U.S. patent application number 16/657216 was filed with the patent office on 2021-04-22 for assessing a downhole state of perforating explosives.
The applicant listed for this patent is Halliburton Energy Services, Inc.. Invention is credited to James Marshall Barker, Thomas Earl Burky.
Application Number | 20210115765 16/657216 |
Document ID | / |
Family ID | 1000005505222 |
Filed Date | 2021-04-22 |
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United States Patent
Application |
20210115765 |
Kind Code |
A1 |
Barker; James Marshall ; et
al. |
April 22, 2021 |
ASSESSING A DOWNHOLE STATE OF PERFORATING EXPLOSIVES
Abstract
A wellbore perforating apparatus and method according to which a
perforating gun and a sensor sub are run into a wellbore toward a
downhole location at which the wellbore is to be perforated.
Detonable components of the perforating gun are energized to
perforate the wellbore at the downhole location. An acceleration of
the perforating gun and a pressure and a temperature of the
wellbore are detected using the sensor sub during a time interval
encompassing the energization of the detonable components. The
detected acceleration, pressure, and temperature are compared to
benchmark energetic responses for both detonation and deflagration
events. Based on this comparison, a decision can be made as to
whether an incubation period is needed to allow a reaction of the
detonable components to weaken before retrieving the perforating
gun from the wellbore.
Inventors: |
Barker; James Marshall;
(Mansfield, TX) ; Burky; Thomas Earl; (Mansfield,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Halliburton Energy Services, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
1000005505222 |
Appl. No.: |
16/657216 |
Filed: |
October 18, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/11855 20130101;
E21B 43/116 20130101; E21B 47/06 20130101; E21B 47/07 20200501 |
International
Class: |
E21B 43/116 20060101
E21B043/116; E21B 47/06 20060101 E21B047/06 |
Claims
1. (canceled)
2. The wellbore perforating method of claim 7, further comprising:
aborting perforation of the wellbore by retrieving the perforating
gun from the wellbore if the calculated first amount of thermal
decomposition exceeds the predetermined threshold.
3. The wellbore perforating method of claim 7, wherein the first
amount of thermal decomposition is calculated at a plurality of
depths within the wellbore; and wherein the detonable components
are energized to perforate the wellbore at the downhole location if
the calculated first amount of thermal decomposition does not
exceed the predetermined threshold at any of the plurality of
depths.
4. (canceled)
5. The wellbore perforating method of claim 7, further comprising:
retrieving the perforating gun from the wellbore if the comparison
of the detected acceleration, pressure, and temperature to the
benchmark energetic responses signifies that detonation of the
detonable components has occurred.
6. (canceled)
7. A wellbore perforating method, comprising: running a perforating
gun and a sensor sub into a wellbore toward a downhole location at
which the wellbore is to be perforated; detecting a temperature of
the wellbore using the sensor sub as the perforating gun and the
sensor sub are run into the wellbore; calculating a first amount of
thermal decomposition undergone by detonable components of the
perforating gun based on the detected temperature of the wellbore;
determining if the calculated first amount of thermal decomposition
exceeds a predetermined threshold; energizing the detonable
components to perforate the wellbore at the downhole location if
the calculated first amount of thermal decomposition does not
exceed the predetermined threshold; detecting an acceleration of
the perforating gun and a pressure and a temperature of the
wellbore using the sensor sub during a time interval encompassing
the energization of the detonable components; comparing the
detected acceleration, pressure, and temperature to benchmark
energetic responses for both detonation and deflagration events;
calculating a second amount of thermal decomposition undergone by
the detonable components if the comparison of the detected
acceleration, pressure, and temperature to the benchmark energetic
responses signifies that deflagration of the detonable components
has occurred; allowing an incubation period for a reaction of the
detonable components to weaken based on the calculated second
amount of thermal decomposition; and retrieving the perforating gun
from the wellbore after the incubation period.
8. (canceled)
9. (canceled)
10. A wellbore perforating method, comprising: running a
perforating gun and a sensor sub into a wellbore toward a downhole
location at which the wellbore is to be perforated; energizing
detonable components of the perforating gun to perforate the
wellbore at the downhole location; detecting an acceleration of the
perforating gun and a pressure and a temperature of the wellbore
using the sensor sub during a time interval encompassing the
energization of the detonable components; comparing the detected
acceleration, pressure, and temperature to benchmark energetic
responses for both detonation and deflagration events; retrieving
the perforating gun from the wellbore if the comparison of the
detected acceleration, pressure, and temperature to the benchmark
energetic responses signifies that detonation of the detonable
components has occurred; calculating a thermal decomposition
undergone by the detonable components if the comparison of the
detected acceleration, pressure, and temperature to the benchmark
energetic responses signifies that deflagration of the detonable
components has occurred; and allowing an incubation period for a
reaction of the detonable components to weaken based on the
calculated thermal decomposition.
11. The wellbore perforating method of claim 10, further
comprising: retrieving the perforating gun from the wellbore after
the incubation period.
12. A wellbore perforating method, comprising: running a
perforating gun and a sensor sub into a wellbore toward a downhole
location at which the wellbore is to be perforated; energizing
detonable components of the perforating gun to perforate the
wellbore at the downhole location; detecting an acceleration of the
perforating gun and a pressure and a temperature of the wellbore
using the sensor sub during a time interval encompassing the
energization of the detonable components; comparing the detected
acceleration, pressure, and temperature to benchmark energetic
responses for both detonation and deflagration events; and
retrieving the perforating gun from the wellbore if the comparison
of the detected acceleration, pressure, and temperature to the
benchmark energetic responses signifies that detonation of the
detonable components has occurred; wherein the benchmark energetic
responses comprise: a first benchmark energetic response for a
detonation event; a second benchmark energetic response for a
strong deflagration event; and a third benchmark energetic response
for a weak deflagration event.
13. The wellbore perforating method of claim 12, wherein the first
benchmark energetic response for the detonation event includes: a
first pressure spike; a first acceleration spike; and a first
temperature increase.
14. The wellbore perforating method of claim 13, wherein the second
benchmark energetic response for the strong deflagration event
includes: a first pressure stagnation or a second pressure spike; a
second acceleration spike; and a second temperature increase;
wherein the second pressure spike is relatively smaller than the
first pressure spike; wherein the second acceleration spike is
relatively smaller than the first acceleration spike; and wherein
the second temperature increase is relatively smaller than the
first temperature increase.
15. The wellbore perforating method of claim 14, wherein the third
benchmark energetic response for the weak deflagration event
includes: a second pressure stagnation; a third acceleration spike;
and a temperature stagnation; and wherein the third acceleration
spike is relatively smaller than the second acceleration spike.
16. (canceled)
17. (canceled)
18. A wellbore perforating apparatus, comprising: a non-transitory
computer readable medium; and a plurality of instructions stored on
the non-transitory computer readable medium and executable by one
or more processors, the plurality of instructions comprising:
instructions that, when executed, cause the one or more processors
to detect, using a sensor sub, an acceleration of a perforating gun
deployed within a wellbore and a pressure and a temperature of the
wellbore during a time interval encompassing energization of
detonable components of the perforating gun to perforate the
wellbore at a downhole location; instructions that, when executed,
cause the one or more processors to compare the detected
acceleration, pressure, and temperature to benchmark energetic
responses for both detonation and deflagration events; instructions
that, when executed, cause the one or more processors to prompt
retrieval the perforating gun from the wellbore if the comparison
of the detected acceleration, pressure, and temperature to the
benchmark energetic responses signifies that detonation of the
detonable components has occurred; instructions that, when
executed, cause the one or more processors to calculate an amount
of thermal decomposition undergone by the detonable components if
the comparison of the detected acceleration, pressure, and
temperature to the benchmark energetic responses signifies that
deflagration of the detonable components has occurred; and
instructions that, when executed, cause the one or more processors
to prompt an incubation period for a reaction of the detonable
components to weaken based on the calculated amount of thermal
decomposition.
19. The wellbore perforating apparatus of claim 18, further
comprising: instructions that, when executed, cause the one or more
processors to prompt retrieval of the perforating gun from the
wellbore after the incubation period.
20. A wellbore perforating apparatus, comprising: a non-transitory
computer readable medium; and a plurality of instructions stored on
the non-transitory computer readable medium and executable by one
or more processors, the plurality of instructions comprising:
instructions that, when executed, cause the one or more processors
to detect, using a sensor sub, an acceleration of a perforating gun
deployed within a wellbore and a pressure and a temperature of the
wellbore during a time interval encompassing energization of
detonable components of the perforating gun to perforate the
wellbore at a downhole location; instructions that, when executed,
cause the one or more processors to compare the detected
acceleration, pressure, and temperature to benchmark energetic
responses for both detonation and deflagration events; and
instructions that, when executed, cause the one or more processors
to prompt retrieval the perforating gun from the wellbore if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that detonation of
the detonable components has occurred; wherein the benchmark
energetic responses comprise: a first benchmark energetic response
for a detonation event; a second benchmark energetic response for a
strong deflagration event; and a third benchmark energetic response
for a weak deflagration event.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to perforating
wellbores, and, more particularly, to assessing a downhole state of
perforating explosives both before and after firing in a
wellbore.
BACKGROUND
[0002] Wellbores are typically drilled using a drill string with a
drill bit secured to the lower free end and then, in the situation
of cased-hole wells, completed by positioning a casing string
within the wellbore and cementing the casing string in position.
The casing increases the integrity of the wellbore and provides a
flow path between the surface and a subterranean formation for: the
injection of treating chemicals into the formation to stimulate
production; receiving the flow of hydrocarbons from the formation;
and permitting the introduction of fluids for reservoir management
or disposal purposes. Perforating has conventionally been performed
by lowering a perforating gun on a carrier string down a casing
string within a wellbore. Once a desired wellbore depth is reached
adjacent the target formation, the gun is secured and then fired.
The gun may have one or many charges that are detonated using a
firing control, which firing control may be activated from the
surface via wireline or by hydraulic or mechanical means. Once the
firing control is activated, the charge is detonated to perforate
(penetrate) the casing, the cement, and, to a short distance, the
formation. This establishes the desired fluid communication between
the inside of the wellbore casing and the formation.
[0003] Typical perforating guns used in service operations for
perforating a formation generally include explosive perforating
charges mounted in a charge tube and ballistically connected
together via explosive detonating cord. However, due to
time-temperature limits of the explosive perforating charges and/or
the detonating cord, that is, due to said components becoming
degraded or unstable over time or at certain temperatures,
incomplete firing of the perforating gun may occur when a firing
attempt is made, presenting both performance and safety
concerns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an illustration of an offshore oil and gas rig
operably coupled to a subsurface wellbore perforating system,
according to one or more embodiments of the present disclosure.
[0005] FIG. 2 is an enlarged elevational view of the wellbore
perforating system of FIG. 1, according to one or more embodiments
of the present disclosure.
[0006] FIG. 3 is a flow diagram illustrating a method for assessing
a downhole state of explosives in a perforating gun of the wellbore
perforating system of FIGS. 1 and 2, according to one or more
embodiments of the present disclosure.
[0007] FIG. 4 is a time-temperature chart showing thermal
decomposition rates for various types of detonable components,
according to one or more embodiments of the present disclosure.
[0008] FIG. 5 is an illustration of charts of possible benchmark
energetic responses for each of a detonation event, a strong
deflagration event, and a weak deflagration event, according to one
or more embodiments of the present disclosure.
[0009] FIG. 6 is an illustration of a computing node for
implementing one or more embodiments of the present disclosure.
DETAILED DESCRIPTION
[0010] The present disclosure introduces a wellbore perforating
method to assess the downhole state of explosives in a perforating
gun both before the perforating gun is fired, and/or after the
perforating gun is fired but before the fired perforating gun is
retrieved from the wellbore. To assess the state of the explosives
in the perforating gun, whether unfired, partially-fired, or
completely fired, the wellbore perforating method uses downhole
measurements, such as, for example, pressure, acceleration, and
temperature (i.e., wellbore conditions during conveyance downhole).
The method yields a prediction of how the perforating gun is likely
to perform downhole. Based on this prediction, a determination can
be made as to whether the perforating trip should be continued or
aborted (e.g., if for operational reasons the perforating gun is
approaching time-temperature limits at which the explosives or
other components of the perforating gun are less likely to function
as desired). Moreover, if a firing attempt is made, the wellbore
perforating method yields an assessment of whether the perforating
gun underwent detonation (i.e., complete firing), strong
deflagration, (i.e., partial firing), or weak deflagration (i.e.,
partial firing). This assessment may be used to determine what type
of operational safety response should be planned when retrieving
the perforating gun from the wellbore.
[0011] FIG. 1 is an illustration of an offshore oil and gas rig
operably coupled to a subsurface wellbore perforating system,
according to one or more embodiments of the present disclosure.
Referring to FIG. 1, in an embodiment, the offshore oil and gas rig
is generally referred to by the reference numeral 100. In an
embodiment, the offshore oil and gas rig 100 includes a
semi-submersible platform 105 that is positioned over a submerged
oil and gas formation 110 located below a sea floor 115. A subsea
conduit 120 extends from a deck 125 of the platform 105 to a subsea
wellhead installation 130. One or more pressure control devices
135, such as, for example, blowout preventers (BOPs), and/or other
equipment associated with drilling or producing a wellbore may be
provided at the subsea wellhead installation 130 or elsewhere in
the system. The platform 105 may also include a hoisting apparatus
140, a derrick 145, a travel block 150, a hook 155, and a swivel
160, which components are together operable for raising and
lowering a conveyance string 165. The conveyance string 165 may be,
include, or be part of, for example, a casing, a drill string, a
completion string, a work string, a pipe joint, coiled tubing,
production tubing, other types of pipe or tubing strings, and/or
other types of conveyance strings, such as wireline, slickline,
and/or the like. The platform 105 may also include a kelly, a
rotary table, a top drive unit, and/or other equipment associated
with the rotation and/or translation of the conveyance string
165.
[0012] A wellbore 170 extends from the subsea wellhead installation
130 and through the various earth strata, including the submerged
oil and gas formation 110. In the situation of a cased-hole well,
as in FIG. 1, at least a portion the wellbore 170 is completed by
positioning a casing string 175 therein and securing the casing
string 175 in position with cement 180 (shown in FIG. 2). The
conveyance string 165 is, includes, or is operably coupled to a
wellbore perforating system 185, which system is positioned within
the wellbore 170 and adapted to perforate the casing string 175,
the cement 180, and the wellbore 170 proximate the submerged oil
and gas formation 110 so that fluid communication is established
between the casing string 175 and the submerged oil and gas
formation 110 surrounding the wellbore 170.
[0013] FIG. 2 is an enlarged elevational view of the wellbore
perforating system 185 of FIG. 1, according to one or more
embodiments of the present disclosure. Referring to FIG. 2, with
continuing reference to FIG. 1, in some embodiments, the wellbore
perforating system 185 includes a cable head 190, a sensor sub 195,
a casing collar location ("CCL") 200, a firing head 205, a
perforating gun 210, and a bull plug 215. The cable head 190 is
connected to a lower end of the conveyance string 165, which
conveyance string, in this instance, is, includes, or is part of an
electrical wireline or a tubing string equipped with electrical
conductor(s). The cable head 190 is used to connect the sensor sub
195 to the conveyance string 165 in a manner that results in a good
electrical path from the electrical conductor(s) of the conveyance
string 165 to electrical contacts of the sensor sub 195 and shields
this electrical path from contact with conductive fluids in the
wellbore 170.
[0014] The sensor sub 195 is connected to the cable head 190
opposite the conveyance string 165 and includes a temperature
sensor 220a, an accelerometer 220b, and a pressure sensor 220c. In
some embodiments, as in FIG. 2, the sensor sub 195 also includes a
controller 225 connected to, and adapted to receive data/signals
from, the temperature sensor 220a, the accelerometer 220b, and the
pressure sensor 220c. Although shown and described in FIG. 2 as
being part of the sensor sub 195, in addition, or instead, the
controller 225 may: be, include, or be part of another component of
the wellbore perforating system 185 and adapted to communicate with
the temperature sensor 220a, the accelerometer 220b, and the
pressure sensor 220c via electrical conductor(s) of the wellbore
perforating system 185 (or some other form of wired or wireless
telemetry); be positioned at a location on the offshore oil and gas
rig 100 outside of the wellbore 170, such as, for example, on the
platform 105 (shown in FIG. 1) and adapted to communicate with the
temperature sensor 220a, the accelerometer 220b, and the pressure
sensor 220c via electrical conductor(s) of the conveyance string
165 (or some other form of wired or wireless telemetry); and/or be
positioned remotely from the offshore oil and gas rig 100 and
adapted to communicate wirelessly therewith. Moreover, although
described as being connected to the cable head 190 opposite the
conveyance string 165, the sensor sub 195 may instead be connected
elsewhere in the wellbore perforating system 185.
[0015] The CCL 200 is connected to the sensor sub 195 opposite the
cable head 190 and is used to ascertain a depth of the wellbore
perforating system 185 in the wellbore 170 using known reference
points on the casing string 175. Specifically, the CCL 200 is an
electric logging tool configured to detect magnetic anomalies
caused by the relatively high mass of casing collars in the casing
string 175 to determine the depth of the wellbore perforating
system 185 in the wellbore 170. Although described as being
connected to the sensor sub 195 opposite the cable head 190, the
CCL 200 may instead be connected elsewhere in the wellbore
perforating system 185.
[0016] The firing head 205 is connected to the CCL 200 opposite the
sensor sub 195 and is used to detonate the perforating gun 210. For
example, if the firing head 205 is mechanical, may include a
percussion detonator that is struck by a firing pin. For another
example, if the firing head 205 is electronic, it may be battery
powered to initiate an electric detonator. Although described as
being connected to the CCL 200 opposite the sensor sub 195, the
firing head 205 may instead be connected elsewhere in the wellbore
perforating system 185.
[0017] The perforating gun 210 is connected to the firing head 205
opposite the CCL 200 and is operable to form perforations 226
through the casing string 175, the cement 180, and the wellbore 170
so that fluid communication is established between the casing
string 175 and the submerged oil and gas formation 110 surrounding
the wellbore 170 (shown in FIG. 1). More particularly, the
perforating gun 210 includes detonable components 228 that are
detonatable to form the perforations 226 through the casing string
175 and the cement 180. In some embodiments, the detonable
components 228 of the perforating gun 210 are, include, or are part
of a detonation train of the perforating gun 210, said detonation
train including perforating charges, a detonating mechanism (e.g.,
detonating cord(s) or other explosives), and primers (e.g.,
explosive boosters) ballistically connecting the detonating
mechanism to the perforating charges to facilitate detonation of
the perforating charges. Although described as being connected to
the firing head 205 opposite the CCL 200, the perforating gun 210
may instead be connected elsewhere in the wellbore perforating
system 185.
[0018] The bull plug 215 is connected to the perforating gun 210
opposite the firing head 205 and is used as an isolation device
before, during, or after the wellbore 170 is perforated using the
perforating gun 210. In some embodiments, the bull plug 215 is a
solid plug. Although described as being connected to the
perforating gun 210 opposite the firing head 205, the bull plug 215
may instead be connected elsewhere in the wellbore perforating
system 185.
[0019] In various embodiments, one or more components of the
wellbore perforating system 185 described herein can be integrated
with one or more other components of the wellbore perforating
system 185. Accordingly, other wellbore perforating systems that do
not include one or more components of the wellbore perforating
system 185 described herein may nevertheless fall within the scope
of the present disclosure.
[0020] FIG. 3 is a flow diagram illustrating a method for assessing
a downhole state of explosives in a perforating gun of the wellbore
perforating system of FIGS. 1 and 2, according to one or more
embodiments of the present disclosure. Referring to FIG. 3, in some
embodiments, the method to assess the downhole state of explosives
in the perforating gun 210 is generally referred to by the
reference numeral 230. At a step 235 of the method 230, the
perforating gun 210 and the sensor sub 195 are run into the
wellbore 170 toward a downhole location at which the wellbore 170
is to be perforated. At a step 240, a temperature of the wellbore
170 is detected using the sensor sub 195 as the perforating gun 210
is run into the wellbore 170. More particularly, temperature
data/signals detected during the perforating gun 210's run into the
wellbore 170 are communicated from the temperature sensor 220a of
the sensor sub 195 to the controller 225. At a step 245, a first
amount of thermal decomposition undergone by the detonable
components 228 is calculated based on the detected temperature of
the wellbore 170. The controller 225 may be used to calculate the
first amount of thermal decomposition based on the detected
temperature in the wellbore 170.
[0021] At a step 250, the calculated first amount of thermal
decomposition of the perforating gun 210 is evaluated to determine
if it exceeds a predetermined threshold. The controller 225 may be
used to evaluate the calculated first amount of thermal
decomposition of the perforating gun 210 to determine if it exceeds
the predetermined threshold. In addition, or instead, the first
amount of thermal decomposition calculated at the step 245 may be
communicated to a surface location outside of the wellbore 170 so
that an operator can manually evaluate the calculated first amount
of thermal decomposition of the perforating gun 210 to determine if
it exceeds the predetermined threshold. FIG. 4 is a
time-temperature chart showing thermal decomposition rates for
various types of detonable components, according to one or more
embodiments of the present disclosure. More particularly, the
predetermined threshold of the step 250 is shown by the various
time-temperature curves in FIG. 4 and depends on the specific type
of explosives used for the detonable components 228 of the
perforating gun 210. For example, the explosives used for the
detonable components 228 of the perforating gun 210 can be
cyclotrimethylene trinitramine, RDX for short, and/or
cyclotetramethylene tetranitramine, HMX for short. When conveyed by
wireline, RDX is limited to exposure of 1 hour at 325.degree. F.
(163.degree. C.), or, when tubing conveyed ("TCP"), to 100 hours at
235.degree. F. (113.degree. C.). Similarly, HMX survives 1 hour at
400.degree. F. (204.degree. C.) for wireline-conveyed applications
and 100 hours at 310.degree. F. (154.degree. C.) for TCP
applications. At higher temperatures or longer exposures,
explosives are available to perforate reliably at up to 600.degree.
F. (316.degree. C.) for wireline-conveyed applications and up to
500.degree. F. (260.degree. C.) for TCP. These high-temperature
explosives, called HNS and PYX, are much more expensive and require
specialty production, but result in a shift of their
time-temperature curves above those for RDX and HMX (and a
correspondingly higher predetermined threshold for the step 250),
as shown in FIG. 4.
[0022] At a step 255, perforation of the wellbore 170 is aborted by
retrieving the perforating gun 210 from the wellbore if the
calculated first amount of thermal decomposition exceeds the
predetermined threshold. In some embodiments, execution of the step
255 prevents, or at least reduces, safety issues associated with
the retrieval of partially-fired detonable components 228 of the
perforating gun 210 (i.e., strong deflagration or weak
deflagration) from the wellbore 170. Such safety issues might
otherwise arise on the deck 125 of the platform 105 in instances
where detonation of the perforating gun 210 is attempted even
though the time-temperature limits of the particular explosive
employed have been exceeded. Moreover, the step 255 ensures that
the detonable components 228 ultimately used in the perforating gun
210 to perforate the wellbore 170 are effective. At a step 260, the
detonable components 228 are energized to perforate the wellbore
170 at the downhole location if the calculated first amount of
thermal decomposition does not exceed the predetermined threshold.
In some embodiments of the step 245, the first amount of thermal
decomposition may be calculated at a plurality of depths within the
wellbore 170. In such embodiments, the detonable components 228 may
be energized at the step 260 to perforate the wellbore 170 at the
downhole location if the calculated first amount of thermal
decomposition does not exceed the predetermined threshold at any of
the plurality of depths. At a step 265, an acceleration of the
perforating gun 210 and a pressure and a temperature of the
wellbore 170 are detected using the sensor sub 195 during a time
interval encompassing the energization of the detonable components
228.
[0023] At a step 270, the detected acceleration, pressure, and
temperature are compared to benchmark energetic responses for both
detonation and deflagration events. FIG. 5 is an illustration of
charts of possible benchmark energetic responses for each of a
detonation event, a strong deflagration event, and a weak
deflagration event, according to one or more embodiments of the
present disclosure. The benchmark energetic response for the
detonation event includes: a pressure spike 271a (e.g.,
11,000-13,000 psi); an acceleration spike 271b (e.g., several
thousand g's); and a temperature increase 271c (e.g., 20-30.degree.
F.). The benchmark energetic response for the strong deflagration
event includes: a pressure stagnation 272a; an acceleration spike
272b; and a temperature increase 272c. The acceleration spike 272b
is relatively smaller than the acceleration spike 271b. The
temperature increase 272c is relatively smaller than the
temperature increase 271c. In some embodiments, the strong
deflagration event may rupture the perforating gun so that, rather
than the pressure stagnation 272a, the strong deflagration event
includes a pressure spike (not shown) that is relatively smaller
than the pressure spike 271a. The benchmark energetic response for
the weak deflagration event includes: a pressure stagnation 273a;
an acceleration spike 273b; and a temperature stagnation 273c. The
acceleration spike 273b is relatively smaller than the acceleration
spike 272b. The controller 225 may be used to compare the detected
response to the benchmark energetic responses to yield a
determination of whether detonation or deflagration (i.e., strong
or weak) of the perforating gun 210 has occurred. At a step 272, a
determination is made as to whether the comparison of the detected
pressure, acceleration, and temperature of the wellbore 170 over
time to benchmark energetic responses signifies the detonation or
the deflagration event.
[0024] At a step 275, the perforating gun 210 is retrieved from the
wellbore 170 if the comparison of the detected acceleration,
pressure, and temperature to the benchmark energetic responses
signifies that detonation of the detonable components 228 has
occurred. At a step 280, a second amount of thermal decomposition
undergone by the detonable components 228 is calculated if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that deflagration of
the detonable components 228 has occurred. The controller 225 may
be used to calculate the second amount of thermal decomposition of
the perforating gun 210. At a step 285, an incubation period is
allowed for a reaction of the detonable components 228 to weaken
based on the calculated second amount of thermal decomposition. In
some embodiments, execution of the step 285 prevents, or at least
reduces, safety issues associated with the retrieval of
partially-fired detonable components 228 of the perforating gun 210
(i.e., strong deflagration or weak deflagration) from the wellbore
170. Such safety issues might otherwise arise on the deck 125 of
the platform 105 in instances where the perforating gun 210 is
retrieved from the wellbore 170 even though an incubation period
has not been allowed. Finally, at a step 290, the perforating gun
210 is retrieved from the wellbore 170 after the incubation
period.
[0025] Advantageously, the operation of the perforating gun 210
and/or the execution of the method 230 can yield: an assessment of
the downhole state of explosives in the perforating gun 210 before
the perforating gun 210 is fired; a prediction of how the
perforating gun 210 will perform downhole; an assessment of the
downhole state of explosives in the perforating gun 210 after the
perforating gun 210 is fired but before the fired perforating gun
210 is retrieved from the wellbore 170; and/or an assessment of
whether the perforating gun underwent detonation (i.e., complete
firing), strong deflagration, (i.e., partial firing), or weak
deflagration (i.e., partial firing). As a result, the operation of
the perforating gun 210 and/or the execution of the method 230
mitigates safety issues associated with the retrieval of
partially-fired detonable components 228 of the perforating gun 210
(i.e., strong deflagration or weak deflagration) from the wellbore
170.
[0026] FIG. 6 is an illustration of a computing node for
implementing one or more embodiments of the present disclosure.
More particularly, referring to FIG. 6, with continuing reference
to FIGS. 1-5, in one or more embodiments, a computing node 1000 for
implementing one or more embodiments of one or more of the
above-described elements, systems (e.g., the wellbore perforating
system 185), apparatus (e.g., the perforating gun 210), controllers
(e.g., the controller 225), methods (e.g., the method 230), and/or
steps (e.g., the steps 235, 240, 245, 250, 255, 260, 265, 270, 275,
280, 285, and/or 290), or any combination thereof, is depicted. The
node 1000 includes a microprocessor 1000a, an input device 1000b, a
storage device 1000c, a video controller 1000d, a system memory
1000e, a display 1000f, and a communication device 1000g all
interconnected by one or more buses 1000h. In several embodiments,
the microprocessor 1000a is, includes, or is part of, the
controller 225. In several embodiments, the storage device 1000c
may include a floppy drive, hard drive, CD-ROM, optical drive, any
other form of storage device or any combination thereof. In several
embodiments, the storage device 1000c may include, and/or be
capable of receiving, a floppy disk, CD-ROM, DVD-ROM, or any other
form of computer-readable medium that may contain executable
instructions. In several embodiments, the communication device
1000g may include a modem, network card, or any other device to
enable the node 1000 to communicate with other nodes. In several
embodiments, any node represents a plurality of interconnected
(whether by intranet or Internet) computer systems, including
without limitation, personal computers, mainframes, PDAs,
smartphones and cell phones.
[0027] In several embodiments, one or more of the components of any
of the above-described systems include at least the node 1000
and/or components thereof, and/or one or more nodes that are
substantially similar to the node 1000 and/or components thereof.
In several embodiments, one or more of the above-described
components of the node 1000 and/or the above-described systems
include respective pluralities of same components.
[0028] In several embodiments, a computer system typically includes
at least hardware capable of executing machine readable
instructions, as well as the software for executing acts (typically
machine-readable instructions) that produce a desired result. In
several embodiments, a computer system may include hybrids of
hardware and software, as well as computer sub-systems.
[0029] In several embodiments, hardware generally includes at least
processor-capable platforms, such as client-machines (also known as
personal computers or servers), and hand-held processing devices
(such as smart phones, tablet computers, personal digital
assistants (PDAs), or personal computing devices (PCDs), for
example). In several embodiments, hardware may include any physical
device that is capable of storing machine-readable instructions,
such as memory or other data storage devices. In several
embodiments, other forms of hardware include hardware sub-systems,
including transfer devices such as modems, modem cards, ports, and
port cards, for example.
[0030] In several embodiments, software includes any machine code
stored in any memory medium, such as RAM or ROM, and machine code
stored on other devices (such as floppy disks, flash memory, or a
CD ROM, for example). In several embodiments, software may include
source or object code. In several embodiments, software encompasses
any set of instructions capable of being executed on a node such
as, for example, on a client machine or server.
[0031] In several embodiments, combinations of software and
hardware could also be used for providing enhanced functionality
and performance for certain embodiments of the present disclosure.
In an embodiment, software functions may be directly manufactured
into a silicon chip. Accordingly, combinations of hardware and
software are also included within the definition of a computer
system and are thus envisioned by the present disclosure as
possible equivalent structures and equivalent methods.
[0032] In several embodiments, computer readable mediums include,
for example, passive data storage, such as a random-access memory
(RAM) as well as semi-permanent data storage such as a compact disk
read only memory (CD-ROM). One or more embodiments of the present
disclosure may be embodied in the RAM of a computer to transform a
standard computer into a new specific computing machine. In several
embodiments, data structures are defined organizations of data that
may enable an embodiment of the present disclosure. In an
embodiment, data structure may provide an organization of data, or
an organization of executable code.
[0033] In several embodiments, any networks and/or one or more
portions thereof, may be designed to work on any specific
architecture. In an embodiment, one or more portions of any
networks may be executed on a single computer, local area networks,
client-server networks, wide area networks, internets, hand-held
and other portable and wireless devices and networks.
[0034] In several embodiments, database may be any standard or
proprietary database software. In several embodiments, the database
may have fields, records, data, and other database elements that
may be associated through database specific software. In several
embodiments, data may be mapped. In several embodiments, mapping is
the process of associating one data entry with another data entry.
In an embodiment, the data contained in the location of a character
file can be mapped to a field in a second table. In several
embodiments, the physical location of the database is not limiting,
and the database may be distributed. In an embodiment, the database
may exist remotely from the server, and run on a separate platform.
In an embodiment, the database may be accessible across the
Internet. In several embodiments, more than one database may be
implemented.
[0035] In several embodiments, a plurality of instructions stored
on a computer readable medium may be executed by one or more
processors to cause the one or more processors to carry out or
implement in whole or in part the above-described operation of each
of the above-described elements, systems (e.g., the wellbore
perforating system 185), apparatus (e.g., the perforating gun 210),
controllers (e.g., the controller 225), methods (e.g., the method
230), and/or steps (e.g., the steps 235, 240, 245, 250, 255, 260,
265, 270, 275, 280, 285, and/or 290), or any combination thereof.
In several embodiments, such a processor may include one or more of
the microprocessor 1000a, the controller 225, any processor(s) that
are part of the components of the above-described systems, and/or
any combination thereof, and such a computer readable medium may be
distributed among one or more components of the above-described
systems. In several embodiments, such a processor may execute the
plurality of instructions in connection with a virtual computer
system. In several embodiments, such a plurality of instructions
may communicate directly with the one or more processors, and/or
may interact with one or more operating systems, middleware,
firmware, other applications, and/or any combination thereof, to
cause the one or more processors to execute the instructions.
[0036] A wellbore perforating method has been disclosed according
to a first aspect. The wellbore perforating method according to the
first aspect generally includes running a perforating gun and a
sensor sub into a wellbore toward a downhole location at which the
wellbore is to be perforated; detecting a temperature of the
wellbore using the sensor sub as the perforating gun and the sensor
sub are run into the wellbore; calculating a first amount of
thermal decomposition undergone by detonable components of the
perforating gun based on the detected temperature of the wellbore;
determining if the calculated first amount of thermal decomposition
exceeds a predetermined threshold; and energizing the detonable
components to perforate the wellbore at the downhole location if
the calculated first amount of thermal decomposition does not
exceed the predetermined threshold.
[0037] The foregoing wellbore perforating method embodiment may
include one or more of the following elements, either alone or in
combination with one another: [0038] the wellbore perforating
method further comprises aborting perforation of the wellbore by
retrieving the perforating gun from the wellbore if the calculated
first amount of thermal decomposition exceeds the predetermined
threshold; [0039] the first amount of thermal decomposition is
calculated at a plurality of depths within the wellbore; and the
detonable components are energized to perforate the wellbore at the
downhole location if the calculated first amount of thermal
decomposition does not exceed the predetermined threshold at any of
the plurality of depths; [0040] the wellbore perforating method
further comprises detecting an acceleration of the perforating gun
and a pressure and a temperature of the wellbore using the sensor
sub during a time interval encompassing the energization of the
detonable components; and comparing the detected acceleration,
pressure, and temperature to benchmark energetic responses for both
detonation and deflagration events; [0041] the wellbore perforating
method further comprises retrieving the perforating gun from the
wellbore if the comparison of the detected acceleration, pressure,
and temperature to the benchmark energetic responses signifies that
detonation of the detonable components has occurred; [0042] the
wellbore perforating method further comprises calculating a second
amount of thermal decomposition undergone by the detonable
components if the comparison of the detected acceleration,
pressure, and temperature to the benchmark energetic responses
signifies that deflagration of the detonable components has
occurred; [0043] the wellbore perforating method further comprises
allowing an incubation period for a reaction of the detonable
components to weaken based on the calculated second amount of
thermal decomposition; and retrieving the perforating gun from the
wellbore after the incubation period.
[0044] A method has also been disclosed according to a second
aspect. The method according to the second aspect generally
includes running a perforating gun and a sensor sub into a wellbore
toward a downhole location at which the wellbore is to be
perforated; energizing detonable components of the perforating gun
to perforate the wellbore at the downhole location; detecting an
acceleration of the perforating gun and a pressure and a
temperature of the wellbore using the sensor sub during a time
interval encompassing the energization of the detonable components;
comparing the detected acceleration, pressure, and temperature to
benchmark energetic responses for both detonation and deflagration
events; and retrieving the perforating gun from the wellbore if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that detonation of
the detonable components has occurred.
[0045] The foregoing wellbore perforating method embodiment may
include one or more of the following elements, either alone or in
combination with one another: [0046] the wellbore perforating
method further comprises calculating an amount of thermal
decomposition undergone by the detonable components if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that deflagration of
the detonable components has occurred; [0047] the wellbore
perforating method further comprises allowing an incubation period
for a reaction of the detonable components to weaken based on the
calculated amount of thermal decomposition; [0048] the wellbore
perforating method further comprises retrieving the perforating gun
from the wellbore after the incubation period; [0049] the benchmark
energetic responses comprise: a first benchmark energetic response
for a detonation event; a second benchmark energetic response for a
strong deflagration event; and a third benchmark energetic response
for a weak deflagration event; [0050] the first benchmark energetic
response for the detonation event includes: a first pressure spike;
a first acceleration spike; and a first temperature increase;
[0051] the second benchmark energetic response for the strong
deflagration event includes: a first pressure stagnation or a
second pressure spike; a second acceleration spike; and a second
temperature increase; wherein the second pressure spike is
relatively smaller than the first pressure spike; wherein the
second acceleration spike is relatively smaller than the first
acceleration spike; and wherein the second temperature increase is
relatively smaller than the first temperature increase; [0052] the
third benchmark energetic response for the weak deflagration event
includes: a second pressure stagnation; a third acceleration spike;
and a temperature stagnation; and wherein the third acceleration
spike is relatively smaller than the second acceleration spike.
[0053] A wellbore perforating apparatus has also been disclosed
according to a third aspect. The wellbore perforating apparatus
according to the third aspect generally includes a non-transitory
computer readable medium; and a plurality of instructions stored on
the non-transitory computer readable medium and executable by one
or more processors, the plurality of instructions comprising:
instructions that, when executed, cause the one or more processors
to detect, using a sensor sub, an acceleration of a perforating gun
deployed within a wellbore and a pressure and a temperature of the
wellbore during a time interval encompassing energization of
detonable components of the perforating gun to perforate the
wellbore at a downhole location; instructions that, when executed,
cause the one or more processors to compare the detected
acceleration, pressure, and temperature to benchmark energetic
responses for both detonation and deflagration events; and
instructions that, when executed, cause the one or more processors
to prompt retrieval the perforating gun from the wellbore if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that detonation of
the detonable components has occurred.
[0054] The foregoing wellbore perforating apparatus embodiment may
include one or more of the following elements, either alone or in
combination with one another: [0055] the wellbore perforating
apparatus further comprises instructions that, when executed, cause
the one or more processors to calculate an amount of thermal
decomposition undergone by the detonable components if the
comparison of the detected acceleration, pressure, and temperature
to the benchmark energetic responses signifies that deflagration of
the detonable components has occurred; [0056] the wellbore
perforating apparatus further comprises instructions that, when
executed, cause the one or more processors to prompt an incubation
period for a reaction of the detonable components to weaken based
on the calculated amount of thermal decomposition; [0057] the
wellbore perforating apparatus further comprises instructions that,
when executed, cause the one or more processors to prompt retrieval
of the perforating gun from the wellbore after the incubation
period; [0058] the benchmark energetic responses comprise: a first
benchmark energetic response for a detonation event; a second
benchmark energetic response for a strong deflagration event; and a
third benchmark energetic response for a weak deflagration
event.
[0059] It is understood that variations may be made in the
foregoing without departing from the scope of the present
disclosure.
[0060] In several embodiments, the elements and teachings of the
various embodiments may be combined in whole or in part in some or
all of the embodiments. In addition, one or more of the elements
and teachings of the various embodiments may be omitted, at least
in part, and/or combined, at least in part, with one or more of the
other elements and teachings of the various embodiments.
[0061] In several embodiments, one or more of the operational steps
in each embodiment may be omitted. Moreover, in some instances,
some features of the present disclosure may be employed without a
corresponding use of the other features. Moreover, one or more of
the above-described embodiments and/or variations may be combined
in whole or in part with any one or more of the other
above-described embodiments and/or variations.
* * * * *