Testing Geothermal-Well

Cements: Strength Measurements

Following Exposures to Simulated

Geothermal Fluids

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Materials Science

Fracture and Deformation Division

Washington, DC 20234

July 1980

Interim Report

Issued December 1981

100

,1156

80 -2099-4

1980

lc. 2 ^

Division of Geothermal Energy

U.S. Department of Energy

Washington, DC

NBSIR 80-2099-4

«• * TESTING GEOTHERMAL-WELL

CEMENTS: STRENGTH MEASUREMENTS

FOLLOWING EXPOSURES TO SIMULATED

GEOTHERMAL FLUIDS

national bubkau

or standabds

library

JAN 2 5 1982

rtot acc ~Ci rc . Qc/oo

• US'G

no.

m I

Ralph F. Krause, Jr. Edwin R. Fuller, Jr.

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Center for Materials Science

Fracture and Deformation Division

Washington, DC 20234

July 1980

Interim Report

Issued December 1981

Prepared for: Division of Geothermal Energy

U.S. Department of Energy

Washington, DC

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
•jiaasia ..ahojt.vv*

-UJCAOKi^TS U v r / zhu

s?f‘ a ;• m.
Abstract

Compressive and splitting tensile strengths were measured for

several set cements at room temperature after they had been exposed for

periods of 1 week and 1 month to a 20 wt percent salt solution pressurized

to 20 MPa and heated to 300 °C. The compressive strength was also

measured following exposures for identical periods to distilled water

pressurized to 20 MPa and heated to 200 °C. Prior to the exposures, the

cements had been set-cured for 2 days in molds immersed in water under

the same pressure and temperature as the distilled water exposure.

These measurements are part of a project being carried out to evaluate

certain physical properties of cements which are candidates for use in

finishing geothermal wells.

1
Introduction

In response to the U. S. Department of Energy (DOE) program to develop

improved cements for use in geothermal wells, nine different laboratories

submitted cementing materials between January and March 1980 to the National

Bureau of Standards (NBS) for property verification tests. An invitation

[10] to laboratories interested in participating in the NBS testing program

had been issued June 1979 through the American Petroleum Institute (API)

Task Group on Geothermal Well Cements, which is serving as a review group

for the DOE program. Table 1 gives the 21 cement formulations that were

received and subsequently assigned letters for ease of identification. The

chemical composition of some of the cement components are given in table 2.

A standard practice [10] for testing geothermal well cements was

generally applied in the present work except that the measurements proposed

for water permeability and for shear-bond strength to steel were deferred.

Only specimens that were destined for compressive or splitting tensile

strength measurements were first set-cured in molds and then exposed to

simulated geothermal fluids at elevated temperature and pressure. While a

first series of tests, conducted between January and March 1980, involved

only compressive strength measurements on cement specimens that had been

exposed only to distilled water, a second series of tests, subsequently

conducted between April and June 1980, also included compressive and splitting

tensile strength measurements on cement specimens that had been exposed to

20 weight percent salt water. The practice was modified because the API

Task Group had requested at its December 1979 meeting that as many of the

candidate cements as possible be partially examined prior to its March 1980

meeting. We believe that the revised schedule of tests best utilized the

limited pressure vessel space in the time available.

2
As of June 1980, 15 cement formulations, which include the first and

second choice of each participating laboratory, were partially examined.

In regard to the first series of tests, seven of the twelve cements tested

had been prepared without their specified retarders because the retarder

for some of them had not been submitted initially. Upon the advice of the

API Task Group, the tests were repeated on most of these cements along with

their retarders as part of the second series of tests. Also, two new

cements (M and N), which were not received until March 1980, were included

in the second series of tests. The results of the two series of tests had

been presented at the March and June 1980 meetings, respectively, of the

API Task Group.

Specimen Preparation

Using a truncated version of the proposed schedule of tests [10], the

preparation of a cement slurry was initiated on separate occasions, usually

twice, but as many as four times, instead of once weekly as originally proposed.

On each occasion the weighed components of a given cement being prepared were

mixed to form 600 mL slurry. After the dry ingredients were hand-blended,

their mix was added during a period of about 15 s to the liquid in a two

speed propeller blender (2 L capacity) operating at the lower speed; next

the slurry was blended for 35 s at the higher speed. The slurry was then

poured into as many as 18 glass tube molds (20 mm o.d. , 150 mm length,

1.5 mm wall) that had been coated lightly inside with silicone grease

beforehand. After the slurry in each tube was puddled to remove trapped

air bubbles, each of the filled tubes was capped with a Teflon stopper

(10 mm length, 1 mm hole); and the capped tubes were secured together in a

stainless steel basket.

The molded slurry of each cement was set-cured nominally two days

(42 h actually) at elevated temperature and pressure. Immediately upon

3
completion of the slurry preparation, the basket of molds of a given cement

was immersed in distilled water at room temperature and sealed in an internally

stirred autoclave of stainless steel (4 L capacity). The water level was

adjusted so that the water occupied about 78 percent of the available fluid

space (autoclave capacity less volume of specimens), and the autoclave was

next pressurized to about 7 MPa with nitrogen gas. Curing was considered

to commence when the contents of the autoclave began being heated at the

rate of about 2.4 °C/min. In about 75 min the temperature of the contents

increased to 200 °C, and the autoclave became pressurized to about and

eventually adjusted to 20 MPa, mainly due to expansion of the water and

compression of the gas. The initial charge of water was deliberately

chosen so that the volume ratio of final gas phase to available fluid space

would be about 10 percent. These conditions were maintained throughout the

remainder of the curing period by automatic temperature control, using a

sheathed thermocouple inside the autoclave. The cure was considered to

terminate when cold water began to circulate through internal coils of the

autoclave, cooling the contents at a rate about the same in magnitude as

the heating rate. When the temperature of the contents decreased to about

50 °C, thermal contraction had reduced the pressure again to 7 MPa; and the

autoclave was further depressurized slowly and dismantled.

Following the two day set-cure of a given cement, the glass tubes were

carefully broken away from the rods of set cement; and each rod was diamond

sawed into three specimens, the length being twice the nominally 17.5 mm

rod diameter. The specimens were immediately immersed in room temperature

water and maintained wet. At this stage six specimens of each set-cured

batch of cement were subjected to strength tests to provide a data base, to

which the results of testing the other specimens of the batch could be

compared, following their exposures as described later.

4
Because the prescribed method of slurry preparation was not appropriate

with some cements, special care was exercised as follows:

1. Cements F and G: The water/solid weight ratio of 0.50 given in table 1

produced a paste slurry. In consultation with reference [5] a weight ratio

of 0.60 was used in the present work, giving a more pourable slurry.

2. Cement H: As reference [1] specified, water was added to the solid

and they were mixed in a low-speed paddle mixer for about 5 min until the

slurry became pourable. Following the two day set-cure, the rods of set

cement tended to stick to the silicone greased glass tubes and were so

friable that many rods did not withstand removal of the glass molds. In a

search to produce sound specimens, other batches of this cement were set-cured

alternatively either in glass tubes on whose inside surface a Teflon spray

release agent had been baked, or in thin-walled Teflon tubes which were

held in split tubes of stainless steel with Teflon-lined copper caps. In

addition several specimens (15 mm square, 30 mm length) were diamond sawed

from three rods (50 mm diameter, 50 mm length) that reference [1] had

set-cured reportedly in saturated steam at about 200 °C.

3. Cement P: As reference [7] specified, this cement was set-cured at

240 °C instead of the customary 200 °C. Since the first shipment of liquid

siloxane monomer failed to set, a second shipment of the liquid to which a

catalyst had been added was used, resulting in set specimens.

4. Cement Q: As reference [3] specified, this cement was set-cured while

the molds of slurry were immersed in diesel fuel oil. Although the autoclave

was controlled at the specified temperature of 115 °C, the exothermic polymerization reaction of the cement occurred so suddenly that the temperature

increased to about 170 °C. The resulting specimens were foam- like, having

5
expanded out of the molds to be twice their length; and they possessed about

one-tenth the roughly 60 MPa strength of specimens that were cured successfully.

A few specimens of this cement were set-cured successfully in another batch

when the proportion of slurry being cured in the fuel oil was reduced to about

one-tenth that ordinarily used, thus limiting the rise in temperature during

the set-cure. In consultation with reference [3] further examination of

this cement was deferred at this time because the preparation of set specimens

proved too difficult.

Exposures

Two separate treatments were used to expose specimens of the cements

at elevated temperature and pressure. Simulating light and heavy geothermal

fluids, distilled water heated to 200 °C and 20 weight percent salt water

heated to 300 °C constituted the two treatments, both being confined under

20 MPa pressure of nitrogen gas. While only distilled water was used in

the first series of tests, a batch of freshly set-cured specimens of a

given cement was usually divided into two separate groups of twelve specimens

each for exposure in the two fluids, respectively, usually along with

specimens of one to three other cements that had already been exposed for

some time.

The chemical composition of the 20 weight percent salt solution was

formulated to represent Sal ton Sea fluids, a somewhat arbitrary task since

their salt content varies considerably. The salt solution consisted of

2.3 molal NaCl , 0.36 molal KC1 , and 0.66 molal CaCl

2

(1 molal = 1 mol

solute per kg water); also, it was equilibrated with 0.2 MPa partial pressure

of C0

2

, giving a pH of about 4.4 at 25 °C in a closed vessel.

6
The exposures were conducted in a recently constructed high pressure,

high temperature fluid handling facility [11], which included a series of

four Hastelloy alloy 0276 pressure vessels (5.1 cm i.d., 26 cm inside

length). Demolded specimens of cement were installed within a given pressure

vessel along with stainless steel blanks as necessary to keep constant the

space that was occupied by as many as thirty specimens. The vessel was

charged initially with a specified quantity of room temperature liquid and

pressurized to 7 MPa with nitrogen gas so that the volume ratio of final

gas phase to available fluid space be about ten percent, the same criterion

as used in the set-cure. This corresponds either to filling 78 percent of

the available fluid space of a vessel with distilled water that is eventually

heated to 200 °C and pressurized to 20 MPa or to filling 64 percent, with

20 weight percent salt water that is eventually heated to 300 °C and also

pressurized to 20 MPa (for example, about 220 or 180 mL, respectively).

Each pressure vessel with its contents was completely enclosed within

a wire coil resistance, split tube furnace whose operation was automatically

controlled by a thermocouple attached at the middle of the vessel exterior.

A second thermocouple in a Hastelloy alloy sheath was used to indicate the

temperature at the inside center of the pressure vessel. About 90 min was

required from the time heating commenced for this internal temperature to

attain 80 percent of its ultimate level. Weekly, the specimens of cement

were cooled to about 50 °C in 2 h by directing compressed air on the pressure

vessels in the furnace cavity. After the vessels were depressurized and

dismantled, some specimens of cement were withdrawn and other specimens

deposited as necessary to fulfill 7 or 28 day periods of exposure. Freshly

made fluid was again installed in the pressure vessels and the cycle of

operations was repeated. Meanwhile, the withdrawn specimens of cement were

immersed in room temperature water until their strengths were measured.

7
Strength Measurements

The detailed procedure for testing the compressive strength (c ) and

the splitting tensile strength (ct^) of the set cements is described elsewhere

[10]. In brief, the load bearing faces of the testing machine and of a

test specimen were wiped clean. The length (L) and the diameter (D) of the

specimen were measured within an accuracy of ± 0.05 mm. Using a wooden

guide, the specimen was centered directly under a freely rotatable, spherically

seated compression tool which was suspended on a gear driven crosshead. In

the diametral splitting tests, unused cardboard strips (0.3 mm thick) were

placed between the specimen and the load bearing faces to distribute the

applied force smoothly. A compression force was applied at a constant

displacement rate (0.5 mm/mi n) until the maximum force (F) necessary to

cause failure of the specimen was recorded. The values of F were observed

in Ibf units (1 Ibf = 0. 45359*9. 80665 N) within an accuracy of ± 0.3 percent

according to a recent calibration of the testing machine. Values of ct c and

2

ct^ were calculated from 4 F/71D and 2 F/71DL, respectively, in tests on

separate specimens.

The results of compressive strength measurements that followed the

initial set-cure and the distilled water exposures at 200 °C are given in

Table 3 and Figures la, lb, and lc. The results of compressive strength

measurements that followed the initial set-cure and the 20 weight percent

salt water exposures at 300 °C are given in Table 4 and Figures 2a and 2b.

Finally, the results of splitting tensile strength measurements that followed

the initial set-cure and the same salt water exposures are given in Table 5

and Figures 3a and 3b. Line entries in the tables which show the same

set-cure values for a given cement indicate specimens that originated from

the same batch.

8
Di scussion

Since the present work, which was designed as part of a preliminary

screening effort, involved a limited number of tests per event, any trends

that the strength data portray with time of exposure should be considered

as approximate. The mean values that are tabulated in Tables 3, 4, and 5

are not based evenly among the 686 specimens tested. Excluding duplicate

entries, 85 of the mean values were based on 6 tests each (2 rods of set

cement sawed into 3 specimens each), 5 of the mean values were based on 4

tests each, and 52 of the mean values were based on 3 tests each (3 specimens

sawed from the same rod of set cement). Statistically meaningful trends

would be based on larger populations than used here. One trend, however,

was confirmed manyfold; the compressive strength of a rod of set cement,

especially a lightweight cement, was found generally to increase with the

depth that specimens were extracted from the rod, no doubt due to segregation

of water from the heavier components prior to setting of the cement. The

standard deviation of a mean value which is based on 3 tests generally

reflects this trend for a given cement.

Very little distinction between the presence or absence of a retarder

in cements A, B, D, F, K, and L is apparent within the precision of measurements.

The presence of a retarder perhaps has made these cements slightly stronger

immediately following their set-cure, but the differences could easily be

due as much to the separate batches of set-curing.

The cements varied in their response to being exposed in distilled

water at 200 °C. The high strength of cement P tended to increase with

exposure time, the high strength of cement D held fairly steady within wide

bounds, and the high strength of cements C and N began to decline somewhat

following the four week period of exposure. Although cements A and B were

9
initially very strong at the one-day set-cure, their strengths retrogressed

to lower levels upon exposure. The same held true to a lesser extent for

the moderately strong cements F and M. The moderate strengths of cements

E, J, K, and L held generally steady. Cements G and H were the weakest.

Although the glass-molded specimens of cement H were moderately strong at

the one-day set-cure, their strength retrogressed severely upon exposure.

The moderately strong cement L appears to have become slightly stronger

in salt water at 300 °C than in distilled water at 200 °C. The respective

strength trends of cements B, D, K, and P appear about the same with time

of exposure in either fluid. Although the glass-molded specimens of cement

H showed about the same strength retrogression in either fluid, the cement

H specimens which were set-cured by reference [1] gave an increase in

strength upon 4 week exposure to salt water at 300 °C; this inconsistency

might possibly be due to the position these latter specimens occupied in

the original stock material. The strengths of cements A, F, and M appear

to have retrogressed slightly more when these cements were exposed to the

salt water at 300 °C than to the distilled water at 200 °C. Drastic reductions

in strength of cements C, E, J, and N were observed when these cements were

exposed to the salt water at 300 °C. A reduction in strength was expected

for cement C, for as reference [7] advised, it is useful at temperatures up

to about 250 °C, above which the organic polymers decompose appreciably.

While the splitting tensile strength has about one- tenth the value of

the compressive strength, both properties yielded parallel trends with time

of exposure of the respective cements to the salt water at 300 °C.

10
Table 1. Formulations of geothermal -wel 1 cements

submitted for testing at the National Bureau of Standards

Identity Parts by Weight Components Referencp

A 100 API

3 class G cement 9

35 si 1 ica flour

54 water

1 lignin/sugar retarder

B 100 API class J cement 9

44 water

0.4 lignin/sugar retarder

C 100 solid aggregate 7 22 liquid organic monomers

D 100 cement 2 45 water

0.7 retarder

E 100 modified g-C^S cement 4

4.5 perlite

1.1 bentonite

85 wa ter

F 30 API class J cement 5 40 pozzolan

30 blast furnace slag

50 water

0.5 carboxy methyl cellulose

G 30 API class J cement 5 40 silica flour

30 pozzolan

50 water

0.5 carboxy methyl cellulose

H 100 hydrothermal cement (250 °F) 1 20.8 water

J 100 ordinary Portland cement 6

50 water

K 100 API class G cement 9 35 silica flour

2 bentoni te

8.5 perl i te

116 water

1 lignin/sugar retarder

L 100 API class G cement 9

35 si 1 i ca* fl our

10 diatomaceous earth

91 water

1 lignin/sugar retarder
Table 1. Lontinueu.

entity Parts by Weiqht Components Reference

M 80 API class J cement 3

20 calcined chrysotile (M-S~)

47.5 wa ter J ^ 0.25 D - 28 Dowell retarder

N 100 system CA-CA

2 cement 8

100 5 um quartz

c 89.1 water

0.9 100XR Pozzolithe

0 60 API class J cement 8

40 calcined chrysotile (M

? S?

) 47.5 water ^ ^ 0.375 D- 28 Dowell retarder

P 100 solid aggregate 7

50 liquid siloxane monomer

Q no mixture containing furfuryl 3

alcohol resin

1 catalyst

R 100 API class B cement 9

35 sil ica flour

20 NaCl

54 water

1 lignin/sugar retarder

S 100 API class G cement 9

100 silica flour

2 sodium silicate extender

1 NaOH

135 water

1 lignin/sugar retarder

T 30 API class J cement 5 30 silica flour

40 blast furnace slag

50 water

0.5 carboxy methyl cellulose

U 30 API class J cement 5 30 pozzolan

40 blast furnace slag

50 water

0.5 carboxy methyl cellulose

V 30 API class J cement 5 30 silica flour

35 blast furnace slag

5 bentonite

50 water

0.5 carboxy methyl cellulose

rfie n can Petroleum Insti tute.
Table 2. Composition of cement components as given by sources

Identity Component

A,K,L,S API class G cement

B API class J cement

(system 3-C

2 S and

silica)

C solid aggregate

C liquid organic

monomers

E modified B-C

2 S

cement

H hydrothermal cement

(250 °F)

M API class J cement

(system B-C^S and

silica)

Composition (parts by wt)

By analysis:

64.2 CaO, 21.5 Si0

2

, 3.9 A1

? 0^ , 3.8 Fe~02

, 1.3 MgO, 2.1 S0

3

, 0.7 alkalies, 0.6 free CaO

By calculation:

60.3 C

3

S, 16.2 C

2 S,

11.5 C

4AF, 3.9 C3

A,

3.5 CaSO^

By analysis:

37.3 CaO, 54.2 Si0

2

,

1 .1 A1

2 03

, 1.0 Fe

2

0

3

, 0.3 S0

3

, 4.6 loss on ignition

30 API class C cement,

70 sand (50 mesh no. 16,

25 mesh no. 30, 25 mesh no. 100 )

50 styrene, 35 acrylonitril e,

5 acrylamide, 10 divinyl benzene,

1 silane A-174

100 (b-C

2

S + silica with

0.65 mol ratio Ca0/Si0

2

),

3 A1

2 03

, 2.25 CaS0

4

-2 H

2

0

7 A1 (0H)

3

, 10 Britesil

,

10 anhydrous sodium silicate,

25 silica flour, 50 sand,

0.5 bentonite

By analysis:

43.79 CaO, 49.25 Si0

2

, 0.76 A1

2 0

3

, 0.59 Fe

2 0

3

, 0.29 MgO, 0.27 S0

3

, 0.46 alkalies,

3.50 loss on ignition

Reference

9

9

7

7

4

1

8
Table 2. Continued.

Identity Component Composition (parts by wt) Reference

N

P

system CA-CA

2

cement

solid aggregate

By analysis:

28.4 CaO, 0.35 Si0

2

, 70.5 A1

2

0

3

, 0.10 Fe

2

0

3

, 0.43 MgO,

0.32 SO^, 0.27 alkalies, 0.38 loss on ignition

10 API class C cement,

90 silica flour

8

7

P liquid siloxane

monomer

97 tetramethyl tetravinyl

cycl otetrasi loxane, 3 polydimethyl

siloxane, 0.5 di-tert-butyl

peroxide

Cement abbreviations: A = A^O^, C = CaO, F = Fe

2

0

3

, M = MgO, S = Si0

2
Table 3. Compressive strength (a ) of set cements at 25°C, following

the set-cure and subsequent exposures to distilled water,

pressurized to 20 MPa and heated to 200°C. Except as noted,

entries give the mean and standard deviation of 6 tests.

Cement

a / MPa

c

2 da set-cure 7 da exposure 28 da exposure

A

a 67.8 + 6.4 34.0 + 7.8 36.3 + 4.2

A 77.1 + 10.2 31 .3 + 3.6 24.4 + 4.1

B a 54.0 + 7.9 27.3 + 2.3 32.8 + 2.5

B 62.1 + 4.1 23.8 + 0.7 30.1 + 2.6

C 155.1 + 9.9 175.8 + 13.4 133.6 + 7.7

D

a 58.3 + 7.8 52.4 + 12.5 63.9 + 15.8

D 57.9 + 18.7 52.0 + 7.7 59.1 j. 7.2

E 21.3 + 2.8 25.4 + 2.0 24.5 + 3.5

Fa 19.8 + 0.3 13.3 + 0.9 15.5 + 0.5

F 25.1 + 2.1 25.1 + 1.5 14.4 + 1.2

G

5 1.6 + 0.3 5.6 + 0.4 3.6 + 0.2

H

b

24.1 + 5.9 5.6 + 0.4 4.4 -L 1.6

H

c 22.4 + 4.9 4.6 + 1.7 2.2 T 1.4

H

d

9.1 + 1 .6 6.1 T 1.5 8.3 1.6

H

d

5.3 + 0.3 3.2 + 0.4 2.4 + 0.5

J 16.1 + 1 .9 14.2 + 2.1 17.9 + 2.2

K

a 12.8 + 0.8 11.2 + 1.8 16.2 + 1.9

K 20.1 + 5.0 9.6 + 3.2 14.1 +" 4.0

L

a 16.9 + 0.8 20.7 + 2.2 26.9 X 1.6

L 28.5 + 3.3 24.6 + 2.7 25.0 T 2.1

M 37.6 + 5.1 26.9 x 0.8 25.0 + 2.1

N 88.9 + 11.3 99.4 + 10.4 58.2 + 6.9

P 60.7 + 2.1 73.4 + 9.1 76.2 + 3.4

1 MPa = 145 psi

a Retarder not added.

^Set-cured in teflon-coated glass tubes.

c Set-cured in teflon tubes.

^Set-cured by reference 1 ; 4 tests conducted per entry.
Table 4. Compressive strength (a ) of set cements at 25°C, following

the set-cure and subsequent exposures to 20 wt per cent salt

water, pressurized to 20 MPa and heated to 300°C. Except as noted, entries for the set-cure and exposures give the mean

and standard deviation of 6 and 3 tests, respecti vely

Cement

a a

c /MPa

2 da set-cure 7 da exposure 28 da exposure

A 77.1 + 10.2 21.6 + 1.0 19.9 + 2.3

B 62.1 + 4.1 30.0 + 2.0 32.4 + 0.9

C 141.8 + 7.0 80 + 28 6.8 + 2.1

D 62.3 + 7.4 37.1 + 4.1 55.9 + 2.5

E 20.0 + 3.0 11.4 + 1.6 1.0 + 0.2

F 25.1 + 2.1 17.1 + 0.9 12.2 + 1.1

H d22.4 + 4.9 5.6 + 0.6 5.9 + 1.6

H d

5.3 + 0.3 4.2 + 0.2 14.5 + 2.5

J 15.2 + 1.3 9.1 + 1.0 1.9 + 0.6

K 20.1 + 5.0 12.1 + 3.9 11.4 + 6.1

L 28.5 + 3.3 37 + 12 33 + 19

M 34.6 + 5.5 18.7 + 1.6 19.2 + 1.1

N 81.6 + 7.4 11.8 + 0.3 19.1 + 0.4

P 60.7 + 2.1 75.7 + 8.4 84.5 + 10.9

1 MPa = 145 psi

b Set-cured in teflon-coated glass tubes.

^Set-cured by reference 1 ; 4 tests conducted per entry.
Table 5. Splitting tensile strength (a^) of set cements at 25°C following

the set-cure and subsequent exposures to 20 wt per cent salt

water, pressurized to 20 MPa and heated to 300°C. Entries for the

set-cure and exposures give the mean and standard deviation of

6 and 3 tests, respectively.

Cement

a

t/MPa

2 da set-cure 7 da exposure 28 da exposure

A 7.00 + 1.68 2.72 + 0.24 2.74 + 0.20

B 5.70 + 1.54 4.78 + 0.51 4.85 + 0.66

C 18.0 + 2.4 8.3 + 2.4 1.41 + 0.39

D 5.14 + 1.29 4.38 + 1.27 5.71 + 0.91

E 2.30 + 0.36 2.26 + 0.14 0.28 + 0.08

F 3.37 + 0.61 1.92 + 0.12 1.50 + 0.22

H

b

3.00 + 0.99 0.76 + 0.37 0.66 + 0.09

J 1 .81 + 0.38 1.44 + 0.37 0.34 + 0.01

K 2.55 + 0.36 2.31 + 0.68 1.70 + 0.46

L 3.49 + 0.65 5.77 + 1.00 6.76 + 0.56

M 4.69 + 0.57 3.23 + 0.25 2.46 + 0.18

N 8.66 + 1.41 1.60 + 0.53 2.96 + 0.13

P 4.22 + 0.76 6.35 + 0.39 6.26 + 1.84

1 MPa = 145 psi

^Set-cured in teflon-coated glass tubes.
III oo

CM o

00 o

CO o*3- oCM o O O O o O 00 CO ^ o o

CM

<D 03 sz C- cdo c c m o 2 C -t—

C 4J ro r— -O > O QJ 0! <4- N "O

•P“ « s_ *a O 3 S- c in ro in wo cnj a> c

s- <v

(V LTi

00 i- -O

+j CD 3 3 +-> fO

<D 03 ESC <d as u "a <d

a> E

<D

00 -i— +j

*4— 03 O •<- T3 UO

00 -c cd

4-4 s> cn 3 I c

a>

s_

4-> in ai

CD +-> > c

•r- CD 00 3

in cr

CD CD

J- 00 Q. -Q E 3 C in O •a

ro

cu

s_

D 3

S_

O 3 I CD 4-> •r- CD

Ll. 00

03

ID

4-

J 3

CD

oo

CD3

a.

CDc

00 "O

ID CD

•r- -O

5- -D

4-> rC 3

LU 4-> O

sz (J S- o a> O T3 S-l

C\J 03

4-0

O OJ

4-> QZ

03 -a

CD

+-> 03 00, CD +> -c m

ID *o +->, 3

<V LO

EdW/’ 0
X £3O

(A>.

CO o

CM

33 co

c. co

03 CO

03 To r— E

QJ c_ E COi OJ

<— CO E44 ~o c co a> co cocm 44 44 E 33 03 CO

•r* o <—

O QJ s 03 cj 44 o 1 r— -a E c ^r

r— CL <C c O N QJ r— • 4- . p— 4- E QJ EJ E QJ +4 CL 0 CO CJ LD CO 44 E E

CM CL r— CL E 4-> E

44 a.

a QJ

03 ' QJ 0J 4-

** co e O) CO e QJ 3 E

44 qj E CJ E 44 O., 1 >3

QJ 03 QJ 44 -C — s E OJ

O) C/0

a cj 33 coC 0)

QJ O) E

44 i

•1“ a> i— e « CJ CO •f— 44 a 1 4-J E 0J 44 4- CO QJ 33 a o r— 33 C/3 33 #> cOO •—

c

uo 0) 44 o 44 44 o • - c E CO

co E 0) .E CL E 43

44 E 00 _aj 3

cn 3 03 ^4 44 E CO E

0)

O 44 03 E E Q. 44 c

+->

X OJ QJ r—

00 OJ

U CC 4- Xra 0)

qj 44 LU 44 > E

•i

QJ * E

O0 3 • UO r—

CO CTO 4-3 QJ QJ 0 UO "3 e 00 c a; QJ Cl o 4—3 E

s= 3 CM 3 o co O <J o c 1 3> 44 4- 44 E O QJ • 03 -a C/0 -C QJ EU

r— CL 44 c E 03 o 3 QJ 4-3 • E O -E rz UO

=5 1 — O) CD 4-> 33 > . •r— CJ E a; X

Li- U0 fO 4-3 o o

in o o

CO CM * BdW/’o o
u

CL E E3 e3

cn 3 cn o o O a a X ® X o

cn o >.

>« >. CO

to o a T3

00

CN) CM

ro QJ C_O cn cm c

•rO 2 -P O

r- -a r— GJ O N

•4— -r-£_ O 3 0 00 on oo

c\j qj

s_ -P Q.

ro

r* oo i_ -P a) C -p

0) rc E 2

0)o *o

QJ -P r—

Q) r—

00 •(— -P

oo

O -r- a

uo

00 .c ai -p s_ CD 3 C 00 O) o

S- CL

-p

X

00 QJ

a; -P > c

•r- QJ

oo 3

oo cr

oj qj

s- 00 CL _Q E 3 O oo o -oc • ro U

r— QJS_

aj 3

su 3 I OO -P

•r- O)

Li_ 00 o o

GO o

CO o o o

04

BdlAI l°°

and

heated

to

200°C.

Entries

represent

the

mean

and

standard

deviation

of 6

tests. a

Retarder

not

added.
o o o o o o O CD CM 00 T

CM i— T“

Figure

2a.

Compressive

strength

(o)

of

set

cements

at

25°C

following

the

set-cure

and

subsequent

exposures

t8

20

wt

per

cent

salt

water,

pressurized

to

20

MPa

and

heated

to

300°C.

Entries

for

the

set-cure

and

exposures

represent

the

mean

and

standard

deviation

of6

and 3

tests,

respectively.
Co

ai> o -r—

+->

MU to -a CJ -U

QJ oj -o Q. 00 .C Nl c 00 OJ

-t-> r— <o CD j-j U S- cn 3 <D or 3 oo s_ *> •r— oo to . r

<D

u +J r— o S_ 1 00 r— CD +-> CJ CJ 1 aj +J u o 00 3

4- S- CO 0J

CD CJ sO 4-> -3 a QJ 0 CO 4-> 3 4-

LO 2 03 aj CM S- s- +j o 40

+-> r— 4- >-

CO (O 4- XI

00 oo

O

(/) CJ o 4-> 4-> •f“ 3 CJ c 3 S- O s_

CJ <D 4-J 3 £ u 3 -u u

<d CD CO 1 o s_ • f— +J

CJ * > aj +j Q.T3 aj OO

<D aj CO

CO +-> 4-> 2 c O 4- 3 u • O O CO 00 CM 00 "C CJ ,—

fO 3 X

UO CO 3

>3 -U +-> -M -M —' Q. 00

oo ai OO .3 aj u a 00

+-> s_

X 3 (O CO 3 DJ (O r— 3 00 CD

0) o 3

s_ CL CO -a

4->

X o aj oj 00 aj c 5 +j o cO aj 4-> aj o > 3 CO j3 u • i

aj -U i 00 3 o 3

oo cr 4-> -t->

O

CD a; 3 r—

CO -o OJ 4- ClX aj oo aj 3 4-3 CJ 4-> O oo CO u o CJ Q.. 3 o CJ • r— 3 s_ • <0 o T3

XI 3 00 OJ CM <r CO OJ U

s_ S- 3

O) CO 3 U

su Q_ 00 I 3 1 - O -t-> CD +-' CL. OJ

•f— a’ o X 40

Ll. CO CM OJQ

+Jc

CJ

s_

CJCL

CD o

UO o o

CO

edIH/'O o

CM o
o

CM

CO CM 00 o cd

a

cnm to 3 3 c. <u O </l O) S- .— CD U O i- CO I 4- Cl aj 44

S- cd " ' 3 OO

C-J i- tOC o a; c w v a

c\j re

x 2 <U >i

4-3 i re +j no

a

CO fO 03 •!—

4—3 to 4-3 C qj o

OJ 4-> i- QJ

EE c 3 CL

O) CD CD 00 u u 1 QJ 4J £_

4—3 S- a; 0) CD to *> co CL to

aj 4-3 <4- —) _3 to O 3 X4 QJ

4-> c i_

4-?VJ

C no o tt- — C nc

4-3 oo z

DC a; o

4-3 to t—

cn CD S_ to o s_ 441 CD C3 3 <t- S- to UJ O

4-3 o

to '-v 3 X • o

CD CD c_> •>-

r

—

C 44

•r— 4-3

O re to 3 G *f- o QJ oo >

CD 3 CD

4-3 CT

O no

CD X3 cn to no 3 _a no s- • r— 3 0) 03

4-> to 44 -a

4-3 re 3

•r— -3 aj re r— DC 44 o ro to on no

CD c no

S_ re 3 • 3 re

03 o re

(T) 1 C_ 3

4—3 s; re CD CD aj S- to o = 3 CVJ CTI CD CD • •— do C -3 ' 4-3 44 44

00 CO *3- CM

O

EdW/'O

in

teflon-coated

glass

tubes.
I I I I

"O

QJ CD Nl 3 r— • f— 3 2 3 O CO r— CO r— QJ o 3

4- Cl „ O 3 0 QJ lo -M

CSJ fC2

-M3 4-> r—

CO fD

(/I c

Q) -M

£T 3

Q> O) u u

4-> 3

O) 0)

c/> CL 4- Jj O 2o

4-f\J c'—- o

-M

r- +J CO CD OJ 3 3

cu 3

s- COO

co CLX

0) a; I—• r- 4-J CO c c O)

O) 3

+-> CT

aj CD co 3 -Q v—

-M CO +J• I— -3 r— C" Q. ro

c/o QJ3 • 3

JDu

oo 1 -M

0J QJ

S- CO 3

CD 0) r— 3: Ll_ +->

L _L

CO CO ^r j

CN4O

*<Ml

x

O

to

20

MPa

and

heated

to

300°C.

Entries

for

the

set-cure

and

exposures

represent

the

mean

and

standard

deviation

of6

and 3

tests,

respectively.
References

1. D. K. Curtice and W. A. Mallow, Southwest Research Institute, 6220

Culebra Road, Post Office Drawer 28510, San Antonio, Texas 78284.

2. F. Fabbri, Ente Nazionale per 1'Energia Elettrica, Compartimento di

Firenze, 56044 Larderello, Italy.

3. C. E. Johnson, Jr., Chevron Oil Field Research Company, P.0. Box

446, LaHabra, California 90631.

4. G. L. Kalousek, Colorado School of Mines, Golden, Colorado 80401.

5. R. S. Kalyoncu, Battel le Columbus Laboratories, 505 King Avenue,

Col umbus, Ohio 43201

6. R. A. Kennerley, Department of Scientific and Industrial Research,

Chemistry Division, Petone, New Zealand.

7. L. E. Kukacka, A. N. Zeldin, and N. Carciello, Brookhaven National

Laboratory, Upton, New York 11973.

8. D. Roy, E. White, and C. Langton, The Pennsylvania State University,

Materials Research Laboratory, University Park, Pennsylvania 16802.

9. B. E. Simpson and L. H. Eilers, Dowell Division of Dow Chemical,

P.0. Box 21, Tulsa, Oklahoma 74102.

10. R. F. Krause, Jr. and E. R. Fuller, Jr., "Testing Geothermal -Wei 1 Cements: Standard Practice," NBSIR 80-2099-2, National Bureau of

Standards, Washington, D.C., Interim Report, July 1979.

11. R. F. Krause, Jr. and E. R. Fuller, Jr., "Testing Geothermal -Wei 1 Cements: High Temperature, High Pressure, and Fluid Handling

Facility," NBSIR 80-2099-3, National Bureau of Standards, Washington,

D.C., Interim Report, October 1979.
N8S-114A tREv. 9-78)

ll.S. DEPT. OF COMM. —

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NESIR 80-2099-42.Gov*t. Accession No. 5. Recintenf s Accession No.

4. TITLE AND SUBTITLE

TESTING GEOTHERMAL-WELL CEMENTS: Strength Measurements

Following Exposures to Simulated Geothermal Fluids

5. Publication Date December 1981

$. Performing Organization Code

7. AUTHOR(S)

Ralph F. Krause, Jr. and Edwin R. Fuller, Jr.

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADORESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

Ilk PmjecS/Tasir/Work Unit No.

11. Contract/Grant No. FA-77-A-01 -6010

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS fSfreaf. City, State, ZIP)

Dr. Robert R. Reeber

Division of Geothermal Energy

U.S. Department of Energy

Wa <thingtnn t fit.

13. Type of ReDort & Period Covered

Interim, July 1980

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

I

I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or leas iactual summary ol moat significant information. If document includes a significant bibliography or

literature survey, mention it here.) Compressive and splitting tensile strengths were measured for

several set cements at room temperature after they had been exposed for

periods of 1 week and 1 month to a 20 wt percent salt solution pressurized

to 20 MPa and heated to 300 °C. The compressive strength was also

measured following exposures for identical periods to distilled water

pressurized to 20 MPa and heated to 200 °C. Prior to the exposures, the

cements had been set-cured for 2 days in molds immersed in water under

the same pressure and temperature as the distilled water exposure.

These measurements are part of a project being carried out to evaluate

certain physical properties of cements which are candidates for use in

finishing geothermal wells.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only die first letter of the first key word unless a proper name;

separated by semicolons)

Compressive strength; geothermal well; set-cement; simulated geothermal fluid;

splitting tensile strength.

18. AVAILABILITY [Xj Unlimited

I | For Official Distribution. Do Not Release to NTIS

j Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SO Stock No. SN003-003- ~ Order From National Technical Information Service (NTIS), Springfield, VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF

PRINTED PAGES

26

22. Price

$6.50

USCOMM-OC

)