U.S. patent application number 14/713130 was filed with the patent office on 2015-11-19 for self-powered microsensors for in-situ spatial and temporal measurements and methods of using same in hydraulic fracturing.
The applicant listed for this patent is Masdar Institute Of Science And Technology. Invention is credited to Rashid Kamel Abu Al-Rub, Irfan Abdulqayyum Saadat, Mohamed Ben Mahmoud Sassi, Manhal Sirat.
Application Number | 20150330212 14/713130 |
Document ID | / |
Family ID | 54538092 |
Filed Date | 2015-11-19 |
United States Patent
Application |
20150330212 |
Kind Code |
A1 |
Sassi; Mohamed Ben Mahmoud ;
et al. |
November 19, 2015 |
SELF-POWERED MICROSENSORS FOR IN-SITU SPATIAL AND TEMPORAL
MEASUREMENTS AND METHODS OF USING SAME IN HYDRAULIC FRACTURING
Abstract
A delayed-activation sensor system includes at least one
microsensor. The microsensor may include at least one sensor module
for sensing a condition in an environment and a dissolvable coating
encapsulating at least a portion of the at least one sensor module
such that the dissolvable coating prevents the at least one sensor
module from sensing the condition in the environment. The
dissolvable coating may be dissolvable in a fluid in the
environment such that the sensor module is activated after being
located in the environment for a period of time. The microsensor
may also include at least one energy harvester module to generate
electrical power for the microsensor from the environment.
Inventors: |
Sassi; Mohamed Ben Mahmoud;
(Moknine, TN) ; Sirat; Manhal; (Uppsala, SE)
; Saadat; Irfan Abdulqayyum; (Santa Clara, CA) ;
Abu Al-Rub; Rashid Kamel; (Amman, JO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Masdar Institute Of Science And Technology |
Abu Dhabi |
|
AE |
|
|
Family ID: |
54538092 |
Appl. No.: |
14/713130 |
Filed: |
May 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61994274 |
May 16, 2014 |
|
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Current U.S.
Class: |
166/250.1 ;
166/66 |
Current CPC
Class: |
E21B 43/26 20130101;
E21B 47/00 20130101; E21B 47/26 20200501; A61B 5/05 20130101; E21B
47/07 20200501; H04Q 2209/886 20130101; E21B 41/0085 20130101; H04Q
9/00 20130101; E21B 47/06 20130101; E21B 47/11 20200501; E21B 47/12
20130101; E21B 43/267 20130101; E21B 47/13 20200501 |
International
Class: |
E21B 47/06 20060101
E21B047/06; E21B 43/267 20060101 E21B043/267; E21B 47/12 20060101
E21B047/12; E21B 43/26 20060101 E21B043/26 |
Claims
1. A delayed-activation sensor system comprising: at least one
microsensor comprising: at least one sensor module for sensing a
condition in an environment; and a dissolvable coating
encapsulating at least a portion of the at least one sensor module
such that the dissolvable coating prevents the at least one sensor
module from sensing the condition in the environment, the
dissolvable coating being dissolvable in a fluid in the environment
such that the sensor module is activated after being located in the
environment for a period of time.
2. The delayed-activation sensor system of claim 1, wherein the
sensor module is configured to sense a condition selected from the
group consisting of temperature, pressure, pH, chemical
composition, magnetic field strength, and stress.
3. The delayed-activation sensor system of claim 1, wherein the
dissolvable coating includes a coating that dissolves due to
temperature, pH, and water.
4. The delayed-activation sensor system of claim 3, wherein the
dissolvable coating includes a thermal dissolvable coating, the
thermal dissolvable coating being selected from a group consisting
of a polyamide, polyglycolide or polyglycolic acid, polyvinyl
alcohol, polyvinyl pyrrolidone, polyethylene glycol,
polystyrenesulfonate, quaternized amine polymers, alkoxomers, and
mixtures thereof.
5. The delayed-activation sensor system of claim 3, wherein the
dissolvable coating includes a water dissolvable coating, the water
dissolvable coating being selected from a group consisting of a
polymer, PC polymer, cellulose, hydroxyethylcellulose,
ethylcellulose, cellulose esthers, resins, and mixtures
thereof.
6. The delayed-activation sensor system of claim 3, wherein the
dissolvable coating includes a pH dissolvable coating, the pH
dissolvable coating being selected from a group consisting of a
cationic polyacrylamide, acrylate, aminoacrylate, alkyl PEG-20, and
mixtures thereof.
7. The delayed-activation sensor system of claim 1, wherein the at
least one coated microsensor has a dimension from 1 mm to 20
mm.
8. The delayed-activation sensor system of claim 1, further
comprising a support body for supporting the sensor module, and
wherein the dissolvable coating encapsulates the support
module.
9. The delayed-activation sensor system of claim 8, wherein the
support body has a cuboid shape, and wherein the dissolvable
coating forms a spheroid shape.
10. The delayed-activation sensor system of claim 1, wherein the
microsensor is made of material that is functionally stable from a
temperature of 100 C to 900 C.
11. The delayed-activation sensor system of claim 1, wherein the
microsensor further comprises at least one energy harvester module
to generate electrical power for the microsensor from the
environment.
12. The delayed-activation sensor system of claim 11, wherein the
energy harvester module includes an electrochemical energy
harvester module including two dissimilar metals that form an
electrochemical cell with a fluid in the environment.
13. The delayed-activation sensor system of claim 1, further
comprising: a plurality of microsensors; and a dissolvable coating
encapsulating each of the microsensors separately to form a
plurality of coated microsensors.
14. The delayed-activation sensor system of claim 13, wherein the
dissolvable coating of at least one of the coated microsensors
dissolves slower than the dissolvable coating of at least another
of the coated microsensors such that the plurality of coated
microsensors provide staggered sensor activation at different
times.
15. The delayed-activation sensor system of claim 1, further
comprising at least one supersensor configured to receive sensor
data from a plurality of microsensors and to retransmit the sensor
data to a receiving point outside the environment.
16. The delayed-activation sensor system of claim 1, further
comprising a plurality of microsensors, wherein the dissolvable
coating is configured to cause said plurality of microsensors to
cluster together through electrostatic surface charge, van der Waal
forces, electrostatic force, or surface polarity.
17. The delayed-activation sensor system of claim 11, wherein the
at least one energy harvester module is selected from the group
consisting of a mechanical energy harvester module and a thermal
energy harvester module.
18. The delayed-activation sensor system of claim 1, further
comprising wireless communication module configured to wirelessly
transmit data.
19. The delayed-activation sensor system of claim 1, further
comprising at least one data storage/signal processing module
configured.
20. The delayed-activation sensor system of claim 1, further
comprising processing circuitry generating location data indicative
of a location of the microsensor.
21. The delayed-activation sensor system of claim 1, further
comprising a fracking mixture and a plurality of the microsensors
mixed therein.
22. The delayed-activation sensor system of claim 1, further
comprising proppants and a plurality of the microsensors mixed
therein.
23. A self-powered microsensor for sensing a condition in an
environment, the self-powered micro-sensor comprising: at least one
energy harvester module to generate electrical power for the
microsensor from the environment; and at least one sensor module
electrically coupled to the electrochemical energy harvester
module.
24. The self-powered microsensor of claim 23, wherein the at least
one energy harvester module includes an electrochemical energy
harvester.
25. The self-powered microsensor of claim 24, further including a
dissolvable coating covering the energy harvester module such that
the dissolvable coating prevents at least one of the energy
harvester module or the sensor module from being activated, the
dissolvable coating being dissolvable in a fluid in the environment
such that the sensor module is activated after being located in the
environment for a period of time.
26. A method of in-situ monitoring a hydraulic fracturing
operation, the method comprising: injecting a plurality of
dissolvable coated self-powered microsensors into a well bore;
dissolving of coating on self-powered microsensors in the well
bore; activating the self-powered microsensors; and obtaining
measurements from each of the self-powered microsensors.
27. The method of claim 26, wherein the self-powered microsensors
are injected with a fracking mixture used to perform hydraulic
fracturing.
28. The method of claim 27, wherein the measurements are obtained
during the hydraulic fracturing.
29. The method of claim 28, wherein the measurements are selected
from the group consisting of temperature, pressure, location, and
chemical composition.
30. The method of claim 27, wherein the self-powered microsensors
include a mechanical energy harvester module for harvesting
vibration energy during the hydraulic fracturing to power the
microsensors.
31. The method of claim 26, wherein the self-powered microsensors
are injected with proppants after the hydraulic fracturing.
32. The method of claim 31, wherein the measurements are obtained
from within fractures created by the hydraulic fracturing.
33. The method of claim 32, wherein the measurements are selected
from the group consisting of temperature, pressure, stresses,
location, and oil presence.
34. The method of claim 26, wherein the self-powered microsensors
include a thermal energy harvester module for harvesting thermal
energy to power the microsensors.
35. The method of claim 26, wherein the self-powered microsensors
include at least one electrochemical energy harvester module formed
by two different metals, wherein the two different metals form an
electrochemical cell with a fluid in an environment of the
hydraulic fracturing.
36. The method of claim 26, further comprising determining a
location of at least some of the self-powered microsensors.
37. The method of claim 26, further comprising creating a map
during and/or after hydraulic fracturing.
38. The method of claim 26, further comprising transmitting
wireless signals between the microsensors to form a sensor network
of microsensor nodes.
39. The method of claim 26, further comprising transmitting signals
from the microsensors to a collection point for telemetry.
40. The method of claim 26, further comprising transmitting signals
to and/or from the microsensors for determining locations of the
microsensors using triangulation.
41. The method of claim 26, further comprising transmitting signals
to and/or from the microsensors for determining propagation paths
indicative of the presence of oil.
Description
PRIORITY
[0001] This application claims benefit under 35 U.S.C. .sctn.119(e)
to U.S. Provisional Patent Application No. 61/994,274 entitled
"SELF-POWERED MICROSENSORS FOR IN-SITU SPATIAL AND TEMPORAL
MEASUREMENTS AND METHODS OF USING SAME IN HYDRAULIC FRACTURING"
that was filed on May 16, 2014, the contents of the
above-identified provisional application being incorporated herein,
in entirety, by reference.
TECHNICAL FIELD
[0002] The present invention relates to microsensors and more
particularly, to microsensors for in-situ spatial and temporal
measurements and methods of using same in hydraulic fracturing.
BACKGROUND INFORMATION
[0003] Sensors are used in a wide range of applications for
measuring various conditions. Designing sensors that are capable of
operating and obtaining the desired measurements in certain
environments and applications may be a challenge. In some
applications, for example, the sensors must be a small size to be
positioned in the environment where the conditions are to be
measured. Sensors may also be damaged by environmental factors,
such as high temperatures, high pressures, and corrosive
materials.
[0004] One application where sensing various conditions is
desirable, but difficult, is hydraulic fracturing. Hydraulic
fracturing is the fracturing of rock by a pressurized liquid and is
commonly known as "fracking." Typically, hydraulic fracturing
involves two steps. In the first step, water is mixed with sand and
chemicals, and the mixture is injected at high pressure (e.g., 1500
to 3000 PSI) into a wellbore to create small fractures (typically
around several mm in width). Fluids such as gas, petroleum,
uranium-bearing solution, and brine water may migrate along these
fractures to the well. In the second step, the hydraulic pressure
is removed from the well, and small grains or particles of proppant
(e.g., sand or aluminum oxide) are injected to hold these fractures
open once the rock achieves equilibrium. The proppants may include
spherical balls with a radius of 3-4 mm and made of ceramic and/or
other hard materials. Because of the size and shape of the
proppants, fluid may diffuse out of the fractures or cracks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] These and other features and advantages will be better
understood by reading the following detailed description, taken
together with the drawings wherein:
[0006] FIG. 1 is a schematic diagram of microsensors being injected
into a well during a hydraulic fracturing operation, consistent
with an embodiment of the present disclosure.
[0007] FIG. 2 is a schematic diagram of microsensors located in
fractures formed by the hydraulic fracturing operation, consistent
with an embodiment of the present disclosure.
[0008] FIG. 3 is a perspective view of microsensors consistent with
at least one embodiment of the present disclosure.
[0009] FIG. 4 is a perspective view of a plurality of microsensors
encapsulated with a group coating.
[0010] FIG. 5 is a schematic diagram of a system/network of
microsensor nodes comprising a plurality of microsensors.
[0011] FIG. 6 is a schematic diagram of a supersensor/satellite
sensor system.
[0012] FIG. 7 is a schematic diagram of a satellite/node sensor
system.
[0013] FIG. 8 is a schematic diagram of a plurality of microsensors
forming a cluster system.
[0014] FIG. 9 is a schematic diagram of a microsensor including an
electrochemical energy harvester module.
DETAILED DESCRIPTION
[0015] Microsensors, consistent with embodiments disclosed herein,
may be used for in-situ spatial and temporal measurements.
According to one aspect, the microsensors may include self-powered
microsensors. As used herein, "self-powered" refers to the
capability of the microsensor to generate sufficient power to
operate the electronics in the microsensor, for example, by
harvesting energy in the environment. Embodiments of self-powered
microsensors generally include one or more sensor elements for
measuring conditions, data processing circuitry for processing data
(e.g., sensor data from the sensor elements and/or location data
from other microsensors or transmitters), circuitry for storing,
transmitting and/or receiving data, and an energy harvester for
self-powering the sensor elements and circuitry. As will be
described in greater detail below, the microsensor design (e.g.,
the types of sensor elements, the type of energy harvester, or the
type of circuitry) may depend on the particular application for the
microsensor.
[0016] A plurality of self-powered microsensors may be used
together for measuring conditions at locations throughout an
environment being monitored and/or for mapping the environment. For
example, a plurality of self-powered microsensors 10a-n may be used
for measurements during and after hydraulic fracturing (also
referred to as "fracking"). As shown in FIG. 1, a plurality of
self-powered microsensors 10a-n may be injected into a well bore
12. The microsensors 10a-n may be injected (e.g., introduced) into
the well bore 12 together with a fluid 14 for monitoring the
dynamics of the fracturing process. The microsensors 10a-n may be
used, for example, with tomography techniques to map the shape of
the reservoir before, during, and/or after the fracking
process.
[0017] According to one aspect, the fluid 14 with which the
microsensors 10a-n may be introduced into the well bore 12 may
include, but is not limited to, a fracking mixture. The fracking
mixture may include any fracking mixture known to those skilled in
the art for creating factures in the rock under high pressure. By
way of example, the fracking mixture may include a mixture of water
and chemical additives. The chemical additives may include, but are
not limited to, one or more of the following: [0018] Acids (such
as, but not limited to, Hydrochloric acid (HCl, 3% to 28%) and/or
muriatic acid) configured to clean up perforation intervals of
cement and drilling mud prior to fracturing fluid injection and
provide accessible path to formation. [0019] Breakers (such as, but
not limited to, peroxydisulfates) configured to reduce the
viscosity of the fluid in order to release proppant into fractures
and enhance the recovery of the fracturing fluid. [0020]
Bactericides/Biocides (such as, but not limited to, gluteraldehyde
and/or 2-bromo-2-nitro-1,2-propanediol) configured to inhibit
growth of organisms that could produce gases (particularly hydrogen
sulfide) that could contaminate methane gas and/or also configured
to prevent the growth of bacteria which can reduce the ability of
the fluid to carry proppant into the fractures. [0021] Buffers/pH
Adjusting Agents (such as, but not limited to, sodium or potassium
carbonate and/or acetic acid) configured to adjust and/or control
the pH of the fluid in order to maximize the effectiveness of other
additives, such as crosslinkers discussed herein. [0022] Clay
Stabilizers/Controls (such as, but not limited to, salts including
tetramethyl ammonium chloride and/or potassium chloride) configured
to prevent swelling and/or migration of formation clays which could
block pore spaces thereby reducing permeability. [0023] Corrosion
Inhibitors (such as, but not limited to, methanol and/or ammonium
bisulfate for oxygen scavengers) configured to reduce rust
formation on steel tubing, well casings, tools, and tanks
(generally used in fracturing fluids that contain acid). [0024]
Crosslinkers (such as, but not limited to, potassium hydroxide
and/or borate salts). The fluid viscosity may be increased using
phosphate esters combined with metals. The metals may be referred
to as crosslinking agents. The increased fracturing fluid viscosity
may allow the fluid to carry more proppant into the fractures.
[0025] Friction Reducers (such as, but not limited to, sodium
acrylate-acrylamide copolymer, polyacrylamide (PAM), and/or
petroleum distillates) configured to allow fracture fluids to be
injected at optimum rates and pressures by minimizing friction.
[0026] Gelling Agents (such as, but not limited to, guar gum and/or
petroleum distillate) configured to increase fracturing fluid
viscosity, allowing the fluid to carry more proppant into the
fractures. [0027] Iron Controls (such as, but not limited to,
ammonium chloride, ethylene glycol, and/or polyacrylate) configured
to prevent the precipitation of carbonates and sulfates (calcium
carbonate, calcium sulfate, barium sulfate) which could plug off
the formation. [0028] Solvents (such as, but not limited to,
aromatic hydrocarbons) which may include one or more additives that
are soluble in oil, water & acid-based treatment fluids that
are used to control the wettability of contact surfaces or to
prevent or break emulsions. [0029] Surfactants (such as, but not
limited to, methanol, isopropanol, and/or ethoxylated alcohol)
configured to reduce fracturing fluid surface tension thereby
aiding fluid recovery.
[0030] As shown in FIG. 2, a plurality of self-powered microsensors
10a-n may also be injected together with proppants 200a-n (e.g.,
after the fracking process) into the fractures or cracks 210 after
the fracturing occurs to monitor production of oil and/or for
measuring conditions, such as temperature, pressure, and presence
of oil. The proppants 200a-n may include any material(s) configured
to be embedded into and/or keep fractures/cracks open to allow
gas/fluids to flow more freely to the well bore. The proppants
200a-n may include, but are not limited to, one or more of sand
(including sintered bauxite, zirconium oxide) and/or ceramic beads.
It should be appreciated that the proppants 200a-n and microsensors
10a-n may be separate from, or included in, the fracking mixture
14. The microsensor 10a-n may have a size and shape consistent with
the form factor of the proppants 200a-n, for example, a spheroid or
spherical shape may range from 1 mm to 20 mm in size.
[0031] As discussed herein, the plurality of self-powered
microsensors 10a-n may be configured to generate wireless signals
(e.g., ping signals such as, but not limited to, an RF
electromagnetic wave) which includes the sensor collected data. The
ping signals may optionally include a unique ID and/or location
parameters. The microsensors 10a-n may transmit ping signals
periodically (e.g., at fixed time intervals such as, but not
limited to, 5 minutes) and/or based on one or more threshold values
(e.g., a power supply threshold and/or buffer threshold). For
example, the microsensors 10a-n if the power supply is below a
threshold, the microsensors 10a-n may wait until the power supply
reaches and/or exceeds the power supply threshold. Alternatively
(or in addition), the microsensors 10a-n may wait until the data
stored in a buffer and/or memory (e.g., sensor data from one or
more microsensors 10a-n) reaches and/or exceeds a buffer/memory
threshold.
[0032] As shown in FIG. 3, one aspect of an individual microsensor
10 consistent with the present disclosure is generally illustrated.
The microsensor 10 may include one or more sensor modules 310, at
least one processing circuitry 312 (e.g., but not limited to, one
or more CPUs, circuitry, processors, logic, or the like), at least
one wireless communication module 314, at least one data
storage/signal processing module 316, at least one energy harvester
module 318, and/or at least one memory 320. The microsensor 10 also
include a support body/structure 302 configured to support sensor
modules 310, processing circuitry 312, wireless communication
module 314, data storage/signal processing module 316, energy
harvester module 318, and/or memory 320. It should be appreciated
that the microsensor 10 shown in FIG. 3 is for illustrative
purposes, and that one of ordinary skill in the art (upon reading
the present disclosure as a whole) will understand that various
functions and/or components may be combined and/or eliminated.
[0033] An individual microsensor 10 may include cubical or cuboid
shaped structure, though other shapes are possible such as, but not
limited to, spherical, oblong, and the like. One or more
microsensors 10a-n may be covered and/or encapsulated with a
coating as described herein. The coating may have a form a
spherical or spheroid shaped. As used herein, a the terms "cube,"
"cubical," and "cuboid" do not require a perfect cube shape and the
terms "sphere," "spherical," and "spheroid" do not require a
perfect sphere shape. To be compatible with high temperatures and a
harsh environment, the microsensor 10, and/or portions thereof, may
be made out of graphene, carbon nanotubes and/or similar materials.
These materials have demonstrated thermal stability up to
700.degree. C. and also are chemically inert such that they can
detect the presence of other materials without chemically reacting
with them. For higher temperature requirements, sensors made from
GaN be used, which can withstand temperatures up to .about.900
C.
[0034] The sensor module 310 may include one or more sensors and/or
sensor arrays. The sensors may include, without limitation,
temperature sensor elements, pressure sensor elements, stress
sensor elements, pH sensor elements, and chemical composition
sensor elements. The sensor module 310 may include a sensor array
with sensors tuned to detect the target physical and chemical
properties of the environment in the fractures or cracks. The
target physical properties may include pressure and/or stress in
the rock formation and other environmental properties in steady
state/production. With reference to FIG. 1, a cubical or cuboid
shaped microsensor 10 may be capable of measuring stress in three
axes (e.g., .sigma.1, .sigma.2, and .sigma.3), for example, by
using sensor elements on at least three faces of the cuboid
structure. To be compatible with high temperature and a harsh
environment, these sensors may also be made out of GaN, graphene,
carbon nanotubes and similar materials. These materials have
demonstrated thermal stability from 700.degree. C. (in case of
carbon nanomaterials) to 900.degree. C. (in case of GaN). The
carbon nanomaterials are chemically inert such that they can detect
the presence of other materials without chemically reacting with
them.
[0035] Referring back to FIG. 3, the processing circuitry 312 may
be configured to process and cause data to be stored, for example,
in memory 320 (such as, but not limited to, a buffer or the like).
For example, the processing circuitry 312 may be configured to
process data generated by the sensor module 310 with time data
(e.g., time data corresponding to sensor data generated by the
sensor module 310), sensor type data (e.g., data associated with
and/or identifying each sensor and/or type of sensor in the sensor
module 310), location data corresponding to the position/location
of the microsensor 10, and/or microsensor identification data which
uniquely identifies the microsensor 10, and cause one or more of
the data to be stored in the memory 320. The processing circuitry
312 may also be configured to determine and/or approximate the
position of the microsensor 10. For example, processing circuitry
312 may also be configured to provide telemetry and/or
triangulation based on pinging signals to or from two probes (e.g.,
in two wells) and/or other location based signals.
[0036] In this embodiment, the processing circuitry 312 may include
high temperature electronics based circuits capable of operating on
low power. High temperature electronics can be made out of GaN,
which can operate in temperatures up to 900.degree. C., and silicon
on insulator (SOI) circuits, which can operate in temperatures up
to 200.degree. C. The processing circuitry 312 may be configured to
receive the data from the sensor module 310, wireless communication
module 314, data storage/signal processing module 316, and/or
memory 320, processes the data, and sends the data to a storage
element (e.g., memory 320) and/or the wireless communication module
314. The data may be used to create temporal and spatial map for a
given property or metric during the fracking process. Processing
circuitry 312 may also process data for telemetry and/or
triangulation based on an external pinging signal.
[0037] A communication module 314 may be configured to cause one or
more signals to be transmitted. For example, the communication
module 314 enables wireless communications for the transfer of data
to and/or from the microsensor 10 to one or more microsensors,
nodes, supersensors, collection/processing controllers, and/or
external devices. The term "wireless" and its derivatives may be
used to describe circuits, devices, systems, methods, techniques,
communications channels, etc., that may communicate data through
the use of modulated electromagnetic radiation through a non-solid
medium.
[0038] Communication module 314 may implement any of a number of
wireless standards or protocols, including, but not limited to,
Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE
802.20, long term evolution (LTE), Ev-25 DO, HSPA+, HSDPA+, HSUPA+,
EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivatives thereof,
as well as any other wireless protocols that are designated as 3G,
4G, 5G, and beyond. Communication modules 314 may therefore include
hardware to support wireless communication, e.g., one or more
transponders, antennas, BLUETOOTH.TM. chips, personal area network
chips, near field communication chips, wired and/or wireless
network interface circuitry, combinations thereof, and the like.
The microsensor 10 may include a plurality of communication modules
314. For instance, a first communication module 314 may be
dedicated to shorter range wireless communications such as Wi-Fi
and Bluetooth and a second communication module 314 may be
dedicated to longer range wireless communications such as GPS,
EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.
[0039] The communication module 314 may be capable of sensing
(e.g., receiving) acoustic pinging signals or RF beacons for
telemetry applications. In addition or alternatively, the
communication module 314 may be capable of transmitting a pinging
signal. For example, the communication module 314 may be configured
to transmit one or more pinging signals to fixed locations to
provide a triangulation capability for obtaining location data.
[0040] The data storage/signal processing module 316 may be
configured to store and/or process data. For example, the data
storage/signal processing module 316 may be configured to store
data generated by the sensor module 310, processed by the
processing circuitry 312, and/or received by the communication
module 314. According to one aspect, the data storage/signal
processing module 316 may store data from a plurality of different
sources (e.g., but not limited to, the sensor module 310, the
processing circuitry 312, and/or the communication module 314)
and/or store data from one or more sources over time until a
threshold amount of data and/or time period has been reached and/or
exceeded. The data storage/signal processing module 316 may also be
configured to cause the collected/stored data to be consolidated
into one or more ping signals. For example, the data storage/signal
processing module 316 may be configured to cause the collected data
to be stored in a single packet (e.g., the payload of a single
packet) of a ping signal that be may be transmitted by the
communication module 314. The header of the ping signal may
identify the destination address and/or the source of the ping
signal. Depending on the size of the data to be transmitted, all of
the data may not fit all within the payload of a single packet. As
such, the data may be split and stored in two or more payloads of
two or more packets.
[0041] The data storage/signal processing module 316 may also be
configured to process and/or condition the data from one or more
different sources (e.g., but not limited to, the sensor module 310,
the processing circuitry 312, and/or the communication module 314).
Non-limiting examples of processing and/or signal conditioning that
the data storage/signal processing module 316 may perform include
filtering, amplifying, signal-to-noise reduction, signal isolation,
encoding, decoding, encryption, decryption, and/or the like. It may
be appreciated that the data may also (or alternatively) be
externally processed, for example, for purposes of creating an
image using location data.
[0042] The energy harvester module 318 may harvest energy (also
known as power harvesting or energy scavenging) from the
environment such as kinetic energy, thermal energy, electromagnetic
energy, salinity gradients, pH gradients, temperature gradients,
and/or electrochemical energy and optionally store the energy (for
example in one or more capacitors, super capacitors, batteries,
and/or the like). A microsensor 10 may also include a
self-contained energy source such as a thin film battery.
[0043] One example of an energy harvester module 318 includes
electrochemical and/or thermoelectric generators (TEGs). TEGs may
include two ore more dissimilar materials coupled together to form
a junction in the presence of a thermal gradient. The voltage may
be increased by connecting a plurality of junctions electrically in
series and thermally in parallel. Thermal energy harvesters or
electrochemical energy harvesters may be used. One example of a
thermal energy harvester includes two different alloy metals, which
produce a voltage drop when placed across a temperature
gradient.
[0044] The energy harvester module 318 may include an
electrochemical energy harvester. An electrochemical energy
harvester may include dissimilar metals that form an
electrochemical cell in the presence of ionic fluid in the
environment in which they are used. If the microsensors 10 only
include vibration based energy harvester modules 318, the
microsensors 10 may become dormant after the fracking process until
they are brought to the surface. If the microsensors 10 include
thermal energy harvester modules 318 and/or electrochemical energy
harvester modules 318, the microsensors 10 may be activated and
powered when the microsensors 10 are stationary after the fracking
process even without movement or vibrations.
[0045] Another example of an energy harvester module 318 includes
piezoelectric crystals or fibers which generate a voltage whenever
they are mechanically deformed. Vibration from the surrounding
environment can stimulate piezoelectric materials, thereby
generating an electrical current or voltage. For example,
piezoelectric materials may convert mechanical strain into electric
current or voltage. Vibration based energy harvester module 318 may
take advantage of the vibration during the actual fracking process.
Thus, the microsensors 10 may be energized as they move down the
well and during the fracking process. One example of a vibration
based energy harvester module 318 includes known energy harvesters
based on AlN and capacitve sensors.
[0046] Yet another example of an energy harvester module 318 may
include pyroelectric materials. Pyroelectric materials convert a
temperature change into electric current or voltage. It is
analogous to the piezoelectric effect, which is another type of
ferroelectric behavior. Pyroelectricity requires time-varying
inputs and may suffer from small power outputs in energy harvesting
applications due to its low operating frequencies. However, one key
advantage of pyroelectrics over thermoelectrics is that many
pyroelectric materials are stable up to 1200.degree. C. or higher,
enabling energy harvesting from high temperature sources and thus
increasing thermodynamic efficiency.
[0047] The energy harvester module 318 may include electrostatic
(capacitive) energy harvesters. Electrostatic energy harvesting is
based on the changing capacitance of vibration-dependent
capacitors. Vibrations separate the plates of a charged variable
capacitor, and mechanical energy is converted into electrical
energy.
[0048] The energy harvester module 318 may include magnetic
induction circuits. For example, movement of one or more magnets
relative to one or more conductors may electrical currents due to
Faraday's law of induction.
[0049] Yet a further example of an energy harvester module 318 may
include metamaterial energy harvesters. Metamaterial-based energy
harvesters wirelessly convert electrical signals (such as, but not
limited to, microwave signals, RF signals, Wi-Fi signals, satellite
signals, or even sound signals or the like) to electrical current
(greater than that of a USB device).
[0050] Another example of an energy harvester module 318 includes
electroactive polymers (EAPs). EAPs have a large strain, elastic
energy density, and high energy conversion efficiency.
[0051] A further example of an energy harvester module 318 may
include antennas configured to collect energy from stray radio
waves. For example, the antennas may include a rectenna and/or a
nantenna.
[0052] It should be appreciated that the microsensor 10 may replace
the energy harvester module 318 with one or more batteries. It
should also be appreciated that while the sensor module 310,
processor 312, wireless communication module 314, data
storage/signal processing module 316, energy harvester module 318,
and memory 320 are illustrated as separate components, the
functionality of one or more of these various components may be
combined.
[0053] Memory 320 may be part of, and/or separate from, the data
storage/signal processing module 316, and may be used to store data
and/or applications/software to be executed by the processing
circuitry 312.
[0054] According to one aspect, the microsensor 10 may optionally
eliminate the wireless communication module 314, and instead may
store all data generated by the sensor module 310 in memory and/or
data storage/signal processing module 316. In particular, the
microsensor 410 may be retrieved from the recirculated fluid after
the fracking process and then read off-line to create an image/map
of the well during the fracking dynamics. It should be appreciated,
however, that the microsensor 10 may also include a wireless
communication module 314 that can transmit the data to collection
nodes, in addition to being configured to be read after being
retrieved from the recirculated fluid.
[0055] The exterior of each of the microsensors 10 may be sealed
and resistant to high temperatures and corrosion and the interior
of the microsensors may include high temperature
electronics/circuitry and components. In one embodiment, one or
more coatings 330 may cover at least a portion of an exterior
surface of the microsensor 10. According to one aspect, the one or
more coatings 330 (either individually and/or collectively) may
encapsulate the entire outer surface of the microsensor 10.
[0056] The coating 330 may be dissolvable and the microsensors 10
may be activated when the coating dissolves. For example, the
coating 330 may dissolve due to temperature, pH, and/or contact
with water, glycol, acids, breakers, buffers/pH adjusting agents,
stabilizers, corrosion inhibitors, crosslinkers, friction reducers,
gelling agents, iron controls, solvents, and/or surfactants as
described herein. Non-limiting examples of dissolvable coatings 330
include polyamide, polyglycolide or polyglycolic acid, polyvinyl
alcohol, polyvinyl pyrrolidone, polyethylene glycol,
polystyrenesulfonate, quaternized amine polymers, alkoxomers,
thermally decomposing polymer films, PC polymer, cellulose,
hydroxyethylcellulose, ethylcellulose, cellulose esthers, resins,
cationic polyacrylamide, acrylate, aminoacrylate, alkyl PEG-20, and
mixtures thereof.
[0057] The dissolvable coating 330 may therefore be triggered by
the chemical environment, a predetermined set temperature, and/or
expose the underlying sensor elements and/or energy harvesters,
thereby activating the microsensors. For example, the thermal
dissolvable coating 330 may be selected from a group consisting of
a polyamide, polyglycolide or polyglycolic acid, polyvinyl alcohol,
polyvinyl pyrrolidone, polyethylene glycol, polystyrenesulfonate,
quaternized amine polymers, alkoxomers, and mixtures thereof. A
water dissolvable coating 330 may selected from a group consisting
of a polymer, PC polymer, cellulose, hydroxyethylcellulose,
ethylcellulose, cellulose esthers, resins, and mixtures thereof. A
pH dissolvable coating 330 may selected from a group consisting of
a cationic polyacrylamide, acrylate, aminoacrylate, alkyl PEG-20,
and mixtures thereof
[0058] According to one aspect, a plurality of microsensors 10 may
be separately coated with dissolvable coatings 330. The coatings
330 on different microsensors 10 may dissolve at different times
and/or under different conditions to provide staggered microsensor
activation. The dissolvable coatings 330 may dissolve by using
different materials and/or thicknesses to control the time for
dissolving from 1 minute to 1 hour to 24 hours or longer. The
dissolvable coatings 330 may thus allow a tunable activation, for
example, in a range of 6-24 hours for each individual microsensor
10. The overall lifetime of a collective group of microsensors 10
may thus be extended by staggering the activation of subsets of the
microsensors 10.
[0059] It may be appreciated that a plurality of microsensors 10a-n
may be combined and encapsulated by a coating 400 as generally
illustrated in FIG. 4. The coating 400 may include one or more
layers of material which may be the same and/or different.
Additionally, one or more of the microsensors 10 (e.g., 10a, 10b)
may have a separate coating covering 330. For example, a group
coating 400 (which may include one or more layers of coating
materials) may cover the plurality of microsensors 10a-n. Within
the group coating 400, one or more microsensors 10a, 10b may
include an individual coating 330 (which may include one or more
layers of coating materials). The group coating 400 may dissolve to
expose one or more microsensors (e.g., 10n) and/or individual
coatings 330 covering one or more microsensors (10a, 10b). The
individual coatings 330 may then dissolve based on different
conditions than the group coating 400.
[0060] According to one aspect, a plurality of the microsensors
510a-n, FIG. 5, may communicate with each other to form a
system/network of microsensor nodes 500 (e.g., the microsensors
510a-n may operate as nodes in a sensor network 500). For example,
the microsensors 510a-n may be configured to transmit a ping signal
to adjacent microsensors 510a-n. A microsensor 510a-n which
receives a ping signal from an adjacent microsensor 510a-n may be
configured to retransmit the ping signal of the adjacent
microsensor 510a-n, along with its own ping signal. The process may
be continued until the ping signals are received by a controller.
The microsensors 510a-n may be configured to determine the shortest
communication path to one or more collection/processing
controllers, for example, based on their location data and/or
unique identifier. As may be appreciated, the ability to determine
the shortest transmission communication path(s) may allow the
wireless communication module of the microsensor 510a-n to transmit
a lower strength/power ping signal, thereby reducing the power
requirements of the microsensors 510a-n. Additionally (or
alternatively), the microsensors 10a-n may be configured to
retransmit up to a predetermined number of ping signals in order to
avoid overloading any one particular microsensor 510a-n, thereby
reducing the power requirements of the microsensors 510a-n. As
discussed herein, the microsensors 510a-n may be configured to
either periodically transmit/retransmit the ping signals and/or may
transmit/retransmit the ping signals upon reach a threshold (e.g.,
supply power and/or buffer thresholds).
[0061] Turning now to FIG. 6, one configuration of
supersensor/satellite sensor system 600 is generally illustrated.
The supersensor/satellite sensor system 600 may include one or more
(e.g., a plurality of) satellite microsensors 610a-n in
communication with one or more supersensor microsensors 612. As
discussed herein, the supersensors 612 may form the backbone in the
supersensor/satellite sensor system 600 through which data
transmitted by their respective satellite sensors 610a-n is
collected, processed and transmitted. For example, the satellite
sensors 610a-n may be configured to generate and transmit ping
signals including the sensor data and optionally location
information and/or a unique identifier. The plurality of satellite
sensors and/or supersensors may include, but not limited to,
sensing functions like temperature, pH, pressure (e.g., but not
limited to, pore-water pressure), stress, magnetic field strength,
chemical composition, and/or various stresses within the fractured
rock and any formation change data as described herein.
[0062] The supersensor 612 may be similar to the satellite sensors
610a-n, except that the supersensor 612 may be configured to
receive and/or store the ping signals from nearby satellite sensors
610a-n (e.g., in a larger memory than the satellite sensors
610a-n), and retransmit the ping signals from nearby satellite
sensors 610a-n along with its own ping signal. The supersensor 612
may therefore act a central node for a dedicated set of satellite
sensors 610a-n, where a supersensor 612 collects and/or processes
various parameters and measurements from the satellite sensors
610a-n. After collection, the supersensor 612 may be configured to
transmit information through one or more additional supersensors
612' (if necessary). The supersensor 612 and other supersensors
612' in the chain are able transmit information to a receiving
point outside the environment (e.g., collection/processing
controllers), typically residing on the surface.
[0063] The satellite sensors 610a-n may therefore be configured to
transmit the ping signals over a relatively short transmission
range compared to the supersensor 612. As such, the power
requirements for the satellite sensors 610a-n may be reduced
compared to the supersensor 612. The reduced power requirements and
transmission range of the satellite sensors 610a-n may allow the
wireless communication module 314, energy harvester module 318,
data storage/signal processing module 316, and/or memory 320 to be
smaller and/or less expensive compared to the supersensor 512. The
reduced size of the satellite sensors 610a-n compared to the
supersensor 612 and/or regular microsensor 10 may allow the
satellite sensors 610a-n to penetrate deeper in the rock formations
which is beneficial in the case of fracking. According to one
example, the supersensors 612 are of larger form factor ranging
from 8 mm to 50 mm in size compared to the satellite sensor 610a-n
which can be 1-20 mm in size. For example, the supersensor 612 may
be 20 mm to 40 mm in size while the satellite sensor 610a-n may be
2-4 mm in size.
[0064] Turning now to FIG. 7, one configuration of satellite/node
sensor system 700 is generally illustrated. The satellite/node
sensor system 700 may include one or more (e.g., a plurality of)
microsensors 710a-n in communication with one or more nodes 712. As
discussed herein, the nodes 712 may form the backbone in the
satellite/node sensor system 700 through which data transmitted by
their respective microsensors 710a-n is collected, processed and
transmitted. For example, the microsensors 710a-n may be configured
to generate and transmit ping signals including the sensor data and
optionally location information and/or a unique identifier. The
fixed nodes and/or collection points may be introduced into the
well bore 12 together with, or separate from, the microsensors
10a-n. The number of fixed nodes and/or collection points may be
determined based on the wireless transmission range of the
microsensors 10a-n, the number of microsensors 10a-n, and/or an
estimate or expected distribution/location of the microsensors
10a-n within the well bore 12.
[0065] The nodes 712 may be similar to the satellite sensors
710a-n, except that the nodes 712 do not include a sensor module.
As such, the nodes 712 are configured to receive and/or store the
ping signals from nearby microsensors 710a-n (e.g., in a larger
memory than the satellite sensors 710a-n), and retransmit the ping
signals from nearby microsatellite sensors 710a-n. The nodes 712
may therefore act a central node for a dedicated set of
microsatellite sensors 710a-n, where a node 712 collects and/or
processes various parameters and measurements from the
microsatellite sensors 710a-n. After collection, the nodes 712 may
be configured to transmit information through one or more
additional nodes 712' (if necessary). The nodes 712 and other nodes
712' in the chain are able transmit information to a receiving
point outside the environment (e.g., collection/processing
controllers), typically residing on the surface.
[0066] Again, similar to the supersensor/satellite sensor system
600, the microsatellite sensors 710a-n may therefore be configured
to transmit the ping signals over a relatively short transmission
range compared to the node 712. As such, the power requirements for
the microsatellite sensors 710a-n may be reduced compared to the
node 712. The reduced power requirements and transmission range of
the microsatellite sensors 710a-n may allow the wireless
communication module 314, energy harvester module 318, data
storage/signal processing module 316, and/or memory 320 to be
smaller and/or less expensive compared to the node 712. The reduced
size of the microsatellite sensors 710a-n compared to the node 712
and/or regular microsensor 10 may allow the microsatellite sensors
710a-n to penetrate deeper in the rock formations which is
beneficial in the case of fracking. Additionally, the cost of the
nodes 712 may be reduced since they do not need to include a sensor
module 310.
[0067] Referring to FIG. 8, one example of a system of microsensors
consistent with the present disclosure is generally illustrated.
The system may include a plurality of microsensors 810a-n that,
once activated, may cluster together to form a single larger
cluster 812. The cluster 812 microsensors 810a-n may aid in keeping
the cracks open during and/or post fracking process. The cluster
812 may be achieved through one or more of electrostatic surface
charge generation and/or surface coatings 814. For example, the
electrostatic surface charge generation and/or surface coatings may
use van der Waals forces that will allow the microsensors 810a-n to
aggregate and/or stick together to form a cluster 812. Conversely,
a cluster 812 of microsensors 810a-n that are coupled or attached
together (e.g., with electrostatic force) can be fragmented into
smaller sensors by aligning the surface polarity and making them
the same for all sensors, thus creating repelling forces that will
fragment the clusters. In other embodiments, similar aggregation
may be accomplished using a supersensor where simple satellites
sensors would adhere by providing a change in the surface polarity
to attract and bind the simple satellites sensors.
[0068] Referring to FIG. 9, a self-powered microsensor 10 including
one aspect of an electrochemical energy harvester module 318 is
generally illustrated. The electrochemical energy harvester module
318 may be formed by two dissimilar metals (e.g., copper and
aluminum) on an outer surface or skin 910 (e.g., in grooves) of the
microsensor 10. When these metals contact an ionic solution during
use, an electrochemical cell is formed, this is capable of
supplying sufficient voltage to power the microsensor 10. Although
the metals may eventually corrode, ceasing operation of
electrochemical energy harvester module 318, dissolvable coatings
may be used to delay activation of the electrochemical energy
harvester module 318 as described above.
[0069] Using microsensors, consistent with embodiments disclosed
herein, provides advantages over other techniques used for tracing
such as including radioactive tracer isotopes in the
hydrofracturing fluid to determine the injection profile and
location of fractures created by hydraulic fracturing. Most of
these other techniques are passive, which cannot sense, store,
process or transmit the data. The self-powered microsensors provide
an advantage by harvesting from the environment to provide energy
for a smart sensor system. The microsensors may also be made from
2-D and 1-D nano-materials capable of operating at high
temperatures, high pressures, and in corrosive environments. The
electronics in these microsensors may be made using high
temperature compatible advanced material systems. Accordingly,
self-powered microsensors, consistent with embodiments of the
present disclosure, are capable of providing the desired
measurements while also surviving extremely harsh environments
(e.g., high temperature, high pressure, and corrosion).
[0070] As used in any embodiment herein, the term "module" may
refer to software, firmware and/or circuitry configured to perform
one or more operations consistent with the present disclosure.
Software may be embodied as a software package, code, instructions,
instruction sets and/or data recorded on non-transitory computer
readable storage mediums. Firmware may be embodied as code,
instructions or instruction sets and/or data that are hard-coded
(e.g., nonvolatile) in memory devices. "Circuitry", as used in any
embodiment herein, may comprise, for example, singly or in any
combination, hardwired circuitry, programmable circuitry such as
computer processors comprising one or more individual instruction
processing cores, state machine circuitry, software and/or firmware
that stores instructions executed by programmable circuitry. The
modules may, collectively or individually, be embodied as circuitry
that forms a part of one or more devices, as defined previously. In
some embodiments, the modules described herein may be in the form
of logic that is implemented at least in part in hardware to
perform various functions consistent with the present
disclosure.
[0071] Consistent with one aspect, the present disclosure features
a delayed-activation sensor system. The delayed-activation sensor
system includes at least one microsensor having at least one sensor
module for sensing a condition in an environment, and a dissolvable
coating encapsulating at least a portion of the at least one sensor
module such that the dissolvable coating prevents the at least one
sensor module from sensing the condition in the environment. The
dissolvable coating may be dissolvable in a fluid in the
environment such that the sensor module is activated after being
located in the environment for a period of time.
[0072] Consistent with another aspect, the present disclosure
features a self-powered microsensor for sensing a condition in an
environment. The self-powered micro-sensor includes at least one
energy harvester module to generate electrical power for the
microsensor from the environment, and at least one sensor module
electrically coupled to the electrochemical energy harvester
module.
[0073] Consistent with a further aspect, the present disclosure
features a method of in-situ monitoring a hydraulic fracturing
operation. The method includes injecting a plurality of dissolvable
coated self-powered microsensors into a well bore, dissolving of
coating on self-powered microsensors in the well bore, activating
the self-powered microsensors, and obtaining measurements from each
of the self-powered microsensors.
[0074] While the principles of the invention have been described
herein, it is to be understood by those skilled in the art that
this description is made only by way of example and not as a
limitation as to the scope of the invention. Other embodiments are
contemplated within the scope of the present invention in addition
to the exemplary embodiments shown and described herein.
Modifications and substitutions by one of ordinary skill in the art
are considered to be within the scope of the present invention,
which is not to be limited except by the following claims.
* * * * *