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Las camisas protectoras o liners son sartas que no se extienden hasta la superficie y se cuelgan de

la anterior sarta de revestimiento. El propsito de esta sarta es prevenir problemas de perdida de

circulacin cuando se requieren altos pesos de lodo. Proporciona la misma proteccin que el

revestidor intermedio.

El sistema de liners de perforacin hace uso de liner como sarta de perforacin la cualnormalmente se instalara en el ltimo revestidor. Como herramienta de perforacin, puede ser

instalada cuando la sarta es atascada debido al colapso de las formaciones o en caso de altas

presiones diferenciales.

The Drilling Liner System makes use of the liner/casing as a drill string that would normally be set

at the casing point. As a drilling tool, it can be set when the string becomes stuck due to formation

collapse or severe differential pressure sticking.

Las tcnicasconvencionales de perforacin se vuelven intiles cuando ocurre una total perdida de

circulacin luego de que la broca perfora capas de rocas de alta presin en yacimientos

severamente agotados. La cada de presin resultante hace que los estratos colapsen y atasquen

la sarta de perforacin.

Conventional drilling techniques became impossible since a total loss of circulation occurred as

soon as the bit drilled through the highly pressured cap rock into the severely depleted reservoir.

The resulting drop of hydrostatic pressure usually causes the shale to collapse and stick the drill

string. The reduced hydrostatic head also induces flow from the shallower salt water sands.

Con el sistema de liners, el linerser colocado simultneamente cuando se perfora a la

profundidad de la formacin de baja presin. Aunque la prdida de lodo ocurre, el liner cumple

con la funcin de proteger el hoyo desnudo. Luego de haber cementado y cambiado el lodo, las

operaciones de perforacin vuelven a comenzar a profundidad de la formacin de baja presin

usando tcnicas convencionales.

With the Drilling Liner System, the liner will be set simultaneously when drilling into the low

pressure formation. Although the mud losses still occur, the liner is then already in place and

protects the borehole. After releasing the running tool, cementing and changing the mud, drilling

operations may resume in the low pressure formation using conventional drilling techniques.

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Sistema De Liner De Perforacin Dirigible

Incrementa la eficiencia en la perforacin.

HOJA DE DATOS

Statoil y Baker Hughes Inc., juntos, desarrollaron el primer sistema de liner de perforacindirigible, probado con xito en el mar del norte.

Statoil and Baker Hughes Incorporated jointly developed the worlds first steerable liner

while drilling system, successfully tested from the Brage platform in the Norwegian sectorof the North Sea.

Con sus experiencias y conocimientos combinados, estas compaas desarrollaron estainnovadora tecnologa para su aplicacin tanto en campos nuevos como maduros.

Working collaboratively with their combined experience and knowledge, the companiesdeveloped this innovative technology for applications in new and mature fields.

Elimina la necesidad de sacar la sarta de perforacion para instalar el revestidor.

Eliminatetheneedtopulldrillstringtoruncasing

Una operacin de perforacin y registros de perfiles de pozo preciso, con un liner instaladoen la sarta ahorra tiempo y costos minimizando el riesgo de colapso del hoyo y reduciendo

el tiempo no productivo. La adicin de la capacidad de ser dirigible ayuda a perforar pozoscon caractersticas complejas. Adems la evaluacin del pozo en tiempo real proporciona al

gelogo datos en tiempo real que le permite tomar decisiones rpidas mientras se perfora en

zonas difciles.

Precise drilling and logging of 3D well profiles with a liner attached directly to the

drillstring saves time and drilling costs by minimizing the risk of borehole collapse andreducing nonproductive time. The addition of rotary steerable capabilities helps drill

complex well profiles while continuously rotating. Additionally, modular formationevaluation technology allows geologists to make critical real-time decisions while drilling

through difficult zones.

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Por qu usar esta tecnologa, en qu nos beneficiaria?

Unsistema de liners permite la instalacin del liner mientras se perfora. El liner previene el colapso

del pozo causados por la variacinsbita de presin que puede ocurrir cuando hay prdida de

circulacin masiva.

The Drilling Liner system sets the liner while drilling and thus prevents hole collapse which can be

caused by sudden borehole pressure changes that can occur during massive lost circulation.

Una aplicacin tpica para esta tecnologa seria en casos donde se perfora una formacin con alta

presin seguida por otra formacin con una muy baja presin con respecto a la anterior.

Supongamos que no se instala un sistema de liner en una perforacin donde se encuentran

formaciones como las anteriores, entonces se presenta la perdida de lodo, la formacion colapsa y

sucede el inevitable atascamiento de la sarta.

A typical application for the Drilling Liner is therefore a wellbore featuring a formation with high

pore pressure, closely followed by another layer with significantly lower pressure. Normal drilling

operations usually run into trouble while drilling from the high pressure formations into the low

pressure layer. Severe mud losses with simcioultaneoushole collapse, kick and stuck pipe are the

common result (Fig. 1).

These circumstances occur now in Mobil's Arun field in North Sumatra, Indonesia. This formation

is a massive, permeable carbonate gas and condensate reservoir which has been extensively

developed by Mobil Oil during the last 18 years. The depleted limestone has become highly proneto lost circulation.

The drilling liner system has recently been used to repair 3 wells which failed due to casing

shearing. Failed wells are sidetracked through 9-5/8" casing with 8-1/2" hole. Conventional

directional drilling proceeds to a depth just above the reservoir with 16.8 ppg oil based mud

needed to overbalance a highly pressured salt water sand and stabilize pressured shales. The 7"

drilling liner is then used to drill from the high pressure environment into the depleted Arun

reservoir.

As the drilling liner penetrates the limestone, massive mud losses still occur, the shale collapses

and the liner becomes stuck. Since the liner is already in place, it protects the borehole. Regular

drilling operations may resume in the low pressure formation (Fig. 2) after the liner is cemented

and the mud is changed.

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Drilling Liner System components

Drilling Liner system components include the drilling liner Tool, the liner, the inner string and the

liner hanger.

Drilling Liner Tool. The drilling liner tool is run on the bottom of the entire drilling liner and serves

as the bit cutting structure necessary to drill. It rotates independently of the liner.