U.S. patent application number 13/642849 was filed with the patent office on 2013-05-02 for compositions and methods for well treatment.
This patent application is currently assigned to Schlumberger Technology Corporation. The applicant listed for this patent is Katia Dennis, Ines Khalfallah, Brice Lecampion, Matteo Loizzo. Invention is credited to Katia Dennis, Ines Khalfallah, Brice Lecampion, Matteo Loizzo.
Application Number | 20130105160 13/642849 |
Document ID | / |
Family ID | 42937360 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130105160 |
Kind Code |
A1 |
Khalfallah; Ines ; et
al. |
May 2, 2013 |
Compositions and Methods for Well Treatment
Abstract
A self-healing cement for use in wells in which carbon dioxide
is injected, stored or extracted, comprises a carbonaceous
material. In the event of cement-matrix failure, or bonding failure
between the cement/casing interface or the cement/borehole-wall
interface, the material swells when contacted by carbon dioxide.
The swelling seals voids in the cement matrix, or along the bonding
interfaces, thereby restoring zonal isolation.
Inventors: |
Khalfallah; Ines; (Issy Les
Moulineaux, FR) ; Loizzo; Matteo; (Berlin, DE)
; Lecampion; Brice; (Paris, FR) ; Dennis;
Katia; (Morangis, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Khalfallah; Ines
Loizzo; Matteo
Lecampion; Brice
Dennis; Katia |
Issy Les Moulineaux
Berlin
Paris
Morangis |
|
FR
DE
FR
FR |
|
|
Assignee: |
Schlumberger Technology
Corporation
|
Family ID: |
42937360 |
Appl. No.: |
13/642849 |
Filed: |
April 28, 2011 |
PCT Filed: |
April 28, 2011 |
PCT NO: |
PCT/EP11/56803 |
371 Date: |
December 16, 2012 |
Current U.S.
Class: |
166/292 ;
166/285 |
Current CPC
Class: |
C04B 2111/00706
20130101; E21B 33/13 20130101; C04B 24/36 20130101; C09K 8/473
20130101; C04B 28/02 20130101; C04B 28/02 20130101; C04B 40/0675
20130101; C04B 24/36 20130101; C04B 40/0236 20130101; C04B 14/024
20130101 |
Class at
Publication: |
166/292 ;
166/285 |
International
Class: |
E21B 33/13 20060101
E21B033/13 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2010 |
EP |
10290266.5 |
Claims
1. A method comprising: (i) including a carbonaceous material in a
pumpable cement slurry; (ii) pumping said slurry downhole; (iii)
allowing the slurry to set thus forming a cement sheath that will
self repair when contacted by carbon dioxide.
2. The method of claim 1, wherein the carbonaceous material is
petroleum coke.
3. A method for maintaining zonal isolation in a subterranean well
having a borehole in which carbon dioxide is injected, stored or
extracted, comprising the following steps: (i) installing a tubular
body inside the borehole of the well, or inside a previously
installed tubular body; (ii) pumping aqueous cement slurry
comprising a material that swells when contacted by carbon dioxide
into the borehole; (iii) allowing the cement slurry to set and
harden; (iv) in the event of cement-matrix or bonding failure,
exposing the set cement to wellbore fluids that contain carbon
dioxide; and (v) allowing the material to swell, thereby restoring
zonal isolation.
4. A method for cementing a subterranean well having a borehole in
which carbon dioxide is injected, stored or extracted, comprising
the following steps: (i) installing a tubular body inside the
borehole of the well, or inside a previously installed tubular
body; (ii) pumping an aqueous cement slurry comprising a material
that swells when contacted by carbon dioxide into the borehole; and
(iii) allowing the cement slurry to set and harden inside the
annular region.
5. The method of claim 4, wherein the cementing process is primary
cementing, and the cement slurry is either pumped down the interior
of the tubular body and up through the annular region, or down the
annular region and up the interior of the tubular body.
6. The method of claim 4, wherein the cementing process is remedial
cementing, performed in either a cased or open hole.
7. The method of claim 3, wherein the material is a carbonaceous
material.
8. The method of claim 3, wherein the material comprises one or
more members of the list comprising coal, petroleum coke, graphite
and gilsonite.
9. The method of claim 3, wherein the concentration of the material
in the cement matrix is between about 5 percent and about 50
percent by volume of solid blend (BVOB).
10. The method of claim 3, wherein the concentration of the
material in the cement matrix is between about 10 percent and 40
percent by volume of solid blend (BVOB).
11. The method of claim 3, wherein the particle-size-distribution
of the material is such that the minimum d.sub.10 is about 100
.mu.m, and the maximum d.sub.90 is about 850 .mu.m.
12. The method of claim 3, wherein the cement comprises one or more
members of the list comprising Portland cement, calcium aluminate
cement, fly ash, blast furnace slag, lime-silica blends,
geopolymers, Sorel cements and chemically bonded phosphate
ceramics.
13. The method of claim 3, wherein the cement slurry further
comprises one or more members of the list comprising dispersing
agents, fluid-loss-control agents, set retarders, set accelerators
and antifoaming agents.
14. The method of claim 3, wherein the tubular body comprises one
or more members of the list comprising drillpipe, casing, liner and
coiled tubing.
15. The method of claim 3, wherein the borehole penetrates at least
one fluid-containing reservoir, the reservoir containing fluid with
a carbon dioxide concentration greater than about five moles per
liter.
16. The method of claim 4, wherein the material comprises one or
more members of the list comprising coal, petroleum coke, graphite
and gilsonite.
17. The method of claim 4, wherein the concentration of the
material in the cement matrix is between about 5 percent and about
50 percent by volume of solid blend (BVOB).
18. The method of claim 4, wherein the particle-size-distribution
of the material is such that the minimum d.sub.10 is about 100
.mu.m, and the maximum d.sub.90 is about 850 .mu.m.
19. The method of claim 4, wherein the cement comprises one or more
members of the list comprising Portland cement, calcium aluminate
cement, fly ash, blast furnace slag, lime-silica blends,
geopolymers, Sorel cements and chemically bonded phosphate
ceramics.
20. The method of claim 4, wherein the borehole penetrates at least
one fluid-containing reservoir, the reservoir containing fluid with
a carbon dioxide concentration greater than about five moles per
liter.
Description
BACKGROUND OF THE INVENTION
[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 and completing wells which penetrate
subterranean formations, into which carbon dioxide is injected,
stored or extracted.
[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. Usually, a plurality of tubular
bodies are placed sequentially and concentrically, with each
successive tubular body having a smaller diameter than the previous
tubular body, set at selected depths as drilling progresses. The
purpose of the tubular body is to support the wellbore and 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.
[0004] 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. However, over time the cement sheath can
deteriorate and become permeable. Alternatively, the bonding
between the cement sheath and the tubular body or borehole may
become compromised. The principal causes of deterioration and
debonding include physical stresses associated with tectonic
movements, temperature changes and chemical deterioration of the
cement.
[0005] There have been several proposals to deal with the problems
of cement-sheath deterioration. One approach is to design the
cement sheath to mechanically survive physical stresses that may be
encountered during its lifetime (U.S. Pat. No. 6,296,057). Another
approach is to employ additives that improve the physical
properties of the set cement. U.S. Pat. No. 6,458,198 describes the
addition amorphous metal fibers to improve the strength and impact
resistance. EP 1129047 and WO 00/37387 describe the addition of
flexible materials (rubber or polymers) to confer a degree of
flexibility to the cement sheath. WO 01/70646 describes cement
compositions that are formulated to be less sensitive to
temperature fluctuations during the setting process.
[0006] A number of proposals have been made concerning
"self-healing" concretes in the construction industry. The concept
involves the release of chemicals inside the set-concrete matrix.
The release is triggered by matrix disruption arising from
mechanical or chemical stresses. The chemicals are designed to
restore and maintain the concrete-matrix integrity. These are
described, for example, in U.S. Pat. No. 5,575,841, U.S. Pat. No.
5,660,624, U.S. Pat. No. 6,261,360 and U.S. Pat. No. 6,527,849.
This concept is also described in the following publication: Dry,
CM: "Three designs for the internal release of sealants, adhesives
and waterproofing chemicals into concrete to reduce permeability."
Cement and Concrete Research 30 (2000) 1969-1977. None of these
concepts are immediately applicable to well-cementing operations
because of the need for the cement slurry to be pumpable during
placement, and because of the temperature and pressure conditions
associated with subterranean wells.
[0007] More recently, self-healing cement systems have been
developed that are tailored to the mixing, pumping and curing
conditions associated with cementing subterranean wells. For
example, EP 1623089 describes the addition of superabsorbent
polymers, that may be encapsulated. If the permeability of the
cement matrix rises, or the bonding between the cement sheath and
the tubular body or borehole wall is disrupted, the superabsorbent
polymer becomes exposed to formation fluids. Most formation fluids
contain some water, and the polymer swells upon water contact. The
swelling fills voids in the cement sheath, restoring the low
cement-matrix permeability. Likewise, should the cement/tubular
body or cement/borehole wall bonds become disrupted, the polymer
will swell and restore isolation. WO 2004/101951 describes the
addition of rubber particles that swell when exposed to liquid
hydrocarbons. Like the superabsorbent polymers, the swelling of the
rubber particles restores and maintains zonal isolation.
[0008] Detailed information concerning the performance of
self-healing cements in the oilfield may be found in the following
publications: Le Roy-Delage S et al.: "Self-Healing Cement
System--A Step Forward in Reducing Long-Term Environmental Impact,"
paper SPE 128226 (2010); Bouras H et al.: "Responsive Cementing
Material Prevents Annular Leaks in Gas Wells," paper SPE 116757
(2008); Roth J et al.: "Innovative Hydraulic Isolation Material
Preserves Well Integrity," paper SPE 112715 (2008); Cavanagh P et
al.: "Self-Healing Cement--Novel Technology to Achieve Leak-Free
Wells," paper SPE 105781 (2007).
[0009] The aforementioned technologies and publications are mainly
concerned with traditional hydrocarbon producing wells. However,
the well-cementing industry also has to contend with wells into
which carbon dioxide is injected, in which carbon dioxide is stored
or from which carbon dioxide is recovered. Carbon dioxide injection
is a well-known enhanced oil recovery (EOR) technique. In addition,
there are some oil and gas wells whose reservoirs naturally contain
carbon dioxide.
[0010] A relatively new category of wells involving carbon dioxide
is associated with carbon-sequestration projects. Carbon
sequestration is a geo-engineering technique for the long-term
storage of carbon dioxide or other forms of carbon, for various
purposes such as the mitigation of "global warming". Carbon dioxide
may be captured as a pure byproduct in processes related to
petroleum refining or from the flue gases from power plants that
employ fossil fuels. The gas is then usually injected into
subsurface saline aquifers or depleted oil and gas reservoirs. One
of the challenges is to trap the carbon dioxide and prevent leakage
back to the surface; maintaining a competent and impermeable cement
sheath is a critical requirement.
[0011] The previously disclosed self-healing cement systems are
concerned with traditional wells and swell when contacted by water
and/or hydrocarbons; none of these aims at behavior of the cement
sheath when contacted by carbon dioxide; therefore, despite the
valuable contributions of the prior art, there remains a need for a
self-healing cement system for wells involving carbon dioxide.
SUMMARY OF THE INVENTION
[0012] The present disclosure pertains to improvements by providing
cement systems that are self healing in a carbon-dioxide
environment, and methods by which they may be prepared and applied
in subterranean wells.
[0013] In an aspect, embodiments relate to the use of a
carbonaceous material in a pumpable cement slurry that ,once pumped
downhole, sets to form a cement sheath that will self repair when
contacted by carbon dioxide.
[0014] In a further aspect, embodiments relate to a method for
maintaining zonal isolation in a subterranean well into which
carbon dioxide is injected, stored or extracted.
[0015] In yet a further aspect, embodiments aim at methods for
cementing a subterranean well having a borehole, in which carbon
dioxide is injected, stored or extracted.
DETAILED DESCRIPTION
[0016] 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 of the invention 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 of the invention 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.
[0017] As stated earlier, it would be advantageous to have
self-healing cement systems that operate in an environment
containing carbon dioxide. In a manner analogous to the
self-healing mechanisms described earlier, such cement systems
would contain materials that swell in the presence of carbon
dioxide. And, the amount of swelling would have to be sufficient to
close voids that may appear in the cement sheath.
[0018] In the literature, there are several journal articles
concerning the effects of carbon dioxide on the behavior of coal
such as: Busch A et al.: "High-Pressure Sorption of Nitrogen,
Carbon Dioxide and their Mixtures on Argonne Premium Coals," Energy
Fuels, 2007, 21 (3) 1640-1645; Day S et al.: "Supercritical Gas
Sorption on Moist Coals," International Journal of Coal Geology 74
(2008) 203-214; Day S et al.: Effect of Coal Properties on CO.sub.2
Sorption Capacity Under Supercritical Conditions," International
Journal of Greenhouse Gas Control 2 (2008) 342-352; Krooss B M et
al.: "High-Pressure Methane and Carbon Dioxide Adsorption on Dry
and Moisture-Equilibrated Pennsylvanian Coals," International
Journal of Coal Geology, 51 (2002) 69-92; Mazumder, S et al.:
"Capillary Pressure and Wettability Behavior of Coal-Water-Carbon
Dioxide System," paper SPE 84339 (2003); Ozdemir E et al.:
"CO.sub.2 Adsorption Capacity of Argonne Premium Coals," Fuel, 83
(2004) 1085-1094; Pan Z et al.: "A Theoretical Model for Gas
Adsorption-Induced Coal Swelling," International Journal of Coal
Geology, 69 (2006) 243-252; Reucroft P J and Sethuraman A R:
"Effect of Pressure on Carbon Dioxide Induced Coal Swelling,"
Energy Fuels, 1987, 1 (1) 72-75; or Siriwardane H et al.:
"Influence of Carbon Dioxide on Coal Permeability Determined by
Pressure Transient Methods," International Journal of Coal Geology,
77 (2009) 109-118.
[0019] Most of the references are aimed at studying the feasibility
of sequestering carbon dioxide and other acid gases in coal seams.
These studies discuss various advantages and drawbacks of such
sequestration; those skilled in the art will appreciate that the
chemical environment associated with well cementing is far
different from that of a coal deposit. For example, the pH of most
hydraulic cements is very high--usually greater than 12. In
addition, the formation fluids encountered downhole are frequently
very saline. Salinity and pH are known to affect the surface
behavior of many materials, and the manner by which the materials
interact with external species.
[0020] The inventors surprisingly found that certain carbonaceous
materials do have utility in the context of well cementing.
[0021] Embodiments relate to methods for maintaining zonal
isolation in a subterranean well having a borehole, into which
carbon dioxide is injected, stored or extracted. First, a tubular
body is installed inside the borehole of the well, or inside a
previously installed tubular body. Second, a pumpable aqueous
cement slurry containing a material that swells when contacted by
carbon dioxide is pumped down the borehole. Then, the slurry is
allowed to set and harden. After that, in the event of
cement-matrix failure, or failure of the cement/tubular body or
cement/borehole wall bonds, exposing the set cement to wellbore
fluids that contain carbon dioxide the material will swell and fill
voids within the cement matrix or at the cement/tubular body or
cement/borehole wall interfaces, thereby restoring zonal
isolation.
[0022] Further embodiments are methods for cementing a subterranean
well having a borehole in which carbon dioxide is injected, stored
or extracted. First, a tubular body is installed inside the
borehole of the well, or inside a previously installed tubular
body. Then, a pumpable aqueous cement slurry containing a material
that swells when contacted by carbon dioxide is pumped down the
borehole. After that, the slurry is allowed to set and harden.
Persons skilled in the art will recognize that this aspect of the
invention encompasses both primary and remedial cementing
operations. For primary cementing, the method may be the
traditional process of pumping the cement slurry down the casing
and up the annulus, or the reverse-cementing process by which the
slurry is pumped down the annulus and up the casing. Remedial
processes include plug cementing and squeeze cementing. Plug
cementing may be particularly useful when the operator wishes to
safely seal a well containing carbon dioxide. The remedial
processes may be performed in either a cased-hole or open-hole
environment.
[0023] With respect now to further embodiments, methods are
disclosed for cementing a subterranean well having a borehole in
which carbon dioxide is injected, stored or extracted. First, a
tubular body is installed inside the borehole of the well, or
inside a previously installed tubular body. Then, a pumpable
aqueous cement slurry containing a material that swells when
contacted by carbon dioxide is pumped down the borehole. After
that, the slurry is allowed to set and harden.
[0024] For all embodiments, the material may be a carbonaceous
material. Preferred materials comprise one or more members of the
list comprising coal, petroleum coke, graphite and gilsonite. The
concentration of the material may be between about 5% and 50% by
volume of solids in the cement slurry, also known as "by volume of
blend (BVOB)." The preferred range is between about 10% and 40%
BVOB. For optimal performance, the particle-size distribution of
the material is preferably such that the minimum d.sub.10 is about
100 .mu.m, and the maximum d.sub.90 is about 850 .mu.m. The
definition of d.sub.10 is: the equivalent diameter where 10 wt % of
the particles have a smaller diameter (and hence the remaining 90%
is coarser). The definition of d.sub.90 may be derived similarly.
Persons skilled in the art will recognize that the present
inventive use of carbonaceous materials like coal and gilsonite is
different and distinct from their use as cement extenders (i.e., to
reduce the amount of cement or to reduce the cement-slurry
density).
[0025] In fact, the present disclosure broadly relates to the use
of a carbonaceous material in a pumpable cement slurry that once
pumped downhole sets to form a cement sheath that will self repair
when contacted by carbon dioxide. Preferably the carbonaceous
material is petroleum coke.
[0026] For all embodiments the cement may additionally comprise one
or more members of the list comprising Portland cement, calcium
aluminate cement, fly ash, blast furnace slag, lime-silica blends,
geopolymers, Sorel cements and chemically bonded phosphate
ceramics. The cement slurry may further comprise one or more
members of the list comprising dispersing agents,
fluid-loss-control agents, set retarders, set accelerators and
antifoaming agents. Also, the tubular body may comprise one or more
members of the list comprising drillpipe, casing, liner and coiled
tubing. In addition the borehole may penetrate at least one
fluid-containing reservoir, the reservoir preferably containing
fluid with a carbon dioxide concentration greater than about five
moles per liter.
EXAMPLES
[0027] The following example are further illustrative:
Example 1
[0028] Several particles of petroleum coke were placed inside a
pressure cell equipped with a window that allows one to observe the
behavior of materials within the cell. The cell supplier is Temco
Inc., located in Houston, Tex. USA. The cell temperature is also
adjustable. A camera captures images from inside the pressure cell,
and image-analysis software is employed to interpret the behavior
of materials inside the cell. After the petroleum coke particles
were introduced into the cell, the cell was sealed.
[0029] The first test was conducted at 22.degree. C. The particles
were allowed to equilibrate at the test temperature for 2 hours.
The camera captured an image of the particles. Then, carbon dioxide
gas was introduced, and the pressure was gradually increased to 21
MPa. The particles were exposed to the gas for a 2-hour period. The
camera captured another image of the particles inside the cell. The
cross-sectional area of the particles was observed to increase by
6%.
[0030] A second test was conducted at 42.degree. C. The particles
were allowed to equilibrate at the test temperature for 2 hours.
The camera captured an image of the particles. Then, carbon dioxide
gas was introduced, and the pressure was gradually increased to 21
MPa. The particles were exposed to the gas for a 2-hour period. The
camera captured another image of the particles inside the cell. The
cross-sectional area of the particles was observed to increase by
2.1%.
* * * * *