U.S. patent application number 14/371898 was filed with the patent office on 2015-08-27 for measurement of cement slurry properties under downhole conditions.
The applicant listed for this patent is HALLIBURTON ENERGY SERVICES, INC.. Invention is credited to Benjamin Iverson, Merouane Khammar, Thomas Singh Sodhi.
Application Number | 20150240621 14/371898 |
Document ID | / |
Family ID | 52628815 |
Filed Date | 2015-08-27 |
United States Patent
Application |
20150240621 |
Kind Code |
A1 |
Khammar; Merouane ; et
al. |
August 27, 2015 |
MEASUREMENT OF CEMENT SLURRY PROPERTIES UNDER DOWNHOLE
CONDITIONS
Abstract
The present invention relates to a method for measuring a cement
slurry property, such as static gel strength or yield stress, under
at least one downhole condition, and apparatuses and systems for
performing the same. In some embodiments, the method includes
detecting a downward force exerted by a curing cement slurry under
at least one downhole condition within a vessel movable along a
vertical axis proportionally to the downward force. A surface
substantially nonmovable along the vertical axis is disposed at
least partially within the cement slurry. The method also includes
determining at least one property of the cement slurry from the
detected downward force.
Inventors: |
Khammar; Merouane; (The
Woodlands, TX) ; Iverson; Benjamin; (Spring, TX)
; Sodhi; Thomas Singh; (New Caney, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HALLIBURTON ENERGY SERVICES, INC. |
Houston |
TX |
US |
|
|
Family ID: |
52628815 |
Appl. No.: |
14/371898 |
Filed: |
September 6, 2013 |
PCT Filed: |
September 6, 2013 |
PCT NO: |
PCT/US2013/058473 |
371 Date: |
July 11, 2014 |
Current U.S.
Class: |
73/152.57 |
Current CPC
Class: |
E21B 47/005 20200501;
G01N 33/383 20130101 |
International
Class: |
E21B 47/00 20060101
E21B047/00 |
Claims
1. A method of measuring a cement slurry property under a downhole
condition, the method comprising: detecting a downward force
exerted by a curing cement slurry under at least one downhole
condition within a vessel movable along a vertical axis
proportionally to the downward force, a surface substantially
nonmovable along the vertical axis being disposed at least
partially within the cement slurry; and determining at least one
property of the cement slurry from the detected downward force.
2. The method of claim 1, wherein the downward force comprises a
buoyancy weight of the slurry minus a weight of the slurry
supported on the surface by shear stress.
3. (canceled)
4. The method of claim 1, wherein detecting the downward force
comprises detecting a vertical position of the vessel.
5. The method of claim 1, wherein the determining the at least one
property comprises determining at least one of a shear stress of
the cement slurry on the surface, a static gel strength of the
cement slurry, a yield stress of the cement slurry, a loss of
weight of the cement slurry due to curing, a variation of
hydrostatic pressure of the slurry over time, a setting time of the
cement slurry, and a dormant time of the cement slurry.
6. The method of claim 1, wherein the determining comprises
determining the approximate shear stress of the cement slurry on
the surface at time t comprising dividing a first quantity by a
surface area of the surface contacted by the cement slurry, wherein
the first quantity comprises the downward force exerted by the
curing cement slurry at time 0 minus the downward force exerted by
the curing cement slurry at time t.
7. The method of claim 6, wherein determining the first quantity
comprises multiplying a spring constant by a second quantity,
wherein the second quantity comprises a vertical position of the
vessel at time 0 minus a vertical position of the vessel at time
t.
8-10. (canceled)
11. The method of claim 1, wherein a compartment encloses the
vessel within an interior of the compartment, wherein the
compartment is configured to provide the at least one downhole
condition within the vessel.
12-15. (canceled)
16. The method of claim 11, wherein the compartment encloses at
least part of a detector within the interior of the compartment,
wherein the detector detects the downward force.
17. (canceled)
18. The method of claim 11, wherein the vessel is movable along the
vertical axis with respect to the interior of the compartment.
19. The method of claim 11, wherein the compartment encloses at
least part of the surface within the vessel.
20. (canceled)
21. The method of claim 11, wherein the surface is secured to the
interior of the compartment and the surface is substantially
nonmovable along the vertical axis with respect to the interior of
the compartment.
22. The method of claim 1, wherein the downhole condition comprises
at least one of temperature, pressure, agitation, and liquid
environment of the slurry.
23-28. (canceled)
29. The method of claim 22, wherein the agitation comprises at
least one of shearing, vibrating, shaking, and stirring.
30. (canceled)
31. The method of claim 1, wherein the surface comprises a textured
surface.
32. The method of claim 1, wherein the detecting of the downward
force comprises using a detector.
33. The method of claim 32, wherein the detector comprises a
scale.
34. The method of claim 32, wherein a resilient member provides
upward resistance proportional to downward vertical movement of the
vessel along the vertical axis.
35. (canceled)
36. The method of claim 1, wherein the cement slurry comprises
Portland cement, pozzolana cement, gypsum cement, high alumina
content cement, slag cement, silica cement, or a combination
thereof.
37-38. (canceled)
39. A method of measuring a cement slurry property under a downhole
condition, the method comprising: providing or obtaining an
apparatus comprising a vessel configured to move along a vertical
axis proportionally to a downward force within the vessel; a
detector configured to detect a vertical position of the vessel
along the vertical axis; and a surface disposed at least partially
within the vessel, wherein the surface is substantially nonmovable
along the vertical axis; wherein the apparatus is configured to
provide at least one downhole condition within the vessel; placing
a cement slurry within the vessel; configuring at least one
downhole condition within the vessel; allowing the cement slurry to
at least partially cure; and determining at least one property of
the cement slurry from the detected vertical position of the vessel
during at least part of the curing of the cement slurry.
40. An apparatus for measuring a property of a cement slurry under
a downhole condition, the apparatus comprising: a vessel configured
to move along a vertical axis proportionally to a downward force
within the vessel; a detector configured to detect the downward
force; and a surface disposed at least partially within the vessel,
wherein the surface is substantially nonmovable along the vertical
axis; wherein the apparatus is configured to provide at least one
downhole condition within the vessel.
41-47. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] Various characteristics of cement under particular downhole
conditions can be valuable to know when performing subterranean
cementing operations in a wellbore designed for petroleum
extraction. For example, after depositing cement downhole, knowing
how much curing time a particular cement mixture will likely
require to reach a particular strength under the downhole
conditions can help an oilfield engineer determine when it is safe
to conduct other downhole operations without sacrificing the
integrity of the curing cement.
SUMMARY OF THE INVENTION
[0002] In various embodiments, the present invention provides a
method of measuring a cement slurry curing property under a
downhole condition. The method includes detecting a downward force
exerted by a curing cement slurry. The cement slurry is under at
least one downhole condition. The cement slurry is within a vessel
movable along a vertical axis proportionally to the downward force.
A surface substantially nonmovable along the vertical axis is
disposed at least partially within the cement slurry. The method
also includes determining at least one property of the cement
slurry from the detected downward force.
[0003] In various embodiments, the present invention provides a
method of measuring a cement slurry property under a downhole
condition. The method includes providing or obtaining an apparatus.
The apparatus includes a vessel configured to move along a vertical
axis proportionally to a downward force within the vessel. The
apparatus includes a detector configured to detect a vertical
position of the vessel along the vertical axis. The apparatus also
includes a surface disposed at least partially within the vessel.
The surface is substantially nonmovable along the vertical axis.
The apparatus is configured to provide at least one downhole
condition within the vessel. The method includes placing a cement
slurry within the vessel. The method includes configuring at least
one downhole condition within the vessel. The method includes
allowing the cement slurry to at least partially cure. The method
also includes determining at least one property of the cement
slurry from the detected vertical position of the vessel during at
least part of the curing of the cement slurry.
[0004] In various embodiments, the present invention provides an
apparatus for measuring a cement slurry curing property under a
downhole condition. The apparatus includes a vessel configured to
move along a vertical axis proportionally to a downward force
within the vessel. The apparatus includes a detector configured to
detect the downward force. The apparatus includes a surface
disposed at least partially within the vessel. The surface is
substantially nonmovable along the vertical axis. The apparatus is
configured to provide at least one downhole condition within the
vessel.
[0005] In various embodiments, the present invention provides a
system for measuring a cement slurry curing property under a
downhole condition. The system includes an apparatus. The apparatus
includes a vessel configured to move along a vertical axis
proportionally to a downward force within the vessel. The apparatus
includes a detector configured to detect the downward force. The
apparatus includes a surface disposed at least partially within the
vessel, wherein the surface is substantially nonmovable along the
vertical axis. The apparatus is configured to provide at least one
downhole condition within the vessel. The apparatus includes a
cement slurry within the vessel. The surface is at least partially
immersed in the slurry.
[0006] Various embodiments of the present invention provide certain
advantages over other methods, apparatus, and systems for measuring
cement properties, at least some of which are unexpected. Various
embodiments can measure the loss of cement weight due to the
development of its yield strength and gel strength, and the
transition time of the cement from a fluid to thickened or gelled
solid and the corresponding change in properties during the
transition, in a more direct and simple way compared to other
methods and apparatus. In some embodiments, unlike other apparatus
for determining cement properties, the apparatus includes fewer or
no energized moving parts, such as motors, except for the pressure
and temperature control equipment. In some examples, the present
invention can provide a determination of curing properties such as
gel strength and set time of cement mixtures on a surface,
including surfaces with various textures to simulate materials to
be cemented downhole, which is not possible with other methods and
apparatus. In some embodiments, a stationary surface can be used to
determine the static gel strength of a curing cement mixture over
time, which is not possible with other methods and apparatus that
use a moving vane in the cement slurry to detect properties. In
some embodiments, the apparatus and method can directly measure
curing properties of a cement mixture over time and under downhole
conditions during gas flow migration through the cement mixture,
which is difficult or not possible with other methods and
apparatus. In some embodiments, the apparatus and method can be
more reliable, more cost-effective, and more robust than other
apparatuses and methods.
BRIEF DESCRIPTION OF THE FIGURES
[0007] In the drawings, which are not necessarily drawn to scale,
like numerals describe substantially similar components throughout
the several views. Like numerals having different letter suffixes
represent different instances of substantially similar components.
The drawings illustrate generally, by way of example, but not by
way of limitation, various embodiments discussed in the present
document.
[0008] FIG. 1a illustrates a stage of cement curing, in accordance
with various embodiments.
[0009] FIG. 1b illustrates a stage of cement curing, in accordance
with various embodiments.
[0010] FIG. 1c illustrates a stage of cement curing, in accordance
with various embodiments.
[0011] FIG. 1d illustrates a stage of cement curing, in accordance
with various embodiments.
[0012] FIG. 2 illustrates an apparatus for measuring yield stress
of cement, in accordance with various embodiments.
[0013] FIG. 3 illustrates yield stress and gel strength over time,
as measured by the apparatus of Example 1, in accordance with
various embodiments.
[0014] FIG. 4 illustrates calorimetry data for the slurry used in
Example 1, in accordance with various embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Reference will now be made in detail to certain embodiments
of the disclosed subject matter. While the disclosed subject matter
will be described in conjunction with the enumerated claims, it
will be understood that the exemplified subject matter is not
intended to limit the claims to the disclosed subject matter.
[0016] Values expressed in a range format should be interpreted in
a flexible manner to include not only the numerical values
explicitly recited as the limits of the range, but also to include
all the individual numerical values or sub-ranges encompassed
within that range as if each numerical value and sub-range is
explicitly recited. For example, a range of "about 0.1% to about
5%" or "about 0.1% to 5%" should be interpreted to include not just
about 0.1% to about 5%, but also the individual values (e.g., 1%,
2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to
2.2%, 3.3% to 4.4%) within the indicated range. The statement
"about X to Y" has the same meaning as "about X to about Y," unless
indicated otherwise. Likewise, the statement "about X, Y, or about
Z" has the same meaning as "about X, about Y, or about Z," unless
indicated otherwise.
[0017] In this document, the terms "a," "an," or "the" are used to
include one or more than one unless the context clearly dictates
otherwise. The term "or" is used to refer to a nonexclusive "or"
unless otherwise indicated. In addition, it is to be understood
that the phraseology or terminology employed herein, and not
otherwise defined, is for the purpose of description only and not
of limitation. Any use of section headings is intended to aid
reading of the document and is not to be interpreted as limiting;
information that is relevant to a section heading may occur within
or outside of that particular section. Furthermore, all
publications, patents, and patent documents referred to in this
document are incorporated by reference herein in their entirety, as
though individually incorporated by reference. In the event of
inconsistent usages between this document and those documents so
incorporated by reference, the usage in the incorporated reference
should be considered supplementary to that of this document; for
irreconcilable inconsistencies, the usage in this document
controls.
[0018] In the methods of manufacturing described herein, the steps
can be carried out in any order without departing from the
principles of the invention, except when a temporal or operational
sequence is explicitly recited. Furthermore, specified steps can be
carried out concurrently unless explicit claim language recites
that they be carried out separately. For example, a claimed step of
doing X and a claimed step of doing Y can be conducted
simultaneously within a single operation, and the resulting process
will fall within the literal scope of the claimed process.
[0019] The term "about" as used herein can allow for a degree of
variability in a value or range, for example, within 10%, within
5%, or within 1% of a stated value or of a stated limit of a
range.
[0020] The term "substantially" as used herein refers to a majority
of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%,
96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999%
or more.
[0021] The term "hydrocarbon" as used herein refers to a functional
group or molecule that includes carbon and hydrogen atoms. The term
can also refer to a functional group or molecule that normally
includes both carbon and hydrogen atoms but wherein all the
hydrogen atoms are substituted with other functional groups.
[0022] The term "solvent" as used herein refers to a liquid that
can dissolve a solid, liquid, or gas. Nonlimiting examples of
solvents are silicones, organic compounds, water, alcohols, ionic
liquids, and supercritical fluids.
[0023] The term "room temperature" as used herein refers to a
temperature of about 15.degree. C. to 28.degree. C.
[0024] As used herein, the term "polymer" refers to a molecule
having at least one repeating unit, and can include copolymers.
[0025] The term "copolymer" as used herein refers to a polymer that
includes at least two different monomers. A copolymer can include
any suitable number of monomers.
[0026] The term "downhole" as used herein refers to under the
surface of the earth, such as a location within or fluidly
connected to a wellbore.
[0027] As used herein, the term "drilling fluid" refers to fluids,
slurries, or muds used in drilling operations downhole, such as the
formation of the wellbore.
[0028] As used herein, the term "cementing fluid" refers to fluids
or slurries used during cementing operations of a well. For
example, a cementing fluid can include an aqueous mixture including
at least one of cement and cement kiln dust. In another example, a
cementing fluid can include a curable resinous material such as a
polymer that is in an at least partially uncured state.
[0029] As used herein, the term "fluid" refers to liquids and gels,
unless otherwise indicated.
[0030] As used herein, the term "subterranean material" or
"subterranean formation" refers to any material under the surface
of the earth, including under the surface of the bottom of the
ocean. For example, a subterranean formation or material can be any
section of a wellbore and any section of a subterranean petroleum-
or water-producing formation or region in fluid contact with the
wellbore; placing a material in a subterranean formation can
include contacting the material with any section of a wellbore or
with any subterranean region in fluid contact therewith.
Subterranean materials can include any materials placed into the
wellbore such as cement, drill shafts, liners, tubing, or screens;
placing a material in a subterranean formation can include
contacting with such subterranean materials. In some examples, a
subterranean formation or material can be any below-ground region
that can produce liquid or gaseous petroleum materials, water, or
any section below-ground in fluid contact therewith. For example, a
subterranean formation or material can be at least one of an area
desired to be fractured, a fracture or an area surrounding a
fracture, and a flow pathway or an area surrounding a flow pathway,
wherein a fracture or a flow pathway can be optionally fluidly
connected to a subterranean petroleum- or water-producing region,
directly or through one or more fractures or flow pathways.
Method of Measuring Cement Curing Properties.
[0031] The prediction of cement yield stress or gel strength
development with time during the dormant period of cement hydration
can help to predict cement hydrostatic pressure loss in the
wellbore over time during curing and to predict the risk of gas or
fluid migration. A device capable of measuring the development of
cement yield stress or cement gel strength under downhole
conditions can be used to design cements that perform as desired
downhole, such as with minimum risk of gas or fluid migration.
[0032] During cement placement in the wellbore, cement can be
pumped as a slurry in the annulus between the formation and the
casing. The pressure in the cement column is initially equal to the
hydrostatic pressure of the slurry. As cement hydrates, it builds
an internal structure and develops an internal supporting network.
It gradually supports its weight on the walls of the formation and
the casing which results in a decrease of the hydrostatic pressure.
Various embodiments of the present invention can measure at least
one of the shear stress, yield strength, and static gel strength
during hydration in the wellbore conditions of temperature and
pressure. In some embodiments, the shear stress, yield strength, or
static gel strength can be used to calculate the loss of cement
hydrostatic pressure over time in a wellbore.
[0033] In various embodiments, the present invention provides a
method of measuring a cement slurry property (e.g., at least one
cement slurry property) under a downhole condition (e.g., at least
one downhole condition). The method can include detecting a
downward force exerted by a curing cement slurry. The cement slurry
can be under at least one downhole condition within a vessel,
wherein the vessel is located in any suitable location, such as
above the surface (e.g., not downhole), or downhole. The vessel can
be movable along a vertical axis proportionally to the downward
force exerted by the curing cement slurry. A surface substantially
nonmovable along the vertical axis can be disposed at least
partially within the cement slurry. The method can include
determining at least one property of the cement slurry from the
detected downward force. The vessel can be movable along the
vertical axis with respect to a fixed reference point along the
vertical axis, and the surface can be nonmovable along the vertical
axis with respect to the same reference point.
[0034] As the cement slurry cures, the cement slurry generates a
shear stress on the surface that is substantially nonmovable along
the vertical axis. The cement slurry exerts a downward force within
the vessel. The downward force can include the buoyancy weight of
the slurry minus the weight of the slurry that is supported on the
surface by shear stress. The method can be used to measure the loss
of weight of the cement slurry due to the shear stress of the
cement slurry on the surface.
[0035] In some embodiments, a resilient member can provide upward
resistance to the vessel proportionally to downward vertical
movement of the vessel along the vertical axis caused by the
downward force exerted by the cement slurry. In some embodiments,
the resilient member can include a spring. The substantially
nonmovable surface can be nonmovable with respect to a fixed
location of the resilient member, e.g., nonmovable with respect to
a portion of the resilient member that is nonmovable with respect
to the fixed reference point along the vertical axis.
[0036] The downward force exerted by the cement slurry can be
detected (e.g., measured) by any suitable method of detection. In
some examples, the detecting of the downward force can be detected
using a suitable detector. In some embodiments, the downward force
can be detected by detecting (e.g., measuring) a vertical position
of the vessel, such as a difference between the vertical position
of the vessel when the cement slurry was fresh (e.g., time 0) and
the vertical position of the vessel at a later time t. In some
embodiments, the detector includes a scale or other
weight-measuring device. In some embodiments, the detector includes
a visual or electronic comparison between markings or reference
points to determine a vertical position of the vessel and determine
the corresponding downward force, e.g., using a spring below the
vessel as a resilient member and measuring the vertical
displacement of the vessel.
[0037] In one approach, the process of cement curing can be
described in four stages as shown in FIG. 1, as described by
Illston J. M., Dinwoodie J. M., Smith A. A., "Concrete, Timber and
Metals", 1979, Van Nostrand Reinhold Co. Ltd. FIG. 1a illustrates
that in stage (a) after mixing to form the cement slurry, cement
grains are dispersed in water. The water to cement ratio can
control the spacing between cement grains. In stage (a), the cement
slurry is in its most liquid-like state of the four stages
described herein. FIG. 1b illustrates that in stage (b), rods of
ettringite and crumpled foils of calcium silicate hydrate can form
on the surface of cement grains. The water can become saturated
with lime, and needle-like formations of calcium silicate hydrate
can appear in the intergranular water. The rheological properties
of the hydrating cement change during stage (b), and the cement
slurry gels but can still flow. FIG. 1c illustrates that in stage
(c), the hydration on the grains expands outwards and inwards. The
hydrates in the intergranular space grow and interconnect to form a
continuous solid skeletal structure with large capillary pores. In
stage (c), cement slurry sets and turns into a porous hardened
cement paste. FIG. 1d illustrates that in stage (d), the skeletal
structure develops to a denser structure with large capillary pores
remaining unfilled. At this stage, the cement slurry or hardened
cement paste develops significant strength. Two general timeframes
can be highlighted: a pre-initial set, e.g., stages (a)-(b), and a
post initial set, e.g., stages (c)-(d). In stage (a), the cement
can behave as a fluid. In stage (d) the cement can behave as a
solid. Stages (b) and (c) can be considered transitional stages
whereby the system behaves as a fluid that has some solid
characteristics (e.g., pre-initial set stage (b)) or as a solid
that has some fluid characteristics (e.g., post-initial set stage
(c)). In some embodiments, the approximate demarcation point
between stages (b) and (c) can be discerned by the generation of a
significant heat of hydration approximately between the stages.
[0038] The cement slurry property measured can be any suitable
property that can be measured with the method and apparatus
described herein. The cement slurry property can be any property of
the cement slurry from the time of addition of water to the cement
to the thickening or substantial solidification of the resulting
mixture. In some embodiments, the cement slurry property can be any
property of the cement that occurs during any one or more of the
stages as illustrated in FIG. 1 and described herein. For example,
the cement slurry property can be any cement slurry property
measured from stage (a), (b), or (c), such as from the beginning,
an intermediate portion, or the end of the stage, to stage (a),
(b), (c), or (d), such as to the beginning, an intermediate
portion, or to the end of the stage. For example, the cement slurry
property measured can be any property that occurs from stage (a),
such as at the beginning, an intermediate part, or the end of stage
(a), to stage (c), such as to the beginning, an intermediate part,
or to the end of stage (c). In another example, the cement slurry
property measured can be any property that occurs from stage (a),
such as at the beginning, intermediate part, or end of the stage,
to stage (b), such as the beginning, intermediate part of, or end
of stage (b).
[0039] The cement slurry property can be one property or more than
one property. In some embodiments, the determination of the at
least one property of the cement slurry includes determining at
least one of a shear stress of the cement slurry on the surface, a
static gel strength of the cement slurry, a yield stress of the
cement slurry, a loss of weight of the cement slurry due to curing,
a variation of hydrostatic pressure of the slurry over time, a
setting time of the cement slurry, and a dormant time of the cement
slurry. In some embodiments, the method includes determining the
approximate shear stress of the cement slurry on the surface at
time t by dividing a first quantity by the surface area of the
surface contacted by the cement slurry. The first quantity includes
the downward force exerted by the curing cement slurry at time 0
minus the downward force exerted by the curing cement slurry at
time t. Determining the first quantity can include multiplying a
spring constant of a spring or other resilient member that provides
an upward force in proportion to the downward movement of the
vessel by a second quantity, wherein the second quantity includes a
vertical position of the vessel at time 0 minus a vertical position
of the vessel at time t.
[0040] In some embodiments, the determining the at least one
property of the cement slurry includes determining the yield stress
of the cement slurry. As used herein, yield stress refers to the
amount of shear stress required to cause a cement slurry to undergo
plastic deformation or yield, wherein yielding occurs when the
applied shear stress exceeds the yield strength. In some
embodiments, the determination of the at least one property of the
cement slurry includes determining the static gel strength of the
slurry. As used herein, static gel strength refers to the yield
stress of the cement slurry after the slurry has been undisturbed
for a period of time, such as 1 s, 5 s, 10 s, 20 s, 30 s, 40 s, 50
s, 60 s, 1.5 m, 2 m, 3 m, 4 m, 5 m, 6 m, 7 m, 8 m, 9 m, 10 m, 15 m,
20 m, 30 m, 40 m, 50 m, 60 m, 1.5 h, 2 h, 3 h, 4 h, 5 h, 10 h, 15
h, 20 h, 1 d, 1.5 d, 2 d or more. The static gel strength can be
determined while substantially no agitation occurs within the
cement slurry, such as substantially no agitation adjacent to the
surface contacting the slurry, for a suitable period of time.
[0041] The at least one downhole condition can be established
within the vessel in any suitable way. In some embodiments, a
compartment encloses the vessel within an interior region of the
compartment. The compartment can be configured to provide the at
least one downhole condition within the vessel. For example, the
interior of the compartment can include the at least one downhole
condition. The interior of the compartment can include any suitable
material, such as a gas or a liquid. The interior of the
compartment can include an aqueous liquid, such as substantially
pure water, or a solution of water and a salt, or a mixture of an
aqueous liquid and another liquid. In some embodiments, the
interior of the compartment can include an organic solvent, such as
any suitable organic solvent, such as ethylene glycol, dipropylene
glycol methyl ether, dipropylene glycol dimethyl ether, dimethyl
formamide, diethylene glycol methyl ether, ethylene glycol butyl
ether, diethylene glycol butyl ether, propylene carbonate,
limonene, a C.sub.2-C.sub.40 fatty acid C.sub.1-C.sub.10 alkyl
ester, 2-butoxy ethanol, butyl acetate, furfuryl acetate, dimethyl
sulfoxide, dimethyl formamide, or a combination thereof.
[0042] In some embodiments, the compartment encloses at least part
of a detector that detects the downward force exerted by the cement
slurry within the interior of the compartment. The vessel can be
movable along the vertical axis with respect to the interior of the
compartment. The compartment can enclose some or substantially all
of the surface within the interior of the compartment. The surface
can be substantially rigidly attached to the interior of the
compartment, such that the vessel is movable along the vertical
axis, while the surface is held substantially stationary by the
rigid connection to the compartment.
[0043] In some embodiments, the compartment encloses substantially
all of the detector within the interior of the compartment. For
example, the compartment can enclose some or all of a spring or
other resilient member that provides an upward force proportionally
to the downward vertical movement of the vessel. A detector that
measures the vertical position of the vessel can be located within
the compartment, outside of the compartment, or a combination
thereof. In some examples, the vertical position of the vessel can
be read manually or automatically from inside or outside the
compartment, for example with a scale printed on the compartment or
other location with a pointer or other indicator that shows the
vertical position of the vessel, or an electronic sensor within or
outside the compartment can measure the vertical position of the
vessel and output this information to a suitable receiver.
[0044] The downhole condition can be any suitable downhole
condition that is consistent with the method and apparatus
described herein. The downhole condition can be one downhole
condition or more than one downhole condition. In some embodiments,
the downhole condition is at least one of temperature, pressure,
agitation (e.g., shear history, agitation over time, conditioning
of the slurry, and the like), and liquid environment of the slurry.
A downhole condition including the liquid environment of the slurry
can be a liquid contacting at least part of or substantially all of
the exterior of the slurry during the curing of the slurry. In some
embodiments, a liquid environment can be absent, and the slurry can
directly contact the interior of the compartment. In other
embodiments, a liquid such as at least one of an aqueous liquid, an
oil, and an organic solvent can form a liquid environment for the
slurry and can be disposed at least partially between the slurry
and the container, or in some embodiments within the slurry. In
some embodiments, the downhole condition is temperature and
pressure. The pressure of the environment within the compartment,
such as a gas or liquid environment, can be controlled using any
suitable means, to generate a downhole pressure within the interior
of the compartment and the vessel. The downhole pressure can be any
suitable downhole pressure. In some embodiments, the downhole
pressure can be about 14 psi to about 100,000 psi, or about 5,000
psi to about 30,000 psi, or about 14 psi or less, or about 15 psi,
20, 30, 40, 50, 75, 100, 150, 200, 250, 300, 400, 500, 600, 700,
800, 900, 1,000, 1,500, 2,000, 3,000, 4,000, 5,000, 6,000, 7,000,
8,000, 9,000, 10,000, 15,000, 20,000, 25,000, 50,000, 75,000 psi,
or about 100,000 psi or more. The temperature of the environment
within the compartment, such as a gas or liquid environment, can be
controlled using any suitable means, to generate a downhole
temperature within the interior of the compartment and the vessel.
The temperature can be any suitable downhole temperature, such as
about 30.degree. C. to about 600.degree. C., or about 150.degree.
C. to about 500.degree. C., or about 30.degree. C. or less, or
about 40.degree. C., 50 60, 70, 80, 90, 100, 125, 150, 175, 200,
225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 550, or
about 600.degree. C. or more. The amount of agitation within the
vessel can be controlled using any suitable means to generate a
downhole agitation condition within the vessel. The agitation can
include applying any type of shearing force to the cement slurry,
and can include, for example, at least one of vibrating, shaking,
and stirring.
[0045] In some embodiments, the method includes injecting gas into
a suitable location within the vessel, such as a lower portion or
the bottom portion, to measure the effect on one or more curing
properties of the cement slurry over time. The measurement can
include analyzing the effect of the gas flow on the shear stress of
the cement on the plate via detecting changes in the downward force
of the cement slurry by methods described herein.
[0046] The surface nonmovable along the vertical axis can be any
suitable surface. The surface can be a sphere, a conical section,
an irregular shape, or a plate. The surface can have any suitable
texture. In some embodiments, the surface can have a texture that
simulates a downhole surface that is desired to be cemented, such
as a rock surface, a casing, a hardened resin, gravel pack, or any
suitable downhole surface.
[0047] The cement slurry used in methods of the present invention
can be any suitable cement slurry. The cement slurry can include an
aqueous mixture including at least one of cement and cement kiln
dust. The cement kiln dust can be any suitable cement kiln dust.
Cement kiln dust can be formed during the manufacture of cement and
can be partially calcined kiln feed which is removed from the gas
stream and collected in a dust collector during manufacturing
process. Cement kiln dust can be advantageously utilized in a
cost-effective manner since kiln dust is often regarded as a low
value waste product of the cement industry. Some embodiments of the
cement slurry can include cement kiln dust but no cement, cement
kiln dust and cement, or cement but no cement kiln dust. The cement
can be any suitable cement. The cement can be a hydraulic cement. A
variety of cements can be utilized in accordance with the present
invention, for example, those including calcium, aluminum, silicon,
oxygen, iron, or sulfur, which can set and harden by reaction with
water. For example, the cement can be Portland cement, pozzolana
cement, gypsum cement, high alumina content cement, slag cement,
silica cement, or a combination thereof. In some embodiments, the
Portland cements that are suitable for use in the present invention
are classified as Classes A, C, H, and G cements according to the
American Petroleum Institute, API Specification for Materials and
Testing for Well Cements, API Specification 10, Fifth Ed., Jul. 1,
1990. A cement can be generally included in the cement slurry in an
amount sufficient to provide the desired compressive strength,
density, or cost. In some embodiments, the hydraulic cement can be
present in the cement slurry in an amount in the range of from 0 wt
% to about 100 wt %, about 0 wt % to about 95 wt %, about 20 wt %
to about 95 wt %, about 50 wt % to about 90 wt %, or about 1 wt %,
2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75,
80, 85, 90, 95, 96, 97, 98 wt %, or about 99 wt % or more of the
slurry. A cement kiln dust can be present in an amount of at least
about 0.01 wt %, or about 5 wt % to about 80 wt %, or about 10 wt %
to about 50 wt %.
[0048] The cement slurry can include at least one of water, brine,
and salt water, in any suitable proportion, such as in an amount of
1 wt %, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65,
70, 75, 80, 85, 90, 95, 96, 97, 98 wt %, or about 99 wt % or more
of the slurry. The cement slurry can include any suitable cement
additive, such as fly ash, metakaolin, shale, a zeolite, a set
retarding additive, a surfactant, a gas, an accelerator, a weight
reducing additive, a heavy-weight additive, a lost-circulation
material, a filtration control additive, a dispersant, a
crystalline silica compound, amorphous silica, a salt, a fiber, a
hydratable clay, microspheres, possolan lime, a thixotopic
additive, or a combination thereof. The cement additive can be
present in any suitable proportion, such as about 0.000, 1 wt % or
less, or about 0.000, 5 wt %, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5,
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,
60, 65, or about 70 wt % or more.
[0049] In some embodiments, the composition can include any
suitable amount of any suitable material used in a downhole fluid.
For example, the composition can include aqueous base, oil, organic
solvent, synthetic fluid oil phase, aqueous solution, alcohol or
polyol, cellulose, starch, alkalinity control agents, density
control agents, density modifiers, emulsifiers, dispersants,
polymeric stabilizers, crosslinking agents, polyacrylamide, a
polymer or combination of polymers, antioxidants, heat stabilizers,
foam control agents, solvents, diluents, plasticizer, filler or
inorganic particle, pigment, dye, precipitating agent, rheology
modifier, oil-wetting agents, breakers, crosslinkers, rheology
modifiers, curing accelerators, curing retarders, pH modifiers,
chelating agents, scale inhibitors, enzymes, resin, water control
materials, oxidizers, markers, or a combination thereof.
Apparatus for Measuring Cement Slurry Properties Under Downhole
Conditions.
[0050] In various embodiments, the present invention provides an
apparatus for measuring a property (e.g., at least one property) of
a cement slurry under a downhole condition (e.g., at least one
downhole condition). The apparatus can be any suitable apparatus
that can carry out the method described herein. In some
embodiments, the apparatus includes a vessel configured to move
along a vertical axis proportionally to a downward force within the
vessel. The apparatus can include a detector configured to detect
the downward force. The apparatus can include a surface disposed at
least partially within the vessel. The surface can be substantially
nonmovable along the vertical axis. The apparatus can be configured
to provide at least one downhole condition within the vessel.
[0051] The detector can be configured to detect the downward force
within the vessel by detecting the vertical position of the vessel
along the vertical axis, such as a change in the vertical position
over time. The downward force within the vessel can be exerted by
contents that can be placed in vessel, e.g., a cement slurry.
[0052] The apparatus can include a compartment that encloses the
vessel within an interior of the compartment. The compartment can
be configured to provide the at least one downhole condition within
the vessel. The compartment can enclose at least part of the
detector within the interior of the compartment. The surface can be
secured to the interior of the compartment. The surface can be
substantially nonmovable along the vertical axis with respect to
the interior of the compartment.
[0053] FIG. 2 illustrates an apparatus for measuring yield stress
of cement, in accordance with various embodiments. The apparatus
(100) includes a compartment (110) encapsulating a vessel (120),
wherein the vessel (120) is movable along a vertical axis, and
wherein the downward movement of the vessel (120) can be detected
by a spring or scale (130). The vessel (120) is filled with a
cement slurry (140). The compartment (110) can be pressurized with
water (150) at a desired pressure to simulate a downhole pressure
condition within the vessel (120). The temperature within the
vessel (120) can be controlled by circulating water (150) or
another suitable fluid at a desired temperature around the vessel
(120) within the compartment (110), to simulate a downhole
temperature. In other embodiments, the temperature within the
vessel (120) can be controlled by using a heater with a temperature
controller. A thin plate (160) is rigidly bound to the frame of the
compartment (110), such that it is nonmovable along the vertical
axis. The surface of the thin plate (160) can be covered with a
desired texture to mimic the tackiness of a formation or the
texture of a steel casing. The plate (160) is at least partially
immersed in the cement slurry (140) in the vessel (120). As the
cement (140) hydrates and builds its internal structure, it
supports partially its weight on the surfaces of the plate (160),
causing the force exerted on the spring to decrease, causing the
vertical position, x, of the vessel to change (170) over time.
System for Measuring Cement Slurry Properties Under Downhole
Conditions.
[0054] In various embodiments, the present invention provides a
system for measuring a cement slurry property under a downhole
condition. The system can include any suitable system that includes
the apparatus described herein or that can carry out the method
described herein. For example, the system can include an apparatus
that includes a vessel configured to move along a vertical axis
proportionally to a downward force within the vessel. The apparatus
can include a detector configured to detect the downward force. The
apparatus can include a surface disposed at least partially within
the vessel, wherein the surface is substantially nonmovable along
the vertical axis. The apparatus can be configured to provide at
least one downhole condition within the vessel. The system can also
include a cement slurry within the vessel, wherein the surface is
at least partially immersed in the slurry. The cement slurry can be
any suitable cement slurry.
Examples
[0055] The present invention can be better understood by reference
to the following Examples which are offered by way of illustration.
The present invention is not limited to the Examples given
herein.
Example 1a
Apparatus
[0056] The apparatus used in this Example included a thin brass
plate covered with sand paper and rigidly bound to a metallic
frame. The plate was partially immersed in a beaker containing
fresh cement slurry. The variation of the apparent weight of the
cement paste with time was recorded using a balance connected to a
computer.
[0057] The cement slurry used in the Example contained 762.3 g of
Texas Lehigh class H, 22.9 g of calcium chloride, 350.7 g of water,
and 4.6 g of D-Air 3000.TM. defoamer.
Example 1b
Derivation of Yield Stress
[0058] During the curing of the cement slurry, the force applied by
the apparent weight of the cement on the spring F(t) represents the
difference between the actual buoyancy weight of the slurry
F(t=0)=(.rho..sub.slurry.rho..sub.water)gVolume.sub.slurry and the
weight supported on the plate by the shear stress 2S.tau.(t), where
S is the surface area of one side of the plate. The variation in
the vertical position of the vessel due to the variation of the
cement weight applied on the spring/scale can be used to calculate
the shear stress applied on the surface of the plate as:
.tau. ( t ) = ( F ( t = 0 ) - F ( t ) ) 2 S . ##EQU00001##
[0059] The apparent weight of the cement on the spring F(t) can be
obtained by measuring the time dependent spring deformation
.DELTA.x(t): F(t)=k*.DELTA.x(t), where k is the spring constant and
.DELTA.x(t) is the spring deformation at time t. The spring
deformation .DELTA.x(t) can be measured, for example, using a
linear variable differential transducer (LVDT). The shear stress
acting on the plate surface can be calculated by combining the
equation for shear stress with the equation for spring
deformation:
.tau. ( t ) = k ( .DELTA. x ( t = 0 ) - .DELTA. x ( t ) ) 2 S .
##EQU00002##
Example 1c
Measurement of Yield Stress
[0060] A comparison between experimental yield stress measurements
obtained using the thin plate experiment and the MACS 2
measurements is shown in FIG. 3. FIG. 3 illustrates yield
stress/gel strength development versus lime. The dashed line (--)
represents measurement obtained using a MACS 2 (performed at
31.7.degree. C. shifted by 5 min to account for the time of filling
and loading the can in the MACS 2), dotted lines(.cndot..cndot.)
represent measurement obtained using a MACS 2 (performed at
25.1.degree. C. and without D-Air 3000.TM. defoamer in the cement
slurry, shifted by 5 min to account for the time of filling and
loading the can in the MACS 2), and the continuous line (-)
represents measurement using the thin-plate apparatus of the
present Example at room temperature (about 25.degree. C.).
[0061] Reasonable agreement between the different measurements was
observed up to about 40 min after mixing. At this time, the slope
of the plot yield stress versus time changes and the MACS 2 results
begin to diverge from those of the thin-plate apparatus. Up to 40
min after mixing, the cement is viscoplastic and is in a dormant
period. Measured mass loss can be attributed to the cement slurry
developing yield strength and supporting part of its weight on the
plate surface. At this stage the material is thought to build
structure and cohesion. After 40 min, the dormant period ends, the
formation of hydrates is accelerated and the exothermic reactions
are initiated, as shown in FIG. 4. Yield stress/gel strength
measurements with the proposed technique appear to be in agreement
with the MACS 2 results in the dormant period, before the
initiation of exothermic reaction and cement setting.
[0062] The terms and expressions which have been employed are used
as terms of description and not of limitation, and there is no
intention in the use of such terms and expressions of excluding any
equivalents of the features shown and described or portions
thereof, but it is recognized that various modifications are
possible within the scope of the invention claimed. Thus, it should
be understood that although the present invention has been
specifically disclosed by specific embodiments and optional
features, modification and variation of the concepts herein
disclosed may be resorted to by those of ordinary skill in the art,
and that such modifications and variations are considered to be
within the scope of this invention as defined by the appended
claims.
Additional Embodiments
[0063] The present invention provides for the following exemplary
embodiments, the numbering of which is not to be construed as
designating levels of importance:
[0064] Embodiment 1 provides a method of measuring a cement slurry
property under a downhole condition, the method comprising:
detecting a downward force exerted by a curing cement slurry under
at least one downhole condition within a vessel movable along a
vertical axis proportionally to the downward force, a surface
substantially nonmovable along the vertical axis being disposed at
least partially within the cement slurry; and determining at least
one property of the cement slurry from the detected downward
force.
[0065] Embodiment 2 provides the method of Embodiment 1, wherein
the downward force comprises a buoyancy weight of the slurry minus
a weight of the slurry supported on the surface by shear
stress.
[0066] Embodiment 3 provides the method of any one of Embodiments
1-2, wherein the method measures a loss of weight of the cement
slurry due to a shear stress of the cement slurry on the
surface.
[0067] Embodiment 4 provides the method of any one of Embodiments
1-3, wherein detecting the downward force comprises detecting a
vertical position of the vessel.
[0068] Embodiment 5 provides the method of any one of Embodiments
1-4, wherein the determining the at least one property comprises
determining at least one of a shear stress of the cement slurry on
the surface, a static gel strength of the cement slurry, a yield
stress of the cement slurry, a loss of weight of the cement slurry
due to curing, a variation of hydrostatic pressure of the slurry
over time, a setting time of the cement slurry, and a dormant time
of the cement slurry.
[0069] Embodiment 6 provides the method of any one of Embodiments
1-5, wherein the determining comprises determining the approximate
shear stress of the cement slurry on the surface at time t
comprising dividing a first quantity by a surface area of the
surface contacted by the cement slurry, wherein the first quantity
comprises the downward force exerted by the curing cement slurry at
time 0 minus the downward force exerted by the curing cement slurry
at time t.
[0070] Embodiment 7 provides the method of Embodiment 6, wherein
determining the first quantity comprises multiplying a spring
constant by a second quantity, wherein the second quantity
comprises a vertical position of the vessel at time 0 minus a
vertical position of the vessel at time t.
[0071] Embodiment 8 provides the method of any one of Embodiments
1-7, wherein the determining comprises determining a yield stress
of the cement slurry.
[0072] Embodiment 9 provides the method of any one of Embodiments
1-8, wherein the determining comprises determining a static gel
strength of the cement slurry.
[0073] Embodiment 10 provides the method of any one of Embodiments
1-9, wherein the vessel is located above the surface.
[0074] Embodiment 11 provides the method of any one of Embodiments
1-10, wherein a compartment encloses the vessel within an interior
of the compartment, wherein the compartment is configured to
provide the at least one downhole condition within the vessel.
[0075] Embodiment 12 provides the method of Embodiment 11, wherein
the interior of the compartment comprises the at least one downhole
condition.
[0076] Embodiment 13 provides the method of any one of Embodiments
11-12, wherein the interior of the compartment comprises a
liquid.
[0077] Embodiment 14 provides the method of any one of Embodiments
11-13, wherein the interior of the compartment comprises an aqueous
liquid.
[0078] Embodiment 15 provides the method of any one of Embodiments
11-14, wherein the interior of the compartment comprises water.
[0079] Embodiment 16 provides the method of any one of Embodiments
11-15, wherein the compartment encloses at least part of a detector
within the interior of the compartment, wherein the detector
detects the downward force.
[0080] Embodiment 17 provides the method of Embodiment 16, wherein
the compartment encloses substantially all of the detector within
the interior of the compartment.
[0081] Embodiment 18 provides the method of any one of Embodiments
11-17, wherein the vessel is movable along the vertical axis with
respect to the interior of the compartment.
[0082] Embodiment 19 provides the method of any one of Embodiments
11-18, wherein the compartment encloses at least part of the
surface within the vessel.
[0083] Embodiment 20 provides the method of any one of Embodiments
11-19, wherein the compartment encloses substantially all of the
surface within the vessel.
[0084] Embodiment 21 provides the method of any one of Embodiments
11-20, wherein the surface is secured to the interior of the
compartment and the surface is substantially nonmovable along the
vertical axis with respect to the interior of the compartment.
[0085] Embodiment 22 provides the method of any one of Embodiments
1-21, wherein the downhole condition comprises at least one of
temperature, pressure, agitation, and liquid environment of the
slurry.
[0086] Embodiment 23 provides the method of Embodiment 22, wherein
the downhole condition comprises temperature and pressure.
[0087] Embodiment 24 provides the method of any one of Embodiments
22-23, wherein the temperature is about 30.degree. C. to about
600.degree. C.
[0088] Embodiment 25 provides the method of any one of Embodiments
22-24, wherein the temperature is about 150.degree. C. to about
500.degree. C.
[0089] Embodiment 26 provides the method of any one of Embodiments
22-25, wherein the pressure is about 14 psi to about 100,000
psi.
[0090] Embodiment 27 provides the method of any one of Embodiments
22-26, wherein the pressure is about 5,000 psi to about 30,000
psi.
[0091] Embodiment 28 provides the method of any one of Embodiments
22-27, wherein the agitation comprises shearing.
[0092] Embodiment 29 provides the method of any one of Embodiments
22-28, wherein the agitation comprises at least one of vibrating,
shaking, and stirring.
[0093] Embodiment 30 provides the method of any one of Embodiments
1-29, wherein the surface comprises a plate.
[0094] Embodiment 31 provides the method of any one of Embodiments
1-30, wherein the surface comprises a textured surface.
[0095] Embodiment 32 provides the method of any one of Embodiments
1-31, wherein the detecting of the downward force comprises using a
detector.
[0096] Embodiment 33 provides the method of Embodiment 32, wherein
the detector comprises a scale.
[0097] Embodiment 34 provides the method of any one of Embodiments
32-33, wherein a resilient member provides upward resistance
proportional to downward vertical movement of the vessel along the
vertical axis.
[0098] Embodiment 35 provides the method of any one of Embodiments
32-34, wherein the resilient member comprises a spring.
[0099] Embodiment 36 provides the method of any one of Embodiments
1-35, wherein the cement slurry comprises Portland cement,
pozzolana cement, gypsum cement, high alumina content cement, slag
cement, silica cement, or a combination thereof.
[0100] Embodiment 37 provides the method of any one of Embodiments
1-36, wherein the cement slurry comprises at least one of water,
brine, and salt water.
[0101] Embodiment 38 provides the method of any one of Embodiments
1-37, wherein the cement slurry comprises fly ash, metakaolin,
shale, a zeolite, a set retarding additive, a surfactant, a gas, an
accelerator, a weight reducing additive, a heavy-weight additive, a
lost-circulation material, a filtration control additive, a
dispersant, a crystalline silica compound, amorphous silica, a
salt, a fiber, a hydratable clay, microspheres, possolan lime, a
thixotopic additive, or a combination thereof.
[0102] Embodiment 39 provides a method of measuring a cement slurry
property under a downhole condition, the method comprising:
providing or obtaining an apparatus comprising a vessel configured
to move along a vertical axis proportionally to a downward force
within the vessel; a detector configured to detect a vertical
position of the vessel along the vertical axis; and a surface
disposed at least partially within the vessel, wherein the surface
is substantially nonmovable along the vertical axis; wherein the
apparatus is configured to provide at least one downhole condition
within the vessel; placing a cement slurry within the vessel;
configuring at least one downhole condition within the vessel;
allowing the cement slurry to at least partially cure; and
determining at least one property of the cement slurry from the
detected vertical position of the vessel during at least part of
the curing of the cement slurry.
[0103] Embodiment 40 provides an apparatus for measuring a property
of a cement slurry under a downhole condition, the apparatus
comprising: a vessel configured to move along a vertical axis
proportionally to a downward force within the vessel; a detector
configured to detect the downward force; and a surface disposed at
least partially within the vessel, wherein the surface is
substantially nonmovable along the vertical axis; wherein the
apparatus is configured to provide at least one downhole condition
within the vessel.
[0104] Embodiment 41 provides the apparatus of Embodiment 40,
wherein the detector is configured to detect a vertical position of
the vessel along the vertical axis.
[0105] Embodiment 42 provides the apparatus of any one of
Embodiments 40-41, wherein a compartment encloses the vessel within
an interior of the compartment, wherein the compartment is
configured to provide the at least one downhole condition within
the vessel.
[0106] Embodiment 43 provides the apparatus of Embodiment 42,
wherein the compartment encloses at least part of the detector
within the interior of the compartment.
[0107] Embodiment 44 provides the apparatus of any one of
Embodiments 42-43, wherein the surface is secured to the interior
of the compartment and the surface is substantially nonmovable
along the vertical axis with respect to the interior of the
compartment.
[0108] Embodiment 45 provides the apparatus of any one of
Embodiments 40-44, wherein the downward force within the vessel is
exerted by contents of the vessel.
[0109] Embodiment 46 provides the apparatus of Embodiment 45,
wherein the contents comprise a cement slurry.
[0110] Embodiment 47 provides a system for measuring a cement
slurry property under a downhole condition, the system comprising:
an apparatus comprising a vessel configured to move along a
vertical axis proportionally to a downward force within the vessel;
a detector configured to detect the downward force; and a surface
disposed at least partially within the vessel, wherein the surface
is substantially nonmovable along the vertical axis; wherein the
apparatus is configured to provide at least one downhole condition
within the vessel; a cement slurry within the vessel, wherein the
surface is at least partially immersed in the slurry.
[0111] Embodiment 48 provides the apparatus, method, or system of
any one or any combination of Embodiments 1-17 optionally
configured such that all elements or options recited are available
to use or select from.
* * * * *