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Патент USA US3022258

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azazis
Patented Feb. 20, 1%52
2
3,022,248
, 5
LOW FLUID LOSS COMPGSETION
Duane B. Anderson and Arthur Park, Tulsa, Okla, as
signors to Pan American Petroleum Corporation,
Tulsa, Okla, a corporation of Delaware
No Drawing. Filed Sept. 21, 1959, Ser. No. 841,049
20 Claims. (Cl. 252--8.5)
soluble) lignin. The alkaline form of lignin is available
in various degrees of alkalinity. For example, sodium
lignates containing 4 percent sodium and about 10 percent
sodium are both commercially available. The product
containing 4 percent sodium is a puri?ed sodium salt of
lignin. The amount of sodium present corresponds to be
tween 1 and 2 mols of sodium per mol of lignin. It is
soluble in water and alkali, but insoluble in acids. In
This invention relates to ?uids used in well-working
the product containing 10 percent sodium, part of the so
operations such as, for example, drilling and well comple 10 dium is present as sodium lignate and part is present in
tion operations. More particularly, it is concerned with
the form of free sodium salts, largely sodium carbonate.
the use of improved low solids liquids for such purposes.
A drilling completion or work-over ?uid should have a
low ?uid loss to avoid the build-up of a thick mud ?lter
. . pack on the Wall of the hole and to minimize ?ushing of
l
I,l . .
I
a production zone. If a low density ?uid can be used,
_, clear water has the advantages of faster penetration rates,
greater footage per bit and lower cost. Morever, a clear
brine completion of work-over ?uid results in-a faster and
cleaner repair job than does mud.
,
.
In .using drilling ?uids of this type, however, ?uid loss
frequently is too high. Keeping water in'the system and
preventing it from leaking into the'formation is essential
to reducing caving and sloughing of water-sensitive shales,
The puri?ed lignin, hereinafter referred to as the acid
form, is generally obtained from pine or other soft wood
and is 99.5 percent organic material. It is insoluble in
Water and acids, but soluble in alkali. The acid lignin
is produced by ?rst subjecting wood to caustic digestion.
The waste cooking liquor containing sodium lignate is
then acidi?ed, causing the acid form to precipitate.
The product containing 4 percent sodium exhibits ap
20 preciable ability to reduce ?uid loss.
A more e?icient
?uid loss retarder is obtained, however, by mixing the
water-soluble and water-insoluble forms of lignin. The
water-soluble form preferably contains about 8 to 10
percent sodium, and when combined with the acid form
etc. In cases of high ?uid loss, it is di?‘icult to circulate 25 in a weight ratio ranging from about 3:1 to about 1:3,
produces a very e?icient ?uid loss retarder. Certainly
the well and to circulate sand and cuttings from it. ‘ Also,
with high ?uid loss there is occasionally the danger of
mixtures of the alkaline and, acid forms of lignin serve
getting tools stuck.
Recently, considerable interest has been shown in the
as a much better ?uid loss reducer than either of these
forms alone, as data appearing below will demonstrate.
While cer 30 Generally speaking, the percentage of alkali present in
tain types of formations have been successfully fractured
the total mixture may range from about 2.5 to about 7.5
with water, its use has been limited generally to forma
Weight percent based on lignin. Expressed otherwise, the
tions of low permeability. Because of their cheapness,
pH of the ?nal aqueous ?uid is preferably from about 7
ease of handling and general availability, it would be most
to about 9. In addition to sodium carbonate and caustic,
desirable to improve the ?uid loss characteristics of frac 35 We may use any of the water-soluble alkali metal com»
turing ?uids consisting primarily of water so that they 7
pounds to bring about the desired conversion of acid lig
could be more widely used in fracturing operations.
nin to the alkaline form. Alkaline earth metal com
use of water as a hydraulic fracturing ?uid.
Accordingly, it is an object of our invention to provide
a novel, aqueous, low ?uid loss, low solids composition
having the advantages of clear water in both drilling and
fracturing operations. Another object‘ of our invention
is to employ a mixture of the so-called acid form of lignin
and the alkaline form of lignin as the ?uid loss retarder in
clear water drilling and fracturingrcompositions, the two
forms of lignin being present in concentrations such that
a time dispersion of the lignin'materials is produced. it
pounds, ir‘on compounds and similar materials are un
satisfactory for this purpose because they tend to render
lignin water-insoluble.
The quantity of lignin mixture containing the two
forms of lignin within the ratios mentioned above may
vary from about 1 to about 10 pounds per barrel. Above
10 pounds per barrel, very little ?uid loss improvement is
generally observed, although the-‘resulting increase in vis
cosity is slight.
is still another object ‘of our invention to render these
We have found that the presence of a small percentage
clear water ?uids stable to ?uctuations in harmful salt
of liquid hydrocarbon, typically from about 1 to about 5
weight percent, and a surface active agent capable of
content, such as sodium chloride and the alkaline‘ earth
metal compounds frequently encountered in drilling or 50 rendering water-wet surfaces oil-wet enhance the ?uid loss
hydraulic fracturing operations.
characteristics of our compositions. In this connection,
the expression “surface, active agent" as used in the claims
vWe have now discovered’that lignin,v a cheap by-product
is intended to be limited to those agents that render water
ofrthe paper industry, can be used in certain forms as an
e?icient ?uid loss retarder for low solids aqueous ?uids
Wet surfaces oil-wet. As examples of surface active
l
t
without causing an increase in the viscosity of said ?uids.
Lignin can be made either soluble or just dispersible in
water by the addition of a suitable alkaline compound.
The solubility of lignin in water depends on the amount ~
of alkaline material added. We have found that if to a
agents. that may be used in preparing the novel composi
. tions of our invention, there may be mentioned the long
chain aliphatic amines, c.g., dodecylamine; the Duomeen
type amines sold by Armour Industrial Chemical Com
pany, such as decyldimethylenediamine, dodecyldimeth
ylenediamine, tetradecyldimethylenediamine, etc.; quater
mixture of water and the acid form of lignin, which is
60
insoluble in water, suf?cient caustic is added to render
nary ammonium salts, such as the N-alkyl ammonium
the lignin just dispersible, a fluid is produced possessing
chlorides, c.g., the Arquad series of quaternary ammoni
excellent ?uid loss properties. The quantity of caustic or
um salts also sold by Armour, e.g., N-alkyltrimethylam
7 other alkali metal compoundvrequired to produce such a
dispersion of lignin in water generally may range from.
about .02 to about 0.1 weight percent.
Instead of adding caustic to a heterogeneous mixture
of the acid lignin and water, the acid and alkaline forms
of lignin can be mixed in the presence of water to produce
monium chlorides, di-N-alkyldimethylammonium chlo- '
rides, etc. These agents are used in emulsifying amounts,
‘ i.e., generally from about 0.1 to about 1.0 weight percent.
The liquid hydrocarbons used in improving the ?uid
loss properties of our ?uid may vary widely in composi
tion. Typical examples of suitable hydrocarbons are
an aqueous dispersion of lignin identical in ?uid loss char,
crude oil, kerosene, diesel oil, gas oil, gasoline, etc.
acteristics to the composition produced by the addition 70 These materials are preferably incorporated into the ?uids
of caustic to an' aqueous mixture of the acid (water-in
of our invention in an amount ranging from about 1 to
3,022,248
>
a
‘tendency to plug the formation permanently. On pro
duction of the formation liquids, the layer is removed
from the rock by baclo?ow of saidliquids into the well.
‘about 5 weight percent, although higher percentages may
be used.
‘
_
.
Inv using the ?uids of our invention either in drilling
‘ or in fracturing operations, brines containing high concen— .
.
bore,
.
I
trations of sodium chloride or alk'alineearth metal com- 5 _ _ Our invention will be .furtherillustrated by reference
pounds are often encountered. 'When our ?uids come into '
contact with materials of this type, the lignin is converted
to thedata appearing inithe table below. in _Table I, the
data; presented therein, weregobtainedby making up sepa- '
to a highly insoluble form, -i'.e.', an alkaline earth metal
rate aqueous mixtures containing the listed components in ,
lignin. As a result,fluid loss can be quite high, causing
the amounts 1nd1cated.= The ?uidloss propertiesoi each
‘ operations to become ine?icient; Accordingly, ‘where this 10 mixture were then determined by, ‘the Standard Field Pro
' condition is encountered in ‘drilling, caving and sloughing
cedure for Testing Drilling Fluids, Section IV,’ A.P.I.,
of water-‘sensitive shales can occur, resulting in sticking of
Test RP 29, 1950.
1
tools in the hole. When fracturing with these compositions.
T[1512 I
under conditions of high calcium content-brines,. for ex-
,
ample, the loss of ?uid tothe formation'becomes' high,
15
W
requiring
sary pressure.
greatly increased
I I
power to
I I maintain
~ ~
the
. . neces-
'Allrallne
lhs./bbl.
Lfgingl,
‘We have found, however, that the disadvantages caused
I Alkaline ,
aifcigg
dium)
,
66%;‘;
dium)1
~ ' lbSJbbL
.
.
_
lbsJbbl.
D6???
I
‘
Agg?o‘gef'
. ,
'
,
A.P.I
lbs'mb
by such high alkaline earth metal concentrations can be
200
satisfactorily overcome by’ the addition of either guar 20
. gum or carboxymethyl cellulose to the ?uid in aconcen-
-
4,
-
..... _l___-.._
i 4
'tration of from about 0.1 to about'l pound per barrel.
4
._-_.
3/2
Ordinarilyr there is no additional stabilizing effect observed 7
2
with concentrations of these additives in excess of about
1 pound per barrel. Use of either of these materials 25
renders the fluid‘ substantially insensitive to excessive con-y
1
2
centrations of alkaline earth metal compounds, as well as
y
other ,matenals ' lvhlqh' QrdmmI?-Yi tend to ' render hgnm
‘
.
250
--
I43
1
'1/2
. 2,
________ “I: _________ __
-
-------------------- "
2p
...................... _-
:32;
. Q
g
------------ -~
1
2.
g
.K-__~..&_2_'é.1.
rq‘llf‘a
.
.
.
-
13.
. 1g
-
,
,
1A1: Nealkyltrimcthylammonlum chloride derived from a mixture of
'W?tGf-JHSOIUIJIB‘. V'FillldSiO which guar gum or carboxy-
coconutfatty ends. I
.
.
,
methyl cellul?seéhas befin added 31‘? found to‘ b? 'qPitB. '30 L To demonstrate the effectiveness of guarigum and-car
Stab1?'°ver P1'_a°t“fa1 pfmods of‘ use ‘Vlthout an. Oblectwn- I
boxymethy'l cellulose as‘a' stabilizer for the. novel ?uids. .
able increase 1111311560513" WE? ha‘ldf?ll?d gllaf gum'anfl
‘oi ouriinvention, a number of tests were carried out using
carboxymefhyl 6611111056 {0 be unlquely' sult?d 50f’ this
i the list ot'components in the amount indicated in the table '
purpose, since numerous materials normally consldered
bciow. The ?uid loss data were determined in accordance .
the equivalent ‘of guar gum for other purposes such, as, 35' with the A.P.I; testing procedure referred to above.
Table II
'
.
Alkaline
Acid
Test No.
Lignln
Lignin,
>
,
lbsJbbl.
.
(10% I
'
Pcnnsyl-
Diesel
' Gum Additive 1, - '
on,
,
lbsJbbl.
Sodium) gals/bill.
lbsJbbl.
-
vsntsn . I
Age
I
Fluid
Additive,
.
. Loss,
'lb'sJbbl.
I
A.P.I.',
Shale,
:
cc.
lbsJbbl.
2
2
3
2
2
3
2
2
2
2
2
2
3
3
a
2
2
2
2
3
a
3
1
3
12.0
10 021804 _-
18.0
10 oaonm10 014804.---
8.5
20.0
30.0
100.0
90.5
__..
23.0
10 021017....
125. 0
1
a
3
2
2
3 .................... ...
2
2
2
2
a
3
21.0
0.5
13.0
2
2
3
10.0
2
2
2
2
a
a
20.0
33.0
10
2
2
a
10 CaClz-..--
75.0
2
2
a
- 10 Cams"..-
81.0
2
2
3
10 oaohm-
14.0
1 Unless speci?cally named, guar gum was the additive used.
for example, agar-agar, gum karaya, acacia, etc., do not
In determining whether or not a ?uid will be satisfactory
exhibit this tendency to inhibit the sensitivity of our ?uids 60 for use in hydraulic fracturing, the rate at which said ?uid.
to high alkaline earth metal compound-containing brines,
passes through a barrier of known permeability‘should be
or formations containing substantial amounts of. the
established. Hydraulic fracturing compositions normally
alkaline earths, iron compounds or other materials, ‘such
regarded as satisfactory should exhibit a ?uid loss of 100
as sodium chloride.
While we do not wish to be limited to any particular
theory or mode of operation by which we are able to
effect a reduction in ?uid loss with the use of lignin in
cc., preferably 50 cc. or less in 30 minutes, as determined
in accordance with the above-mentioned A.P.I. test. Our
?uids were subjected to this test and compared to the
performance of other compositions falling outside the
‘drilling ?uids or in fracturing ?uids, in accordance with
scope of our invention. Another series of tests was per
our invention, we ‘believe that the dispersion of mixed
formed in which the ?uid was placed under pressure
70
lignins is laid down on the walls of the Well during either
against a wafer-thin core section. A core was mounted
drilling or fracturing operations to form a thin, tough
in a transparent plastic (Lucite) sleeve, sealed under pres
water impervious skin or layer on the face of the forma
sure, and the core wafers were then sliced from the
tion. This layer, however, remains on the formation face
mounted core. The wafers were constructed so that they
only so long as the pressure at said face exceeds the
could be pressed in a high-temperature, high-pressure
formation pressure. These lignin dispersions show no 75 ?lter press. The use of‘the ?lter press reduces consider
8,022,249
5
ably the time required to perform the experiments. The
mixture containing the acid lignin and alkali metal ligninv
?nished core wafers were placed in the ?lter press and
in a weight ratio of from about 3:1 to about 1:3.
4. The process of claim 3 in which‘said'lignins are
their permeability checked to eliminate those containing
small fractures, etc. The wafers were then saturated with
present in substantially equal amounts by weight.
25 centipoise mineral oil under a vacuum prior to the
5. A substantially clear aqueous composition contain
?uid. loss tests, ‘and the volumesof liquid passing through
ing as a ?uid loss retarder a mixture of from about 1 to
the core section measured. overdifferent time intervals.
In carrying out both sets oftests, the .same ?uid was used
and consisted of a mixture of.2_ grams of acid lignin, '2
about 10 pounds of an acid lignin and an alkali metal
and the results obtained are indicated below.
of from about 7 to about 9.
6. The composition of claim 5 in which the alkali metal
lignin per barrel of said composition, said acid and alkali
metal 'ligni'ns being present in a weight ratio ranging from
grams of alkaline lignin. (lOpercent sodium), and 8 cc. 10V about 1:3 to about 3:1, the alkali metal being present in
of diesel oil in 350 cc. of water. The conditions used
an amount sufficient to produce a pH in the ?nal mixture
In both
tests a pressure of 1000 psi. was used.
lignin is sodium lignin.
Table III
7. A substantially clear aqueous composition contain
ing as a ?uid loss retarder a mixture of from about 1 to
about 10 pounds of an acid lignin and an alkali metal
Core Wafer Test
Volume
00.
,
14.0
17.5
18 5
Temp" 0 F’
701 ........ -70 1 ______ __
701 ______ -.
Time
(Min)
1
4
9
Volume,
cc.
lignin per barrel of said composition, said acid and alkali
metal lignins being present in a weight ratio ranging from
20 about 1:3 to about 3:1, said alkali metal being present in
an amount su?icient to produce a pH in the ?nal mixture
of from about 7 to about 9, and a water soluble gum se
18.5
21.5
23. 5
19.5
70
15
24.5
lected from the group consisting of carboxymethyl cel
21.0
23.0
701.
701.
25
35
25.5
28.5
lulose and guar gum in a concentration of from about 0.1
40.0
1252
1
9.0
44.5
43.5
1251
1251
4
9
11.5
14.5
52. 0
125 1 ..... __
57. 0
125 1-.-
50. 0
125 I _______ __
10
15.5
25
19. 0
a0
21. 5
1 Initial permeability of core, ‘27.1 Ind.
* Initial permeability of core, 28.4 md.
From the foregoing description, it will be apparent that
25 to about 1 pound per barrel of said composition.
8. The composition of claim 7 in which the water
soluble gum is guar gum.
9. The composition of claim 7 in which the water
30
soluble gum is carboxymethyl cellulose.
10. The composition of claim 7 to which has been
added in a minor amount a normally liquid hydrocarbon
in a concentration of at least about 1 weight percent.
11. The composition of claim 7 in which the alkali
we have provided an aqueous low solids ?uid suitable for
metal lignin is sodium lignin.
use as a drilling ?uid or as a fracturing liquid. By the 35
12. A low solids aqueous composition containing as a
use of a dispersion of mixed lignins, as taught by our in
?uid loss retarder a mixture of an acid lignin and an alkali
vention, we are able to deposit a substantially water im
metal lignin, said acid and alkali metal lignins being pres
pervious layer on a formation face, which may then be
used in building up high pressures against said face with
out substantial loss of the ?uid carrying said lignins.
Accordingly, our invention is intended to cover and in
clude any means or method by which such an impervious
layer is laid down in an aqueous system against a per
meable barrier.
ent in a weight ratio ranging from about 1:3 to about 3:1,
said alkali metal being present in an amount sui?cient to
produce a pH in the ?nal mixture of from about 7 to about
9, and a surface active agent in a concentration of not
more than about 5 Weight percent.
13. A substantially clear aqueous composition contain
ing as a ?uid loss retarder a mixture of an acid lignin and
As used in the present description and claims, the ex 45 an alkali metal lignin, said acid and alkali metal lignins
pression “low solids ?uids” is intended to refer to ?uids
being present in a weight ratio ranging from about 1:3 to
containing not more than about 7 weight percent clay
about 3:1, said alkali metal being present in an amount
solids; usually this ?gure is in the range of 3 to about 4
su?icient to produce a pH in the ?nal mixture of from
weight percent.
We‘ claim:
about 7 to' about 9, a water soluble gum selected from
50 the group consisting of carboxym-ethyl cellulose'and guar
1. A method of forming a substantially water imper~
gum in a concentration of from about 0.1 to about 1
vious layer on a permeable barrier which comprises con
tacting said-barrier with an aqueous mixture of lignin
' containing from about 2.5 to about.7.5 weight percent of
a water-soluble alkali metal compound, based on the
pound per barrel of said composition, ‘and a surface ac;
tive agent in a concentration of not more than about
5 weight percent.
14. The composition of claim 13 in which the water
lignin, which is present in said mixture in a concentration
soluble gum is guar gum.
of from about 1 to about 10 pounds per barrel.
15. The composition of claim 13 in which the water
2. A method of forming a substantially water imper
soluble gum is carboxymethyl cellulose.
'
vious layer on a permeable barrier which comprises con
16. A low solids aqueous composition-containing as a ‘
tacting said barrier with an aqueous mixture of lignin 60 ?uid loss retarder a mixture of an acid lignin and an
alkali metal lignin, said acid and alkali metal lignins be
and sufficient water-soluble alkali metal compound to
ing present in a weight ratio ranging from about 1:3 to
produce a pH in said mixture in the range of from about
.' about 3:1, said alkali metal being present in an amount
7 to about 9, said lignin being present in a concentration
sufficient to produce a pH in the ?nal mixture of from
of from about 1 to about 10 pounds per barrel.
3. ha process for reducing the loss of ?uid to a forma 65 about 7 to about 9, a water soluble gum selected from the
group consisting of carboxymethyl cellulose and guar gum
tion penetrated by a well bore when the face of said
in a concentration of from about 0.1 to about 1 pound
formation is exposed to an aqueous low solids ?uid, the
per barrel of said‘ composition, a surface active agent in a
improvement which comprises incorporating in said low
concentration of not more than about 5 weight percent
solids ?uid a sufficient amount of a mixture of an acid
70 and a minor amount of a normally liquid hydrocarbon in'
lignin and an alkali metal lignin in which the alkali metal
a concentration of at least about 1 weight percent.
content is not more than about 8 to 10 weight percent and
17. The composition of claim 16 in which the water
thereafter bringing the resulting mixture into contact with
soluble gum is guar gum.
the face of said formation to form a thin, substantially
18. The composition of claim 16 in which the water
water impervious layer of said lignins on said face, said 75 soluble gum is carboxyrnet-hyl cellulose.
3,022,248
I
19. An aqueous low solids composition containing as
a fluid loss retarder from about 1 to about 10 pounds per
barrel of substantially equal amounts by weight of an acid
lignin and an alkali metal lignin, said composition having
a pH in the range of from about 7 to about 9.
20. An aqueous low solids composition containing as
a ?uid loss retarder from about 1 to about 10 pounds per
barrel of substantially equal amounts by weight of an acid
Iignin and an alkali metal lignin and guar gum in a con
centration of from about 0.1 to about 1 pound per barrel 10
8
of said composition, said composition having a pH in the
range of from about 7 to about 9.
References Cited in the tile of this patent
UNITED STATES PATENTS
2,212,108
2,425,768
2,801,218
Zacher ______________ -_ Aug. 20, 1940
Wagner _____________ __ Aug. 19, 1947
2,854,407
Mallory ______________ - Sept. 30, 1958
Park et a1. __________ .__‘_ Mar. 10, 1959
2,877,180
Menaul ____ _; ________ .__ July 30, 1957
UNITED STATES PATENT OFFICE
CERTIFICATE OF CORRECTION
Patent No. 3,022,248
February 20, 1962
Duane B. Anderson et a1.
It is hereby certified that error appears in the wove numbered pet
ant requiring correction and that the said Letters Pat ent
should read as
corrected below.
Column 4, Table II, under the heading "Fluid Loss,
A.P.I. v cc." for "90.5" read —- 90,0 —-; column 5, line 70,
for "sufficient" read —— significant -—.
Signed and sealed this 19th day of June 1962.
(SEAL)
Attest:
ERNEST w. SWIDER
Attesting Officer
DAVID L- LADD
Commissioner of Patents
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