U.S. patent application number 14/791201 was filed with the patent office on 2017-01-05 for methods for monitoring well cementing operations.
The applicant listed for this patent is Schlumberger Technology Corporation. Invention is credited to Jose Contreras Escalante, Gunnar Gerard De Bruijn, Nicolas Flamant, Pavel Nyaga, Edward Smetak, Andrew Whiddon.
Application Number | 20170002622 14/791201 |
Document ID | / |
Family ID | 57609202 |
Filed Date | 2017-01-05 |
United States Patent
Application |
20170002622 |
Kind Code |
A1 |
De Bruijn; Gunnar Gerard ;
et al. |
January 5, 2017 |
METHODS FOR MONITORING WELL CEMENTING OPERATIONS
Abstract
Cement placement simulations and post-placement simulations are
traditionally performed before the cementing operation takes place.
Several simulation iterations may be performed, allowing engineers
to develop an optimal cement treatment design. When the cementing
operation takes place, engineers may follow the procedure
prescribed by the simulator. After the operation is complete and
the cement has set, logging operations may be performed to verify
that the goals of the cementing operation have been met. Monitoring
the progress of the cementing operation in real time allows a
determination of whether cementing events are unfolding as
predicted by the simulator. If deviations from the plan occur, some
real-time adjustments may be made to improve cementing results.
Inventors: |
De Bruijn; Gunnar Gerard;
(Houston, TX) ; Nyaga; Pavel; (Houston, TX)
; Smetak; Edward; (Katy, TX) ; Whiddon;
Andrew; (Houston, TX) ; Contreras Escalante;
Jose; (Richmond, TX) ; Flamant; Nicolas;
(Clamart, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schlumberger Technology Corporation |
Sugar Land |
TX |
US |
|
|
Family ID: |
57609202 |
Appl. No.: |
14/791201 |
Filed: |
July 2, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 33/14 20130101 |
International
Class: |
E21B 33/13 20060101
E21B033/13 |
Claims
1. A method for cementing a subterranean well, comprising: (i)
preparing a cement slurry; (ii) pumping the slurry into the well
through a casing interior and, after exiting the casing interior,
through an annulus between a casing exterior and a borehole wall;
(iii) real-time monitoring of parameters comprising temperature,
pressure or return rate or a combination thereof; and (iv)
comparing the real-time monitored parameters to a previously
generated cement placement simulation or a previously generated
post-cement placement simulation or both.
2. The method of claim 1, wherein temperature sensors are located
at a wellhead, at a casing shoe, along fibers installed throughout
the well, or at a return line or a combination thereof.
3. The method of claim 1, wherein pressure sensors are located at a
wellhead, at a casing shoe, along fibers installed throughout the
well, or at a return line or a combination thereof.
4. The method of claim 1, wherein flow rate sensors are located at
a wellhead, at a casing shoe, along fibers installed throughout the
well, at a mud pit, or at a return line or a combination
thereof.
5. The method of claim 1, wherein the monitored parameters are
synchronized and displayed together on a computer screen.
6. The method of claim 1, wherein the post-placement simulation
employs calorimetry data to provide a post-placement well
temperature prediction.
7. The method of claim 1, wherein the monitored parameters provide
a real-time prediction of when the cement slurry will reach a given
location in the well.
8. A method for confirming cement-placement events, comprising: (i)
preparing a cement slurry; (ii) pumping the slurry into a well
through a casing interior and, after exiting the casing interior,
through an annulus between a casing exterior and a borehole wall;
(iii) real-time monitoring of parameters comprising temperature,
pressure or return rate or a combination thereof; and (iv)
comparing the real-time monitored parameters to a previously
generated cement placement simulation or a previously generated
post-cement placement simulation or both.
9. The method of claim 8, wherein temperature sensors are located
at a wellhead, at a casing shoe, along fibers installed throughout
the well, or at a return line or a combination thereof.
10. The method of claim 8, wherein pressure sensors are located at
a wellhead, at a casing shoe, along fibers installed throughout the
well, or at a return line or a combination thereof.
11. The method of claim 8, wherein flow rate sensors are located at
a wellhead, at a casing shoe, along fibers installed throughout the
well, at a mud pit, or at a return line or a combination
thereof.
12. The method of claim 8, wherein the monitored parameters are
synchronized and displayed together on a computer screen.
13. The method of claim 8, wherein the post-placement simulation
employs calorimetry data to provide a post-placement well
temperature prediction.
14. The method of claim 8, wherein the cement-placement events
comprise landing of a cementing plug, landing of a cementing dart,
passage of a fluid interface past a given location in a well,
setting of the cement slurry, or arrival of a cement slurry at a
given location in the well, or combinations thereof.
15. A method for modifying a cement placement simulation,
comprising: (i) preparing a cement slurry; (ii) pumping the slurry
into a well through a casing interior and, after exiting the casing
interior, through an annulus between a casing exterior and a
borehole wall; (iii) real-time monitoring of parameters comprising
pump rate, pressure, fluid volume, fluid density or fluid
temperature or combinations thereof; (iv) entering real-time data
into a cement placement simulator and allowing the simulator to
predict future cement-placement events.
16. The method of claim 15, wherein a cement placement simulation
has been performed before pumping the slurry into the well.
17. The method of claim 15, wherein a cement placement simulation
has not been performed before pumping the slurry into the well, and
future cement-placement events are predicted in real time.
18. The method of claim 15, wherein temperature sensors are located
at a wellhead, at a casing shoe, along fibers installed throughout
the well, or at a return line or a combination thereof.
19. The method of claim 15, wherein pressure sensors are located at
a wellhead, at a casing shoe, along fibers installed throughout the
well, or at a return line or a combination thereof.
20. The method of claim 15, wherein flow rate sensors are located
at a wellhead, at a casing shoe, along fibers installed throughout
the well, at a mud pit, or at a return line or a combination
thereof.
Description
BACKGROUND
[0001] The statements in this section merely provide background
information related to the present disclosure and may not
constitute prior art.
[0002] The present disclosure broadly relates to methods for
monitoring well cementing operations. In particular, the methods
relate to monitoring well cementing parameters and comparing the
parameters to cement placement simulations in real time.
[0003] Primary cementing is a technique for placing cement slurries
in the annular space between the casing and the borehole. After
placement, the cement hardens to form a hydraulic seal in the
wellbore, preventing the migration of formation fluids in the
annulus. Therefore, primary cementing is one of the most important
stages during the drilling and completion of a well. This procedure
must be planned and executed carefully, as there is but one chance
to complete the job successfully.
[0004] In addition to providing zonal isolation, the set cement
sheath should anchor and support the casing string (preventing
formation sloughing or caving into the wellbore) and protect the
casing string against corrosion by formation fluids. Uncemented
steel casing can corrode rapidly when exposed to hot formation
brines and hydrogen sulfide. It can also be subjected to erosion by
the high velocity of produced fluids, particularly when solid
particles such as formation sand are being transported. Lateral
loads on poorly cemented casing strings can result in buckling or
collapse because of overloading at certain points. On the other
hand, properly cemented casing is subjected to a nearly uniform
loading approximately equal to the overburden pressure.
[0005] In principle, primary cementing techniques are the same
regardless of casing-string purpose and size. The cement slurry is
pumped down inside the string to be cemented, exits the bottom, and
displaces drilling mud as it moves up the annulus. Or, a "reverse
cementing" technique may be performed wherein fluids are pumped in
the opposite direction--down the annulus and up the casing.
[0006] Pumping dense fluids such as cement slurries down a casing
string can result in a phenomenon known as free-fall or U-tubing.
The fluids inside the casing and in the annulus will naturally tend
to achieve a hydrostatic-pressure equilibrium. During the course of
the cement job, some interesting effects may be observed.
[0007] The density of cement slurries is usually higher than those
of the drilling fluid, chemical wash or spacer. When the cement
slurry is introduced inside the casing, a hydrostatic pressure
imbalance is created between the inside of the casing and the
annulus. As a result, the cement slurry has a tendency to
"free-fall" and draws a vacuum inside the upper part of the
casing.
[0008] In many cementing operations, the pump rate into the casing,
Q.sub.in, is insufficient to keep the casing full during the early
part of the job. This results in a net flow or efflux of fluid from
the well. The rate of efflux, Q.sub.out, may be much greater than
Q.sub.in. Eventually, as hydrostatic pressure equilibrium is
approached, Q.sub.out falls below Q.sub.in and the casing gradually
refills. At some point, Q.sub.out may reach zero and the fluid
column in the annulus may become stationary. Such events are easily
misinterpreted as partial or complete loss of circulation. Finally,
when the casing is again full of fluid, Q.sub.in and Q.sub.out will
be equal. However, these values may not remain so for the remainder
of the job. If a low-density wash is present, it may cause an
annular-pressure reduction as it flows past the casing shoe. This
will in turn cause a second period of free-fall, accompanied by
another surge of high returns. The beginning and end of a U-tubing
event can easily be detected by measuring the surface pressure
during the cement job
[0009] Considering the importance of annular fluid velocities and
pressures to the safe and successful execution of a cement job, it
is clear that U-tubing must be considered in any job design.
Algorithms exist that permit accurate simulations of these
phenomena. These algorithms have been validated against carefully
measured field parameters during cementing operations.
[0010] Computer simulators are also used to determine the number of
centralizers on a casing string to achieve optimal standoff and
encourage complete removal of drilling fluids from the annulus.
Other factors that the simulators consider in their calculations
include temperature, wellbore geometry, formation fracture
gradients, mud conditioning, rheological properties of cementing
fluids (e.g., mud, chemical washes, spacer fluids and cement
slurries), casing movement via reciprocation and rotation and pump
rates.
[0011] The simulators may generate several predictions, including
mud displacement, cement slurry coverage, flow rates, temperature
and pressure evolution at various locations in the well and well
control. One such simulator is CEMENTICS, available from
Schlumberger.
[0012] Further information about well cementing operations and
simulators may be found in the following publications.
[0013] Piot B: "Primary Cement Job Design," in Nelson E B and
Guillot D (eds.): Well Cementing-2nd Edition, Houston: Schlumberger
(2006): 435-458.
[0014] Piot B and Cuvillier G: "Primary Cementing Techniques," in
Nelson E B and Guillot D (eds.): Well Cementing-2 nd Edition,
Houston: Schlumberger (2006): 459-501.
SUMMARY
[0015] This summary is provided to introduce a selection of
concepts that are further described below in the detailed
description. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used as an aid in limiting the scope of the claimed
subject matter.
[0016] The present disclosure reveals methods relating to
monitoring well cementing parameters and comparing the parameters
to cement placement simulations in real time. Additionally,
adjustments to the cementing operation may be performed in real
time in response to operational deviations from the simulation
predictions.
[0017] In an aspect, embodiments relate to methods for cementing a
subterranean well. A cement slurry is prepared and pumped into the
well through a casing interior. After exiting the casing interior
at the bottom of the casing string, the slurry is pumped through an
annulus between the casing string exterior and a borehole wall.
During the operation, real-time of cementing parameters takes
place. The parameters may be temperature, pressure or return rate
or a combination thereof. The real-time monitored parameters are
then compared to a previously generated cement placement
simulation, or a previously generated post-placement simulation or
both.
[0018] In a further aspect, embodiments relate to methods for
confirming cement-placement events. A cement slurry is prepared and
pumped into the well through a casing interior. After exiting the
casing interior at the bottom of the casing string, the slurry is
pumped through an annulus between the casing string exterior and a
borehole wall. During the operation, real-time of cementing
parameters takes place. The parameters may be temperature, pressure
or return rate or a combination thereof. The real-time monitored
parameters are then compared to a previously generated cement
placement simulation, or a previously generated post-placement
simulation or both.
[0019] In yet a further aspect, embodiments relate to methods for
confirming cement-placement events. A cement slurry is prepared and
pumped into the well through a casing interior. After exiting the
casing interior at the bottom of the casing string, the slurry is
pumped through an annulus between the casing string exterior and a
borehole wall. During the operation, real-time monitoring of
cementing parameters takes place. The parameters may be pump rate,
pressure, fluid volume, fluid density or fluid temperature or a
combination thereof. The real-time monitored parameters are then
entered into a cement placement simulator, and the simulator is
allowed to predict future cement placement events.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a well diagram showing the location of sensors
that are employed in the disclosed methods.
DETAILED DESCRIPTION
[0021] At the outset, it should be noted that in the development of
any such actual embodiment, numerous implementation--specific
decisions are 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 disclosure 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. The term about
should be understood as any amount or range within 10% of the
recited amount or range (for example, a range from about 1 to about
10 encompasses a range from 0.9 to 11). 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 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 possible number along the continuum between about 1
and about 10. Furthermore, one or more of the data points in the
present examples may be combined together, or may be combined with
one of the data points in the specification to create a range, and
thus include each possible value or number within this range. Thus,
even if specific data points within the range, or even no data
points within the range, are explicitly identified or refer to a
few specific, it is to be understood that inventors appreciate and
understand that any data points within the range are to be
considered to have been specified, and that inventors possessed
knowledge of the entire range and the points within the range.
[0022] Cement placement simulations and post-placement simulations
are traditionally performed before the cementing operation takes
place. Several simulation iterations may be performed, allowing
engineers to develop an optimal cement treatment design. When the
cementing operation takes place, engineers may follow the procedure
prescribed by the simulator. After the operation is complete and
the cement has set, logging operations may be performed to verify
that the goals of the cementing operation have been met.
[0023] Applicant has determined that advantages may be gleaned by
monitoring the progress of the cementing operation in real time,
thereby allowing a determination of whether cementing events are
unfolding as predicted by the simulator. If deviations from the
plan occur, some real-time adjustments may be made to improve
cementing results.
[0024] In an aspect, embodiments relate to methods for cementing a
subterranean well. A cement slurry is prepared and pumped into the
well through a casing interior. After exiting the casing interior
at the bottom of the casing string, the slurry is pumped through an
annulus between the casing string exterior and a borehole wall.
During the operation, real-time monitoring of cementing parameters
takes place. The parameters may be temperature, pressure or return
rate or a combination thereof. The real-time monitored parameters
are then compared to a previously generated cement placement
simulation, or a previously generated post-placement simulation or
both.
[0025] The cement placement events may comprise landing of a
cementing plug, landing of a cementing dart, passage of a fluid
interface past a given location in a well, setting of the cement
slurry, or arrival of a cement slurry at a given location in the
well, or combinations thereof.
[0026] In a further aspect, embodiments relate to methods for
confirming cement-placement events. A cement slurry is prepared and
pumped into the well through a casing interior. After exiting the
casing interior at the bottom of the casing string, the slurry is
pumped through an annulus between the casing string exterior and a
borehole wall. During the operation, real-time monitoring of
cementing parameters takes place. The parameters may be
temperature, pressure or return rate or a combination thereof. The
real-time monitored parameters are then compared to a previously
generated cement placement simulation, or a previously generated
post-placement simulation or both.
[0027] In yet a further aspect, embodiments relate to methods for
confirming cement-placement events. A cement slurry is prepared and
pumped into the well through a casing interior. After exiting the
casing interior at the bottom of the casing string, the slurry is
pumped through an annulus between the casing string exterior and a
borehole wall. During the operation, real-time monitoring of
cementing parameters takes place. The parameters may be pump rate,
pressure, fluid volume, fluid density or fluid temperature or a
combination thereof. The real-time monitored parameters are then
entered into a cement placement simulator, and the simulator is
allowed to predict future cement placement events.
[0028] The cement placement events may comprise landing of a
cementing plug, landing of a cementing dart, passage of a fluid
interface past a given location in a well, setting of the cement
slurry, or arrival of a cement slurry at a given location in the
well, or combinations thereof.
[0029] A cement placement simulation may or may not have been
performed before pumping the slurry into the well.
[0030] For each aspect, temperature sensors may be located at a
wellhead, at a casing shoe, along fibers installed throughout the
well, or at a return line or a combination thereof.
[0031] For each aspect, pressure sensors may be located at a
wellhead, at a casing shoe, along fibers installed throughout the
well, or at a return line or a combination thereof.
[0032] For each aspect, flow rate sensors may be located at a
wellhead, at a casing shoe, along fibers installed throughout the
well, at a mud pit, or at a return line or a combination
thereof.
[0033] For each aspect, the monitored parameters may be
synchronized and displayed together on a computer screen.
[0034] For each aspect, the post-placement simulation may employ
calorimetry data to provide a post-placement well temperature
prediction.
[0035] For each aspect, the monitored parameters may provide a
real-time prediction of when the cement slurry will reach a given
location in the well.
[0036] For each aspect, the parameters may be monitored at a
wellsite or from a remote location.
[0037] For each aspect, the cement placement simulation may include
a U-tube simulator.
[0038] For each aspect, the monitored parameters may provide a
real-time prediction of when the cement slurry will reach a given
location in the well.
[0039] For each aspect, the telemetry between the sensors and the
receivers may be transmitted along wires, optical fibers or
wirelessly or a combination thereof. Wireless communication may be
in the form of electromagnetic signals, acoustic signals or
both.
[0040] A non-limiting embodiment of the disclosure is portrayed in
FIG. 1. An example well 100 comprises several elements: a wellhead
101, a casing string 102, a casing shoe 103, a return line 104, a
mud pit 105, a fiber cable 106 placed along the casing string 102,
a temperature sensor 107, a pressure sensor 108 and a flow rate
sensor 109. Although the sensors 107-109 are shown only at the
casing shoe 102, they may also be located at the wellhead 101,
along the fiber cable 106, at the return line 104 or at the mud
pits or a combination thereof.
[0041] Although various embodiments have been described with
respect to enabling disclosures, it is to be understood that this
document is not limited to the disclosed embodiments. Variations
and modifications that would occur to one of skill in the art upon
reading the specification are also within the scope of the
disclosure, which is defined in the appended claims.
* * * * *