreme altitude.

Other important modi cations were madeto accommodate the large diameter holes to bedrilled which are not normal for this type of rig.Furthermore, mud cooling and steam diversionsystems were added for full scale geothermal

drilling. Large BOPs(Blowout Preventors)were also purchased andthe rig was completely tand function tested in thecontrolled environment of arig-up yard in Texas beforedispatching the rig to thehigh altitude site in Chile.

MobilizationThe rig was carefully

broken down and packagedfor the long journey toNorthern Chile. A cargovessel was selected tosuit delivery timing and below deck stowage areato protect against seawater

Drilling bit at the well site.


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34 GRC Bulletin

Geothermal in Chile

damage. The shipment arrived in the Chilean portof Antifogasta in July 2009 and was o oaded tothe holding area from where it was trucked to the

rst location. Prior route planning was performedto ensure that there were no obstructions or risk ofimpact to the environment and local communities.Road repair machines and towing support wereprovided for the last 20 km as the conditionsdeteriorated and vehicle power was reducedabove 4000 m (13,120 ft). In less than two weeksthe complete rig plus critical spares, consumablesand auxiliary equipment were delivered to the rstlocation called Cerro Pabelln 1 at 4750 m (15,584 ft).

OperationsThe rst well was spudded (started) in August2009 and the rig drilled continuously completingfour wells with excellent performance. After thedrilling of each well, the rig was moved o andtesting was conducted by the operator. Followingthe rst major rig move from the port, three othermoves have been made to new locations in the areato drill the four deep holes.

Working continuously at this altitude withlarge equipment and large numbers of people has

been a signi cant challenge. The rig has reducedthe well times from the similar drilling projects in

the area by over 30%. This has been achieved bytaking a multifaceted approach to improvement.Some of the key areas where special a ention has been required are summarized as follows:

Health and Safety All personnel are given a pre-arrival

medical exam to check for altitude capa- bility. These tests examine blood, heartand lung conditions against set limits toensure that every worker is t to live andwork at this altitude.

Complete onsite medical service with24 hour availability ensures that there issupport at all times. Operations person-nel must report to onsite medical sta onarrival and regularly throughout theiremployment for blood pressure and oxy-gen counts.

Strict safety and job analysis techniquesare vigorously employed to ensure thataccidents are avoided. (To date, onesmall nger injury has been the only de -viation, however, several people had to

Top drive system.

Houston ret.


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Geothermal in Chile

be relocated to other job sites due to theirreaction to the altitude.)

Additional geothermal drilling train -

ing was provided to personnel who hadcome from the mining, oil and gas sec-tors. Personnel with experience in drill-ing large scale geothermal wells were brought in to assist with the supervisionand training.

Automation As mentioned in the Rig Preparation,

speci c equipment has been addedto the rig to minimize the manuallabour required. Included in this is theTop Drive system that has proven itsdurability in di cult drilling conditions,providing immense advantages for thedrilling function. The Iron Roughneck

and automatic catwalk have also beenvery valuable to the process.

Winterization

The rig has been specially ed withwind protection and a steam generatorto maintain heated working areas andnon-freezing conditions for pipework.This has proved invaluable in sub-zerotemperatures.

Spares and Consumables A large amount of spares and repair

equipment has been provided with therig to ensure that all equipment can runcontinuously. Spare parts can take as

Working continuously at this

altitude with large equipment and

large numbers of people has been a

signicant challenge.

Rig during ow testing operations.


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36 GRC Bulletin

long as a week for delivery,hence it is important thatonsite spares are carefullymanaged and maintained.

Base Camp With over 70 people

involved in the dailyoperation, GeoEstrellawas charged with theresponsibility to constructand operate a largecamp. A small camp wasconstructed at the wellsite, but a large complexwas installed at a lowerelevation of 3200 m about 40 minutes fromthe drilling locations. This provides moreliveable conditions for the work team toeat and sleep during their o -shift.

In general, operations have been conductedwithout any major problems. However, a severedust storm with more than 60 mph winds cameearly in the program and lasted for over 12 hours.

Geothermal in Chile

Communications were lost and activities wereshut down for almost a day. This acted as a goodreminder that the weather conditions at thisaltitude can be very severe and unpredictable.Work and travel in the area is hazardous andmany precautions are taken to prevent losses.

Many hurdles have been overcome andactivities are continuing on a daily basis to

Another view looking down from the mountains.

The weather

conditions at this

altitude can be

very severe and

unpredictable.

Flow testing.


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Geothermal in Chile

Workers muscle a wellbore pipe.

explore the geothermalassets in Northern Chilewith improved safety,

environmental control ande ciency using the Estrella1601 rig. Above all, thoseinvolved have gained agreat respect for the highaltitude and remote natureof the location. Planningand maintenance are vitalingredients to the successof the operation and manylessons have been learned.

Further improvements are being sought everydayto make the project acomplete success.

Gary Pidcock can be reached at gpidcock@estrella sp .com.

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