U.S. patent application number 15/985126 was filed with the patent office on 2018-09-20 for retarded cement compositions and methods for well completions.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Laurent Gabilly, Michel Michaux.
Application Number | 20180265406 15/985126 |
Document ID | / |
Family ID | 43514071 |
Filed Date | 2018-09-20 |
United States Patent
Application |
20180265406 |
Kind Code |
A1 |
Michaux; Michel ; et
al. |
September 20, 2018 |
Retarded Cement Compositions and Methods for Well Completions
Abstract
Cement retarders are based on blends of lignosulfonate
compounds, borate compounds and gluconate compounds. The compounds
are present in certain ratios that allow the retarders to operate
at temperatures and pressures up to and exceeding about 176.degree.
C. and 152 MPa. The retarders may also be provided in liquid form,
improving their suitability for use at offshore well-site
locations.
Inventors: |
Michaux; Michel;
(Verrieres-Le-Buisson, FR) ; Gabilly; Laurent;
(Malakoff, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
43514071 |
Appl. No.: |
15/985126 |
Filed: |
May 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13881709 |
Jun 25, 2013 |
9975807 |
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PCT/EP2011/005533 |
Oct 28, 2011 |
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15985126 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C04B 28/04 20130101;
C09K 8/467 20130101; E21B 33/13 20130101; C04B 40/0039 20130101;
C04B 2103/22 20130101; C04B 24/006 20130101; C04B 40/0039 20130101;
C04B 22/0013 20130101; C04B 24/10 20130101; C04B 24/18 20130101;
C04B 28/04 20130101; C04B 22/0013 20130101; C04B 24/10 20130101;
C04B 24/18 20130101; C04B 2103/22 20130101; C04B 22/0013 20130101;
C04B 24/10 20130101; C04B 24/18 20130101 |
International
Class: |
C04B 24/00 20060101
C04B024/00; C04B 40/00 20060101 C04B040/00; C04B 28/04 20060101
C04B028/04; C09K 8/467 20060101 C09K008/467; E21B 33/13 20060101
E21B033/13 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 5, 2010 |
EP |
10290598.1 |
Claims
1. A well-cementing composition, comprising Portland cement, water
and a retarder comprising a lignosulfonate compound, a borate
compound and a gluconate compound, wherein the
lignosulfonate:borate-compound concentration ratio in the
composition is lower than about 0.75:1, and the lignosulfonate
compound, the borate compound and the gluconate compound are
present in the blend at a lignosulfonate compound:borate
compound:gluconate compound concentration ratio between 0.1:1.0:0.1
and 0.5:1.0:0.5 by weight, wherein the lignosulfonate compound is
an oxylignin and the borate compound is sodium pentaborate
decahydrate, sodium tetraborate decahydrate or both, and wherein
the composition further comprises AMPS-acrylamide copolymer or
styrene butadiene latex.
2. The composition of claim 1, wherein the lignosulfonate compound
comprises sodium lignosulfonate, and the gluconate compound
comprises sodium gluconate.
3. The composition of claim 2, wherein the sodium
lignosulfonate:sodium gluconate concentration ratio is between
about 70:30 and about 30:70 by weight.
4. (canceled)
5. (canceled)
6. The composition of claim 1, wherein the retarder is liquid.
7-15. (canceled)
Description
BACKGROUND
[0001] The statements in this section merely provide background
information related to the present, disclosure and may not
constitute prior art.
[0002] This disclosure relates to compositions and methods for
treating subterranean formations, in particular, compositions and
methods for cementing subterranean wells.
[0003] During the construction of subterranean wells, it is common,
during and after drilling, to place a tubular body in the wellbore.
The tubular body may comprise drillpipe, casing, liner, coiled
tubing or combinations thereof. The purpose of the tubular body is
to act as a conduit through which desirable fluids from the well
may travel and be collected. The tubular body is normally secured
in the well by a cement sheath. The cement sheath provides
mechanical support and hydraulic isolation between the zones or
layers that the well penetrates. The latter function is important
because it prevents hydraulic communication between zones that may
result in contamination. For example, the cement sheath blocks
fluids from oil or gas zones from entering the water table and
polluting drinking water. In addition, to optimize a well's
production efficiency, it may be desirable to isolate, for example,
a gas-producing zone from an oil-producing zone. The cement sheath
achieves hydraulic isolation because of its low permeability. In
addition, intimate bonding between the cement sheath and both the
tubular body and borehole is necessary to prevent leaks.
[0004] Optimal cement-sheath placement often requires that the
cement slurry contain a retarder. Cement retarders delay the
setting of the cement slurry for a period sufficient to allow
slurry mixing and slurry placement in the annular region between
the casing and the borehole wall, or between the casing and another
casing string.
[0005] A wide range of chemical compounds may be employed as cement
retarders. The most common classes include lignosulfonates,
cellulose derivatives, hydroxycarboxylic acids, saccharide
compounds, organophosphonates and certain inorganic compounds such
as sodium chloride (in high concentrations) and zinc oxide. A more
complete discussion of retarders for well cements may be found in
the following publication--Nelson E B, Michaux M and Drochon B:
"Cement Additives and Mechanisms of Action," in Nelson E B and
Guillot D. (eds.): Well Cementing (2.sup.nd Edition), Schlumberger,
Houston (2006) 49-91.
[0006] Certain types of retarders have been blended with other
compounds to extend their useful temperature range, improve
cement-slurry properties, or both. For example, the useful
temperature range of certain lignosulfonate retarders may be
extended to more than 260.degree. C. by adding sodium tetraborate
decahydrate (borax). Sodium gluconate may be blended with a
lignosulfonate and tartaric acid to improve the rheological
properties of the cement slurry. Thus, a myriad of retarders and
retarder blends exist which may be applicable to a wide range of
subterranean-well conditions.
[0007] Cement-retarder technology for well cements is
sophisticated; however, as exploration and production operations
continue to move into environmentally sensitive areas, the
population of retarders that may be used is increasingly
restricted. This is particularly true in the North Sea. The
countries that operate in the North Sea (UK, Norway, Denmark and
Holland) maintain a list of chemical products that "pose little or
no risk to the environment". These materials should meet the
following criteria. (1) All of the organic components present in
the material must be biodegradable in seawater. (2) All of the
components should have a low toxicity to fish (Scophthalamus
Maximum), marine species (Acartia Tonsa) and algae (Skeletonema
Costatum). (3) All of the components should not bioaccumulate. (4)
The additive should not contain any prohibited chemicals.
[0008] It thus becomes more and more challenging to develop
efficient cement retarders (and other types of additives) that can
meet these criteria. This is especially true when the cement
slurries must be placed in high-pressure/high-temperature (HPHT)
wells.
[0009] Despite the valuable contributions of the prior art, it
would be advantageous to have efficient retarders which perform
suitably in HPHT environments. In addition, for logistical reasons
in offshore locations, it would be advantageous if the retarders
were available in liquid form.
SUMMARY
[0010] In an aspect, embodiments relate to well-cementing
compositions. In a further aspect, embodiments relate to methods
for cementing a subterranean well. In yet a further aspect,
embodiment relate to uses of Portland-cement retarders comprising a
borate compound, a lignosulfonate compound and a gluconate
compound.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a graph showing the effect of the sodium
lignosulfonate-to-sodium gluconate ratio on the thickening time of
cement slurries containing sodium tetraborate decahydrate.
DETAILED DESCRIPTION
[0012] At the outset, it should be noted that in the development of
any such actual embodiment, numerous implementation--specific
decisions must be made to achieve the developer's specific goals,
such as compliance with system related and business related
constraints, which will vary from one implementation to another.
Moreover, it will be appreciated that such a development effort
might be complex and time consuming but would nevertheless be a
routine undertaking for those of ordinary skill in the art having
the benefit of this disclosure. In addition, the composition
used/disclosed herein can also comprise some components other than
those cited. In the summary and this detailed description, each
numerical value should be read once as modified by the term "about"
(unless already expressly so modified), and then read again as not
so modified unless otherwise indicated in context. Also, in the
summary and this detailed description, it should be understood that
a concentration range listed or described as being useful,
suitable, or the like, is intended that any and every concentration
within the range, including the end points, is to be considered as
having been stated. For example, "a range of from 1 to 10" is to be
read as indicating each and every possible number along the
continuum between about 1 and about 10. Thus, even if specific data
points within the range, or even no data points within the range,
are explicitly identified or refer to only a few specific, it is to
be understood that inventors appreciate and understand that any and
all data points within the range are to be considered to have been
specified, and that inventors possessed knowledge of the entire
range and all points within the range.
[0013] All ratio or percentages described here after are by weight
unless otherwise stated.
[0014] As stated earlier, it would be advantageous to have cement
retarders that meet the "North-sea" list criteria and operate
efficiently in a HPHT environment--preferably at temperatures as
high as at least 176.degree. C. (350.degree. F.) and 152 MPa
(22,000 psi). In addition, availability of the retarder in liquid
form would be desirable. The inventors have provided such
retarders. They discovered that certain blends of lignosulfonates,
gluconates and borates satisfy the goals described above.
[0015] Embodiments relate to well-cementing compositions that
comprise Portland cement, water and a retarder comprising a
lignosulfonate compound, a borate compound and a gluconate
compound. The retarder is formulated such that the
lignosulfonate:borate-compound concentration ratio is below about
0.75:1. The composition may also be pumpable. Those skilled in the
art will recognize that a pumpable cement slurry usually has a
viscosity lower than 1000 mPa-s at a shear rate of 100
s.sup.-1.
[0016] The lignosulfonate compound may be (but would not be limited
to) sodium lignosulfonate, calcium lignosulfonate, ammonium
lignosulfonate and combinations thereof. The gluconate compound may
be (but would not be limited to) sodium gluconate, calcium
gluconate, ammonium gluconate, zinc gluconate, iron gluconate and
combinations thereof. Sodium lignosulfonate and sodium gluconate
are preferred.
[0017] It is also preferred that the lignosulfonate compounds be
refined. Without wishing to be bound by any theory, the refining
process removes carbohydrates (mostly pentoses and hexoses). The
use of lignosulfonates based on oxylignins is particularly
preferred. Oxylignins are derived from lignin that has been
oxidized by the vanillin process.
[0018] The borate compound may be (but would not be limited to)
boric acid, sodium metaborate, potassium metaborate, sodium
diborate, potassium diborate, sodium triborate, potassium
triborate, sodium tetraborate, potassium tetraborate, sodium
pentaborate, potassium pentaborate and combinations thereof. The
borate compounds may contain waters of hydration or be anhydrous.
Sodium tetraborate decahydrate and sodium pentaborate decahydrate
are preferred.
[0019] Embodiments relate to methods for cementing a subterranean
well, comprising providing a well-cementing composition that
comprises Portland cement, water and a retarder comprising a
lignosulfonate compound, a borate compound and a gluconate
compound. The retarder is formulated such that the
lignosulfonate:borate-compound concentration ratio is below about
0.75:1. The composition is placed in the well. Those skilled in the
art will recognize that the method may pertain to both primary and
remedial cementing operations.
[0020] Embodiments relate to uses of a Portland-cement retarder
comprising a lignosulfonate compound, a borate compound and a
gluconate compound, wherein the lignosulfonate:borate-compound
concentration ratio is below about 0.75:1.
[0021] For all embodiments, the sodium lignosulfonate:sodium
gluconate concentration ratio is preferably between about 70:30 and
30:70. Moreover, the preferred ratio lignosulfonate:borate
compounds:gluconate compounds is between 0.1:1.0:0.1 and about
0.5:1.0:0.5, more preferably between 0.25:1.0:0.25 and 0.5:1.0:0.5.
In yet even further preferred version, when the borate compound
comprises sodium tetraborate decahydrate, the preferred sodium
lignosulfonate:sodium tetraborate decahydrate:sodium gluconate
concentration ratio is preferably between about 0.1:1.0:0.1 and
about 0.5:1.0:0.5 by weight. Also, when the borate compound
comprises sodium pentaborate decahydrate, the preferred sodium
lignosulfonate:sodium pentaborate decahydrate:sodium gluconate
concentration ratio is preferably between about 0.1:1.0:0.1 and
about 0.5:1.0:0.5 by weight, and more preferably between about
0.25:1.0:0.25 and about 0.5:1.0:0.5 by weight.
[0022] The cement compositions may further comprise more additives
such as (but not limited to) extenders, fluid-loss additives,
lost-circulation additives, additives for improving set-cement
flexibility, self-healing additives, antifoam agents, dispersants,
gas generating additives and anti-settling agents.
EXAMPLES
[0023] The following examples serve to further illustrate the
disclosure.
[0024] For all examples, cement slurries were prepared with
Dyckerhoff Black Label Class G cement, at a density of 1917
kg/m.sup.3. Liquid additives were added to the mix fluid, and solid
additives were dry blended with the cement.
[0025] The compounds that comprised the retarder formulations were
sodium lignosulfonate (an oxylignin), sodium gluconate and either
sodium tetraborate decahydrate or sodium pentaborate
decahydrate.
[0026] All cement slurries contained 2.66 L/tonne of
polypropylene-glycol antifoam agent. The test temperatures exceeded
110.degree. C.; therefore, silica flour was added at a
concentration of 35% by weight of cement (BWOC). An antisettling
agent based on welan gum was often added to decrease the free-fluid
volume.
[0027] The compatibility of the retarder formulations with a
fluid-loss additive (AMPS-acrylamide copolymer) and a
gas-migration-prevention additive (styrene-butadiene latex) was
evaluated.
[0028] Cement-slurry preparation, free-fluid measurements,
thickening-time measurements, fluid-loss measurements and
rheological measurements were performed according to procedures
published in ISO Publication 10426-2. Thickening-time tests were
performed at three temperatures (Table 1). Fluid-loss measurements
were performed with a stirred fluid-loss cell.
TABLE-US-00001 TABLE 1 Experimental Parameters for Thickening-Time
Tests Time to Initial Final Initial Final Temperature/ Heating
Temperature Temperature Pressure Pressure Pressure Rate (.degree.
C.) (.degree. C.) (MPa) (MPa) (min) (.degree. C./min) 27 110 12.1
92 29 2.86 27 150 13.8 111 34 3.62 27 176 13.8 152 44 3.39
Example 1
[0029] Five cement slurries were prepared, all with the same
sodium-tetraborate-decahydrate concentration: 2% BWOC. The combined
sodium-lignosulfonate and sodium-gluconate concentration was held
constant at 1% BWOC. The sodium lignosulfonate-to-sodium gluconate
ratio was varied: 0:100; 25:75; 50:50, 75:25; and 100:0. The
experimental results are given in Table 2.
TABLE-US-00002 TABLE 2 Effect of sodium lignosulfonate-to-sodium
gluconate ratio on cement-slurry properties. Sodium Tetraborate (%
BWOC) 2 2 2 2 2 Sodium Lignosulfonate -- 0.25 0.5 0.75 1 (% BWOC)
Sodium Gluconate (% BWOC) 1 0.75 .5 0.25 -- Mixing Rheology Plastic
Viscosity (mPa s) 132 142 129 130 135 Yield Stress (Pa) 11.9 8.6
6.7 6.7 7.2 ISO/API Rheology at 85.degree. C. Plastic Viscosity
(mPa s) 58 58 58 60 58 Yield Stress (Pa) 5.7 4.3 4.1 3.4 3.8 Free
Fluid at 85.degree. C. (%) 0.8 1.6 1.2 1.6 1.6 Thickening Time
at.176.degree. C. 2:59 4:56 7:43 6:37 3:50 and 152 MPa (hr:min)
[0030] The thickening times were short when only either sodium
gluconate or sodium lignosulfonate were present with sodium
tetraborate decahydrate. However, when sodium gluconate and sodium
lignosulfonate were present together with sodium tetraborate
decahydrate, the thickening times were longer. This behavior
highlights the synergy between sodium lignosulfonate and sodium
gluconate. As shown in FIG. 1, the longest thickening times are
achieved when the sodium lignosulfonate-to-sodium gluconate weight
ratio is close to 50:50 (i.e., 0.5% BWOC sodium lignosulfonate and
0.5% BWOC sodium gluconate).
[0031] The rheological properties and free-fluid values of the
cement slurries were not significantly affected by varying the
sodium lignosulfonate-to-sodium gluconate ratio. The cement
slurries were also well dispersed, as shown by the low yield-stress
values.
Example 2
[0032] The concentrations of sodium lignosulfonate and sodium
gluconate were maintained constant at 0.5% BWOC. The concentration
of sodium tetraborate decahydrate was varied between 1% and 3%
BWOC. The thickening times of the cement slurries were measured at
176.degree. C. and 152 MPa. The experimental results are shown in
Table 3.
TABLE-US-00003 TABLE 3 Effect of sodium-tetraborate-decahydrate
concentration on cement-slurry properties. Sodium Tetraborate (%
BWOC) 1 2 3 Mixing Rheology Plastic Viscosity (mPa s) 156 129 153
Yield Stress (Pa) 10 6.7 11 ISO/API Rheology at 85.degree. C.
Plastic Viscosity (mPa s) 61 58 63 Yield Stress (Pa) 5.3 4.1 4.2
Free Fluid at 85.degree. C. (%) 0.6 1.2 0.4 Thickening Time at
176.degree. C. 2:43 7:43 11:08 and 152 MPa (hr:min)
[0033] The thickening time was lengthened significantly when the
sodium-tetraborate-decahydrate concentration increased. Maintaining
a constant sodium-lignosulfonate and sodium-gluconate concentration
highlighted the strong synergy between the sodium tetraborate
decahydrate and the 50:50 mixture of sodium lignosulfonate and
sodium gluconate. The rheological properties and free-fluid values
were not affected significantly when the
sodium-tetraborate-decahydrate concentration was varied. The low
yield-stress values show that the slurries were well dispersed.
Example 3
[0034] The sodium-tetraborate-decahydrate concentration needed to
achieve long thickening times at 176.degree. C. and 152 MPa was
typically 1% to 3% BWOC. The solubility of sodium tetraborate
decahydrate in water is about 50 g/L at 25.degree. C. This
solubility is relatively low to formulate a practical liquid
version of the retarder.
[0035] The solubility of sodium pentaborate decahydrate in water is
about 150 g/L at 25.degree. C.; therefore, it may be a better
candidate to prepare a liquid retarder. Sodium pentaborate
decahydrate contains 61.8 mass percent of B.sub.10O.sub.16, while
sodium tetraborate decahydrate contains 40.8 mass percent of
B.sub.4O.sub.7. Thus, it would be expected that the pentaborate
would be the stronger retarder at an equal concentration. However,
the chemical structures of the two borates being different, this
may affect their performance. The performance of the two borates,
in combination with a 50:50 blend of sodium lignosulfonate and
sodium gluconate, was compared at 176.degree. C. and 152 MPa. The
results are presented in Table 4.
TABLE-US-00004 TABLE 4 Performance of sodium pentaborate
decahydrate vs sodium tetraborate decahydrate. Sodium Tetraborate
(% BWOC) 2 -- -- -- Sodium Pentaborate (% BWOC) -- 1.42 2 2 Sodium
Lignosulfonate (% BWOC) 0.5 0.5 0.5 0.75 Sodium Gluconate (% BWOC)
0.5 0.5 0.5 0.75 Mixing Rheology Plastic Viscosity (mPa s) 129 150
160 162 Yield Stress (Pa) 6.7 6.2 9.1 7.2 ISO/API Rheology at
85.degree. C. Plastic Viscosity (mPa s) 58 61 62 63 Yield Stress
(Pa) 4.1 4.1 3.6 3.4 Free Fluid at 85.degree. C. (%) 1.2 0.8 0.8
1.2 Thickening Time at 176.degree. C. and 152 7:43 8:34 9:02 15:16
MPa (hr:min)
[0036] Keeping the sodium-lignosulfonate and sodium-gluconate
concentrations at 0.5% BWOC each, the sodium pentaborate retarder
is slightly stronger than the sodium tetraborate. A very long
thickening time was obtained when the sodium-lignosulfonate and
sodium-gluconate concentrations were raised to 0.75% BWOC,
respectively. In the presence of sodium pentaborate decahydrate,
the plastic viscosity of the cement slurries was slightly higher
than that of the slurry containing sodium tetraborate decahydrate.
All cement slurries were well dispersed, and the free-fluid volumes
were similar.
Example 4
[0037] A liquid retarder was prepared by dissolving 140 g of sodium
pentaborate decahydrate, 35 g of sodium lignosulfonate and 35 g of
sodium gluconate in deionized water. Thus, the sodium pentaborate
decahydrate-to-sodium lignosulfonate+sodium gluconate ratio was 2
by weight.
[0038] The effect of the liquid retarder on the thickening time of
cement slurries was tested at 176.degree. C. and 152 MPa. Tests
were performed with the retarder alone, and in concert with either
the AMPS-acrylamide fluid-loss additive or the styrene-butadiene
latex. The liquid-retarder concentration was 133 L/tonne of cement,
corresponding to 1.67% BWOC sodium pentaborate decahydrate, 0.42%
BWOC sodium lignosulfonate and 0.42% BWOC sodium gluconate.
Fluid-loss was also measured at 176.degree. C. The results are
presented in Table 5.
TABLE-US-00005 TABLE 5 Performance of a liquid retarder formulated
with sodium pentaborate, sodium lignosulfonate and sodium
gluconate. Anti-Settling Agent (% BWOC) 0.5 -- 0.3 AMPS-Acrylamide
Copolymer (L/tonne of cement) -- 58 -- Styrene-Butadiene Latex
(L/tonne of cement) -- -- 284 Liquid Retarder (L/tonne of cement)
133 133 133 Mixing Rheology Plastic Viscosity (mPa s) 125 306 158
Yield Stress (Pa) 7.2 8.1 12.9 ISO/API Rheology at 85.degree. C.
Plastic Viscosity (mPa s) 60 125 90 Yield Stress (Pa) 4.0 4.3 5.3
Free Fluid at 85.degree. C. (%) 1.5 2 2 Thickening Time at
176.degree. C. and 152 MPa (hr:min) 8:11 13:51 11:13
[0039] The sodium pentaborate decahydrate formulation was a more
efficient retarder than the sodium tetraborate decahydrate
formulation (2.51% BWOC vs 3% BWOC as shown in Table 4). Again,
AMPS-acrylamide copolymer and styrene-butadiene latex acted as
retarders. The rheological properties of the cement slurries and
the free-water volumes were similar. The fluid-loss volumes were
slightly higher compared to those observed with sodium tetraborate
decahydrate, but remained acceptable.
Example 5
[0040] The effect of the liquid retarder described in Example 4 was
tested at 110.degree. C. and 92 MPa, and at 150.degree. C. and 111
MPa. The liquid-retarder concentration was 53 L/tonne of cement at
110.degree. C. and 111 L/tonne of cement at 150.degree. C. The
results are presented in Table 6.
TABLE-US-00006 TABLE 6 Performance of the inventive liquid retarder
at 110.degree. C. and 150.degree. C.: Anti-Settling Agent (% BWOC)
0.1 0.4 Liquid Retarder (L/tonne of cement) 53 89 Bottom Hole
Circulating Temperature (.degree. C.) 110 150 Bottom Hole Pressure
92 111 Thickening Time at BHCT and BHP (hr:min) 10:50 6:00
[0041] The results show that the retarder may be employed within a
wide temperature range.
* * * * *