1 SRPC

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*Mark of Schlumberger

W E L L S E R V I C E S

Ultra Lightweight Cementing

Solutions

Overview and Case Studies

2 SRPC

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Depleted Reservoirs & Mature Fields Challenges

• Low Fracture gradient / High Permeability– ECD Management during drilling

phase– High risk of Lost Circulation

during cementing operations– Achieve required TOC or to

surface– Formation damage by cement

losses – production impairment

3 SRPC

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Depleted Reservoirs & Mature Fields Challenges

• Mud Removal• Production Quality Cement

– Must provide good, long term zonal isolation to maximize production

• Environmental compliance– Discharge on returns– OH excess requirements

4 SRPC

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Agenda

• System Application Ranges– Density Selection - LiteCRETE– Applications

• Ultra LiteCRETE• Success stories

– Ultra LiteCRETE– Coal-bed methane

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System Application Ranges

High DensityParticle

LightParticle

SandFlexibleAdditiveLight

Particle

7.5lb/gal

23lb/gal

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LiteCRETE – Density Selection

• Density Range: 7.5 –13 ppg– Ranges correspond to the

LiteCRETE portfolio of products

7.5

8.0

8.7

10.5

12.0

13.0

Ultra LiteCRETE

LiteCRETE

LiteCRETE HP

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Ultra LiteCRETE

• Density Range: 7.5 –8.7 ppg– The ultra lightweight

production quality cementing system

8.77.5 8.0

Ultra LiteCRETE

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Ultra LiteCRETE Features & Applications

• Extremely fractured or depleted formations

• Production liners/casing

• Cement to surface

– Production quality

• Density: 7.5 – 8.7 ppg

• Temperature: 80º - 450ºF

• Compressive > 1000 psi Ultra LiteCRETE

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Critical Water Zones

• Traditionally – 2 stages

• Redesigned casing program to eliminate stage tool

• Saved stage tool running time and associated risks

• No need for full production string

• Production liner instead

– Saved time and money

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Fibered LiteCRETECemNET

• Synergy with LiteCRETE systems– Rapid plugging of voids– Not reliant on high rheology– Related to PSD

• Value of fiber usage directly related to the high-solids content of LiteCRETE systems

A 1-mm slot plate plugged by fibered HPLW cement slurry (silica fiber concentration = 2.1 lbm/bbl), photgraphed from the bottom of the cell.

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Case Studies

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Cement to surfaceUAE

• Cementing a 7in Tie-Back Liner to surface– Inside perforated 9 5/8in

casing

– Well used as an injector

• Formations– UER (Um Raduma)

– Simsima

• Highly fractured formations• Communication

– between scab liner and perforations

• Objective:– Shut off perforations

and cement tie-back liner to surface

– Replace scab liner

– Recomplete the well as a single string dual injector

• Performance indicator– Get TOC above upper-

most perforations inside 7in x 9 5/8in annulus

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Cement to surfaceUAE

Schedule

• Spacer: 24m3 ONELOCK*

• LEAD: 46m3 Ultra LiteCRETE at 1.02 SG

• TAIL:14.3m3 Class G Cement at 1.9 SG

Results• Achieved good returns

after ZONELOCK and Ultra LiteCRETE

• 3.2m3 of slurry returned to service after treatment

• A positive pressure test was achieved on 7in x 9 5/8in annulus lap

*Mark of Schlumberger

LiteCRETE

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Complete LossesOffshore Mexico

• Used with Mexico Marine (Offshore Cantarell)– Fractured or vugular Paleocen, Cretacic and

Jurassic age carbonates– One of the most expensive problems while

drilling the production zone• PARTIAL TO TOTAL LOST CIRCULATION

• Permeability up to 5 Darcies• Frac gradient of 0.26 psi/ft

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Complete LossesOffshore Mexico

• During drilling 5 7/8” O.H. was drilled with NO RETURNS

– total of 8190m3 of 0.9 s.g. OBM

were lost from 2208 m to

2410m.

• Very good results previously obtained with LiteCRETE at 1.1 SG– decided to decrease further

down the density

• 0.98 SG LiteCRETE– selected as the best option to

isolate production interval from 2655 to 2705 m

• CS = 1650 psi @ 14 hrs• Displacement performed

with 0.9 SG OBM– During all the operation no

returns were observed

• Evaluation:– The pay interval that will be

exploited is from 2655 to 2705m

– CBT/USIT showed very good bond index going from 80% to 90%. This assured client of good pay-zone isolation

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OffshoreUAE

• Lost circulation common across Simsima and Umm El Radhuma formations

• Problems– Stage tool failure

– Corrosion

– Low TOC

• Very challenging to cement

• First time use• Utilized Ultra LiteCRETE

to gain correct TOC

• Successful cementing made possible with this system

• Based on results additional work now planned

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Ultra LiteCRETE Kuwait

• Leader in Ultra LiteCRETE jobs– 30 jobs at 0.9 SG YTD

• Loss circulation zones across Damman, 1st Eocene and Maestrichian formations

• Primary Objective– Circulate cement to surface in

a single stage providing zonal isolation and casing support

– 100% OH Excess

• Results– Saved $40k per well, now a

standard system

– Eliminated the need for costly stage tools and wasted rig time between stages, cement to surface in one go!

– No need for multiple top out jobs to bring cement to surface

– No costly workover operations

– Proposed for steam injection wells

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Coal-Bed Methane CementingLiteCRETE CBM

• Production Quality Cement to surface - even if the well won’t support a column of water!

LiteCRETE

CemNET:Fibrous

material forms a mat

at the fracture opening

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Summary

• System Application Ranges– Density Selection - LiteCRETE– Applications

• Ultra LiteCRETE• Success stories

– Ultra LiteCRETE– Coal-bed methane

20 SRPC

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Questions and Feedback

What do you think…..?