CA1258366A

CA1258366A - High temperature well cementing methods and compositions

Info

Publication number: CA1258366A
Application number: CA000491790A
Authority: CA
Inventors: Jerry D. Childs; Roosevelt Love; Willis A. Weigand
Original assignee: Halliburton Co
Current assignee: Halliburton Co
Priority date: 1984-09-27
Filing date: 1985-09-27
Publication date: 1989-08-15
Also published as: DK436385D0; DK436385A; NO853766L

Abstract

Abstract of the Disclosure Set retarded hydraulic cement compositions for cementing high temperature subterranean zones penetrated by wellbores and methods of using the compositions are provided. The cement compositions include effective amounts of a setting rate retarder comprised of one or more methylene phosphonic acid derivatives.

Description

y - ~

~51~3 Ei6 E~IGH TEMPERATURE WELI. CEMENTIN(~;
METHODS AND COMPOSITIONS
This invention relates to cementing compositions and methods of usin~ such compositions in applications where the compositions are subjected to elevated temperatures, e.g~, above about 400F. More particularly, the invention provi-des set retarded cement compositions for cementing high tem-perature zones in wells and methods of cementing such zones using the compositions.
In cementing operations carried out in oil, gas and water wells, Portland cement is normally mixed with about 40% to 50~ of water, based on the weight of dry cement, to form a pumpable slurry which is pumped into a subterranean zone to be cemented by way of the wellbore penetrating such zone. After placement in the zone, the cement slurry sets into a hard mass.
While cement compositions are utilized in carrying out a variety of operations in wells to accomplish a variety of purposes, cement compositions are most commonly used in well operations for bonding casing within the wellbore and sealing zones whereby ~ndesirable communication between zones is prevented. With the drilling of wells for the pro-duction of hydrocarbons to increased depths during recent years, extended cementing times are required to mix cement compositions and pump them to the desired zones in the !33~i~
wells. In addition, at the greater depths, elevated tem-peratures are encountered which accelerate the normal sets of cement compositiOns to the point where the cementing times, i.e., t~le mixing and placement times, exceed the pum-pable times of the cement compositions, making it difficult or impossible to place the cement compositions at the desired locations in the wells. The term "pumpable time" is used herein to mean the total time between when a cement composition is mixed and when the composition becomes too thick to pump.
Various methods of retarding the sets of cement com-positions and thereby increasing the pumpable times thereof have heretofore been employed in order to make possible the cementing of deep wells where high temperatures are encoun-tered. These include the use of special slow setting hydraulic cements and/or the addition of set retarding agents to the cement slurries. While various set retardin~
agents have been effective in extending the pumpable times of cement compositions subjected to temperatures up to about 400F, problems have been encountered where the cement com-positions are subjected to temperatures above about 400F.
That is, hereto~ore, even when the cement compositions include set retarders, in deep wells where the cement com-positions are subjected to temperatures above about 400F, the cementing times often have exceeded the pumpable times ~51~3~
of the cement compositions whereby cementing operations have been unsuccessful Gr incomplete.
By the prese~t invention~ set retarded cement compo-sitions are provided which are particularly suitable for use in cementing subterranean zones wherein the cement com-positions are subjected to elevated temperatures. Methods of cementing high temperature subterranean zones penetrated by wellbores using the cement compositions are also pro-vided.
The set retarded cement compositions of the present invention are comprised of a hydraulic cement, sufficient water to form a pumpable cement slurry which will set into a hard mass, and an effective amount of a set retarder comprised of a methylene phosphonic acid derivative or a mixture of such derivatives. The pumpable times of such compositions are of durations such that the compositions can be effectively utilized for cementing wells wherein the com-positions are subjected to temperatures up to 550F and higher.
The methylene phosphonic acid derivatives which are suitable for use in accordance with this invention as set retarders are as follows.
(1) Compounds having the structural formula:
Rl - N - R3 ~5~ 6 ~herein:
Rl, R2 and R3 are independently hydrogen, -CH2Po3(x)2 or -CH2CH2-0-P03(x)2 with the limitation that one of Rl, R2 and R3 is always -CH2P03(X)2 or -CH2CH2-O-Po3(x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one X is hydrogen which is associated with the nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom.

(2) Compounds having the structural formula:

N - CH2(CH2 - I - CH2)n - CH2 - N\
R2 Rl R2 wherein:
n is an integer from 1 to 4;
Rl is hydrogen or -CH2P03(X)2;
R2 is hydrogen, -CH2P03(X)2 or -CH2CH2N(R3)2 wherein R3 is hydrogen or -cH2po3~x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and --D~--r at least one of Rl r R2 or R3 is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom.

(3) Compounds having the struc-tural formula:
R2 ~ N N - CH2 - (CH2 ~ N - CH2)n - CH2 - R3 Rl wherein:
n is an integer from O to 4;
Rl is hydrogen or -CH2P03(X)2;
R2 is hydrogen, -CH2P03(X)2 or -cH2cH2N(R4)2 wherein R4 is hydrogen or -CH2Po3(x)2;
R3 is -NtRs)2 or -N N - Rs wherein Rs is hydrogen or -CH2Po3(x)2;
X is hydrogen, an alkali metal cation, ammonium~
a protonated amine or an alkaline ~arth metal cation in which case there is only one X per methylene phosphonate group; and at least one of Rl, R2 or R3 is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom.

(4) Compounds having the structural formulao ~2~
R \ R
N ~ (C~12)n ~ N\
R R

wherein:
n is an integer from 2 to 6;
R is hydrogen, -CH2P03(X)2 or -CH2CH2N(Rl)2 wherein R1 is hydrogen or -cH2po3(x~2i X is hydrogen, an alkali metal cat.ion, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one R is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom.

(5) Compounds having the structural formula:
R O R

N - C - N \

R R

wherein:

R is hydrogen, -cH2po3(x)2 or -CH2cH2N(Rl)2 wherein Rl is hydrogen or -CH2P03(X)2;

X is hydrogen, an alkali metal cation, ammonium,

6~

a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one R is -CH2P03~X~2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom.
(6) A compound having the structural formula:
R R
N - CH2CH2 - O - CH2C~2 - N
R R
wherein:
R is hydrogen, -CH2P03(X)2 or -CH2CH2N(Rl)2 wherein Rl is hydrogen or -CH2P03(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline ear~h metal cation in which case there is only one X per methylene phosphonate group; and at least one R is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom.

7) Compounds having the structural formula:

~2~
fH

Rl wherein:
Rl is hydrogen or -CH3;
R2 is -CH2Po3(x)2 or -CH2N~CH2PO3(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and when nitrogen is present, at least one X is hydrogen which is associated with the nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom.

(8) Compounds having the structural formula-~,0 ~, ¦ \o C - C - CH2PO3(X)2 HO CH2 o CH2 - C~
OH

wherein:
X is hydrogen, an alkali metal cation/ ammonium, 3~

a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group.
~ s mentioned above, most of the derivatives include at least one intramolecular hydrogen bond between a nitrogen atom and an oxygen atom which is attached to a phosphorous atom. The hydrogen involved in this bond is different from the other acidic hydrogens in that it it difficult to neu-tralize and should be left intact in the compound. That is, the removal of the intramolecular hydrogen bond formed when the methylene phosphonic acid derivative contains nitrogen greatly decreases or eliminates the effectiveness of the derivative as a cement composition setting rate retarder.
The other acidic protons may however be neutralized as indi-cated above.
Examples of suitable compounds falling in the various categories listed above are as follows:
(1) aminotri(methylene phosphonic acid), the sodium salt of aminotri(methylene phosphonic acid), and triethanolamine substituted with 3 moles of methy-lene phosphonic acid;
(2) ethylenediamine substituted with 2 or 3 moles methylene phosphonic acid, the sodium salt of the foregoing compound diethylenetriamine substituted with 2 or 3 moles of methylene phosphonic acid and ~2~ 3~i6 triethylenetetramine substituted with 1 to 6 moles of methylene phosphonic acid;
(3) piperazinoethylethylenediamine substituted with 3 moles of methylene phosphonic acid and the sodium salt of this compound;
(4) propylenediamine substituted with 3 moles of methy-lene phosphonic acid, the sodium salt of the fore-going compound, and butylenediamine substituted with 3 moles of methylene phosphonic acid;
(5) urea substituted with 1 to 3 moles of methylene phosphonic acid;
(6) diethyleneamine ether substituted with 2 to 3 moles of methylene phosphonic acid;
(7) ethanol substituted with 1 or 2 moles of methylene phosphonic acid; and (8) ~-phosphono-butane-tricarboxcylic acid.
Of the foregoing compounds ethylenediamine substituted with 2 or 3 moles of methylene phosphonic acid, diethylene-triamine substituted with 2 or 3 moles of methylene phospho-nic acid, triethylenetetramine substituted with 1 to 6 moles of methylene phosphonic acid, and mixtures of such compounds are preferred.
The most preferred compounds for use in the set retarded cement compositions of this invention are methylene phospho-nic acid substituted triethylenetetramine compounds havin~

~5~3~;~

in the range of from 1 to 6 methylene phosphonic acid groups per mole, preferably from 1 to 3 methylene phosphonic acid groups per mole, and most preferably 3 methylene phosphonic acid groups per mole.
The substituted triethylenetetramine compounds are formed by the addition of formaldehyde and orthophosphorous acid to triethylenetetramine in the presence of an acid catalyst, preferably hydrochloric acid. Methylene phospho-nic acid is generated in situ and substitutes at one or more of the six active sites of the triethylenetetramine to form a methylene phosphonic acid substituted triethylenetetramine compound having in the range of from 1 to 6 methyl phospho-nic acid groups per mole. A liquid product can be formed by neutralization of the acid reaction product to a pH of 7.0 +
0.1 with additional triethylenetetramine. A solid product can be formed by addlng calcium hydroxide to the acid reac-tion product until a pH of 2.0 ~ 0.1 has been reached. The thick viseous product produced is then precipitated as the calcium salt in an excess of methyl alcohol, filtered and dried. An alternate and more preferred technique for pro-ducing a solid product is to absorb the liquid product onto a quantity of silica flour at about a 50% loading rate.
A set retarded cement composition of this invention is comprised of an aqueous hydraulic cement slurry containing an effective amount of a methylene phosphonic acid deriva-tive or a mixture of such derivatives selected from thegroup consisting of compounds haviny the structural formula:
Rl - I - R3 wherein:
Rl, U2 and R3 are independently hydrogen, -CH2P03(X)2 or -cH2cH2-o-po3(x)2 with the limitation that one of Rl, R2 and R3 is always -CH2P03(X)2 or -CH2CH2-O-Po3(x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one X is hydrogen which is associated with the nitrogen atom by way of an intramole-cular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom;
compounds having the structural formula:

R2 \ ~ R2 N - CH2 (CH2 - N - CH2)n - CH2 - ~ \
R2 Rl R2 wherein:

n is an integer from 1 to 4;
Rl is hydrogen or -CH2P03(X)2;
R2 is hydrogen, -CH2P03(X)2 or -CH2CH2N(R3)2 3~

wherein R3 .is hydrogen or -CH2P03(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one of Rl, R2 or R3 is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intra~olecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom;
compounds having the structural formula:
R2 - N ~_~ N - CH2 - (CH2 - N ~ CH2)n - CH2 - R3 R
wherein:
n is an integer from O to 4;
Rl is hydrogen or CH2po3(x)2;
R2 is hydrogen, -CH2P03(X)2 or -CH2CH2N(R4)2 wherein R~ is hydrogen Or -CH2Po3(x)2;

R3 is -N(R5)2 or -N ~_~ N - R5 wherein R5 is hydrogen or -CH2Po3(x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and at least one of Rl, R2 or R3 is -CH2P03(X)2 and ~25~3~i~

one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom;
compounds having the structural formula:
R R R O R

N - (CH2)n - N or N - C - N or R R R R

R
N - CH2CH2 ~ O - CH2CH2 ~ N \
R R
wherein:
n is an integer from 2 to 6;
R is hydrogen, -CH2P03(X)2 or -cH2cH2N(Rl)2 wherein Rl is hydrogen or -cE2po3(x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal - cation in which case there is only one X per methylene phosphonate group; and at least one R is -CH2P03(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorous atom;

~2~;ii3~66 compounds having the structural formula:
OH
F
~ 1 or O~ IH2 - C OH
C - C - CH2PO3(X)2 wherein:
Rl is hydrogen or -CH3;

R2 i~ -cH2po3(x)2 or -CH2NHCH2PO3(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and when nitrogen is present, at least one X is hydrogen which is associated with the nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom; and mixtures of such compounds.
Generally, the methylene phosphonic acid derivatives or mixture of derivatives are present in the cement composition -15~

~25~3~i in an amount in the range of from about 1% to about 10% by weight of dry cement utilized.
A preferred setting rate retarded cement composition is comprised of a hydraulic cement and water slurry containing a set retarder selected from the group consisting of ethyl-enediamine substituted with 2-3 moles of methylene phospho-nic acid, diethylenetriamine substituted with 2-3 moles of methylene phosphonic acid, methylene phosphonic acid substi-tuted triethylenetetramine and mixtures of such compounds, the retarder being present in said composition in an amount of from about 1% to about 10% by weight of dry cement utlized in the slurry.
A more preferred set retarded cement composition of this invention is comprised of a hydraulic cement, sufficient water to form a pumpable slurry which will set into a hard mass, and methylene phosphonic acid substituted triethylene-tetramine having in the range of from 1 to 6 methyl phospho-nic acid groups per mole present in the composition in an amount in the range of from about 1% to about 10~ by weight of dry cement. In a most preferred such composition, the retarder is comprised of methylene phosphonic acid substi-tuted triethylenetetramine having 3 methyl phosphonic acid groups per mole present in the composition in an amount in the range of from about 2% to about 8% by weight of dry cement.

~J
~ ~jl3366 A particularly suitable composition is comprised of Portland cement, water present in the composition in an amount in the range of frorn about 3s% to about 62~ by weight of dry cement, and methylene phosphonic acid substituted triethylenetetramine having 3 methylene phosphonic acid groups per mole present in the composition in an amount in the range of from about 2% to about 8% by weight of dry cement.
In order to improve the stability and permanent strenqth of the cement composition after setting in a high tempera-ture environment, a particulate crysta~line silica component can be included in the composition. The silica material is a particulate crystalline silica having a particle size of less than about 10 mesh, preferably 20-80 mesh and most pre-ferably 30 mesh. When particulate crystalline silica is included in the cement compositions of this invention it is preferably present in the compositions in an amount in the range o from about 17% to about 35% by weight of dry cement therein with the methylene phosphonic acid derivative retarder or retarders being present therein in an amount in the range of from about 2% to about 8% by weight of dry cement.
A particularly preferred composition which includes particulate crystalline silica is comprised of Portland cement, silica present in the composition in an amount in 33~i6 -the range of from about 25~ to about 35~ by weight of dry cement, water present in the composition in an amount in the range of from about 45% to about s5% by weight of dry cement and methylene phosphonic acid substituted triethylenetetra-mine having 3 methylene phosphonic acid groups per mole pre-sent in the composition in an amount in the range of from about 3% to about 6% by weight of dry cement.
The most preferred composition including silica is comprised of Portland API Class H cement, particulate crystalline silica present in an amount of about 35% by weight of dry cement, water present in an amount of about 54% by weight of dry cement and methylene phosphonic acid substituted triethylenetetramine having 3 methylene phospho-nic acid groups per mole present in an amount in the range of from about 3~ to about 6% by weight of dry cement.
The water utilized to form the compositions of this invention can be fresh water, salt water, brine, seawater or other water which does not contain materials adversely reac-tive with components of the compositions. As will be understood by those skilled in the art, known components and/or additives can also be included in the compositions for bringing about desired results such as dispersing agents, density reducing components, fluid loss reducing additives, friction reducing additives, etc.
In carrying out the methods of the present invention for cementing a zone penetrated by a wellbore using a settable ' ~5~336~

hydraulic cement slurry wherein the slurry is subjected to elevated temperatureS, a pumpable set retarded cement com-position described above is ~irst prepared using conven-tional equipment. The methylene phosphonic acid derivative retarder or retarders can be added to the cement in either solid or liquid form prior to combining water therewith to form a slurry thereof or the retarder can be mixed with the slurry after it is formed.
Once the cement composition has been prepared, it i5 pumped or otherwise introduced into the zone to be cemented and then allowed to set into a hard mass therein.
The particular quantity of retarder utilized in a cement composition of this invention determines the pumpable time of the composition and the pumpable time is increased by increasing the quantity of retarder. Generally, com-positions containing relatively small quantities of retarder (1~ to 3% by weight of cement) have long pumpable times (up to 8 hours) at temperatures above 400F. The compositions have sufficient pumpable times, i.e., pumpable times exceeding cementing times ~or deep wells wherein the com-positions are subjected to temperatures up to 600F.
The principles of this invention are broadly applicable to hydraulic cements, including Portland cements, high alu-mina content cements, pozzolan~ high gypsum cements, high silica cements and cements which contain a high calcium alu-~2~i~3~i~

minate content. Preferably, Por-tland cemen-t is u-tilized and can be, for example, one or more of the various types identified as API Classes A-H and J cements. These cements are identified and defined in API Specification 10, First Edition, January, 1982, of the American Petroleum Institute.
In order to facilitate a clear unders-tanding of the invention, the following examples are given.
With regard to amounts given in the examples, the term "sack" refers to a standard sack weighing 94 pounds as defined in API Bulletin 10-C, Third Edition, April 15, 1984, of the American Pe-troleurn Institute. This publication sets forth the nomenclature used in oil well cementing technology.

Example 1 A number of cement compositions comprised of Portland cement, i.e., Lone Star Class H cement, particulate crystalline silica having a particle size of from 20-80 mesh in an amoun-t of 35% by weight of dry cement, fresh water in an amount of 54~ by weight of dry cement (6.1 gallons water/sack) and various quan-tities of methylene phosphonic acid substituted triethylenetetra-mine (TÉTA) having various degrees of Methyl phosphonic acid group (-CH2PO3H2) substitution are prepared. The compositions are tested for thickening time at 450F
in accordance with the standard API -thickening time -tes-ting procedures se-t forth in the publication API Specification 10, Second Edition, June 15, 1984. The results of these tests are given in Table I below.

Quanti ty of TETA Retarder in Number of -C~l2Po3H2 Thickening Time Slurry ~ by Weight Substituents per at 450F, of Dry Cement Mole of TETA Hours:Minutes 0.517 1 ~~- ~- - 1:491 0.775 1 2 341 1.030 1 4:451 0.488 2 2:101 00610 2 3:g31 0.732 2 5:201 0.853 2 5:302 0.323 3 2~
0.388 3 3 131 0.517 3 8:09 0.647 3 6:20~
0.905 3 6:oO2 0.273 4 2:001 0.410 4 6:403 0.547 4 12:153 0.683 4 6:352 0 957 4 6:152 0.333 6 2:181 0.500 6 ~:433 0.666 6 6:243 1 These slurries pumped normally on the thickening time tester, i.e., the initial viscosity was low and remained low until a sllarp rise indicated cement hydration.
2 These slurries were thin fluids when removed from the thickening time testerO No sign of hydration was observed.
3 These slurries gelled to viscosities in excess of 70 Bc and did not undergo hydration to a hard set.
_ --21-- ~ ~

~5~33~

From Table I it can be seen that the cement com-positions of the present invention have excellent thickening times at 450F. The compositions containing TETA substi-tuted with one, two and three -Cll2PO3H2 substituentS per mole all yielded good response properties with the coln-positions containing TETA substituted wi-th three -CH2PO3H2 substituents giving the best results, i.e., the longest thickening times witll the least retarder quantities. The compositions containing TETA substituted with four and six -CH2Po3H2 substituents responded similarly except that gellation prior to strength development occurs at some retarder concentrations.

Exam~le 2 A number of cement compositions comprised of Lone Star Class ~I cement, Trinity Class H cement or Centex Class H
cement, particulate crystalline silica having a particle size oE 20-80 mesh in an amount of 35% by weight of dry cement, fresh water in an amount of 54~ by weight of dry cement (6.1 gallons/sack) and various quantities of TETA
substituted with tllree -CH2PO3H2 groups per mole are pre-pared.
The substituted TETA is prepared by reacting for-maldehyde and phosphorus acid with TETA in the presence of a hydrochloric acid catalyst. Tlle resulting liquid is ~;836~

adsorbed onto silica flour at a 50~ loading rate. The resulting solid retarder is utilized in preparing the compositions.
The compositions are tested for thickening times in accordance with the testing procedures set forth in the publication API Specification 10, Second Edition, June 15, 1984, at 400F, 450F, 500F and 550F. The results of these tests are given in Table II below.

. -23-~2~

TABLE II - I`HICKENI~G ~r~ ESTS AT 400F, 450F, 500F AND 550F

, Quantlty of Substituted TEl'~ Retarder in Type of Slurry % by Weight C~nent Thickening Time of Dry Cement Used Hours:Minutes @400 @45 o-~~-O
1.0 LYIe Star Class H 2:46 1.2 L~ne Star Class H 4:18 1.3 Lale Star Class H 4:52 1.5 Lone Star Class H 8:12~
1.2 Lone Star Class H 3r22 1.3 Lcne Star Class H 5:23 1.5 Lone Star Class H 6:29 1.7 Lone Star Class H 7:36 1.2 Trinity Class H 1:28 1.5 ~rrinity Class H 1~59 1.8 Trinity Class H 4:25 2.0 'l'rinity Class H 6:22 1.2 Centex Class H 1:52 1.3 Centex Class H 2:28 1.5 Cerltex Class H 4:06 1.7 Centex Class H 8:00+
1.8 Lone Star Class H 4:20 2.0 L~le Star Class H 5:14 2.2 Lone Star Class H 7:05 2.5 ~le Star Class H 4:00 2.7 Lone Star Class H 5:00 2.8 Lone Star Class H 7:30 .. . _ .. . . _ . _ _ From Table II it can be seen that the compositions of this invention have excellent thickening times at elevated temperatures.

Example 3 Cement ~omposi.tions of the type described in Example 1 above are prepared using salt ~NaCl) water instead of ~resh 3~i water. Tllese compositions are tested for thickening times at 450 F. The results oE these tests are given in Table III
below.

TABLE III - THICKENING ~rIME TESTS AT 450F

. . -- --Quantity of Substituted l`ETA Retarder in Type of Thickening Slurry ~ by Weight Cement Water Time at of Dry Cement Used Used 450F
Elours-Minutes 3.0 Lone Star Class H 18% NaCl 2:43 Solution 3.3 Lone Star Class H 18% NaCl 3:32 Solution 4.0 Lone Star Class H 18~ NaC1 8:00+
Solution 3.3 Lone Star Class ~ 35~ NaCl 2:26 Solution 3.8 Lone Star Class H 35% NaCl 4:27 Solution 4.0 Lone Star Class H 35% NaCl 8:00 Solution Example 4 Cement compositions of the present invention containing additional components and additives to form high density ~19.0 lb/gal.) slurries are prepared. The compositions are comprised of Lone Star Class H cement, fresh water in an amount of 6.8 gal/sack of dry cement, particulate ! ~
crystalline silica having a particle size of 20-80 mesh in ~"

~2~83~

an amount of 35~ by weight of dry cement, Hematite in an amount of 73 lb/sack, sodium chloride in the amount of 21.1 lb/sack, carboxymethylhydroxyeth~lcellulose in an arnount of 1.0~ by weight of dry cement, an additive containing an admixture of deltagluconolactone in an amount o l.U% by weight of dry cement, an additive containing polypropylene glycol in an amount of about 0.25% by weight of dry cement and various amounts of TETA substituted with three -C~2Po3H2 groups per mole. T~le compositions are tested for thickening times at 450F. The results of these tests are given in Table IV below.

Quantity o Substituted TETA Retarder in Slurry ~ by Weight Thickening Time of Dry Cement Hours:Minutes 4.3 2:56 4.9 3:07 5-5 3:28 6.5 5:02 ~ _ _ . . . _ _ . _ . _ _ Example 5 Methylene phosphonic acid derivative co~npounds from the eight categories of derivatives set forth above are utilized to orm set retarded cement compositions. Each of the -26~

~583~;~

compositions includes Lone Star Class ~ cement, particulate crystalline silica having a particle size of 20-80 mesh in an amount of 35% by weight of dry cement, fresh water in an amount of 54~ by weight of dry cement and a quantity of one oE the set retarding compounds. The compositions are tested for thickening time at 450F or 500F in accordance with the standard ~PI thickening time procedures set forth in API
Specification 10, Second Edition, June 15, 1984. The results of these tests are set forth in Table V below.

36~

TABLE V - Tll~(~KEN~NG TIME TESTS AT 450F OR 500DF

Quantity of SpecificRetarder Retarderin Slurry,Thickening Time, Compound% by Weiyht }irs:Mins.
Cateqory Used of Dry Cement 450 F 500F
(1) aminotrim~tllylene 5.0 5:33 phosphonic acid (2) diethylenetriamine 1.0 6:30+
substitued with 5 moles of methylene phosphonic acid (3) piperazinoethyl 6.7 4:20+
ethylenediamine substituted with 10~ methylene phosphonic acid (4) ethylenediamine 4 . 0 24: 0 0+
substituted with 4 moles of methylene phosphonic acid (5) urea substituted 0.6 3:04 with 4 moles of methylene phosphic acid (6) diethyleneamine 1.5 1:40 ether substituted with 4 moles of methylene phosphic acid (7) 2-propanoldiamine 0.3 6:00+
substituted with 2 moles of methylene phosphonic aicd . _ , . . --28--~ .

3~i~

Thus, by the present invention, well cementing methods and compositiOns are provided which are particularly suitable for high temperature deep well applications-Although the above description of tlle invention has dealt with certain preferred cement compositions, it is to be understood that variations in both the composi-tions and the steps carried out in practicing the methods can be effected Witllout departure Erom the basic principles which underlie the invention. Changes in materials used and the steps followed which are of this type are thereEore deemed to be within the spirit and scope of this invention as defined by the appended claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A set retarded cement composition for cementing high temperature zones in wells comprising:
a hydraulic cement;
sufficient water to form a pumpable slurry; and an effective amount of a methylene phosphonic acid derivative retarder selected from the group consisting of compounds having the general formula:
wherein:
R1, R2 and R3 are independently hydrogen, -CH2PO3(X)2 or -CH2CH2-O-PO3(X)2 with the limitation that one of R1, R2 and R3 is always -CH2CH2-O-PO3(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alka-line earth metal cation in which case there is only one X per methylene phosphonate group; and at least one X is hydrogen which is associated with the nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom;

compounds having the structural formula:

wherein:
n is an integer from 0 to 4;
R1 is hydrogen or -CH2PO3(X)2;
R2 is hydrogen, -CH2PO3(X)2 or -CH2CH2N(R4)2 wherein R4 is hydrogen or -CH2PO3(X)2;
R3 is -N(Rs)2 or - R5 wherein R5 is hydrogen or -CH2PO3(x)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alka-line earth metal cation in which case there is only one X per methylene phosphonate group; and at least one of R1, R2 or R3 is -CH2PO3X2 and one X is hydrogen which is asso-ciated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom compounds having the structural formula:

or wherein:

R is hydrogen, -CH2PO3(X)2 or -CH2CH2N(R1)2 wherein R1 is hydrogen or -CH2PO3(X)2;
X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alka-line earth metal cation in which case there is only one X per methylene phosphonate group; and at least one R is -CH2PO3(X)2 and one X is hydrogen which is associated with a nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom;
compounds having the structural formula:

wherein:
R1 is hydrogen or -CH3;
R2 is -CH2PO3(X)2 -CH2NHCH2PO3(X)2:

X is hydrogen, an alkali metal cation, ammonium, a protonated amine or an alkaline earth metal cation in which case there is only one X per methylene phosphonate group; and when nitrogen is present, at least one X is hydrogen which is associated with the nitrogen atom by way of an intramolecular hydrogen bond between the nitrogen atom and an oxygen atom attached to a phosphorus atom; and mixtures of such compounds.

2. The composition of claim 1 wherein said retarder is present in said composition in an amount in the range of from about 1% to about 10% by weight of dry cement therein.

3. The composition of claim 2 which is further characterized to include particulate crystalline silica having a particle size of less than about 10 mesh present in said composition in an amount in the range of from about 17% to about 35% by weight of dry cement.

4. A set retarded cement composition for cementing high temperature zones in wells comprising:
a hydraulic cement;
sufficient water to form a pumpable slurry;
and a retarder comprised of methylene phosphonic acid substituted triethylenetetramine having in the range of from 1 to 6 methylene phosphonic acid groups per mole percent in said composition in an amount in the range of from about 1% to about 10% by weight of dry cement.

5. The composition of claim 4 wherein said retarder is methylene phosphonic acid substituted triethylenetetramine having 3 methylene phosphonic acid groups per mole.

6. The composition of claim 5 wherein said retarder is present in said composition in an amount in the range of from about 2% to about 8% by weight of dry cement.

7. The composition of claim 4 which is further characterized to include particulate crystalline silica having a particle size of less than about 10 mesh present in said composition in an amount in the range of from about 17% to about 35% by weight of dry cement.

8. The composition of claim 5 wherein said hydraulic cement is Portland cement, said water is present in said composition in an amount in the range of from about 35% to about 62% by weight of dry cement and said retarder is present in said composition in an amount in the range of from about 2% to about 8% by weight of dry cement.

9. The composition of claim 7 wherein said hydraulic cement is Portland cement, said silica is present in said composition in an amount in the range of from about 25% to about 35% by weight of dry cement, said water is present in said composition in an amount in the range of from about 45% to about 55%
by weight of dry cement and said retarder is methylene phosphonic acid substituted triethylenetetramine having 3 methylene phosphonic acid groups per mole present in an amount in the range of from about 3% to about 6% by weight of dry cement.

10. A method of cementing a zone penetrated by a wellbore using a settable hydraulic cement slurry wherein the slurry is subjected to elevated tempera-tures greater than about 400°F comprising:
forming a pumpable set retarded cement slurry comprised of hydraulic cement, water and methylene phosphonic acid substituted triethylenetetramine having in the range of from 1 to 6 methylene phosphonic acid groups per mole present in said slurry in an amount in the range of from about 1%
to about 10% by weight of dry cement therein;
introducing said cement slurry into said zone to be cemented; and allowing said cement slurry to set into a hard mass in said zone.

11. The method of claim 10 wherein said methylene phosphonic acid substituted triethylene-tetramine has 3 methylene phosphonic acid groups per mole and is present in said cement slurry in an amount in the range of from about 2% to about 8% by weight of dry cement used therein.

12. The method of claim 10 wherein said cement slurry is further characterized to include particulate crylstalline silica having a particle size of less than about 10 mesh present in said cement slurry in an amount in the range of from about 17% to about 35% by weight of dry cement used therein.

13. The method of claim 11 wherein said hydraulic cement is Portland cement, said water is present in said cement slurry in an amount in the range of from about 35% to about 62% by weight of dry cement used therein and said methylene phosphonic acid substituted triethylenetetramine is present in said cement slurry in an amount in the range of from about 3% to about 6% by weight of dry cement used therein.

14. The method of claim 12 wherein said hydraulic cement is Portland cement, said silica is present in said slurry in an amount in the range of from about 25% to about 35% by weight of dry cement used therein, said water is present in said slurry in an amount in the range of from about 45% to about 55%
by weight of dry cement used therein and said methylene phosphonic acid substituted triethylene-tetramine has 3 methylene phosphonic acid groups per mole and is present in said slurry in an amount in the range of from about 3% to about 6% by weight of dry cement used therein.