U.S. patent application number 14/971178 was filed with the patent office on 2016-06-23 for oil/gas burners and method.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Francis Dominique Allouche, Raynald Fabrice Eloundou, Christophe M. Rayssiguier.
Application Number | 20160178197 14/971178 |
Document ID | / |
Family ID | 52358554 |
Filed Date | 2016-06-23 |
United States Patent
Application |
20160178197 |
Kind Code |
A1 |
Rayssiguier; Christophe M. ;
et al. |
June 23, 2016 |
Oil/Gas Burners and Method
Abstract
Methods and systems of burning waste effluent include a burner
apparatus having a manifold assembly with an inlet, a first outlet,
a second outlet, and a first control valve movable between a first
and second position. The burner apparatus also includes a first
burner head assembly fluidly communicating with the first outlet
and a second burner head assembly fluidly communicating with the
second outlet. The first control valve is selectively controllable
to direct a combustible mixture to the first burner head assembly
when in the first position and to the first and second burner head
assembly when in the second position.
Inventors: |
Rayssiguier; Christophe M.;
(Melun, FR) ; Allouche; Francis Dominique; (Le
Plessis Robinson, FR) ; Eloundou; Raynald Fabrice;
(Paris, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
52358554 |
Appl. No.: |
14/971178 |
Filed: |
December 16, 2015 |
Current U.S.
Class: |
431/5 ; 431/202;
431/280 |
Current CPC
Class: |
F23G 7/05 20130101; F23G
7/06 20130101; F23G 7/085 20130101; F23D 14/04 20130101; F23D
17/002 20130101; F23G 2207/20 20130101; F23G 5/50 20130101 |
International
Class: |
F23G 7/06 20060101
F23G007/06; F23G 7/08 20060101 F23G007/08; F23D 14/04 20060101
F23D014/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2014 |
EP |
14290392.1 |
Claims
1. A burner apparatus, comprising: a manifold assembly, comprising:
an inlet; a first outlet; a second outlet; and a first control
valve movable between a first position and a second position; a
first burner head assembly fluidly communicating with the first
outlet; and a second burner head assembly fluidly communicating
with the second outlet, wherein the first control valve is
selectively controllable to direct a combustible mixture to the
first burner head assembly when in the first position and to the
first and second burner head assemblies when in the second
position.
2. The burner apparatus of claim 1, wherein the burner apparatus
has a turndown ratio greater than 10.
3. The burner apparatus of claim 1, wherein the first and second
burner head assemblies are positioned concentric with each
other.
4. The burner apparatus of claim 1, wherein the first and second
head assemblies are positioned non-coaxially with each other.
5. The burner apparatus of claim 1, further comprising: a third
burner head assembly fluidly communicating with a third outlet of
the manifold assembly, wherein the first, second, and third burner
head assemblies are positioned in a triangular pattern proximate
the manifold assembly; and wherein the first control valve directs
the combustible mixture to the first, second, and third burner head
assemblies when in a third position.
6. The burner apparatus of claim 1, wherein the first burner head
assembly is a central burner having a first burning capacity.
7. The burner apparatus of claim 6, wherein the second burner head
assembly is a large annular burner having a second burning capacity
greater than the first burning capacity.
8. The burner apparatus of claim 7, further comprising: a piston
control system; wherein the first control valve comprises a piston
housed within the manifold assembly, the piston forming a first
chamber and a second chamber together with the manifold assembly;
and wherein the manifold assembly forms an annular path around the
central burner that fluidly communicates with the second
outlet.
9. The burner apparatus of claim 8, wherein the piston is
selectively controllable and movable between the first and second
position, such that when the piston is in the first position, the
combustible mixture flows solely to the first burner head assembly,
and when the piston is in the second position, the combustible
mixture flows to the first burner head assembly and through the
annular path to the second burner head assembly.
10. The burner apparatus of claim 9, wherein the burner apparatus
further comprises: a second control valve movable between an open
position and a closed position such that when the first control
valve is in the second position and the second control valve is in
the closed position, the second control valve blocks the
combustible mixture from flowing to the first burner head
assembly.
11. The burner apparatus of claim 8, wherein the piston control
system comprises: a pressurized fluid supply line; a pressurized
fluid in the first chamber and the second chamber; a first inlet
line for supplying pressurized fluid to the first chamber, the
first inlet line fluidly communicating with the pressurized fluid
supply line and the first chamber; a second inlet line for
supplying pressurized fluid to the second chamber, the second inlet
line fluidly communicating with the pressurized fluid supply line
and the second chamber, wherein a pressure regulator and a check
valve are positioned along the second inlet line such that constant
pressure is provided to the second chamber causing the piston to,
by default, be in the second position.
12. The burner apparatus of claim 8, wherein the piston control
system is remotely controlled.
13. A system for burning waste effluent containing hydrocarbons,
the system comprising: a waste effluent conduit fluidly
communicating with a source of waste effluent; a manifold assembly
fluidly communicating with the waste effluent conduit, the manifold
assembly comprising: an inlet; a first outlet; a second outlet; and
a first control valve movable between a first position and a second
position; a pilot configured to generate a pilot flame; a first
burner head assembly fluidly communicating with the first outlet;
and a second burner head assembly fluidly communicating with the
second outlet, wherein the first control valve is selectively
controllable to direct the waste effluent to the first burner head
assembly when in the first position and to the first and second
burner head assemblies when in the second position.
14. The system of claim 13, further comprising: a piston control
system; wherein the first control valve comprises a piston within
the manifold assembly, the piston forming a first chamber and a
second chamber within the manifold assembly; and wherein the
manifold assembly forms an annular path around a portion of the
second burner assembly that fluidly communicates with the second
outlet.
15. The system of claim 14, wherein the burner apparatus further
comprises: a second control valve movable between an open position
and a closed position such that when the first control valve is in
the second position and the second control valve is in the closed
position, the second control valve blocks the waste effluent from
flowing to the first burner head assembly.
16. The burner apparatus of claim 14, wherein the piston control
system comprises: a pressurized fluid supply line; a pressurized
fluid in the first and second chamber; a first inlet line for
supplying pressurized fluid to the first chamber, the first inlet
line fluidly communicating with the pressurized fluid supply line
and the first chamber; a second inlet line for supplying
pressurized fluid to the second chamber, the second inlet line
fluidly communicating with the pressurized fluid supply line and
the second chamber, wherein a pressure regulator and a check valve
are positioned along the second inlet line such that constant
pressure is provided to the second chamber causing the piston to,
by default, be in the second position.
17. A method of burning a waste effluent containing hydrocarbons
produced from a well during a well test, the method comprising:
initiating a well test; producing a waste effluent containing
hydrocarbons from the well at an initial flow rate; directing the
waste effluent to a burner apparatus, the burner apparatus
comprising: a manifold assembly housing a first control valve
movable between a first position and a second position; and a first
burner head assembly and a second burner head assembly fluidly
communicating with the manifold assembly, wherein the first control
valve is selectively controllable to direct the waste effluent to
the first burner head assembly when the first control valve is in
the first position and to the first and second burner head assembly
when the first control valve is in the second position; burning the
waste effluent with the first burner head assembly when the first
control valve is in the first position; monitoring the flow rate of
the waste effluent produced from the well to determine if the waste
effluent flow rate will surpass a burning capacity of the first
burner head assembly; burning the waste effluent with both the
first and second burner head assemblies when the flow rate
surpasses the burning capacity of the first burner head assembly
and without stopping production of the waste effluent from the
well.
18. The method of claim 17, wherein burning the waste effluent with
both the first and second burner head assemblies is accomplished by
moving the first control valve to the second position.
19. The method of claim 17, further comprising: monitoring the flow
rate of the waste effluent to determine if the flow rate will be
greater than the burning capacity of the first burner head assembly
but smaller than a burning capacity of the second burner head
assembly; and burning the waste effluent solely with the second
burner head assembly when the flow rate surpasses the burning
capacity of the first burner head assembly but not the second
burner head assembly and without stopping production of the waste
effluent from the well.
20. The method of claim 19, wherein burning the waste effluent
solely with the second burner head assembly is accomplished by
moving a second control valve housed in the burner apparatus to a
closed position, such that when the first control valve is in the
second position and the second control valve is in the closed
position, the second control valve blocks the waste effluent from
flowing to the first burner head assembly.
Description
BACKGROUND
[0001] 1. Field
[0002] This disclosure relates to burners and more particularly to
oil and gas burners that may be used in the oil field industry.
[0003] 2. Description of the Related Art
[0004] Hydrocarbons are widely used as a primary source of energy,
and have a great impact on the world economy. Consequently, the
discovery and efficient production of hydrocarbon resources is
increasingly noteworthy. As relatively accessible hydrocarbon
deposits are depleted, hydrocarbon prospecting and production has
expanded to new regions that may be more difficult to reach and/or
may pose new technological challenges. During typical operations, a
borehole is drilled into the earth, whether on land or below the
sea, to reach a reservoir containing hydrocarbons. Such
hydrocarbons are typically in the form of oil, gas, or mixtures
thereof which may then be brought to the surface through the
borehole.
[0005] Well testing is often performed to help evaluate the
possible production value of a reservoir. During well testing, a
test well is drilled to produce a test flow of fluid from the
reservoir. During the test flow, parameters such as fluid pressure
and fluid flow rate are monitored over a period of time. The
response of those parameters may be determined during various types
of well tests, such as pressure drawdown, interference, reservoir
limit tests, and other tests generally known by those skilled in
the art. The data collected during well testing may be used to
assess the economic viability of the reservoir. The costs
associated with performing the testing operations may be
substantial, however, and therefore testing operations should be
performed as efficiently and economically as possible.
[0006] Fluids produced from the test well are generally considered
to be waste and therefore are typically disposed of by burning,
which raises environmental and safety concerns. Conventionally, the
fluids are separated into gas and liquids inside a separator
vessel, then burned using one of three types of burners: 1) an oil
burner for liquid phase that will mix crude oil and air for a good
combustion, 2) a gas flare that will directly burn the dry gas, and
3) a multiphase burner that can burn both phases simultaneously
within certain limits.
[0007] Burners are designed to combust waste effluent at a maximum
flow rate which corresponds to its burning capacity. The waste
effluent also typically should be provided at a much lower flow
rate to test the well under any conditions. A burner's operational
range of flow rates is called a turndown ratio, which is defined as
a ratio of its maximum flow rate capacity to its minimum flow rate
capacity. Burners typically do not exceed a turndown ratio of 5. If
the flow rate of waste effluent were decreased below that limit,
the combustion would no longer be acceptable. When the waste
effluent flow rate drops below the minimum flow rate, a condition
known as "fall out" may occur during which the
hydrocarbon-containing waste effluent is not combusted but instead
is discharged into the surrounding environment.
[0008] Well testing implies very large variations of flow rates
because wells can be very different from one another. The well test
burner should be adapted to that large range of flow rates during
well testing, but is limited by its turndown ratio. To account for
large fluctuations in effluent flow rates, the current practice is
to provide at the well test site a set of separate burners having
different sizes and burning capacities. For example, gas flares
having various diameters may be located at the well test site in
anticipation and preparation of large waste gas effluent flow rate
fluctuations. Another example is an oil burner composed of a set of
identical nozzles, where several nozzles can be replaced by plugs
in order to reduce the flow rate characteristics of the burner.
Based on the estimated maximum and minimum waste effluent flow
rates, which may be difficult to predict, the operator will then
select and assemble the most appropriate burner before beginning
the well test in order to optimize the combustion and withstand the
maximum and minimum forecasted flow rates.
[0009] In those situations, the well test operator will select the
appropriate burner according to the estimated maximum and/or
minimum flow rate of the specific well subjected to a well test.
During a well test, however, flow rates may greatly vary, so there
will be some phases with low flow rates with non-optimized
combustion or even no combustion, which is also environmentally
unfriendly and potentially hazardous to the operators. When those
situations arise, the operators shut down the well test, wait for
associated equipment to cool off, modify the burner currently used
to account for the changing flow rates or even exchange the burner
currently used with a different burner altogether that is more
suitable to the current flow rate from the well. After the
operators have modified or replaced the burner, they then restart
the well test. These interruptions may result in lengthy delays
lasting several hours to even days.
SUMMARY
[0010] Certain aspects of some embodiments disclosed herein are set
forth below. It should be understood that these aspects are
presented merely to provide the reader with a brief summary of
certain forms the embodiments might take and that these aspects are
not intended to limit the scope of the disclosure. Indeed, the
disclosure may encompass a variety of aspects that may not be set
forth below.
[0011] In some embodiments, a burner apparatus includes a manifold
assembly having an inlet, a first outlet, a second outlet, and a
first control valve movable between a first and second position.
The burner apparatus also includes a first burner head assembly
fluidly communicating with the first outlet and a second burner
head assembly fluidly communicating with the second outlet. The
first control valve is selectively controllable to direct a
combustible mixture to the first burner head assembly when in the
first position and to the first and second burner head assembly
when in the second position.
[0012] In some embodiments, a system for burning waste effluent
containing hydrocarbons includes a waste effluent conduit fluidly
communicating with a source of waste effluent and a manifold
assembly fluidly communicating with the waste effluent conduit. The
manifold assembly includes an inlet, a first outlet, a second
outlet, and a first control valve movable between a first and a
second position. The system also includes a pilot configured to
generate a pilot flame, a first burner head assembly fluidly
communicating with the first outlet, and a second burner head
assembly fluidly communicating with the second outlet. The first
control valve is selectively controllable to direct the waste
effluent to the first burner head assembly when the first control
valve is in the first position and to the first and second burner
head assembly when the first control valve is in a second
position.
[0013] In some embodiments, a method for burning a waste effluent
containing hydrocarbons produced from a well during a well test
includes starting a well test, producing a waste effluent
containing hydrocarbons from the well at an initial flow rate, and
directing the waste effluent to a burner apparatus. The burner
apparatus includes a manifold assembly housing a first control
valve movable between a first and a second position and a first and
second burner head assembly fluidly communicating with the manifold
assembly. The first control valve is selectively controllable to
direct the waste effluent to the first burner head assembly when
the first control valve is in the first position and to the first
and second burner head assembly when the first control valve is in
the second position. The method also includes burning the waste
effluent with the first burner head assembly when the first control
valve is in the first position and monitoring the flow rate of the
waste effluent produced from the well to determine if the waste
effluent flow rate will surpass a burning capacity of the first
burner head assembly. The method further includes burning the waste
effluent with both the first and second burner head assembly when
the flow rate surpasses the burning capacity of the first burner
head assembly without stopping production of the waste effluent
from the well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] So that the manner in which the above recited features can
be understood in detail, a more particular understanding may be had
when the following detailed description is read with reference to
certain embodiments, some of which are illustrated in the appended
drawings in which like characters represent like parts throughout
the drawings. It is to be noted, however, that the appended
drawings illustrate only some embodiments and are therefore not to
be considered limiting of its scope, and may admit to other equally
effective embodiments.
[0015] FIG. 1 shows a schematic view of a burner apparatus
according to some embodiments of the disclosure.
[0016] FIG. 2A shows a schematic view of a burner apparatus
according to some embodiments of the disclosure.
[0017] FIG. 2B shows a frontal view the embodiment shown in FIG.
2A.
[0018] FIG. 3 shows a cross-sectional view of a burner apparatus
using a single burner head assembly according to some embodiments
of the disclosure.
[0019] FIG. 4 shows a cross-sectional view of the burner apparatus
in FIG. 3A using two burner head assemblies according to some
embodiments of the disclosure.
[0020] FIG. 5 shows a cross-sectional view of a burner apparatus
according to some embodiments of the disclosure.
[0021] FIG. 6 shows a cross-sectional view of the burner apparatus
in FIG. 4A according to some embodiments of the disclosure.
[0022] FIGS. 7A and 7B show a cross-sectional view of piston
control system according to some embodiments of the disclosure.
DETAILED DESCRIPTION
[0023] Methods and apparatus are disclosed herein for combusting
waste effluent generated by well testing, oil spill cleanup, or
other operations. The term "waste effluent" is intended to
encompass any fluid having a hydrocarbon content capable of being
disposed of by combustion. The waste effluent may include a liquid
hydrocarbon content (such as oil), a gas hydrocarbon content (such
as methane), and non-hydrocarbon containing content (such as
seawater), thus forming a combustible mixture. Other fluids and
solids may also potentially be part of the waste effluent, some of
which will be separated from the waste effluent in a separator tank
before combusting the waste effluent. Still, the waste effluent
sent to the burner apparatus for combustion may include some of the
other fluids and solids. The waste effluent may be obtained from
effluent from a supply line formed during well testing operations,
oil-water mixtures created during an oil spill cleanup, or other
sources.
[0024] FIG. 1 schematically illustrates a burner apparatus 20 for
combusting waste effluent having a hydrocarbon content. A waste
effluent conduit, such as main burner pipe 26, is coupled to a
burner apparatus 20 so that the main burner pipe 26 fluidly
communicates with the main burner apparatus 20. Accordingly, waste
effluent communicated from a source 25 of waste effluent will pass
into the main burner pipe 26 and to the burner apparatus 20. The
source 25 may be a separator tank or the well head itself.
[0025] The burner apparatus 20 includes a manifold assembly 30 for
directing the waste effluent to one or more burner head assemblies
42, 44 in fluid communication with the manifold assembly 30. The
burner head assemblies 42, 44 may discharge the waste effluent in a
pattern suitable for combustion by open flame. The manifold
assembly 30 has a first inlet 31 and multiple outlets 32, 34, 36.
The first inlet 31 fluidly communicates with the main burner pipe
26 for directing the waste effluent to the manifold assembly 30 and
to a first control valve 35 housed within the manifold assembly 30.
The first control valve 35 is movable between a first position and
a second position, as will be shown and described in more detail in
FIGS. 3-6. A first burner head assembly 42 fluidly communicates
with a first outlet 32 of the manifold assembly 30. A second burner
head assembly 44 fluidly communicates with a second outlet 34 and
in some embodiments with a third outlet 36. As will be subsequently
described, the first control valve 35 is movable between a first
(closed) position which blocks fluid communication between the
waste effluent conduit and the second burner head assembly 44, and
a second (open) position, which permits fluid communication between
the waste effluent conduit and the second burner head assembly 44.
The burner head assemblies may have the same or different burning
capacities. Burning capacity, as used herein, refers to the maximum
volumetric flow rate the burner head assembly can combust, which
may be measured in barrels per day (BOPD) for liquid, million
standard cubic feet per day (MMSCFD), or other similar volumetric
flow rate units.
[0026] The burner apparatus 20 provides burner head assemblies 42,
44 that share the same inlet 31 via a manifold assembly 30 having
one or several control valves to select the burner assembly to be
used during the burning operation. The control valve(s) may be
remotely controlled with an electric, pneumatic, or hydraulic
control system. By selecting different sizes of burner assemblies,
the result is a wide-range burning capacity combustion system that
can ensure good burning regardless of fluctuations in flow rates,
thereby preventing fall out or other environmental concerns when
combusting waste effluent when performing a well test.
[0027] The first control valve 35 is selectively controllable to
direct the waste effluent, a combustible mixture, to the first
burner head assembly 42 when the control valve 35 is in the first
position and to the first and second burner head assemblies 42, 44
when it is in the second position as will be shown in more detail
in FIGS. 3-6. In some embodiments, the first and second burner head
assemblies 42, 44 are positioned concentric with each other, while
in other embodiments the burner head assemblies 42, 44 are
positioned non-coaxially aligned with each such as schematically
shown in FIGS. 2A and 2B.
[0028] FIG. 2A shows a schematic view of a burner apparatus 120
according to some embodiments and FIG. 2B shows a frontal view the
embodiment shown in FIG. 2A. The manifold assembly 130 of burner
apparatus 120 includes an inlet 131 and three outlets 132, 134, and
136. The manifold assembly 130 houses a selectively controllable
control valve 135 for directing effluent waste to a first burner
head assembly 142 fluidly communicating with the first outlet 132,
a second burner head assembly 144 fluidly communicating with the
second outlet 134, third burner head assembly 136 fluidly
communicating with the third outlet 136. The three burner head
assemblies 142, 144, and 146 may be positioned in a triangular
pattern 125 proximate the manifold assembly 120 as shown in FIG.
2B. The control valve 135 is movable between a first, second, and
third position. The control valve 135 directs waste effluent to one
of the burner head assemblies when it is in the first position, to
two of the burner head assemblies when in the second position, and
to the three burner head assemblies 142, 144, 146 when it is in the
third position. Whether using burning apparatuses as shown in FIGS.
1 and 2 or the those shown in any of other FIGS., well test
operators are able to quickly change the flow of waste effluent to
the different burner head assemblies in real-time as the waste
effluent flow rate fluctuates during a well test and without
stopping the well test.
[0029] Turning to FIGS. 3-6, a burning apparatus 320 is shown where
the first burner head assembly 42 may be a central burner 342 and
the second burner head assembly 44 may be a large annular burner
344 in some embodiments. The central burner 342 may be a flare type
burner and the large annular burner 344 may be a coanda type
burner. In some embodiments, the large annular burner 344 may have
a second burning capacity greater than a first burning capacity of
the central burner 342. The burner apparatus also includes a pilot
system for initiating flame. In the illustrated embodiment, the
pilot system includes a pilot 345. More pilots (not shown) may also
be used with the burner apparatus as desired. The pilot 345 fluidly
communicates with a pilot pipe 346. The pilot pipe 346, in turn,
fluidly communicates with a pilot fuel source, which may be
obtained from or independently of the waste effluent. An electric
igniter (not shown), usually a high voltage source generating
sparks, can be used to initiate the pilot flame.
[0030] In some embodiments, the first control valve 335 is a piston
333 housed within a manifold assembly 330. The piston 333 together
with the manifold assembly 330 form a first chamber 338 and a
second chamber 339 within the manifold assembly 330. A piston
control system 700 as shown in FIGS. 7A and 7B may be used to
selectively control and move the piston 333. The manifold assembly
330 forms an annular path 337 around a portion of the manifold
assembly and/or a portion of the central burner 342 that fluidly
communicates with the second annular outlets 334, 336. The manifold
assembly 330 may include two sub-housings 329 and 331 coupled
together and enclosing portions of the piston 333. A base
sub-housing 329 together with the piston may form the first chamber
338. The second chamber 339 may be formed by the piston 333, the
base sub-housing 329, and the top sub-housing 331. A top
sub-housing 331 together with portions of the manifold assembly 330
and the central burner 342 may form the annular path 337.
[0031] The piston 333 is movable and selectively controllable
between a first (closed) position 350 and a second (open) position
450, such that when the piston 333 is in the first position 350 as
shown in FIG. 3, the waste effluent flows solely to the first
burner head assembly, such as central burner 342, via inlet 327 as
indicated by arrows 355. When the piston 333 is in the second
position 450 as shown in FIG. 4, the waste effluent flows to both
first burner head assembly, such as central burner 342, through the
annular path 337 and to the second burner head assembly, such as
large annular burner 344, as indicated by arrows 455. As the piston
333 slides open, a passageway 452 formed in either the manifold
assembly 330 and/or a central flow conduit of the central burner
342 opens to the annular path 337 so that the waste effluent may
flow to the large annular burner 344. The piston 333 can be
remotely controlled using the piston control system 700 to open and
close the annular path 337 to the large annular burner 344. This
design may also provide a robust burning apparatus having light
packaging that is compact and easily transportable and
assembled.
[0032] FIG. 7A illustrates a piston control system 700 according to
some embodiments of the disclosure and a partial cut away view of
the burning apparatus 320, valve manifold assembly 330, and piston
333 controlled by the piston control system 700. The piston control
system 700 has a pressurized fluid supply line 760 for supplying
pressurized fluid to the system 700. Instruments and control tools
that may be provided along the supply line 760 include an isolation
valve 765, a pressure gauge 770, and a filter 775. A first inlet
line 761 fluidly communicates with the first chamber 338 and the
pressurized fluid supply line 760. Similarly, a second inlet line
762 fluidly communicates with the second chamber 339 and the
pressurized fluid supply line 760. The first inlet line 761
supplies pressurized fluid 738 to the first chamber 338 and the
second inlet line 762 supplies pressurized fluid 739 to the second
chamber 339 (FIGS. 3-4). Thus, the piston control system 700 also
includes pressurized fluid in the first and second chambers 338,
339.
[0033] A pressure regulator 780, a check valve 785, and a pressure
gauge 790 may be positioned along the second inlet line 762 such
that constant pressure is provided to the second chamber 339
causing the piston 333 to be in the second position 450 by default.
The pressure regulator 780 may generate a permanent intermediate
pressure in the second chamber 339. The pressure regulator 780 can
be set to deliver half of the inlet pressure so that it maintains a
P/2 at any time in the second chamber 339. That pressure can push
the piston to the open position (towards the left as shown in FIGS.
3-6). When the pressure P is applied to the inlet 764 of
pressurized fluid supply line 760, the fluid pressurizes the first
chamber 338. The piston 333 is subjected to a differential pressure
of P-P/2, so it will be pushed to the closed position (towards the
right as shown in FIGS. 3-6). The piston control system 700 may
remotely control the manifold assembly 330 from a single
pressurized fluid supply line 760. This design simplifies the
piping all along the boom that supports the burner. Also, the
control panel for the operator can be very simple: a simple valve
can be used to pressurize or bleed-off the unique supply line 760.
Finally, the system becomes a failsafe: in case of leak in the
supply line or lack of pressure (empty gas bottle), the manifold
will automatically switch to the safe position for the largest
waste effluent flow rate.
[0034] In another embodiment, the piston control system may simply
be two pressurized fluid supply lines directly to the first and
second chambers 338, 339 as shown in FIG. 7B and discussed below.
In that case the control panel for the operator will be composed of
two valves to pressurize or bleed off separately the two lines.
[0035] The piston 333 may slide between open and closed positions
using a moderate pressure differential, such as a few bars. That
pressure can be provided by a pressurized fluid, such as oil or
water, or compressed air or nitrogen. Nitrogen may be a beneficial
choice as it increases the safety of the burning apparatus should a
leak occur as nitrogen is not combustible unlike oxygen. Some
benefits the piston control system 700 may provide include use of
one pressurized fluid inlet, thereby decreasing the cost of
pressurized fluids involved for operating the burning apparatus and
a simplified control panel and piping. Other benefits may include
that some pressure trapped into the second chamber 339 will act as
a spring to make a fail-safe system. In the absence of any operator
or controller commands, the piston will remain open to both burner
head assemblies, allowing any flow rate for safety. The system
shown also allows low flow rate combustion through the central
burner 342 alone and high flow rate combustion through both burners
when the piston 333 opens the annular path 337. The burner
apparatus may have a turndown ratio greater than 10 and as high as
20, or anywhere between those ranges.
[0036] Turning to FIGS. 5-6, some embodiments of a burning
apparatus 520 may house a second control valve 535 that is movable
between an open and a closed position such that when the first
control valve 335 is in the second (open) position and the second
control valve 535 is in the closed position (FIG. 6), the second
control valve 535 blocks the waste effluent from flowing through
the first outlet 332 to the first burner head assembly 42, such as
central burner 342. That is, the second control valve 535 is
movable between a closed position which blocks fluid communication
between the waste effluent and the first burner head assembly, such
as central burner 342, and an open position, which permits fluid
communication between the waste effluent conduit and the first
burner head assembly, such as central burner 342. The second
control valve 535 may be housed within the manifold assembly 330 or
within part of the first burner head assembly, such as a shaft 500
of central burner 342. The second control valve 535 may be a ball
valve placed in the central pathway of either the manifold assembly
330 or a portion of the central burner 342. The ball valve yoke may
be linked to the piston 333 to control opening and closing of the
second control valve 535. In some embodiments, a second piston
could be housed within the burning apparatus 520 and linked to the
second control valve 535 in order to independently control both the
first and second control valves 335, 535.
[0037] In view of the foregoing, systems and methods are provided
for burning waste effluent containing hydrocarbons, such as a waste
effluent produced from a well during a well test. The method
includes initiating a well test by the operators, producing a waste
effluent containing hydrocarbons from the well at an initial flow
rate, and directing the waste effluent to a burner apparatus. The
burner apparatus includes a manifold assembly housing a first
control valve movable between a first and second position and a
first burner head assembly and a second burner head assembly
fluidly communicating with the manifold assembly. The first control
valve is selectively controllable to direct the waste effluent to
the first burner head assembly when the first control valve is in
the first position and to the first and second burner head
assemblies when the first control valve is in the second
position.
[0038] The method also includes burning the waste effluent with the
first burner head assembly when the first control valve is in the
first position. Further, the method includes monitoring the flow
rate of the waste effluent produced from the well to determine if
the waste effluent flow rate will surpass a burning capacity of the
first burner head assembly. If the flow rate does surpass the
burning capacity of the first burner head assembly, the operators
burn the waste effluent with both the first and second burner head
assemblies without stopping production of the waste effluent from
the well. The operators may accomplish this by moving the first
control valve to the second position while waste effluent flow
continues unabated.
[0039] The method may also include monitoring the flow rate of the
waste effluent to determine if the flow rate will be greater than
the burning capacity of the first burner head assembly but smaller
than a burning capacity of the second burner head assembly. If the
operators observe that the flow rate surpasses the burning capacity
of the first burner head assembly but not the second burner head
assembly, then the waste effluent may be burned solely with the
second burner head assembly without stopping production of the
waste effluent from the well. This may be accomplished by moving a
second control valve housed in the manifold assembly to a closed
position, such that when the first control valve is in the second
position and the second control valve is in the closed position,
the second control valve blocks the combustible mixture from
flowing through the first outlet to the first burner head
assembly.
[0040] As shown and described herein, some embodiments of the
disclosure include a system for burning waste effluent containing
hydrocarbons. The system includes a waste effluent conduit 26
fluidly communicating with a source of waste effluent 25 and a
manifold assembly 30 fluidly communicating with the waste effluent
conduit 26. The manifold assembly 30 has an inlet 31, a first
outlet 32, a second outlet 34, and a first control valve 35. A
pilot 345 is configured to generate a pilot flame to ignite the
waste effluent. A first burner head assembly 42 fluidly
communicates with the first outlet 32, and a second burner head
assembly 44 fluidly communicates with the second outlet 34. The
first control valve 35 is selectively controllable to direct the
waste effluent to the first burner head assembly 42 when in a first
position and to the first and second burner head assemblies 42, 44
when in a second position.
[0041] In some embodiments the system for burning was effluent
includes a piston control system 700 and the first valve 35 may be
formed as a piston 333 disposed within a manifold assembly 340. The
piston control system 700 may be used to selectively control the
piston 333. The piston 333 together with the manifold assembly 330
form a first chamber 338 and a second chamber 339 within the
manifold assembly 330. The manifold assembly 330 forms an annular
path 337 around the central burner 342 that fluidly communicates
with a second outlet 334 and a third outlet 336.
[0042] Some embodiments of the system for burning waste effluent
may include a second control valve 335 housed within the burning
apparatus 520. The second control valve 335 has an open and a
closed position such that when the first control valve 335 is in
the second position and the second control valve 535 is in the
closed position (FIG. 6), the second control valve 535 blocks the
waste effluent from flowing through the first outlet 332 to the
first burner head assembly, such as central burner 342.
[0043] Some embodiments of the system for burning waste effluent
may also include a piston control system 700 that has a pressurized
fluid supply line 760 for supplying pressurized fluid to the system
700. A first inlet line 761 fluidly communicates with the first
chamber 338 and the pressurized fluid supply line 760. Similarly, a
second inlet line 762 fluidly communicates with the second chamber
339 and the pressurized fluid supply line 760. The first inlet line
761 supplies pressurized fluid 738 to the first chamber 338 and the
second inlet line 762 supplies pressurized fluid 739 to the second
chamber 339. Thus, the piston control system 700 also includes
pressurized fluid in the first and second chambers 338, 339. A
pressure regulator 780, a check valve 785, and a pressure gauge 790
may be positioned along the second inlet line 762 such that
constant pressure is provided to the second chamber 339 causing the
piston 333 to be in the second position by default. The pressure
regulator 780 may generate a permanent intermediate pressure in the
second chamber 339. FIG. 7B shows two lines in parallel each having
an isolation valve 765 which provides a simple, limited maintenance
piston control system.
[0044] Although the preceding description has been described herein
with reference to particular means, materials and embodiments, it
is not intended to be limited to the particulars disclosed herein;
rather, it extends to all functionally equivalent structures,
methods, and uses, such as are within the scope of the appended
claims.
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