GB2535598B

GB2535598B - Oil/gas burners and method

Info

Publication number: GB2535598B
Application number: GB1521941.3A
Authority: GB
Inventors: Rayssiguier Christophe; Allouche Francis; Eloundou Raynald
Original assignee: Schlumberger Holdings Ltd
Current assignee: Schlumberger Holdings Ltd
Priority date: 2014-12-17
Filing date: 2015-12-14
Publication date: 2019-07-31
Anticipated expiration: 2035-12-14
Also published as: GB2535598A; US20160178197A1; BR102015031701A2; GB201521941D0

Description

OIL/GAS BURNERS AND METHOD

BACKGROUND

Field [0001] This disclosure relates to burners and more particularly to oil and gas burners that may be used in the oil field industry.

Description of the Related Art [0002] 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.

[0003] 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.

[0004] 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.

[0005] 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.

[0006] 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.

[0007] 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

[0008] In accordance with a first aspect, the invention provides a burner apparatus for combusting waste effluent during well testing, the burner assembly 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; a second burner head assembly fluidly communicating with the second outlet; and 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; and the first and second burner head assemblies have different burning capacities.

[0009] In accordance with a second aspect, the invention provides a system for burning waste effluent containing hydrocarbons during well testing, 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 positon and a second position; a pilot configured to generate a pilot flame; a first burner head assembly fluidly communicating with the first outlet; a second burner head assembly fluidly communicating with the second outlet; and 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; and the first and second burner head assemblies have different burning capacities.

[0010] In accordance with a third aspect, the invention provides 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; 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, the first burner head having a first burning capacity; 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; and burning the waste effluent with the second burner head assembly 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, the second burner head assembly having a second burning capacity different from the first burning capacity of the first burner head assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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.

[0012] FIG. 1 shows a schematic view of a burner apparatus according to some embodiments of the disclosure.

[0013] FIG. 2A shows a schematic view of a burner apparatus according to some embodiments of the disclosure.

[0014] FIG. 2B shows a frontal view the embodiment shown in FIG. 2A.

[0015] FIG. 3 shows a cross-sectional view of a burner apparatus using a single burner head assembly according to some embodiments of the disclosure.

[0016] 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.

[0017] FIG. 5 shows a cross-sectional view of a burner apparatus according to some embodiments of the disclosure.

[0018] FIG. 6 shows a cross-sectional view of the burner apparatus in FIG. 4A according to some embodiments of the disclosure.

[0019] FIG. 7A and 7B show a cross-sectional view of piston control system according to some embodiments of the disclosure.

DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] 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 have 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.

[0023] 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.

[0024] 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. 2Aand 2B.

[0025] 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 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.

[0026] 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.

[0027] 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.

[0028] 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 shnwn in Flf1! Δ. thp wasfp pffhipnt flnws tn hnth first hiirnpr hparl asspmhlv siirh as rpntral hiirnpr 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 [0035] 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 the second burner head assembly (and optionally 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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, within the scope of the appended claims.

Claims

1. A burner apparatus for combusting waste effluent during well testing, the burner assembly 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; and 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; and the first and second burner head assemblies have different burning capacities.

2. The burner apparatus of claim 1, wherein the second burner head assembly has a greater burning capacity that the first burner head assembly.

3. The burner apparatus of claim 1 or claim 2, wherein the burner apparatus has a turndown ratio greater than 10.

4. The burner apparatus of any of the preceding claims, wherein the first and second burner head assemblies are positioned concentric with each other.

5. The burner apparatus of any of claims 1 to 3, wherein the first and second head assemblies are positioned non-coaxially with each other.

6. The burner apparatus of claim 5, 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.

7. The burner apparatus of any of claims 1 to 4, wherein the first burner head assembly is a central burner having a first burning capacity.

8. The burner apparatus of claim 7, wherein the second burner head assembly is a large annular burner having a second burning capacity greater than the first burning capacity.

9. The burner apparatus of claim 8, 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.

10. The burner apparatus of claim 9, 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.

11. The burner apparatus of claim 9 or claim 10, 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 any of claims 9 to 11, wherein the piston control system is remotely controlled.

13. The burner apparatus of any of claims 8 to 11, 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.

14. A system for burning waste effluent containing hydrocarbons during well testing, 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; a second burner head assembly fluidly communicating with the second outlet; and 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; and the first and second burner head assemblies have different burning capacities.

15. The system of claim 14, 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.

16. The system of claim 15, 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. The system of any of claims 14 to 16, further comprising: 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.

18. The system of any of claims 14 to 17, wherein the second burner head assembly has a greater burning capacity that the first burner head assembly.

19. 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, the first burner head having a first burning capacity; 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; and burning the waste effluent with the second burner head assembly 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, the second burner head assembly having a second burning capacity different from the first burning capacity of the first burner head assembly.

20. The method of claim 19, wherein burning the waste effluent with the second burner head assembly is accomplished by moving the first control valve to the second position.

21. The method of claim 19 or claim 20, 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.

22. The method of claim 21, 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.