DwC Brochure.pdf

8/10/2019 DwC Brochure.pdf

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™Drilling-with-Casing (DwC ) andDrilling-with-Liner (DwL ) Systems™

Increases drilling efficiency and reduces risk exposure by removingthe need to trip pipe and bottom-hole assembly components.

Making Trouble Zones Comfort Zones





3© 2005-2006 Weatherford. All rights reserved.

DwC Benefits

Faster and More EfficientThan Conventional Drilling

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Reduces flat time in the drillingcurve and minimizes downholetrouble time (fighting lostcirculation or wellbore instability).

Speeds drillingprograms—typically by 30percent or more—by reducingdownhole trouble time andminimizing drillpipe and wirelinetripping and associatedcirculating hours.

Provides superior hole cleaningwith almost continual circulation(uninterrupted by tripping),mono-diameter annular geometryand higher annular velocities.

Enables lower mudweights—thus lower costs—byeliminating the trip marginbecause no trip out of the hole is

required. High borehole qualityand the equivalent circulatingdensity (ECD) effect also helpsto hold back the formation.

Reduces torque, drag and holecleaning problems, and improveshole quality. Avoids drillpipe key-seating and other stuck pipeissues and provides a stifferdrillstring.

Creates a less tortuous and moreconcentric wellbore, potentiallyenhancing cement quality.

Reduces borehole exposure toformation and completiondamage.

Aids in running casing stringsand liners completely to bottomin difficult borehole conditions.

Reduced Drilling Risks Compared toConventional Drilling

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Reduces well control incidents by limiting drillpipe tripping (swab/surge)and related hazards.

Isolates shallow gas, water and thief zones.

Mitigates borehole instability issues with simultaneous drilling andcasing.

Reduces open-hole risk exposure and associated drilling problems.

Requires fewer personnel on the rig floor, reducing risk exposure.

Improved Cementing Compared to Conventional Drilling

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Allows cementing to begin almost immediately upon reaching totaldepth, as DwC technology keeps the casing on or near the bottom.

Enhances cementing integrity and quality, as DwC technology allowscontinual circulation (uninterrupted by tripping) until cementing begins.

Optimizes cement volume and bonding by the high-quality, near-gaugeborehole, helping avoid channeling.

™Drilling-with-Casing (DwC ) and™Drilling-with-Liner (DwL ) Systems



Weatherford products and services are subject to the Company’s standard terms and conditions,available on request or at www.weatherford.com. For more information contact an authorizedWeatherford representative. Unless noted otherwise, trademarks and service marks herein are theproperty of Weatherford. Specifications are subject to change without notice. Weatherford sells itsproducts and services in accordance with the terms and conditions set forth in the applicablecontract between Weatherford and the client.

515 Post Oak Blvd., Suite 600Houston, Texas 77027 USATel: 713-693-4000www.weatherford.com

© 2005-2006 Weatherford. All rights reserved. Brochure 3708.01

Ensuring Success from Top Drive to™DrillShoe Assembly

1Top drive

Pup joint

Kelly valve

Pump-insub

Cross oversub

DwCinternal

drivecasing tool

(ICDT)

Casing string

Double valve floatcollar (placed asdesired for optimumshoe track)

DrillShoe tool –drillable casing bitseliminate the time-intensive process ofretrieving bitbottomholeassemblies required

with other methodsof casing drilling.Once the bottomholecasing setting depthis achieved, cementoperations can beginalmost immediately.

The basic DwC system includes a drillable drill bit/casing shoe (our DrillShoe tool), a float collar, acentralizer/stabilizer, a drive system to transmit torquefrom the top drive to the casing string, and a top drive.

1The top drive is not a product of Weatherford.

Kelly valve

Significantreductions in drillingflat time arereflected in thischart, whichcompares a welldrilled with casingto a conventionallydrilled offset well.The DwC job wasexecuted from asemisubmersible,using a surfaceblowout prevention(BOP) system. Anestimated time

savings of 80percent was reported. The cost savings was US$1 million,60 percent of which was attributed to the use of the surfaceBOP system and 40 percent to Weatherford's DwC technology.

Days from Spud

1,000

900

800

700

600

500

400

300

200

100

0

0 6 1611

DwC Well

Offset M e a s u r e d D e p t h ( m )

DwC Well vs. OffsetConventional

Drilling-with-Liner(DwL) System:In addition to our DwC system, we offer acompanion suite ofproducts and servicessuch as our DwL system, which providegood insurance whendrilling in troublezones. DwL is a veryefficient way to drillthrough, or top setcasing into,troublesome intervalsincluding excessivecavings, swelling, ormobile formations

™Drilling-with-Casing (DwC ) and™Drilling-with-Liner (DwL ) Systems

Documents

DwC Brochure.pdf