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2014 BAKER HUGHES INCORPORATED. ALL RIGHTS RESERVED. TERMS AND CONDITIONS OF USE: BY ACCEPTING THIS DOCUMENT, THE RECIPIENT AGREES THAT THE DOCUMENT TOGETHER WITH ALL INFORMATION INCLUDED THEREIN IS THE
CONFIDENTIAL AND PROPRIETARY PROPERTY OF BAKER HUGHES INCORPORATED AND INCLUDES VALUABLE TRADE SECRETS AND/OR PROPRIETARY INF ORMATION OF BAKER HUGHES (COLLECTIVELY " INFORMATION"). BAKER HUGHES RETAINS ALL RIGHTS
UNDER COPYRIGHT LAWS AND TRADE SECRET LAWS OF THE UNITED STATES OF AMERICA AND OTHER COUNTRIES. THE RECIPIENT FURTHER AGREES TH AT THE DOCUMENT MAY NOT BE DISTRIBUTED, TRANSMITTED, COPIED OR REPRODUCED IN WHOLE OR
IN PART BY ANY MEANS, ELECTRONIC, MECHANICAL, OR OTHERWISE, WITHOUT THE EXPRESS PRIOR WRITTEN CONSENT OF BAKER HUGHES, AND MA Y NOT BE USED DIRECTLY OR INDIRECTLY IN ANY WAY DETRIMENTAL TO BAKER HUGHES INTEREST.
Fundamental of Cementing Services
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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What is Cementing ???
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What is Cementing ???
Oil well cementing is a process of mixing a slurry of cement and water and pumping it through the casing pipe into the annulus between the casing pipe and the drilled
hole.
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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Classifications of Cementing
Primary
Plug Method
Inner String Method
Stage Cementing
Secondary
Plug Back Cementing
Squeeze Cementing
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Objectives of Primary Cementing
Main objectives of primary cementing are :-
to support the casing pipe
to restrict the movement of formation fluids behind the casing
Cement also provides the following advantages :-
seal off zones of lost circulation (fractured formation)
protect the casing from shock loads during drilling deeper section
protect casing from corrosion
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Secondary Cementing
Purpose
Supplementing faulty primary
cement job
Repair casing defects
Stop loss circulation
during drilling
Shut off old perfs for
recompletion
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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API Classification of Cements
API provides specs covering eight classes of oil well cement designated as class A, B, C, D, E, F, G and H
The most common cement used in Malaysia??
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API Class G Cement
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API Class G Cement
Considered as basic cement; Can be modified by adding accelerator or retarder to suit wide range of depth and temperature (etc: deep wells, HPHT, lost circulation
zones)
Intended for use from surface up to 8000 ft depth
The recommended water to cement ratio according to API for class G cement is 44% (5 gal/sack or 18.9 ltr/sack)
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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Cement Additives
Shorten thickening time Accelerator
Lengthen thickening time Retarder
To ease mixability at surface Dispersant
Control amount of fluid loss to formation Fluid Loss Additive
Prevent foam production Defoamer
Prevent gas migration Gas Block
Increase slurry density Weighting Agent
Reduce slurry density (maintain strength) Light Weight Agent
Seal off lost circulation zone LCM
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The accelerator is used to reduce the thickening time and set the cement faster by accelerating the hydration of chemical compound of cement.
Common Accelerators used are Sodium Chloride, Calcium Cholride and Calcium Sulphate (gypsum)
CEMENT ADDITIVES Accelerator
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The retarder will increase the thickening time or prolong the time of cement to set.
It is necessary since more time is needed to place cement in deeper wells or to combat the thickening time reduction in high temperature environment
Common retarder are saturated NaCl, lignosulfonate and its derivatives, cellulose derivative and sugar derivatives
CEMENT ADDITIVES Retarder
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Primary effect to reduce viscosity. As a result, higher pumping rates are possible.
Secondary effect lengthens thickening time requirement
Common dispersants are synthetic sulfonate polymers, lignins
Dispersant
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Fluid loss additives are used to control amount of liquid loss from cement slurries to the surrounding environment.
Common fluid loss additives are organic polymers, dispersants and synthetic polymers
CEMENT ADDITIVES Fluid Loss
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CEMENT ADDITIVES
Foam will formed during mixing the cement slurry with the chemicals detrimental to good cement jobs
Defoamer
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Hydration in place the hydrostatic reduce
Gas block chemicals- to fill up the pores between the cement particles
Gas Block
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Weighting materials are used to increase the density of cement slurry depending on the requirement
The weight of cement slurries can be increased by adding barite or
hematite
DITIVES Weighting Agents
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The weight of cement slurry can be reduced by :-
Adding material that increases the water content such as clay and silicate materials
Using light weight materials such as microspheres or nitrogen
Light weight cement is used on weak formation or loss circulation zones
Light Weight Additives
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The lost circulation materials are used to combat cement lost into very permeable, cavernous or fractured formations
The lost circulation materials prevent the loss of cement by one or more of the following mechanisms
Preventing fracture inducement by reducing hydrostatic pressure as in lightweight cement
Cure the lost circulation by forming a low permeability bridge across the permeable opening
Common LCM can be classified as fibrous, granular and flakes
CEMENT ADDITIVES Lost Circulation Materials
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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CEMENT/SPACER DENSITY
CEMENT SLURRY DESIGN
Co
nsi
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atio
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Prevent losses to formation
Prevent flow from permeable formations
Strength development
Slurry stability
Cement Slurry Design
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15.8ppg typically used for neat class G based on API recommend water ratio of 44%
RULE OF THUMB : < <
Density of slurry normally 1 ppg higher than mud weight
Density Density
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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Determined using rotational viscometer
Concentric bob and rotor to shear cement slurry in small gap
Shear rate versus shear stress relationship is determined
Cement is non-Newtonian fluid
Its flow regime is determined using
Bingham Plastic model
Power Law model
Other models
Rheology
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Influenced by:
Cement density (water contents)
Dispersant
Retarder
Fluid loss additive
Extender
Solids content
Cement fineness
Ratios of cement components
CEMENT SLURRY DESIGN Rheology
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Cement slurries more commonly behaves as Bingham Plastic fluids.
Common acceptable values:
Pv = 100 40 cp
Yp = 5 45 lbf/ft3
Good rheology is important for Mud removal efficiency.
Cement displacement efficiency
Achievement of turbulent flow
Excessive annular pressure buildup
Excessive pump rate requirements
Potential for lost circulation occurrence
CEMENT SLURRY DESIGN Rheology
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RHEOLOGY
Fann viscometer to determine cement rheology
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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CEMENT SLURRY DESIGN Fluid Loss
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Fluid Loss
Low Temperature (
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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CEMENT SLURRY DESIGN Free Water, Sedimentation & Segregation
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CEMENT SLURRY DESIGN Free Water Control
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Free Water Test Setup with 250 ml
Graduated Cylinder
Free Water
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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Defined as elapsed time from initial mixing with water to achievement of a final consistency of 100 Bearden Units (Bc)
Thickening times should be designed so that slurries set from the bottom to the top of the well.
Requirements: Slurry Volume, Displacement Volume, Pumping Rates, Logging temperature
Calculating Cement Volumes:
Thickening Time
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Excess Cement Volumes:
Does not account for washouts
Expressed as % of the slurry required to fill the theoretical volume of the annulus
Excess is based on the OPEN-HOLE ANNULUS volume only
REQUIREMENT
Ensure sufficient time to perform:
Slurry mixing and pumping
Shutdowns: Drop plugs, change tanks
Displacement
Safety margin: AT LEAST 1 hour
Rates dependent
CEMENT SLURRY DESIGN Thickening Time Calculation
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High Pressure Consistometer
PRESSURIZED CONSISTOMETER
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Consistometer Chart
THICKENING TIME CHART
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Cement Slurry Design
Density Rheology Fluid Loss
Free Water Thickening
Time Compressive
Strength
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CEMENT SLURRY DESIGN
Test procedures are governed by API Specification 10A and 10B
Cement is cured under downhole conditions
Slurry placed at BHST
Slurry placed in cube moulds
Typically 12 hrs and 24 hrs are used
Cubes are tested using Carver Press
Destructive cube crush
Unconfined compressive strength (UCS)
Pressure applied uniaxial only
Ultrasonic cement analyzer (UCA)
Relative strength determined by measuring change in velocity of ultrasonic transmitted through cement
As strength develops, transit time through cement decreases, allowing relative strength to be calculated
Compressive Strength
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Compressive Strength (Destructive Method)
Fann viscometer to determine cement rheology
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Compressive Strength (Destructive Method)
Fann viscometer to determine cement rheology
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Compressive Strength (UCA)
Fann viscometer to determine cement rheology
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Compressive Strength Chart
Fann viscometer to determine cement rheology
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CEMENT SLURRY DESIGN
Increasing cement densities typically increases CS
Reduces water: cement ratio
Can also be enhanced without increasing densities:
Adding solid content in cement slurry
Grinding the cement particles into finer grinds
Typical practices:
Adding silica fume additive
Adding colloidal silica additive
Adding silica flour
Using ultrafine cement
Compressive Strength
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Minimum Compressive Strengths Preferred for Various Functions
FUNCTION
AXIAL LOAD SUPPORT
DRILLING AHEAD
PERFORATING
KICK OFF PLUG (WHIPSTOCK)
ABANDONMENT PLUG
LOST CIRCULATION PLUG
COMPRESSIVE STRENGTH
500 - 1000 psi
500 - 1000 psi
1200 - 2000 psi
3000 psi
1000 psi
50 psi
SLURRY TYPE/OPERATION
LEAD SLURRIES
TAIL SLURRIES
LINER/PRODUCTION CASING SLURRIES
SIDE TRACK DENSIFIED SLURRIES
TAGGING/DRESSING OFF
THIXOTROPIC SLURRIES
Compressive Strength cont..
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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PRE JOB PLANNING- INFO REQUIRED
MD/TVD/Liner hanger
Accurate log temperature - depth of log and time since circulation
Trajectory
Hole size
Pressure Plot
Casing/ Liner size & weight
Type of mud spacer planning
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JOB CONSIDERATION
State & Federal Regulation
Formation integrity Hole washout, Weak Zone/Thief Zone, High pressure Zone
Gas migration
TOC
Mud displacement
Cement Placement Technique
Slurry Properties
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Outline What is Cementing?
Objective
API Cement Classification
Additives
Slurry Design
Pre Job Planning
Job Execution
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JOB EXECUTION
Well Conditioning
Condition mud
Reciprocate or rotate casing
Circulate at highest possible rate
Use fluid caliper to verify hole volume
Monitor bottoms up gas
Monitor returns
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JOB EXECUTION
Cement Mixing
Accurately measure density
Control density fluctuations
Use both top and bottom plug
Use preflush or compatible spacer
Mix and displace at the designed rates
Monitor fluid returns
Monitor job parameters using D.A.U.
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Q & A
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CEMENTING METHODS AND SYSTEM FOR THE CO2
WELL
Agenda
Challenges for CO2 wells SealBond & Ultraflush Micro Emulsion spacer Improved cementing systems for CO2 Expansion feature Case histories
2012 Baker Hughes Incorporated. All Rights Reserved.3
Possible leakage pathwayscasing and cement
casing and cement
cement matrix
casing
fractures
cement and formation
SOURCE: Celia et al. (2004)
Results From Field Studies
Portland cement degradation due to CO2:
Agenda
Challenges for CO2 wells SealBond & Ultraflush Micro Emulsion spacer Improved cementing systems for CO2 Expansion feature Case histories
2012 Baker Hughes Incorporated. All Rights Reserved.6
SealBond - Benefits
Prevents formation breakdown & fall back of cement tops Strengthens wellbore for improved cement slurry placement SPE 140723
Typicalspacer
applied priorcementing
SealBond
applied priorcementing
More Benefits of SealBond
SealBond sealing acts like a condom Potentially protects cement sheath towards corrosive fluids
CO2
Sealing
Mg2+
H2S SO42-
Cement
Microemulsion Spacer Technology
The MICRO-WASH high-definition remediation system Removes OBM filter cake damage Water-wets surface Requires no energy Solubilizes oil phase
The MICRO-CURE E2 cased-hole remediation system: nonaromatic solvent Cleans sand surfaces easily Improves fluid mobility Removes in situ emulsions Increases water-wettability Mobilizes most asphaltene and paraffin
The MICRO-PRIME spacer system: mesophase spacer Cleans casing and tools Provides ultralow interfacial tension Provides fast phase inversion Provides excellent rheological compatibility
9 2012 Baker Hughes Incorporated. All Rights Reserved.
MICRO-WASH SystemCleaning Plugged Screens
10 2012 Baker Hughes Incorporated. All Rights Reserved.
As received
After MICRO-WASH system
After rinse
MICRO-PRIME SystemSouth Louisiana Operator Case History
First failed competitor displacement Same tools after MICRO-PRIME system
11 2012 Baker Hughes Incorporated. All Rights Reserved.
Purpose of Cement Spacers
Cement spacers are designed to: Effectively displace the drilling
fluid in the annulus Convert an oil-wet surface to
a water-wet surface Provide a clean and water-wet surface
to which cement can strongly bond Success in the field is defined by:
Shoe test Cement bonding logs (CBL)
12 2012 Baker Hughes Incorporated. All Rights Reserved.
New Microemulsion Spacer
The UltraFlushME microemulsion spacer system Based on the microemulsion surfactant in
MICRO-PRIME technology Provides ultralow interfacial tension Provides a fast phase inversion Provides rheological compatibility
With S/OBM With cement
Completely removes SBM quickly Solubilizes the oil Cleans and water-wets solid surfaces
Stable at temperatures to 300F (149C)
13
MesophaseSpacer
2012 Baker Hughes Incorporated. All Rights Reserved.
Spacer Wettability Apparatus
Used to determine the apparent wettability of cement spacer systemsand clean nonaqueous drilling fluids
Cement will not bond to oil-wet surfaces
When the spacer is properly used: Prevents mud and cement contamination Provides better bonding potential Ensures a proper annular seal Improves displacement efficiency
14 2012 Baker Hughes Incorporated. All Rights Reserved.
UltraFlushME SpacerScreening Conductivity
Initial: OBM Post-titration withspacer poured out
Post-water rinse
15 2012 Baker Hughes Incorporated. All Rights Reserved.
SSCT with 10-14 ppg SBM
16
Fresh Water Cement Pre-Flush SpacerOil-in-brine emulsionWater-Wet Surfaces
Brine-in-oil emulsionOil-Wet Surfaces
Phaseinversion
17 2012 Baker Hughes Incorporated. All Rights Reserved.
Goniometer
A liquid droplet rests on a solid surface and is surroundedby gas. The contact angle, C, is the angle formed by a liquid at the three phase boundary where the liquid, gas,and solid intersect.
18 2012 Baker Hughes Incorporated. All Rights Reserved.
Measurement of Angle of Deflection
UltraFlushME Cleaning Spacers
Cement preflush spacers Water-wets casing and formation ahead of cement Improves cement bond
Brine in oil emulsion(invert emulsion)oil-wet surfaces
Phase transition Oil in brine emulsion(direct emulsion)
water-wet surfaces
Transition phases for mesophase cleaning solutions
Contact angle 74
19 2012 Baker Hughes Incorporated. All Rights Reserved.
Contact angle < 30
Effective Laminar Flow (ELF)
First ELF rule governs fluid density hierarchy Each displacing fluid should be at least 10% heavier than the fluid it is
displacing Second ELF rule governs friction hierarchy
Each displacing fluid should exert a friction pressure gradient (dP/dz) thatis at least 20% higher than the fluid it is displacing
Third ELF rule governs minimum pressure gradients Each displacing fluid has to be able to break the gel strength of the
displaced fluid on all sides of the annulus, even the smaller side of aneccentric annulus, in either a vertical or nonvertical wellbore
Fourth ELF rule governs differential velocity The velocity of the displacing fluid in the wide side of an eccentric annulus
should not exceed the velocity of the fluid being displaced in the narrowside of the same annulus
20 2012 Baker Hughes Incorporated. All Rights Reserved.
Effective Laminar Flow (ELF)
If all four hierarchies are met for both the spacer/mud interface andthe cement/spacer interface, then even in the case of laminar flow inan eccentric, inclined annulus, ELF displacement is possible
21 2012 Baker Hughes Incorporated. All Rights Reserved.
Optimize Flow Regime
Fluid friction pressure curves Better design tool insures viscosity and density hierarchy in fluid
sequences Up to four charts with reference temperatures
22 2012 Baker Hughes Incorporated. All Rights Reserved.
Fluids Data RheologyCementing Simulator & Modules
Allows users to enter up to 12 shear rates Using more realistic shear rates (300-10 rpm)
Auto calculates best fit model, reports r2
Results tie into mud removal calculations and ECDs
Agenda
Challenges for CO2 wells SealBond & Ultraflush Micro Emulsion spacer Improved cementing systems for CO2 Expansion feature Case histories
2012 Baker Hughes Incorporated. All Rights Reserved.27
Main Minerals of Set API Cement
Portlandite = Ca(OH)2C-S-H phases
C-S-H grab onto another (e.g. zipper) causing high strength Portlandite does not contribute to the strength (weak point):
Disruptive, easy to be leached out & increase brittleness
Source: TUM
Portlandite in the Cement Matrix
Polarization microscopy of the set API Cementlight: Ca(OH)2 - dark: C-S-H phases or clinker
Source: Blaschke, R. 1985
CO2 Attack in conventional API Cement
API class G / silica flour (15.8 ppg) Exposed to CO2-loaded water (650 psi & 250F) Static conditions for 30 days
1.27 cm
Thin sectionSee next slide
Slicedintohalf
Cutintohalf2.54 cm
CO2 attack in cement
I. unalteredset cement
III. carbonatedcement
IV. poroussilica (soft)
CO2 +
H2O
H2CO3
H+ +
HCO3-
V. corrosivefluid
Leaching frontCarbonation front
C-S-H phases
Ca(OH)2dissolve
Ca2+aqOH-aq
precipitates dissolves
Ca2+aqH+aqHCO3-aq
CaCO3
Reducing the amount of portlandite by adding:
selected pozzolanic materials:SiO2 (Al2O3)
Ca(OH)2 + SiO2 (Al2O3) C-S-H (C-A-S-H) phases
Cement matrix will become denser
Design criteria: pozzolanic reaction
Improve the Resistance of Cement
1. CO2 / corrosive fluids preferentially react with the Portlandite=> Eliminate the Portlandite in set cement
2. Carbonation / corrosion of C-S-H phases also takes place=> Partly substitution of API cement with inert material
3. Corrosion reactions are diffusion controlled processes Lower permeability of set cement = slower corrosion
=> Reduce the permeability
Improved vs API Class G
cured at 200 F,3000 psi
Slurrydensity(lbs/gal)
Waterpermeability
(microdarcy)
Ca(OH)2portlandite
content(%)
Compressive strength72 hrs (psi)
Tensilestrength72 hrs(psi)
Improved Systems 15.8 0.002Not
detectable 4,674 459Set API Class G 15.8 2.100 9.5 4,807 378
PortlanditeCa(OH)2
Improved Set API Class G
cured at 200 F,3000 psi
Slurrydensity(lbs/gal)
Waterpermeability
(microdarcy)
Ca(OH)2portlandite
content(%)
Compressive strength72 hrs (psi)
Tensilestrength72 hrs(psi)
Improved extended 14.0 0.15Not
detectable 2,529 272Set API Class G 14.0 10.80 9.2 1,633 170
Improved vs API Class GPortlanditeCa(OH)2
Improved Set API Class G
Improved vs. API Class G (96 hrs curing)
ConventionalImproved
CO2 Lab Testings
Specimens pre-cured at 3,000 psi & 300 F for 96 hrs Exposure to CO2 loaded water at 3,000 psi & 300 F
Improved Conventional
CO2
HTHP curing chamber
Effect of CO2 on Cements MechanicalProperties
Cementsystem
density(ppg)
Youngsmodulus
(Mpsi)Confining
Stress: 1000psi
Poissonsratio
ConfiningStress:
1000 psi
Compressivestrength
(psi)Confined
Tensilestrength
(psi)Unconfined
After 96 hrs curing at 3,000 psi / 300 F (before CO2 exposure)
Improved 15.0 1.52 0.32 >5,800 354
Conventional 15.0 2.07 0.33 >5,860 258
After 30 days exposure to CO2 at 3,000 psi / 300 F
Improved 16.1 0.85 0.26 >5,850 468
Conventional 16.5 1.17 0.23 >5,850 438
After 6 Months Exposure to CO2
Cement specimen flaked off (diameter =-0.6 mm)Cement bond failure / migration pathways=> Loss of zonal isolation
Improved cement Conventional API cement
Durability in 1 M HCl (24 hrs)
Dissolving attack:
2 H+ + Ca(OH)2 Ca2+ + 2 H2O
12 H+ + C6-S5-H6 6 Ca2+ + 5 SiO2 + 6 H2O
ConventionalImproved
Conventional
C.S.= 1,520 psiW.P.= 0.00123 mD
fell apart no strength squishy morph.
Durability in 1 M HCl (250 d)
Improved
Cement Sheath Failure Mechanisms
Bonding failure: due to excessive radial stress producing a compressive failure
Vertical radial cracking: due to tangential stress producing a tensile failure
Tensile Strength Test Methods
Direct Uniaxial TensileStrength(UTS) : ASTM C190-85
HTHP Tensiometer
Gato do mato field, Campus basin (off shore Brazil), 11/04/2010
Patent: US 7,191,663 B2
Available only from BAKER HUGHES
Testing up to 600 F & 5,000 psi
HTHP Tensiometer
SPE 97967
Testing Cement Tensile Behavior Under Downhole Conditions
Design giving higher Tensile Strength at HPHT
Improved cement
Field proven technology (SPE 143772)
Agenda
Challenges for CO2 wells SealBond & Ultraflush Micro Emulsion spacer Improved cementing systems for CO2 Expansion feature Case histories
2012 Baker Hughes Incorporated. All Rights Reserved.48
Split ring test accurate method?
A split, expandable ring placed between flat metal plates with a screw Slurry poured in assembly and allowed to initial set Measurement across the 2 points, spanning the split in the ring
=> Assembly cooled and de-pressurerized=> Only single point-in-time test result=> Cured samples undergo stresses & pot. dimensions altering effects=> Cannot quantify linear expansion in an uninterrupted downhole environment
2012 Baker Hughes Incorporated. All Rights Reserved.49
Real-time Expansion & Shrinkageunder Temperature & Pressure
Expansion / shrinkagemold for cement
Modified curing chamber: continuous in-situ measuring at downhole conditions
Example for cement shrinkage
Right Sample: Class G cement + 35% S-8 + 5.0% EC-2 + 0.8% FL-25 + 0.6% CD-32 + 0.5% R-8 mixed at 16.7 ppg, Yield = 1.40 cu ft/sk and fresh water = 5.02 gal/sk
-2
0
2
4
6
8
10
12
0 5 10 15 20 25 30 35 40 45 50Elapsed Time (hr)
%Li
near
Expa
nsio
nor
Shr
inka
ge
0
500
1000
1500
2000
2500
3000
3500
4000
Test
Pres
sure
(psi
)and
Tem
pera
ture
(F)
% Linear Expansion
Test Temperature
Test Pressure
Out of ranges (expansion device)
Base-line
The cement was heated in 4 hrs to its final (BHST) temperature and pressure. After 4 hrs, the temp and pres has estabilized.Any test data above the base-line are consider expansion and below are shrinkage.
Examples for cement expansion
Design expansion carefully:
Compensate shrinkage
Slight expansion to support bond
Too much expansion results in cracks
Agenda
Challenges for CO2 wells SealBond & Ultraflush Micro Emulsion spacer Improved cementing systems for CO2 Expansion feature Case histories
2012 Baker Hughes Incorporated. All Rights Reserved.53
Case history 1: Middle EastWell for an EOR-CO2 project, 07/22/2011
Depth: 2,672 meters (8,765 feet)Job Type: 7 LinerBHST: 121 C (250 F)BHCT: 82 C (180 F)Cement: Expanding improved cement (84 bbl)Density: 2002 kg/m (16.7 ppg)Yield: 0.691 m/tonneWater: 0.180 m/tonneThickening Time: 5:05 hr:mn (70Bc)Compressive strength@24 hrs at 250 F: 5800 psiRheology @ 80 F (180 F)PV (cps): 240 (144)YP (lbf/100 sqft): 13 (10)Fluid loss: 18 cc/30 minutesFree fluid: 0.0 %
Case history 1: Middle East
Cementation of a 7 liner for an EOR-CO2 project
7 liner run in 8-in. hole to 8,765 ft; prev. 9-5/8 csg shoe at 8,480 ft
Drilling fluid was a non-damaging fluid (NDF) weighted to 10.4 ppg
48 bbls of expansive cement system batch-mixed at 16.7 ppg
Pumped & displaced into 7x8 annulus w/o any operational incidents
Customer: very satisfied w/ technical support, operational performance& excellent slurry properties witnessed on site
7'' liner USIT LOG available with excellent cement bond results
2012 Baker Hughes Incorporated. All Rights Reserved.56
Results look good for entire interval
>8480 ft. attempt to log in a csg x csgenvironment picking up reflection ofthe outer csg string
Reason for the large quantity of dataerrors seen in the evaluation, whichare presented as green on the log
Some interference in the csg tracks tothe left side that appear to look likestripes on the log
These errors are transmitted acrossthe entire log & are not reflective ofthe cement quality in the interval
Case history 1: Middle East
2012 Baker Hughes Incorporated. All Rights Reserved.57
In the open hole - no issues thatwould lead to believe there are anyisolation problems
In several places cycle skip on thelog, indicating excellent dampening ofthe signal
Some minor issues with tooleccentering, but not significant
Results of the evaluation show a wellisolated interval
Case history 1: Middle East
Case history 2: CO2 Capture StorageSpain: 09/10/2012
Depth: 2071 meters (6790 feet)Job Type: 9 5/8" & 7 CEMENTINGBHST: 50C (122F)BHCT: 45C (113F)Cement: tail slurryDensity: 15.86 ppg (1.90 g/cc)Thickening Time: 5:28 hr:mn (100Bc)Rheology300 rpm: 231200 rpm: 165100 rpm: 976 rpm: 113 rpm: 4Fluid loss: 24 cc/30 minutesFree fluid: 0.0 %Compressive Strength:3.5 MPa (500 psi): 8.00 hours24 hours: 40.6 MPa (5890 psi)
Case history 2: CO2 Capture Storage
Case history 2: CO2 Capture Storage
2012 Baker Hughes Incorporated. All Rights Reserved.61
Case history 2: CO2 Capture Storage
Case history 2: CO2 Capture Storage
7 production liner cementing job
CBL/VDL shows a good zonal isolation throughout the annulus
Contamination at TOL because job was performed w/o any wiper plugs
Explains the CBL/VDL not very good in upper part of the section at TOL
For the rest the client was very happy about the operation, especially
since no surface release plugs system was used
Case history 3: CO2 wellsNatural CO2/ H2S producer (Neuqun, Argentina), July 2011
Depth (MD=TVD): 3,300 meters (10,827 feet)Job Type: 9 5/8intermediateBHST: 81C (178F)BHCT: 76C (169F)Cement: Improved cement (batch-mixed)Density: 1680 kg/m (14.0 ppg)Yield: 1002 m/tonne (1,509 ft3/sk)
Thickening Time: 5:20 hr:mn (Bc)Rheology (76C)300 rpm: 255200 rpm: 191100 rpm: 108
6 rpm: 123 rpm: 10
Fluid loss (76C): 12 cc/30 minutesFree fluid: 0.0 %
Case history 3: CO2 wellsNatural CO2/ H2S producer (Neuqun, Argentina), July 2011
Case history 4: CO2 wells8 wells EOR: 4 prod. + 4 inj. (Middle East), 07/15/2011
Depth (MD=TVD): 2,275 meters (7,465 feet)Job Type: 4 1/2 LinerBHST: 104C (220F)BHCT: 65C (149F)Cement: Improved cement (25 bbl, batch-mixed)Density: 1953 kg/m (16.3 ppg)Yield: 0.604 m/tonne (0.91 ft3/sk)Water: 0.133 m/tonne (1.50 gal/sk)Thickening Time: 7:30 hr:mn (100 Bc)
Rheology (149F)PV (cps): 228YP (lbf/100 sqft): 42Fluid loss: 35 cc/30 minutesFree fluid: 0.0 %
Case history 4: CO2 wells
8 wells EOR: 4 prod. + 4 inj. (Middle East), 07/15/2011
The first job in (Middle East) was performed on the first oil-producer welldrilled in an eight-well enhanced oil recovery (EOR) CO2 project, whichwill eventually consist of four producers and four injectors. Improvedcement was selected as the customers preferred cementing medium forthe 4-in. liner sections. The liner was run in 6-1/8-in open hole to adepth of 7,465 ft with the top of the liner placed at 6,731 ft. The previous7-in liner shoe was at 7,051 ft. The mud was a water-based systemweighted to 10.5 pounds per gallon (ppg) with calcium carbonate. A totalvolume of 25 barrels of the improved cement was batch-mixed for the joband pumped at a density 16.3 ppg. The client expressed satisfaction withthe entire operation, including technical support and operationalexecution.
Case history 5: CO2 wellsOff shore Brazil, 11/04/2010
Depth: 5850 meters (19,193 feet)Job Type: 7 linerBHST: 108C (227F)BHCT: 92C (197F)Cement: Improved cementDensity: 1797 kg/m (15.0 ppg)Yield: 0.846 m/tonneWater: 0.378 m/tonneThickening Time: 6:12 hr:mn (70Bc)Rheology BHCT (ambient)300 rpm: 180 (202)200 rpm: 137 (137)100 rpm: 78 (80)YP 21.9 (13.3)Fluid loss: 18 cc/30 minutesFree fluid: 0.0 %
Case history 6: CO2 wells
British Columbia
Depth: 1010 meters (3310 feet)Job Type: production casingBHST: 37C (99F)BHCT: 31C (88F)Tail Cement: Improved cementDensity: 1770 kg/m (14.8 ppg)Yield: 0.809 m/tonneWater: 0.432 m/tonneThickening Time: 4:43 hr:mn (100Bc)Rheology300 rpm: 249200 rpm: 171100 rpm: 906 rpm: 8Fluid loss: 10 cc/30 minutesFree fluid: 0.0 %
Case history 7: CO2 wells
British Columbia
Depth: 1600 meters (5250 feet)Job Type: production casingBHST: 56C (133F)BHCT: 38C (100F)Tail Cement: Improved cementThickening Time: 4:41 hr:mn (100Bc)
Case history 8: CO2 Capture Storage
North eastern British Columbia
Depth: 2071 meters (6790 feet)Job Type: intermediate casingBHST: 117C (243F)BHCT: 60C (140F)Cement: Improved cementThickening Time: 4:53 hr:mn (100Bc)Rheology300 rpm: 141200 rpm: 100100 rpm: 586 rpm: 13Fluid loss: 8 cc/30 minutesFree fluid: 0.0 %Compressive Strength:0.35 MPa (50 psi): 5.10 hours0.7 MPa (100 psi): 5.13 hours3.5 MPa (500 psi): 5.30 hours24 hours: 15.5 MPa (2250 psi)
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SELF HEALING CEMENT A SIMPLE SOLUTION FOR
COMPLEX WELL
Agenda
Issue
Causes
Solutions
Why Self Healing
Test Apparatus
Results
When to Use
Summary
2011 Baker Hughes Incorporated. All Rights Reserved. 2
Challenge
Sustained casing pressure
Observed in more than 11,000 casing strings in 8,000 wells in OCS
Magnitude of leak rate is as important as magnitude of pressure when determining potential hazard
2012 Baker Hughes Incorporated. All Rights Reserved. 3
Gulf of Mexico Wells (LSU Study, 2002)
Causes
High-compressive strength vs. lower compressive
strength compressible systems
Poor cement bonding
Cement best practices
Cement failure
Pressure changes
Temperature changes
Reservoir changes
2012 Baker Hughes Incorporated. All Rights Reserved. 4
What Do We Do Today
Follow best practices
Centralization
Spacers
Displacement rates
Pipe movement
Set for Life cementing system designs
DuraSet system
Low Youngs Modulus
Higher Poissons ratio
Improved tensile to compressive strength ratio
IsoVision software modeling application
What if assumptions are incorrect
2012 Baker Hughes Incorporated. All Rights Reserved. 5
Simple Solution to a Complex Problem
Self-healing cement system
Must be easily blended and mixed in cement
No negative effect on other cement properties
Works over a wide range of temperatures
Must be capable of plugging flow of hydrocarbons
Through cement matrix
Through microannulus
Capable of healing multiple times
Able to define size of cracks in matrix or microannulus capable of healing
2012 Baker Hughes Incorporated. All Rights Reserved. 6
Test Apparatus
Test apparatus designed and built
Cement cured under temperature and pressure
Adjustment of desired crack or microannulus width
Cement hydraulically cracked under temperature
Capable of controlling, measuring and recording developed crack size
Test through cracked cement matrix or induced microannulus
Measure and record flow and pressure
Capable of testing with gas, oil or other fluids
2012 Baker Hughes Incorporated. All Rights Reserved. 7
00.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0
100
200
300
400
500
600
700
800
900
0 50 100 150 200
DS
BO
LT a
nd
PIS
TON
TR
AV
EL (i
nch
es)
FRA
CTU
RIN
G P
RES
SUR
E (p
si)
ELAPSED TIME (seconds)
CLASS H cement + Self-Healing Additives mixed at 15.2 ppgCuring Time = 96 hrs, room temp, 3000 psi
Fracturing Test, C-Frac WIDTH = 0.013", Crude oil
DS bolt adjusted to
= 0.013 "
max PISTON
TRAVEL = 0.0142"
max Frac Pressure
= 760 psi
Self-Healing Cement
2012 Baker Hughes Incorporated. All Rights Reserved. 8
05
10
15
20
25
0
100
200
300
400
500
600
700
0 100 200 300 400 500 600 700 800 900
CR
UD
E O
IL F
LOW
(cc
)
Pre
ssu
re t
o B
REA
K S
EAL
(psi
)
ELAPSED TIME (secs)
Class H cement + Self-Healing Additive mixed at 15.2 ppg Curing time = 96 hrs, room temp, 3000 psi
BREAK-SEAL TEST, C-FACTURE WIDTH = 0.013" , fractured with Crude Oil
max Pressure to Break-Seal= 654 psi.
Crude Oil Flow
Self-Healing Cement
2012 Baker Hughes Incorporated. All Rights Reserved. 9
Self-Healing Cement
979
894 880
791
357
250
0
200
400
600
800
1000
1200
0 1 2 3 4 5 6 7
Test
Pre
ssu
re (
psi)
Ageing Time (days)
Fracturing - Break and Seal test Controlled crack width = 0.003", curing time = 96 hrs, Heal Time = 24 hrs, rm temp
Crack
Initiation
Pressure
Break-Seal # 1
Break-Seal # 2
Break-Seal # 3
Break-Seal # 4
Break-Seal # 5
2012 Baker Hughes Incorporated. All Rights Reserved. 10
Results
Material easily mixed and blended in cement at effective
concentrations
No negative effects on cement properties
Enhanced mechanical properties
Tests being performed over a wide
temperature range
Sealed cracks up to .006
Capable of sealing multiple times
Ready for field trials in Q3/Q4 2012 Fig # 3: The picture is showing the induced Crack Width of 0.003across entry and exit port.
2012 Baker Hughes Incorporated. All Rights Reserved. 11
When To Use
Every Well?
Fields with a history of sustained casing pressure
High tectonic stress areas
Risk mitigation
Unable to follow all of best practices
Less than optimal centralization
No pipe movement
Gas storage wells
Plug and Abandonment
2011 Baker Hughes Incorporated. All Rights Reserved. 12
Summary
Sustained casing pressure is a concern
Improvements have been made but there are still issues
Developed test apparatus that can measure
Size of crack
Flow rate and pressure
Look at cement matrix and microannulus
Product capable of sealing multiple times
Not for every well but when used correctly, it can be
effective
Simple solution to a complex problem
2012 Baker Hughes Incorporated. All Rights Reserved. 13
Questions
2012 Baker Hughes Incorporated. All Rights Reserved. 14
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Q & A
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THANK YOU
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