U.S. patent application number 08/981611 was filed with the patent office on 2001-10-04 for 09342446well cementing method using hmhpg filtrate remover.
Invention is credited to ARGILLIER, JEAN-FRANCOIS, AUDIBERT, ANNIE, MOLTEN, GUISSEPPE, PFEIFFER, UGO.
Application Number | 20010025709 08/981611 |
Document ID | / |
Family ID | 9491418 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010025709 |
Kind Code |
A1 |
AUDIBERT, ANNIE ; et
al. |
October 4, 2001 |
09342446WELL CEMENTING METHOD USING HMHPG FILTRATE REMOVER
Abstract
This invention concerns a process for controlling filtration
loss during the installation of slag cement in a well. The
procedure entails the addition of a specific quantity of at least a
derivative of galactomannan, hydrophilically and hydrophobically
modified. In one version, the derivative is hydrophobically
modified hydroxy propyl guar (HMHPG). This invention concerns slag
cement and a filtrate reductant additive containing a specific
quantity of at least a derivative of galactomannan, hydrophilically
and hydrophobically modified.
Inventors: |
AUDIBERT, ANNIE; (CROISSY
SUR SEINE, FR) ; ARGILLIER, JEAN-FRANCOIS; (SURESNES,
FR) ; PFEIFFER, UGO; (MILAN ITALIA, IT) ;
MOLTEN, GUISSEPPE; (VARESE ITALIA, IT) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Family ID: |
9491418 |
Appl. No.: |
08/981611 |
Filed: |
March 31, 1998 |
PCT Filed: |
April 17, 1997 |
PCT NO: |
PCT/FR97/00697 |
Current U.S.
Class: |
166/293 |
Current CPC
Class: |
C04B 2103/46 20130101;
C04B 24/38 20130101; C09K 8/487 20130101; C09K 8/90 20130101; C09K
8/46 20130101; C09K 8/206 20130101; C04B 28/08 20130101; C04B 28/08
20130101; C04B 24/38 20130101; C04B 24/383 20130101; C04B 28/08
20130101; C04B 24/2652 20130101; C04B 24/38 20130101; C04B 28/08
20130101; C04B 24/38 20130101; C04B 24/38 20130101 |
Class at
Publication: |
166/293 |
International
Class: |
E21B 033/13 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 18, 1996 |
FR |
96/04990 |
Claims
1. A method applied in a well bored through at least one geological
formation of a certain permeability in which a clinker cement is
circulated in a well, characterised in that filtration through the
walls of said well is limited when applying a clinker cement by
adding a given quantity of at least one derivative of
hydrophilically and hydrophobically modified galactomannan.
2. A method as claimed in claim 1, in which said derivative is
hydrophobically modified hydroxy propylated guar (HMHPG).
3. A method as claimed in one of the preceding claims, in which
said derivative of hydrophilically modified galactomannan is
substituted, on the oxygens, with radicals of the general formula
(1): 3where A=a linear or branched oxyalkylenic O--C.sub.pH.sub.2p
group where p is 2 to 4, n=0 to 30; m=0 or 1 where m may not be
zero unless n is zero, R=a linear or branched (hydrophobic) alkyl
radical, which may or may not be ethylenically saturated having
between 10 and 32 carbon atoms, preferably between 12 and 30.
4. A method as claimed in one of the preceding claims, in which the
molecular mass of said hydrophobically modified galactomannan is
less than 2000000 dalton and preferably within the range of between
50000 and 1600000 dalton.
5. A method as claimed in one of claims 3 or 4, characterised in
that R has between 18 and 28 carbon atoms.
6. A method as claimed in one of claims 1 to 5, in which said
clinker also contains at least one polymer selected from the group
comprising xanthane, scleroglucan, wellane, hydroxy ethylated
cellulose (HEC), CMC, guar gum and the polyacrylamides.
7. A clinker cement designed to be cemented in a well bored through
at least one geological formation of a certain permeability,
characterised in that it contains a given quantity of at least one
derivative of hydrophilically and hydrophobically modified
galactomannan.
8. A clinker as claimed in claim 7, characterised in that its
filtrate is controlled by the addition of said given quantity of
derivative of hydrophilically and hydrophobically modified
galactomannan.
9. A clinker as claimed in one of claims 7 or 8, characterised in
that said derivative of guar gum is hydrophobically modified
hydroxy propylated guar (HMHPG).
10. A clinker as claimed in one of claims 7 to 9, characterised in
that its viscosity is mainly controlled by the addition of at least
one polymer selected from the group comprising xanthane,
scleroglucan, wellane, hydroxy ethylated cellulose (HEC), CMC, guar
gum and the polyacrylamides.
11. A filtrate reducer additive for clinker cement, characterised
in that it contains at least one derivative of hydrophilically and
hydrophobically modified galactomannan.
Description
[0001] The present invention relates in particular to operations
conducted as a means of exploiting subsoil deposits containing
hydrocarbons. More specifically, the invention describes a method
of controlling fluid loss by filtration in a geological formation
when cementing a well with clinker.
[0002] When a clinker cement is placed in contact with a porous
geological formation, an aqueous element of the clinker tends to
penetrate the pores of the formation. This is generally referred to
as filtration. This quantity which is lost from the clinker
compound is referred to as filtration loss or filtrate. It is
desirable to limit this loss, particularly of water, from a
clinker, since any such loss will alter its physical-chemical
properties, for example its rheological properties. The
characteristic which allows it to be pumped may be seriously
affected or its setting capacity might be altered due to a decrease
in the amount of water needed to bring about the various chemical
reactions causing it to set and these factors are clearly
detrimental to the cementing operation in the well as well as to
the mechanical properties of the cement once it has set. This
filtration through a porous formation also incurs the risk of
destabilising the walls of the well or clogging geological
production or potential production zones. Additives specific to
clinker cements which act as filtrate reducers, are therefore
incorporated with the clinker cements as a means of restricting
filtration, for example by reducing the filtration speed,
especially by reducing the permeability of the cake formed on the
well walls.
[0003] Clearly, these filtrate reducer products used with clinker
cement will depend on the composition of the clinker in terms of
how high the solid content is and in view of the fact that the
clinker by definition undergoes a physical-chemical change along
the formation during the setting process. In addition, it is
desirable that the cake formed due to filtration will do virtually
nothing to damage the mechanical bond of the cement with the wall
of the well.
[0004] Numerous filtrate reducer products for clinker cements are
known in the profession. Finely divided mineral particles may be
used, for example, or water-soluble polymers such as the
sulphonated derivatives of polyacrylamide or HEC (hydroxyethyl
cellulose). However, the polymers used in the profession are very
sensitive to the high temperatures which can be encountered at
subsoil level, and thus lose their initial properties.
[0005] The present invention therefore relates to a method
implemented in a bore drilled through at least one geological
formation of a certain permeability, whereby a clinker cement is
moved through said well. During the method, filtration through the
walls of said well is limited as the clinker is being cemented by
adding a given quantity of at least one derivative of a
hydrophilically or hydrophobically modified galactomannan.
[0006] In one embodiment, the derivative is hydrophobically
modified hydroxy propylated guar.
[0007] The hydrophilically modified galactomannan may be
hydrophobically modified by fixing, on the oxygens, radicals having
the general formula (1): 1
[0008] where
[0009] A=a linear or branched oxyalkylenic O--C.sub.pH.sub.2p group
where p is 2 to 4, n=0 to 30; m=0 or 1 where m may not be zero
unless n is zero,
[0010] R=a linear or branched (hydrophobic) alkyl radical, which
may or may not be ethylenically saturated, having between 10 and 32
carbon atoms, preferably between 12 and 30 and more particularly
between 18 and 28.
[0011] The molecular mass of the modified galactomannan may be less
than 2000000 dalton and preferably within the range of between
50000 and 1600000 dalton.
[0012] The clinker may include other polymers of the polysaccharide
type or synthetic polymer selected from the group comprising
scleroglucan, derivatives of the hydroxy ethylated cellulose type
(HEC), CMC, Guar gum and the derivatives of polyacrylamide.
[0013] The invention also relates to a clinker cement to be applied
in a well bored through at least one geological formation of a
certain permeability, the clinker containing a given quantity of at
least one derivative of a hydrophilically and hydrophobically
modified galactomannan.
[0014] The filtrate of this clinker may be controlled by adding a
given quantity of at least one derivative of hydrophilically and
hydrophobically modified galactomannan.
[0015] In one embodiment, the derivative may be hydrophobically
modified hydroxy propylated guar.
[0016] The viscosity of the clinker may be essentially controlled
by adding at least one polymer selected from the group comprising
xanthane, scleroglucan, wellane, hydroxy ethylated cellulose (HEC),
CMC, gum of guar and the polyacrylamides or their derivatives.
[0017] The invention also relates to a filtrate reducing additive
for clinker cement, the additive containing a given quantity of at
least one derivative of hydrophilically and hydrophobically
modified galactomannan.
[0018] Galactomannans are polysaccharides essentially consisting of
galactose and mannose units. They are produced from the endosperm
of leguminous seeds such as guar, carob and suchlike.
[0019] In particular, guar gum is a natural polymer made up of
monomeric units of D-mannose linked to one another by 1-4 bonds
forming the main chain on which units of D-galactose are branched
by 1-6 bonds. This derivative is functionalised to render it
hydrophilic by reaction with an alkylene oxide of 2 to 4 carbon
atoms or by reaction in the presence of monochloroacetic acid. The
hydrophilic substituents are selected from the group comprising
hydroxethyl, hydroxypropyl, hydroxybutyl, carboxymethyl. This
derivative is functionalised to render it hydrophobic by reaction
with an epoxyalkane and/or alkene, or alkyl and/or alkenyl glycidyl
ether in a basic medium, by means of the method described in
document U.S. Pat. No. 4,960,876, for example, whereby from 0.001 t
2% of functions can be grafted (1).
[0020] The products obtained thereby (HM guar) can be used as they
are or purified by a process of extraction in organic solvents or
in a mixture of water and organic solvent in order to remove
certain impurities.
[0021] Water-soluble HM guar can be prepared from a derivative of
guar gum by chemically incorporating a long chain corresponding to
the radical given in formula (1).
[0022] The hydrophobic functions are grafted onto the hydrophilic
chain by functions of the type 2
[0023] where A=a linear or branched oxyalkylenic O--C.sub.pH.sub.2p
group where p is 2 to 4, n=0 to 30; m=0 or 1 where m may not be
zero unless n is zero,
[0024] These functions of the "spacer" type enable the hydrophobic
groups to be separated from the main chain.
[0025] The number of hydrophobic units varies from 0.00001 to
approximately 0.02 substituents per unit of anhydroglucoside,
preferably between 0.00005 and 0.01 and is more especially
efficient between 0.0001 and 0.001 substituents per unit of
anhydroglucoside.
[0026] The HM guar polymer may have a molar substitution rate per
hydrophilic unit of 0.7 and preferably between 0.7 and 4, the molar
ratio between the hydrophilic and hydrophobic substituents being
within the range between 35/1 and 400000/1. The hydrophilic unit
may be of the hydroxyethyl, hydroxypropyl, hydroxybutyl type or a
carboxylated substituent. The hydrophobic unit may be of the alkyl,
linear or branched alkylenyl type having from 10 to 32 carbon
atoms. The hydrophobically modified hydroxy propylated guar is
referred to here as HMHPG.
[0027] The efficiency of the polymers used for the purposes of the
present invention exhibit at least an improvement as a means of
controlling filtration as compared with the known synthetic acrylic
polymers in particular. In addition, however, the polymers of the
invention are natural products and have the specific advantage of
being biodegradable and compatible with the relatively stringent
laws governing environmental protection. Compared with the other
natural polymers conventionally used, the polymers of the invention
exhibit a good capacity to control the filtration of clinker
cements.
[0028] The applicant has demonstrated that GM guar polymer, as
defined above, is efficient as a means of controlling the
filtration of a clinker cement, which is a fluid whose liquid phase
is aqueous. The clinker circulated in a well or cemented by
circulation through a well may include reactive, clay-based
viscosifying products and/or polymers of a specific nature to
produce a viscosifying function. For certain applications, the
clinker may include other mineral fillers, such as silica, silica
fumes, barite, etc., for example, as a means of modifying the
Theological and physical characteristics of the clinker.
[0029] Surprisingly, the polymer of the present invention exhibits
a better resistance to high temperatures than the polymers
currently used for this application. This means that the polymer of
this invention can be used in a much wider range of
applications.
[0030] A clinker is a fluid which is displaced through a well so
that it can fixed in a production well. As it moves or is cemented,
this clinker is in contact with the productive or potentially
productive geological formation for a shorter or longer period.
[0031] The physical and/or chemical characteristics of these
clinkers are controlled and adjusted to suit the nature of the
geological formation and the effluents present, the down-hole
conditions and various other roles assumed by such fluids, such as
sealing, pressure control, etc. In addition and as far as possible,
these fluids must do nothing which will modify the output of the
productive geological formation, i.e. they must not irreversibly
reduce the permeability of the productive formation. Controlling
filtration is an important parameter in all situations.
[0032] The HM guar used for the purposes of the present invention
exhibits a good capacity for controlling filtration, whether in
combination with certain polymers having a viscosifying effect or
not, and does so increasingly as the temperature increases. This
can not generally be said of the natural polymer derivatives
conventionally used as a filtrate reducer in clinker formulae.
[0033] The tests described below demonstrate the characteristics of
the HM guar under various application conditions and under
conventional test procedures. The various clinker cements and their
different formulae are described in the publication "Well
cementing", Developments in Petroleum Science, 28, ed. E. B.
Nelson, Elsevier, 1990. The filtrate reducers conventionally used
in clinker cements are HEC (hydroxyethyl cellulose) or sulphonated
derivatives of acrylamide, for example. These latter are marketed
by Halliburton (USA) under the Halad brand name and are described
in U.S. Pat. Nos. 4,557,763 or 4,703,801. API standards (American
Petroleum Institute) were rigorously applied during the clinker
characterisation tests: API SPEC 10-88, section 5--Preparation of
clinker, section 9--Measuring with the consistometer, Appendix
F--Filtration. The filtrates are expressed in milliliters (ml) and
the setting time in hours.
[0034] Various clinker formulae were tested, with or without the
addition of retarding agents. The formulation is generally based on
a cement of the Class G type mixed with 44% water in accordance
with API procedure. The polymer used as a filtrate reducer is
hydrated for 16 hours beforehand and then added to the clinker to
produce a concentration of 0.325%. The mixture is homogenised in
the mixer for 15 s at low speed and then 35 s at high speed. A
retarding agent is added to the clinker in a concentration of
between 0.2 and 0.6% after measuring the setting time at different
temperatures in order to adjust this time to the high temperature
tests. The clinker is placed at the requisite temperature with a
view to filtration by means of the Halliburton consistometer for 20
minutes.
[0035] The formulae of the invention were compared with
conventional formulations containing filtrate reducers familiar to
those in the profession, such as HEC (hydroxy ethylated cellulose),
which can be regarded as one of the best products currently
available, hydroxypropyl guar HPG, a precursor of hydrophobically
modified hydroxypropyl guar gum, Halad 344 and 100A, polyacrylamide
derivatives marketed by Halliburton (USA).
[0036] The various derivatives of guar gum used in the tests are
hydrophobically modified hydroxy propylated guar HMHPG. The
viscosity characteristics .eta. correspond to a Brookfield
viscosity (mPa.s) measured at a polymer concentration of 20 at 20
revs./min. The molecular mass of the products was measured by light
diffusion at small angles on diluted polymer solutions. Their
intrinsic viscosity [.eta.] is calculated from the relative
viscosities of weakly concentrated diluted solutions in the
presence of KCl 5 g/l, the Huggins constant k' being characteristic
of the polymer/polymer interactions:
[0037] HPG: hydroxypropyl guar gum of formula (1) where R=0, n=0
and m=0; .eta.=14000; [.eta.]=1050 cm.sup.3/g, k'.sup..about.0.8,
Mw=2.6 10.sup.6 dalton.
[0038] HMHPG 7: modified guar of formula (1) where
R=C.sub.18H.sub.37, n=0, m=1; .eta.=7000; [.eta.]=800 cm.sup.3/g,
k'.sup..about.0.8.
[0039] HMHPG 8: modified guar of formula (1) where
R=C,.sub.12H.sub.25, n=0, m=1; .eta.=7800.
[0040] HMHPG 9: modified guar of formula (1) where
R=C.sub.22H.sub.45, n=0, m=1; .eta.=2000.
[0041] HMHPG 10: modified guar of formula (1) where
R=C.sub.18H.sub.37, n=0, m=1; .eta.=8000.
[0042] HMHPG: modified guar of formula (1) where
R=C.sub.18H.sub.37, n=0, m=1; .eta.=5400; [.eta.]=950 cm.sup.3/g,
k'.sup..about.1.5.
[0043] The various modified products tested (HMHPG 7, HMHPG 8,
HMHPG 9, HMHPG 10 and HMHPG) have molecular masses ranging between
1.5 and 2 10.sup.6 dalton.
[0044] Below are other hydrophilically and hydrophobically modified
products of the invention:
[0045] HMHPG 14: R=C.sub.18H.sub.37, n=0, m=1, p=2, n=500,
[0046] HMHPG 15: R=C.sub.16H.sub.33, n=0, m=0, n=4300,
[0047] HMHPG 17: R=C.sub.22H.sub.57 to C.sub.45H.sub.57, n=0, m=1,
n=4400,
[0048] HMHPG 18: R=C.sub.14H.sub.29, n=0, m=0, n=3200.
[0049] It should be noted that in the case of the four products
listed above, the viscosity was measured at a 1% polymer
concentration.
Test 1
A Comparison of the Efficiency of HMHPG with Conventional Filtrate
Reducers at Different Temperatures
[0050] Conditions: API Standard,
[0051] Basic formula BF: type G cement, 44% distilled water.
[0052] The polymers are metered at 0.325%.
1 Filtrate (cc) 30 mm 86 F. 140 F. Temperature (30.degree. C.)
(60.degree. C.) Additive to BF HEC 32 53.5 HPG 30 102 HMHPG 20.5 41
HMHPG/HPG (50/50) -- 64 Hal 344 19 35 Hal 100A -- 155
[0053] The additives of the Halad type (HAL 344, Hal 100 A) and HEC
used are marketed by Halliburton and Aqualon respectively.
[0054] Comments
[0055] The filtration characteristics in the presence of HMHPG are
the same as those of Halad or HEC, which are currently regarded as
the best products available.
[0056] Using a mixture of HPG/HMHPG products allows the volume of
filtrate to be reduced.
Test 2
Adding a Retarding Agent to the Formulation
[0057] Conditions: API Standard,
[0058] Base formula BF: G type cement, 44% distilled water.
[0059] The polymers are metered at 0.325% and the retarding agent
HR 15 at 0.5%.
[0060] The setting retarding agents HR15 and HR6 are marketed by
Halliburton (USA).
2 Filtrate (cc) 30 mm 140 F. 200 F. 230F Temperature (60.degree.
C.) (93.4.degree. C.) (110.degree. C.) Additive to BF HEC + HR15 --
>150 -- HMHPG 41 120 -- HMHPG + HR15 15 54 >150 Hal 344 --
127 >150 Hal 344 + HR15 -- >150 >150
[0061] Using retarding agent which is a polyacrylate derivative and
thus essentially acts as a dispersant will homogenise the clinker
and thus probably improve the efficiency of the filtrate reducer
product.
[0062] The setting times were measured for these different formulae
and are set out in the table below:
3 Setting time (h-mn) 200 F. 230 F. Temperature (93.3.degree. C.)
(110.degree. C.) Additive to BF HEC + HR15 20h 10 12h 46 HPG
>23h 30 -- HMHPG lh 49 -- HMHPG + HR15 17h 34 16h 21 Hal 344 lh
10 -- Hal 344 + HR15 >17h 16h 46
[0063] It may be noted from the above measurements that the setting
times are too high with this type of retarding agent; in
particular, they exceed the requisite time by approximately 5
hours. This can be optimised by optimising the concentration of
retarding agent or by selecting the retarding agent. The following
results were thus obtained:
4 Setting time (b-mn) Concentration 0.25% 0.3% 0.4% 0.5% HMHPG +
HR15 0h 55 lh 43 12h 26 20h 10 HMHPG + HR6 -- -- -- 3h 34
[0064] Similarly, at higher temperatures, the formulae must be
specifically optimised by adding a mineral filler, which also
allows the volume of filtrate to be reduced.
Test 3
The Effect of the Hydrophobic Chain Length
[0065] Conditions: API Standard,
[0066] Base formula BF: G type cement, 44% distilled water.
[0067] The polymers are metered at 0.3256 and retarding agent HR6
is metered at 0.5% for the tests at 230F (110.degree. C.) only.
5 Filtrate (cc) 30 mm 140 F. 230 F. Temperature (60.degree. C.)
(110.degree. C.) Additive to BF (+ HR6) HMHPG 41 >150 HMHPG 7 70
70 HMHPG 8 20 >100 HHMPG 9 70 >150 HMHPG 10 >100
>100
[0068] These tests show that under the conditions of usage,
specifically temperature, it is possible to optimise by selecting
an appropriate molecular mass and hydrophobic chain length in
particular or a specific "spacer".
Test 4
[0069] Conditions: API Standard,
[0070] Base formula BF: G type cement, 446 distilled water
[0071] The polymers are metered at 0.325% and the retarding agent
at 0.2%.
6 Filtrate (cc) at 30 mn Temperature 60.degree. C. Setting time
(h-mn) HMHPG 14 3h 34 HMHPG 18 40 5h 10
[0072] The various tests described above therefore confirm that the
clinker formulations can exhibit a good filtration characteristic
using an effective quantity of HMHPG as a filtrate reducer. There
is reason to think that the specific structure of the GM guar of
the present invention is conducive to forming a low permeability
cake. In addition, it was noted that the stability of the HM guar
structure at different temperatures means that it can be used for
those applications of interest to the profession. The advantages
and functions of HM guar are to be found in polymers of this class
at molecular masses of less than approximately 2000000 dalton.
* * * * *