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Патент USA US3070460

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EXAMINER
56
Dec. 25, 1962
w, G. BEARDEN ETAL
3,070,450
BLOWN ASPHALT CENENTS
Filed Nov. 25, 1959
3 Sheets-Sheet 1
24 HR. TENSILE
STRENGTH AT 80' F
‘\9
"J0
Q)o
v9
0o
30
WEIGHT PERCENT WATER —-I
FIG. I
WILLIAM G. BEARDEN
JOE C. STALL
INVENTORS
M4461 mc¢47
ATTORNEY
Dec. 25, 1962
3,070,450
W. G. BEARDEN ETAL
BLOWN ASPHALT CEMENTS
3 Sheets-Sheet 2
Filed Nov. 25, 1959
24 HR. TENSILE
D
STRENGTH A1‘ BO'F
@o9/
WEIGHT PERCENT WATER—-I
FIG. 2
WILLIAM G. BEARDEN
JOE c. STALL
INVENTORS
. 8M)”:
AT TORNE Y
12
Dec. 25, 1962
W. G. BEARDEN ET'AL
3,070,450
BLOWN ASPHALT CEMENTS
3 Sheets-Sheet 3
Filed Nov. 25, 1959
ASPHALT EMULSION
F Wu. 4
BLOWN ASPHALT CEMENT
W l l M M a B EA R DE N
JOE C. STALL
INVENTORS
>411
BLOWN ASPHALT KEROSENE EMULSION CEMENT
ATTORNEY
S
3,070,450
United States Patent 0 ” 1C6
Patented Dec. 25, 1962
1
2
ranging in screen size from about 14 mesh to pan, with
3,070,450
BLOWN ASPHALT CEMENTS
William G. Bearden and Joe C. Stall, Tulsa, Okla., as
signors to Pan American Petroleum Corporation, Tulsa,
Okla., a corporation of Delaware
approximately 90 percent of the particles being smaller
than 14 mesh and larger than 100 mesh.
The use of
smaller particle size blown asphalt is advantageous where
it is desired to avoid the hazards of premature bridging.
If lost circulation characteristics are important, the asphalt
should include a portion, say 50 percent, of a larger
particle size, e.g., from about 4 to about 10 mesh.
This invention is concerned with cement compositions
Mineral oils suitable for use in preparing certain of
of the type suitable for oil ?eld application. More par
10 the compositions of our invention may be selected from
ticularly, it relates to a new and improved cement con
a number of crude oil fractions or, in some instances,
taining blown asphalt, which imparts a number of de
crude oil itself may be used. T o avoid vaporization of
sirable properties to the composition.
the oil, which may establish an undesirable degree of
Numerous disadvantages exist in the various kinds of
permeability in the cement while it is setting, the oil
cements now used in oil ?eld work. For example, the
should have a relatively low volatility. By this, we
slurry weight of some cements is so great that they pro
mean any crude petroleum or fraction thereof having a
duce excessive bottom hole pressures which, in turn, re
vapor pressure less than the pressure under which the
sult in loss of cement to the formation via fractures, etc.
cement slurry is to set in the well. Normally, a light oil
When it is desired to reduce the slurry weight of cements
fraction, such as kerosene or diesel fuel, is most desirable.
containing bentonite, diatomaceous earth, etc., by the 20 Gasoline is too volatile for most purposes and, in addi
addition of water, so much of the latter must be added to
tion, is considered too hazardous for the majority of uses.
obtain any weight reduction ‘that the strength of the
Many crude oils have light ends which are too volatile,
cement is seriously impaired. Also, with cements cur
and some contain an undesirable amount of natural
rently available, excessive shattering or fracturing occurs
emulsifying agents. Most crude oils should be avoided
Filed Nov. 25, 1959, Ser. No. 855,300
10 Claims. (Cl. 106-96)
when casing backed by such cement is perforated. This
is not only bad from the standpoint of permitting leakage
for these reasons.
of water from above or below the perforation into the
inert or extender materials may be present.
well, but also aggravates the corrosion problem. More
In addition to the blown asphalt and cement, certain
For ex
ample, the water used may contain inorganic salts or the
cement may contain a small amount of inert solids. T_1_i_e
e.g., neat Portland cement, the bond strength is affected 30 com osition however should consist essentially of blowg
by electrolysis, showing a trend to a weakened bond with
asphalt, cement, kerosene and7or water in flie?ilrpimtswof
an increase in ampere exposure time. This bond damage
c'oficcntration hereinafter referred to. Diluents or ex
is caused by failure of the cement due to migration of
tenders, ‘as previously 1nd1cated, may or may not be
cations to the casing (cathode).
present. If they are present, they should constitute not
Accordingly, it is an object of our invention to provide 35 more than about 5 percent by weight of the slurry. Also,
a light-weight cement suitable for use in high column
any of the usual cement retarders or accelerators may be
cementing jobs, and having good perforating character
incorporated in the customary amounts.
istics and relatively high tensile strength. It is also an
We have found that the above-mentioned desirable
object of our invention to provide a cement composition
characteristics ‘are present in cements of the type con
over, we have observed that in the case of many cements,
offering substantially increased protection to the casing
from electrolytic or other types of corrosion. Another
object of our invention is to provide a cement that can
be perforated without fracturing, thereby preventing com
munication of ?uids past the annular cement. Still an
other object of our invention is to provide a cement com
templated herein only if the ratio of ingredients is main
tained within certain rather well-de?ned limits.
These
limits, in the case of compositions consisting essentially
of blown asphalt, cement and water, are illustrated by
reference to the ternary diagram ‘in FIGURE 1. Thus,
45 the compositions possessing properties which make them
position having reduced ?uid loss.
highly desirable as oil well cements are illustrated by the
Brie?y, our invention contemplates the incorporation
area within the lines connecting points A, B, C and D.
of a preferably dry, granular or powdered blown asphalt
The long-dashed lines designated “a” show the slurry
into Portland or other hydraulic cement slurries with or
weights of cements whose composition is represented by
without a non-volatile mineral oil. The weight ratio of
blown asphalt to cement used may generally vary from
1:1 to about 1:13. With the use of mineral oil in these
compositions, the maximum ratio of asphalt to cement
that can be employed decreases as the oil content in
creases due to the resulting slurry becoming too thick
for practical application.
In preparing these cements, a dry mixture of thgasphglt
4a,,1,.
and cement in proper proportions is added to the mineral
oil and/ or water and blended in a high-speed jet or equiva
lent mixer. Within a short time the composition is ready
for use. In the case of compositions employing both
blown asphalt and a re?ned mineral oil such as, for ex
ample, kerosene, the appearance of the material varies
from gray to black, depending upon the amount of oil
used. While the effect of particle size of the blown
asphalt on cement properties has not been evaluated,
we generally prefer to use the smaller particle sizes, e.g.,
,
.
,
r
_
.
a point falling on or near any of the so designated lines.
Short-dashed lines "b” represent speci?c tensile strengths
of cements having the indicated composition after curing
for 24 hours at 80° F.
Cement slurries having a com
position falling to the left of line AB are too thick for
convenient haridling owing to insufficient mixing water.
Below line BC, the strengths are insu?icient for general
cementing practices. To the right of line CD, the slurries
are too thin for satisfactory solid suspensions. To the
right of line AD, the cements do not contain enough
60 asphalt to produce a cured product materially different
from neat cement.
The area ABCD, then, de?nes a
series of cementing compositions with slurry weights
ranging from about 10 pounds per gallon to 15 pounds
per gallon and having tensile strengths ranging from about
30 to about 200 p.s.i.
FIGURE 2 shows speci?c compositions prepared by
8,070,450
adding kerosene and water to a mixture containing blown
asphalt and cement in a weight ratio of 1:3. These slur
ries possess properties which render them outstanding for
oil ?eld use.
Table I
percent Percent Percent Percent
Kerosene
‘l at“ Cement
The composition ranges capable of giving
a cement having the desired properties lie within the 5
____
area surrounded
by lines connecting points .A, B, C,. D and
.
E. As in FIGURE 1, the long-dashed hues designated
,,,
,,
.
.
.
.
.
-
0
_
a indicate
(.ensities (lbs./gal.), while the short
dashed hnes b show tensile strengths (lbs/sq. in.) deo
'
-_
veloped in 24 hours at 80 F., as a function of composi 10
non. Above line AB, the consistencies of the slurries
36
34
30
0
5
27
68
0
5
46
49
are generally too high, making them di?icult to handle.
'5
18
23
54
To the left of the boundary BC, the external phase of
the slurry reverts from water to kerosene and will not
120
15
20
45
set.
i 22
14
22
42
Below the line CD, the strengths are inadequate and 15
Remarks
'
.
asphalt concen
tration and minimum cc
Maximum
merit.
Minimum asphalt comcmm
tion and maximum cc
merit.
Minimum 85pm“ and ma“
mum water.
asphalt and °°‘
Maximum asphalt (gn- co
containing 2044mm.
Maximum kerosene.
below the line DE, the slurries are thin and the compo
nents
to separate.
Thus,
the area
ABCDE' de?nes
_ seem
'
'
~
g'l‘lhe above statreriaspmlatlirna
minim?
aire céincernledu'ith
etlimcntsin
tat to and
cement
is z‘.
‘or at er aspiia
occult-zit
w ici tie ratio 0
light weight cementing materials having the practical and
mics di?eremmxima and minim appm
desirable characteristics of a good 011 ?eld cement. The
maximum density is about 13 pounds per gallon, indicated 20
In order to demonstrate the advantages the novel ce
at A. The minimum density is slightly greater than 10.5
merit compositions of our invention have over neat ce
pounds per gallon for compositions adjacent point C.
ment, asphalt emulsion cement and kerosene emulsion
The cements within the aforesaid de?ned area have tensile
cement, the following table is included which gives a
strengths ranging from 30 to about 100 psi.
typical composition for each of the cements involved.
Table II
Mimirnum
Bottom Hole
Slurry ComposiTypeot Cement
Temperature
Electrical Perforating
tion, Wt. Percent Density. Fluid Loss at 80° F. to Develop 50 Resistivity, ChzirncterLbs/Gal.
p.s.i. Tensile ohmcm.
istics
Strength in 24
Proposed Uses
hours, ° F.
Neat Portland _____________ __ 68.5 cement, 31.5
15.5
115 cc.l1.5 min_..-
<80
1,062
Poor .... .. Conventional jobs.
water.
Kerosene Emulsion Gement.. 48 cement, 22
11.5
204 cc./1.0 111111...-
80
1,151
Fair _____ ._ High column cementing
14.4
75 cc./3.2 min_..___
80
1,135
Fair ..... .. Low
kerosene, 30
JObS and in corrosive
water.
Asphalt Emulsion CemenL. 62
areas.
cement, 10
asphalt, emulslon, % water.
fluid
permeability
quiretl.
Blown Asphalt Cement ____ __ 42 cement, 24
blown asphalt,
11. 5
85 cc.,/0.5 miu....--
80
1,264
re
not
recommended
where low fluid loss
11.5
60 cc./8.4 min_..._-
propertiesarerequired.
80
2, 522
Good ._..-. High column cementing,
highly corrosive areas,
where low ?uid loss
propertiesarerequired.
Substitute
cement.
FIGURE 2 de?nes the useable range of compositions
for slurries exhibiting a constant asphalt-cement ratio of
1:3; however, this invention is not limited by this ratio.
For example, FIGURE 1 shows that suitable cements are
formed at a rati
1:1, i.e., 30 percent cement, 36 per
p rcent water.
is
highly corrosive areas;
_
cent asphalt,
jobs,
Good ____ -. High column cementing,
34 water.
Blown Asphalt-Kerosene...“ 48 cement, 16
Emulsion Cement.
asphalt, 15
kerosene, 21
water.
loss
highly corrosive areas,
and jobs where low
Kerosene can be added
to this mixture, however, the consistency of the slurry
would increase and would soon be too thick for practical
application. Thus, in a ternary diagram for slurries of
1:1 asphalt-cement ratio, the useable range of slurries
would be represented by essentially one point (35 percent
asphalt, 30 percent cement, 1 percent kerosene and 2'4 per
for
neat
It will be observed from the above table that the kero
sene emulsion cements, the blown asphalt cements and
the blown asphalt-kerosene emulsion cements all form
light-weight slurries. These three types of cements can
be mixed so as to give a density of 11.5 pounds per gallon
r
and still develop a tensile strength of 50 p.s.i. within 24
hours at 80° F. Higher strengths can, of course, be
achieved it higher densities are permissible. The ad
vantage of using blown asphalt as an additive to produce
light-weight cements is also shown in the above table, as
6O well as in FIGURE 1. Such cements have been prepared
having densities ranging from slightly below 10.5 up to
about 16.5 pounds per gallon. The ?uid loss character
cent water). This useable area would increase in size
istics of blown asphalt cements are higher than those of
with decreasing asphalt-cement ratios and would be as
neat Portland cement. However, the relatively high ?uid
shown on FIGURE 2 for a 1:3 mixture. At still lower 65 loss properties can be of value in squeeze cementing oper
ratios (decreasing asphalt), the area increases in size. At
ations to obtain high ?nal squeeze pressure and reduce the
ratios less than about 1:13, the advantages of the asphalt
amount of cement required. The resistivity measure.
become nil.
ments indicate that this type cement offers better cathodic
The table below illustrates further the composition of
typical cements coming within the scope of our invention. 70 protection than neat Portland cement, kerosene emulsion
cement and asphalt emulsion cement. The pumpability
These ?gures show the weight relationships that should
time is not affected by the blown asphalt and the slurry
be maintained in order to retain the desired characteristics
develops strength for most ?eld applications. Mixing in
in the cements of our invention and particularly point out
the ?eld is accomplished by dry blending the asphalt in the
how, as the mineral oil concentration increases, the blown
75 cement at the bulk blending station like any other cement
asphalt content decreases.
.-
.
s
w’
3,070,450
6
5
corresponding to that employed in preparation of the test
additive, hauling to location then mixing with water in
section shown in FIGURE 4, has a tensile strength slightly
the conventional manner.
under 75 p.s.i.
The results in the above table, as well as in FIGURE
FIGURE 5 shows results from perforating a blown
2, show that slurries formed with blown asphalt, kerosene,
water and cement exhibit slurry weights less than 11
pounds per gallon. The pumpability time as compared
with neat Portland cement, is not appreciably affected
and the ?uid loss approaches that of low ?uid loss cement.
Cathodic protection and ?uid loss characteristics are ap
preciably improved by those properties exhibited by neat
asphalt~kerosene emulsion cement having the composition
indicated in the above-mentioned table. This ?gure like
wise shows that no shattering or cracking occurred dur
ing the perforating operation and indicates that the blown
asphalt in the composition imparts su?icient resiliency to
10 the cement to withstand the shock imposed by the per
forating charge. At the same time, the tensile strength
cements. In ?eld operations, the blown asphalt-kerosene
emulsion cements are mixed by blending the blown asphalt
and the dry cement at bulk stations then adding this
of this cement, as may be seen from FIGURE 2, is of the
order of 50 p.s.i.
We claim:
blend to a ?xed ratio of kerosene and water metered into
a jet mixer.
The ordinary asphalt emulsion cement slurries are
shown in the above table to exhibit only moderate re
in which the weight ratio of blown asphalt to cement
ductions in slurry weight, while the low ?uid loss char
to about 45 weight percent water, said asphalt and cement
1. A pumpable blown asphalt hydraulic cement slurry
ranges from about 1:1 to about 1:13 and from about 25
being the essential solid components of said slurry.
acteristics offer an improvement over those of neat Port
land cement slurries. With certain blends of AR]. class 20 2. A pumpable slurry having as its essential solid in
gredients blown asphalt and a hydraulic cement in which
A cements, the asphalt emulsion used therewith was ob
said asphalt and cement are present in a weight ratio of
served to cause a high false body gel or premature thick
from about 1:1 to about 1:13, and from about 25 to 35
ening of the slurry within the ?rst 30 minutes after mix
weight percent water together with from about 1 to about
ing. This trend was not constant and appeared to vary
with the temperature, the blend of cement and the batch 25 25 weight percent of a non-volatile mineral oil.
3. The composition of claim 2 in which the non-vola
tile mineral oil is kerosene.
of asphalt emulsion. Compared to blown asphalt cement
and blown asphalt-kerosene emulsion cement, the asphalt
emulsion cement is less desirable from the standpoint of
4. The composition of claim 2 in which the'non-vola
tile mineral oil is diesel oil.
electrical resistivity.
The exceedingly good perforating characteristics of the 30 5. A pumpable aqueous blown asphalt-non-volatile
mineral oil oil’well Portland cement slurry containing
blown asphalt cements of our invention are shown and
from about 5 to about 35 weight percent blown asphalt,
compared to the results obtained with ordinary asphalt
emulsion cement in FIGURES 3, 4 and 5. In each case,
the composition of the cement used was the same as that
from about 5 to about 20 weight percent of a non—
volatile mineral oil having a vapor pressure less than that
cements.
cement is employed.
9. The slurry of claim 2, in which the hydraulic cement
indicated in the table above. To test the perforating 35 of gasoline, from about 30 to about 70 weight percent
cement and from about 20 to about 35 weight percent
characteristics of the cements, the annular space between
water, said asphalt and cement being the essential solid
18-inch lengths of SVz-inch casing and 10%-inch casing
components of said slurry.
was ?lled with each type of cement, cured for 72 hours
6. The composition of claim 5 in which the mineral oil
and perforated with a single Du Pont 26-A shaped jet
charge. After shooting, the outer casing was removed to 40 is kerosene.
7. The composition of claim 5 in which the mineral oil
expose the perforated section of the cement. For com
is diesel oil.
parative purposes, a neat Portland test specimen was
8. The cement slurry of claim 1, in which Portland
poured and perforated at the same time as the special
While the results of perforating tests on neat
Portland cement are not illustrated by actual photographs,
the notation appearing in the above-mentioned table ade
quately describes the perforating characteristics of this
material.
The exceedingly good perforating characteristics of the
blown asphalt cements of our invention are shown and
is Portlant cement.
10. The composition of claim 1 in which the blown
asphalt is in a dry, ?nely divided form.
50
compared with the results obtained with ordinary asphalt
emulsion cement in FIGURES 3, 4 and 5. In each case,
the composition of the cement used was the same as that
indicated in the table above. While the ordinary asphalt
emulsion cement performed better in perforation tests
than either neat cement or kerosene emulsion cement,
fractures (designated by the arrows) can be seen in FIG
URE 3 extending radially from the perforation.
Al
though the ability of such cement to withstand the shock 60
of perforating operations can be improved by the addi
tion of more asphalt, this results in a substantial reduc
tion in tensile strength.
The improved perforating characteristics of the blown
asphalt emulsion cement are shown in FIGURE 4. It 65
will be seen that no shattering or cracking of the cement
occurred. The irregular portion of the perforation was
caused by de?ection of a small piece of the copper liner
from the shaped charge. As can be seen from FIGURE
1, a blown asphalt emulsion cement having a composition
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,563,755
1,599,903
1,711,727
1,726,708
1,744,869
2,297,660
2,776,010
Leonardt _____________ __ Dec. 1,
Lord ________________ __ Sept. 14,
Forrest ______________ __ May 7,
Levin _______________ __ Sept. 3,
Cross _______________ __ Jan. 28,
Mazee _______________ __ Sept. 29,
Rike __________________ __ Jan. 1,
1925
1926
1929
1929
1930
1942
1957
2,798,003
Morgan et al. _________ __. July 2, 1957
2,812,161
2,861,004
2,878,875
2,923,643
Mayhew ______________ __ Nov. 5,
Sucetti ______________ __ Nov. 18,
Dunlap ______________ -_ Mar. 24,
Rodwell ______________ __. Feb. 2,
3,036,633
Mayhew _____________ __ May 29, 1962
1957
1958
1959
1960
OTHER REFERENCES
Oil and Gas Journal, March 30, 1959, vol. 57, No. 14,
pages 104-105, “Gilsonite Used in Cement Jobs.”
UNITED STATES PATENT OFFICE
‘CERTIFICATE, OF CORRECTION
Patent No, 3,070v4‘5o
December 25a 1962
William Ge 'Bearden et ale
It is hereby certified that error appears in the above numbered pat
ent requiring correction and that the said Letters Patent should read as
corrected below.
Column 3? line 56? 62 and 63‘I for "24 pelz‘centmI each
occurrence‘, read -- 34 percent --; column 69 line 31‘, after
"mlneral 'oil" insert a commao
v
Signed and sealed this 18th day of June 1963:.
:SEAL)
Attest:
ERNEST w. SWIDER
Attesting Office!‘
DAVID L- LADD
‘
.
Commissioner of Patents
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