cementing pratices for thermal wells.pdf

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C e m e n t i n ~ g Practices for Thermal Wells

By R

W.

POLLOCW ,

W.

H BEECROFT*

and

L. G, CARTER*

(17th

Annual

TechnicaL

Meet ing, The

Pet rn[eum SfJciety

oj

C.L.U_. Edmontoll,

May,

19(6)

ABSTRACT

The

introduction

of steam

as a

means of stimulation

fo r oil

production has

p re sent ed many problems in oil

u ell cOffi ll letions.

Some

of

th e

difficulties

experienced

haH

been

c a s i n ~ failures. pipe g rowth , c emen t f ail ur e

and cem ent

bond breakdown.

Data are presented

on

cementing compositions and cas

ing e m e n t i n ~ techniques which maJ help

build

a

sound

steam

injectIon

well

or one

which

can

w iths tan d th e

stresses and

strains

of

intermittent

steam injection

and

production.

INTRODUCTION

P

RODUCTION of low-gravity, high-viscosity

c.rude

oil has

been increa:;ed in recent

years by

o w n ~

hole electric heaters, in-. : itu combustion and s team sti

mulation 1 . Of these

methods,

steam stimulation ap

pears

to

be the most

promising

and

is

being used

by

many producers

in

th e

oil field::; of \Vestern Canada.

Steam

injection, b) either of two systems, has become

a

complex

problem.

The

displacement or

flood

tech

nique is

considered

to be less troublesome once

the

field has been

prepared

for it, bu t

th e

necessary flow

line ';

and

permanent

stearn

generating equipment

makes

the

initial expem;e

very

high,

Most

of the Ca

nadian pl oducers have utilized

the

second

steam

stimu

lation

tec.hnique, that of

intermittent

steam injection

,. ith portable equipment - or, as

it

is

more

com

monly

called,

Huff and Puff. Although this

second

approach is

less

costly

than

the

use

of the permanent

generating

station,

most of

th e

problems inherent

with s team stimula tion

s ti ll exist .

The most common

problems em:ountered

are

those

of ca sing failure

and/Ol-

cement

failure_

As long as

steam

injection

t empera tu res remain below 400

c

F,

these

problems

seem to be

at

a minimum; however, as

injection p r e s s u r e ~

increase,

,,:ith

th e

corresponding

i n c r e a ~ e in temperature, the quality of the

casing,

cement and cemen t placement

become

important

fac

tors

in

th e

success or

failure

of

the

treatment.

1\iost of

the Huff and Puff

projects in Canada

to

date have been

in

th e temperature range of 550

c

to

620

F

(1,200

to 1.800 psi),

although equipment

is

available to

raise

these conditions

to 670

c

F and 2,500

psi, respectively. Many treating f ail ures have been

reported at the

lo, ·e r treating levels and many more

failures

are expected to occur when

the equipment is

u ti li zed to

th e

maximum extent.

The four

main

causes of well treatment

failure

have apparent ly

been:

I . -Cement deterioration

because

of the

strength

re

trogl e8sioll and permeabil ity increm;e of conven

t ional cements

used

in

the past.

·:fHuU1 bu.l tOfZ Oi l

Tf ell

Ceil/cnti11Y Co_ Ltd_ Edmon-

tun Alta.

r.: :f[{alllfmrfoll COlnlJany Duncan Oklahoma.

2.-8I eak-down

of cement

bond

to

formation and

pipe

becau::;e of

pipe

finish,

lack

of adequat e mud l'e

moval 01 surface ,

etability.

;3.-Poor placement techniques.

,L-Failure of casing and cement by overstre: ;Hing

during high temperature and preHsure steaming,

In this

paper.

we

will

attempt

to

suggest

placement

techniques

and

cementing materials

which

will tend

to minimize

th e

chance

of failure.

GENERAL

PROPERTIES

OF i\:IATERIALS

Laboratory

illYestigations conducted thl oughouL the

.rears

have studied the effect of heat on cementing

compositions.

has been reported that, above 230

c

F,

there

s

a

pronounced decrease

in c o m p r e s ~ ; i \ e

strength

and inc rease in

the p e l m e b i l i t ~ r

of man.\' commonly

llsed eementing m ~ l t e r j a ] s (2, 3). Additives

which

are

not chemically reactive with

th e

cement and which

re

quire a high water to cement. ratio

produce

a

cement

of

POOl

temperature

stabil ity. Bentoni te

is

probably

the

wors t o ffender

and should no t

be

u ~ e d

in any

composition

in

excess

of 4 per cent by weight of the

cement.

The

limitation of

Portland cements

at ele atec\

t emperatures has

been

stressed

in many

p r e v i o u ~

pa

penL The advantages of silica flour as a . -itabilizing

additive at t he se elevated

temperatures

have been

eva luated with a

variety

of cementIng

c o m p o ~ i t i o n

l2, 3, 4. 5, 6, 7, 8) _ The l'esLlltg of

th e

tests indicate

that

a

maximum of

60

per cent or

a minimum

of

80

pel' cent gilica flour by weight of the cement was re

quired

t.o

obtain

temperature

stability.

The

most com

mon quantity being used at the

p resent t ime 40

pe r cent_

Table

I presents t h t ~ slurry p rope rtie s of

compositions

having application in thermal p r o j e c t ~

Table

II

indicates the

effects

of temperature upon

th e

compressive

strength of the set materiaL

Cemellting

blends being used in thermal projects,

where

strength

retrogression is

critical, are discl1s.5iefl

in detail below_

L-Blends of API Class B eement with 30-40

PCI

cent

silica flour are designed to ha\ e

a slurry densit.y

of 15.7 to 15_9

pounds

per

gallon

and

may

be

accelerat

eeL

retarded

or densified to

achieve

the desired place

ment

and drill-out time. They

develop

excellent

strength.5i with respect to

compression and

shear

bond

ing_ They

can

be anticipated 1.0 have good tempera

ture

stabilitJ

r

to

460

c

F or higher_

2.-Pozzolan cements,

consi st ing of 0.5

cubic foot

of API Cla::;s B cement with 0.5 cubic foot of pozzolan.

30-40 per cent silica flour and 0-2 per cent bentoni te

by weight of the

pozzolan

cement mixture,

are

used.

Pozzolan cements

normal ly can

be mixed at slurry

densities of 14.5 to 15.3

pounds

pe r

gallon and call

a lso be accelel a ted, retarded or densified aH

th e

paL'-

ticular well condition8

require.

Pozzolan

cements

de-



.1

T BLE

I

SLURRY PROPERTIES OF S IL IC A F LO UR CEMENT

Per Cent

Water Ratio Slurr Volume

Slurry

Wefght

Cement

Silica Flour gal./sack

cubic foot/sack

pounds/gallon

API Class B.

30

5.5

1.34 15.9

40 6.1 1.48

15.7

50 50 Class B - Pozzolan

..

30 4.3

1.16

15.2

40

4.5

1.23

15.3

Calcium Aluminate -

40

5.88

1.45

15.8

T BLE

COMPRESSIVE STRENGTH OF CEMENTING COMPOSITIONS

Strength

-

psi

80 F

Days

Cured 1 Then Heated 7 Days

PeT Cent

Cement

Silica

Fluur

8O F WO F

400 F

500 F

600 F

Class B

. . . .

30

1400

1985

6600

4450

2600

Class B

40

1215

W

6550 6300 5020

1:

1 C lass B - Pozzolan

..

_. 30 560 1225

4200 4850

6000

1:

1 C lass B - Pozwlan.

40

775

[240

3400

4200

5850

Calcium Aluminate ..

40

2900 3700 620

[230

1575

velop excellent shear bond with the pipe.

They

ar e

slower

than Clas s B silica f lour cements

in

develop

ing

compressive strength, bu t are temperature stable

to

600 F

or

higher.

3.-Calcium

Aluminate

cement a

refractory cement

used

with

or

without

silica flour, is

particularly

suit

able

for

use

in

wells

where

temperatures ar e expected

to

exceed

700°F.

It s

temperature stability

is

in

excess

of

2 OOO°F. Calcium

Aluminate

cement

,ith

30-50

pe r cent silica

flour

is

mixed at

slurry densities of

14.7 to 15.8 pounds pe r gallon and develops good com

pressive

strength

and bonding properties. t

can be

accelerated or

retarded,

bu t i s s om et im es

variable

in

it s

performance

and

s hou ld be

tested

in

the labora

tory

prior to use.

4.-Salt

cements

containing

10 to 18

per

cent salt

by

weigh t o f the mixing

water to

both

Class Band

pozzolan

cement mixtures,

have been very

successful

in increasing

the

expansion of

th e

se t cement to im

prove the bonding properties

to

the casing and for

mation both before and after

steaming

(0).

Other

materials

ar e available to

increase

th e expansion of

the

cement bu t

these show little advantage

over

salt

and ar e

general ly more

expensive.

In

addition

to compressive

strength

and permeabili

ty

other

factors

attributing

to the

success

or fai lu re

of a thermal cement ar e the

bonding properties

of

the cement and

a

proper cementing

t ec hn iq ue . C e

ment slurries, when cur ed in

a

moist atmosphere,

ex

hibit

expansion upon setting.

Under these curing

con

ditions pozzolan cements produce

greater

expansion

than do Cla ss B c em en ts .

Further expansion

is exhi

bited

by th e

addition of salt to

these

fresh-water

slurries.

This

aids in

th e development of bonding

strength

bo th to

the

pipe and to th e forma ti on . The

use

of an expansive cement can int en si fy the ini ti al

bonding

strength

of

th e s et cement.

Sodium

chloride

added

to one of

the basic cementing

compositions

in

concentrations of

from

10 to 18 per cent by

weight

of

Technology, July-Sepf en1ber

1966, Montreal

t he miX in g water, will p ro du ce a cement

which

exhi

bits

a

linear

expansion of as much as 0.17 per cent.

I n s team injection wells where high-level

stresses

ar e

built up in the pipe

and

th e c emen t s he at h, t he h igh

est

pO::isible b on d b et we en

the pipe

and cement

and

the

cement

and

formation

is necessary_ Failure of the

b on d c an allow fluid communication and possible pipe

grm\ th

the ultimate being p ipe failure

by

buckling

or

telescoping

(10).

The

pipe finish

and surface condition of the

pipe

and

the formation

have a

profound

effect on the de

ve[opment of bond strength (11) . Fai[ure of th e bond

can

be minimized

by

proper mud

removal

with

th e

cement or

preferably

by a c he mic al

wash

ahead of th e

cement

slurry.

The chemical washes should

contain

a good mud

thinner and

a surfactant

which

is a

,vater

wetting agenL

These washes

normally

water based

are

easily pu t

into

turbulence

and

do an effective job

of

sweeping the mud ahead of the cement

s lur ry. Be

cause o f the variat ion in the mud sys tems which ar e

used the

best

chemical

wash should be

selected

for

the

particular mud system.

Placement of

the cement

slurry in

turbulence

vill

further

assist in

mud

removal

resulting in

more

com

plete filling of

the

annular space with

cement

and

better bonding of cement to formation and pipe. The

addition

of

a

frict ion-reducing dispersant addit ive

assists

in producing a slurry to a ch ie ve this condi

tion

at

minimum pumping

rates.

ApPLICATION

OF LABORATORY AN D

TEST WELL DATA

Laboratory studies

have b ee n c on du ct ed to better

understand the various physical properties of cement

ing slurr ies for these

applications.

The coefficient of

thermal expansion

for cement

containing

40

per

cent

silica

flour

was found to be approximately 6.0 x 10 6

illches/inch/ F. The coefficient of thermal expansion

for

s te el will

vary slightly

over

different tempera

ture

ranges

for dif ferent

grades o f cas ing;

however

131

··

·

\ :



Pigu l e

a

value

of

6.7 x

inches/inch/oF

ha d

been con

sidered as an

appropriate

value to use in making cai

c u l a t i o l l ~ o f e xp an si on d ue to

t em p er at ur e. T h e d if fe r

ence ill thermal

expansion

valueg, an d

th e earl.}r tem

p er at ur e g ra d ie n t

across

th e cem en t sheath

du e

to

relatively

low

heat conductivity, indicate

'I/hy

longi

tudinal compressive

stresses are created in th e c a ~ i n g

and buth radial

an d

l on g it u di n al t ens i le stresses in

th e c em en t

sheath

during

steaming.

The

heat transfer across

a

cement sheath

ha.::;

been

determined while

:;teaming

t hr ou gh e it he r casing or

tubing with

th e

annulus filled with an inert gas.

The

data indicate

that it

takes

about 8 hours for the ce

ment sheath

to

reach th e casing

temperature

while

steaming down 5 ~ ~ - i n . casing. This haE> been verified

in tw o test wells

and

is i n a gr ee me nt w ith

t he m et ho d

of calculation suggested by

Ramey

13). FiguTe 1

d ep ic ts t he temperature

gradient atrog::; A PI

Class

G

cement

Ia basic Portland

type)

containing 40 pe r

cent silica

flour while

i nj ec ti ng 6 0 0° F steam. On the

left is

th e

condition

f or s te am i ng

down

tubing

where

th e

low heat

t ra ns fe r r at e of t he a nn ul us

reduces the

actual

temperature a t the casing to about 200°F

below steam temperature in 1

hour

- t hi s g ra du al ly

increases to

100°F

after

24

hours. Th e curves on

th e

right indicate t he t em pe ra tu re g ra di en t

after

~ t m

injectiun through th e

casing,

132

The effect of pressure

an d

temperature ha s alfl'l

b ee n e va lu at ed in

a well

ce me nted t o

s ur fa ce . T hi s

showed

that

an

increase in either pressure

or

tempe

rature

inside

th e c as in g r es ul te d in a corresponding

i n c r e a ~ e in

th e

radial

an d

l on gi tu di na l e xp an si on o f

the

casing.

The amount

of

r ad ia l c as in g

expansion

caused

by

an

increase in

e i th e r p r es s ur e

Equation

o r t em pe ra tu re

Equation

2) inside th e

casing for

5:, S.-.

7- an d 8 r } ~ - i n . c as in g w ei gh in g 15.5 , 26.0

an d

36.0

Ib:i./fL

respectively, are

shown

in igltre 2

an d

i[lw e

l

At

th e

present time, th e following equations appeal

to be

appropriate

f or c al cu la ti ng

th e

radial

casing

c h an g e c r ea te d by t em p er at ur e o r pressure.

However.

these

calculations

a isume that t he ca si ng is

not sup

ported on the

outside

by

cement.

P

E

, , , - 1 - - -2 -)

-'fl,,,,, \

(2,

To calculate

th e

p r e S ~ l l r e

equivalent in sid e t he

cas

in g to

r:reate equal

lateral ~ t r e s . s

du e

to

a

thermal

change,

Equation 1 is

equated to Equation

2 Lo de

r iv e E q ua ti on 3

when

th e ca:)ing is

no t

supported al l

th e out iide by cement.

Preliminary

labol atory cbta indicale that th e

of thick-shell stress equations

foL

both

th e ca::;ing

and

t he c em en t sheath ca n

be

uti li ze d to

calculate

stress

conditions

in the cement due to differentials, or to

calculate:

maximum

pressure

or

t em p er at ur e w it hi n

the

limits

of

th e

s t r c s ~

capability of the

cement.

T h i ~

information. ho we ve r, h as n ot ye t been fulb

r

developed

to d e ~ i g n statu:;, an d

there

still rem ains the

difficult

evaluation

of th e ef fect of Lhe formation a.s a sup

portilLg cement for

th e

cement sheath.

Laboratory

tests

on casing supported by only

sheath

of cement

sho\'\:ed good

con elation b e t w e ~

th e calculated and actual t es t t em p er at ur e required

to crack

th e

cement ~ h e a t h both ra dia lly and

longitu

dinally.

\Vhen a similar

specimen was tested

with

th e cement

being

supported by

steel

ea. ing to simu

late formation bac.k-up, th e cement sheath di d

no t

crack at h i gh e r t e m pe r at u re

differentials,

which

in a gree me nt w ith

c a l c u l a t i o l l ~ .

Therefore.,

in

cement-

The Journal of C a na d io n P et ro le um



ing wells fo r steaming i t is very important to remove

the

dri ll ing mud from th e annulus so

that

the

cement

ca n

be

supported by the form ation to help

prevent

damage to either

th e cas ing or

cement.

Prior

to cementing a well

for

thermal use,

the

bore

hole should be calipered

to

determine

if

the hole is in

gauge or

if

washouts exist. Thorough mud removal

f rom these areas is necessary to help prevent prema

ture cement and casing failure. Where excessive

washed-out areas have

been

encountered during dril

ling,

it

is

advisable to

repair these zones by plugging

with a temperature-stable

cement

before

further

dril

ling. Once the cement

has

set,

drilling

can be resumed,

leading to

improved

support of

the

cement

sheath in

a section of the hole where

mud

removal would have

been difficult

during

th e primary job.

RECOMMENDATIONS

A typical new

Canadian well should be cemented in

the

following manner

fo r

use as a steam injection

well:

SU1 jace ca sing

-

Either

9 -in_

casing

in a 12IA,-in.

hole

or

1 0 ~ 4 i n

casing

in

a 151,1.i,-in.

hole would be ce

mented

with Class

B cement containing

30-40 per

cent silica flour

and

0-3

pe r

cent calcium chloride.

P1·odiwtion

sing - Either 5lf2-in.

casing

in a

7Vg-in. hole or 7-in.

casing

in a 9-in. hole would be

cemented

with one

of the

following: l

Class B

cement

plus 40

per

cent silica f lour and 0.75

per cen t

friction-reducing additive; 2 1:1 Class B

cement

- pozzolan plus 30-,10 pe r

cent

silica fl ou r and 0.5

to 0.75 per cen t f ri ct ion reducer.

In o rde r

to

minimize possible failure during steam

ing,

th e

well should

be

thoroughly circulated bl ' th e

well operator

prior

to cementing.

A

chemical wash,

tailored for the

mud s:r stem in use, of at least 1,000

linear feet of

annulus should precede the

cementing

of

the production casing.

Recent ly, a modification to the above cementing

program

has

been

introduced

to

attempt

to minimize

cas ing and

cement failures by pre-stressing the

pro

duction casing.

The

primarJr casing,

which

might be 51J2-in. or 7

in. N-80 Grade material , is equipped with a Conven-

tional

multiple-stage co ll ar p laced at 150-300 ft_ off

bottom. The lower s tage o f casing is cemented with a

fast-setting,

temperature-stable

cement.

When this

cement has developed

sufficient

tensile

strength to

res train the

casing while th e pre-stl-essing is

carried

out, the operator mechanically stresses th e

pipe

in

t ension unt il it has reached a condition calculated

to provide opt imum protect ion

for

th e anticipated

temperature and pressure conditions which will de

velop

during

steaming

operations.

Stress

is

held

while

the second stage of cement is placed

through

th e

stage collar. Tension is maintained

until

th e cement

has se t

long

enough to attain sufficient

strength

and

bond to hold tb e pipe under th e stressed

condition

when forces

are

released at surface. In

this

case,

the

upper stage

is

brought to surface

using a

temperature

stable

cement.

Table II I indicates

th e

elongation

of

tubing

or casing

due to temperature

change.

This

anticipated e longat ion is used in

calculating

the stress

applied to th e cas ing

prior

to

cementing

th e final

stage.

For reconditioning old wells in an exis ti ng s te am

drive, additional considerations fo r

cementing

a fun

string inside the original string ( th e mos t common

method of repai r) are: (1) to

determine an

accurate

bottom-hole

temperature to

attain

sufficient slurry

pumping t ime; 2 sandblasting

of

the inner

string

and

scraping or scratching

of

the inner surface of th e

outside string f01 better bond;

and

(3 ) selection of

the new

casing

size

which

will allow about

-in.

or

more of cement sheath .

The recommended cementing

materials would be similar to tho se used on the pro

duction casing of

a new well.

Nm.·IENCLATURE

.6.R

dmr

Change

in

mean radius of steel,

inches.

Internal pressure at steel, psi.

r ~ m ~

I vlean

radius

of

steel.

inches.\'8 Poisson's

Ratio

for steel,

0.3

E

8

Tvlodulus

of

elasticity [or steel,

psi.

t

d

Steel wall thickness, inches.

lX,

Coefficient

of

expansion for steel,

inches/inchI F.

T

Temperature

change

at

steel

mean

radius,

OF.

...

Tr'I.BLE

ELONGATION DUE TO

TEMPERATURE CHANGE

Eloflga1ion oj Tubing or Casing due Temperature Clra lge

in of.

Length of

I

-

Pipe 50 ' 100°

150 200

250· 300

350 400

450

0

500

Feet

Inches

500 . . . . . . . . .. . 2.07

4.14 6.21 8.28 10.35

12042

14.·19

16.56

18.63

2070

-

1000.

-1.14

8.28 12 12

1656

20.70

24.84

28.98 33.12

37.26

41.40

1500. 6.21

12.42

18.63 24.84 31.05

37.26

43.47 49.68

55.89 62.10

-

2000 . .

8.28 16.56

24.84 33.12 41.40 49.68 57.96 66.24

74.52 82.80

2500

. . .

1035 20.70 31.05

-lIAO

51.75 62.10

72.45

82.80 93.15 103.50

3000 . . .

.. .

12.42 24.84 37.26

49.68 62.10

7<1.52

86.9·1 99.36 111.78 124.20

3500

. .

14.49 28.98 43.47 57.96 72.45

86.94

101.43 11592

130.41

144.90

4000

. .

16.56 33.12

49.68 66.24 82.80 99.36

11592

132.48

159.04 165.60

? J

::: .

;

TechnDIDgYr

July-September

r

966

Montreal

133



ACKNOWLEDGMENT

BEECROFT

R. W. «(job) Pol lock

attended

the UniverSIty of Alberta.

graduating

in 1959

with

0 B.Sc, in petroleum

engineering.

~

wes emp loyed

by Halliburton

Oil Well Cementing

Ca.

Ltd.

dUring

the

summers

of 1956,

1957

and 1958, and began

permanent employmer:t with t he Hal li bu rt on

Compony

in

1959 as district enginee,r in

Estevan, Saskatchewan.

In O c t o ~

ber,

1965, he was transferred to Edmonton as district

engi

nee r. Mr . Pollock is a member of A.I.M.E an d the Association

o f Pro fes siona l Enginee rs o f A lber ta ,

7)

Ostroot, G.

lValTcn,

and Shryodc, Stanlel f, Cement

in g

Geothermal Steam 'Wells, Jaw . Pet.

Tech.

(Dec_, 1964),

p.

1425_

(S ,

lFalkc1 , TVayne

A

.• Cementing Compositions

for

Thermal Recovery Wel ls , ' Jaw . Pet. Tech. (Feb ..

1962), p_ 139_

9)

CU1·tC1·,

L. G., H ltg g 0 1 W/ , H. F .•

and Gcorge,

CIW-l lC8.

Expanding Cements for Primary

Cementing,

Jour. Pet. Tech.

i.\by

1966).

10) Humphrey,

H.

C

.• Casing

L ailures

Caused

by Thel'

mal

Expansion, World Oil (Nov.,

1960),

p

105.

l l Cartel , L.

G and

ElJall.<;.. G.

W .• A

Study

of

Ct

ment-Pipe Bonding; ' /010

Pf t. TI clt.

Feb, 19l j· l

p_

157_

12 )

Caill,

./ E Shryock. S and Cal lCl·. L. G_ Cc.

menting fo r S team Inj ec ti on \Vells

in

Cnlifamia.

J O/ I .

Pf:t

Tech. (April , HI6G).

13) Ramey,

H . ./

./1 .•

Wellbore

Heat Transmission.

.}ow·_

Pet.

Tech. (April.

1962), p.

127

Williom

(Bill)

Harvey Beecrof t graduated from the Univer

sity of

Alberta

in 1947 with a B.Sc in Arts an d SCIence.

After

working for two years in Eastern Canadian Pharrnaceutical

Laborator ies, he returned to Western

Canada

ond wos em

p l o ~ e d for over five y ~ a r s as a chemist with Chemica l

Geological

Laboratories. In

1956,

Mr. Beecroft Joined the

staff

of

the

Holliburton

Oil

Weir

Cementing

Co.

Ltd., and

he

is

presently employed by

tho t Company division chemi st.

Greg Corter

received his B.Sc, degree

chemlslry an d

mathematics

from Southeostern State

College

In

Durant, Okla·

homo, in

1954.

He held a teaching position for one year

prior

to

joining Halliburton

Company in

1955.

He

now serves

as

a

senior

chemist

in

th e

Research

and

DeveloDment

group

of the Cement Section, Chemica l Research an d ·Development

Department, of Hal liburton Company ,

REFERENCES

OweHS,

If .

D

.• and

SutCI ,

YaHI ;

E.,

Steam

Stimu

lation

- e w e ~ t Form

of Seconda ry Pet ro le um

Recovery, Th e Oi l

Ga s

Jonnral (4-26-65).

p 82_

LHdwig, N. C_. and Pence, S. A .•

Propert ies

of

Portland Cement

Pastes Cured

a t Elevated Tempe

ratures

and P re ssur es , Jou,rnal of American COH-

crete Institute (Feb., 1956). V-27. No.6 .

Ca,.ter. G1 Cg. and

SmitlL,

D. Ie, P r o p e r t i e ~ of Ce

menting COITIllOsitions a t

Elevated

Temperatures and

Pressures,

.}o/{I

Pe t, Tc ch.

(Feb.,

1957),

p.

20.

KaloHsck. G. L. , The

Reac-tions

of Cement Hydra

tion

a t Elevated

Temperatures. Paper

No. 11,

Thh d 11de1·nati-rrllal Symposillm 01 / Chemistry

of CI

1JIcnts, 1952.

Patchen, P. D .• Reaction and P rope rt ie s of Silic.a _

Port land

Cement i\'1ixtures

Cured

a t Elevated Tern.

pcratures, Jour. P et. Tech.

(Nov.,

1960), p. 281.

O ~ t . o o t G. Wa n cli . and

Walker,

Wayne

A

hIm.

proved Composit ions

f or Cemen ti ng \Vells with

treme

Tempera tures : ' .low·.

P( t.

Tl ch. (Mar.,

1961),

p_

1425_

(

I)

(3 )

(2 )

(6 )

5

(4)

CONCLUSIONS

There is

more thought

and

planning

being put into

drilling

and completing an

oil well

which

is a steam

injection candidate than there ,vas a year

ago.

Good

dri ll ing and

cementing

practices. an anly.si ; of the

weight

and

grade of casing

t h ~ l t should be

used, pro

per join t

selection

and

th e

usage of new methods of

inject ing steam

into

th e

wells is prevalent.

Prope l' selec tion by

the

veil

operator

of a cement

in g c o m p o ~ i t i o n

to

perform

sui tably under

the

condi

t ions anticipated is necessary. Don't expect the cement

to perform

miracles.

t

has

limitations,

just as

casing

has.

and should be

used

,

r ithin i ts

limitations. Labora

tory

work is currently being done to more thoroughly

def ine these limi ta tions and

to

obtain

more

complete

data. thus permitting the

better

adaptation of cement

to it s ta3k.

Employ

th e

best

po.ssible cementing

practices.

tak

ing :ldvantage of additives and techniques which will

benef it the

placemp.nt and distribution of the cement.

Bottom plugs,

chemical

·ashes. movement of the

casing. excess

cement and

good

annular

space clear

ance

beh

een

the

casing and hole

are

factors

which

should not

be

overlooked.

The

authors wish to express their appreciation

tl l

the

Halliburton

Company

fo r granting permission to

prepare and publish this

paper_

Special t h a n k ~ are

also extended

to

those in

t he l aboratory and

field

whll

a s s i ~ t e d

in

it s prepi l.ration.

cementing pratices for thermal wells.pdf

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