AU2010257268A1 - Flare and blast solid control tank - Google Patents

Abstract

Abstract A solids collection tank includes a housing with an arrangement for collecting solids located therein. The collecting arrangement includes a pipe formed with a series of apertures along its underside for said solids and associated liquids to fall therethrough into a number of hoppers. A venturi pumping arrangement is provided to evacuate the solids and liquids into a pit or storage tanker. Vents are formed in the housing for emission therethrough of gases associated with the solids and a controllable ignition means is provided for igniting and flaring off the gases. The tank includes wheels to enable it to be moved from site to site. f'% T f% 17 e~% OT I T Cl Ot 7 1 '7 f% T f% 17

Description

AUSTRALIA PATENTS ACT 1990 Complete Patent Specification FLARE AND BLAST SOLID CONTROL TANK The following statement is a full description of the best method of performing this invention known to the applicant(s): 1 FLARE AND BLAST SOLID CONTROL TANK TECHNICAL FIELD 5 The present invention relates to tanks for collecting solids from drilling and well services and for burning off drilling and operation gas associated therewith. BACKGROUND 10 The reference to any prior art in the following discussion is not to be interpreted as any admission, or evidence, that such prior art formed or forms part of the common general knowledge. Flare tanks, fractional distillation tanks, i.e. "frac tanks" hopper collector units 15 and tank structures are known in the prior art. These assemblies are used to collect and burn off byproducts from drilling operations. Typically, flare tanks of the prior art are housed in pits. Sumps are located beneath them for receiving collected matter. Alternatively, where sumps are 20 not provided, the tanks must be shut down from time to time for draining of collected liquids by means of a tanker truck. A problem associated with prior art tanks is that the collected solids need to be removed manually, i.e. by workers with shovels, which is a laborious and 25 unpleasant task. It is an object of the present invention to address the above problem and to provide a solids collection tank which is an improvement, or at least a useful alternative, to those hitherto known in the prior art. 30 2 SUMMARY OF THE INVENTION According to a first aspect of the present invention, there is provided a solids collection tank including: a housing; 5 an arrangement for collecting solids within the housing; at least one vent formed in the housing for emission therethrough of gases associated with the solids; and a controllable ignition means for igniting the gases. 10 Preferably the solids collection tank is provided with wheels in order that it may be moved as required. Alternatively the tank may be skid mounted. In a preferred embodiment the arrangement for collecting solids within the housing includes a pipe formed with a series of apertures along its underside 15 for said solids to fall therethrough. Preferably the pipe within the housing is of a larger diameter than the pipe which carries the product (gas, water and solids) from the well so that the velocity of the gas, water and solids passing into the pipe within the housing is 20 reduced. Preferably adapters are provided to transition between the two pipe diameters. 25 Preferably one or more receptacles are located beneath the apertures for collection of the solids. In a preferred embodiment the receptacles take the form of hoppers. 30 In a preferred arrangement a pumping assembly is provided for evacuating the solids from the hoppers when required. The pumping assembly may comprise a venturi effect suction pump arrangement.

3 Preferably the venturi effect suction pump arrangement is configured to use water as a working fluid. In a preferred assembly each of hoppers includes an output port located 5 above a corresponding venturi nozzle of the said suction pump arrangement. A manifold may be provided to interconnect inlet sides of the venturi nozzles. Preferably a pump is provided in communication with the manifold for forcing 10 the water through the nozzles. An outlet side of each of the nozzles is preferably placed in communication with one or more ports for connection to a vacuum tanker for evacuation of solids from said hoppers. 15 Preferably the pump is located on an operators platform separable from the housing. A motor may be located on the platform and coupled to the pump for driving 20 the pump. Preferably the controllable ignition means includes at least one igniter associated with the at least one vent. 25 Said igniter is preferably coupled to a control unit remote from said burner for operation thereof. Preferably the pump, flarekit, motor, compressor and gas bottles are fast with an operator's station. 30 The operator's station preferably has a base structure which may be pinned to the housing for transport. During operations the operators station is located a safe distance away from the housing. The pump is connected to the housing through flexible hoses. The unit also has provision for transporting the hoses.

4 BRIEF DESCRIPTION OF THE DRAWINGS Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient 5 information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows: 10 Figure 1 is an isometric view of the rear left hand side and topside of a solids collection tank according to a preferred embodiment of the present invention. Figure 2 is an elevation view of the solids collection tank. Figure 3 is a cross section view through line A-A of Figure 2 of the solids 15 collection tank Figure 4 is a view of the right hand side of the solids collection tank. Figure 5 is an elevation view of the underside of the solids collection tank. Figure 6 is an elevation view of the front of the solids collection tank. 20 Figure 7 is an elevation view of the rear of the solids collection tank. Figure 8 is a cross sectional view through line C-C of Figure 6 of the solids collection tank. Figure 9 is a cross sectional view through line B-B of Figure 2 of the solids collection tank. 25 Figure 10 is a hydraulic circuit diagram of the solids collection tank. Figure 11 is an elevation view of the left hand side showing the attitude adopted during towing of the solids collection tank. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 30 The Figures illustrate a solids collection tank 1 according to a preferred embodiment of the present invention. With reference to Figures 1 and 2, the tank 1 includes a rectangular trailer base 3 which supports a box like housing 5.

5 A number of mesh covered vents 7 are spaced along roof 9 of housing 5. Burners 11 are positioned in the centre of each vent. At the rear of trailer base 3 there are located wheels 13 to assist in towing of 5 the trailer. Opposite the wheels, at the front end of the trailer base 3 and fastened thereto 3, there is positioned an operating station platform 15 which supports a number of modules for operation of the solids collection tank 1. These modules include a pump, an air compressor, an engine for operating the pump and a flare kit for operating igniters located close to the burners. 10 At the forward end of housing 5 there is located a flanged inlet port 15 for receiving drilling operation waste from a blooie line into the tank 5. Figure 3 is a cross sectional top plan view along line A-A of Figure 2 revealing 15 some of the internal structure of the tank. It will be observed that inlet port 15 comprises an inlet for a forward end of main pipe 17. The rearward end of the main pipe 17 is closed with a cap 23. A series of apertures 19 is disposed along the underside of the main pipe 17. Located beneath main pipe 17 is a deck formed of deck portions 22 and 24. Receptacles in the form of three 20 conical hoppers 21 open upward flush with the deck. The deck is tapered to assist the solids moving into the hoppers and also to assist cleaning the tank after use. With reference to Figure 8, the conical hoppers 21 have open circular mouths which face upwards to receive material falling through apertures 19 of the main pipe 17, in use. 25 The sides of each hopper converge downward to form a hopper outlet as can be best seen in Figure 9. The hopper outlet is connected to the intermediate suction line 29 of a T-piece 30 31. A replaceable nylon wear insert 27 is located at the hopper outlet to reduce wearing on steel at the bottom as the solids and water enter the T piece 31. Within the inlet side of the T-piece 31 there is located a venturi jet nozzle 33. The venturi jet nozzle 33 is directed towards the outlet side 32 of the T-piece 31, which in turn is coupled to a waste outlet pipe 35 via an air- 6 actuated gate valve 34. The jet nozzles 33 are provided in a range of sizes which can be unscrewed from the T-piece 31 and replaced as desired to suit the operating conditions in the tank. 5 With reference to Figure 10, the venturi jet nozzle 33 is fed with water under pressure from pump 37 via hoses 43 and inlet pipe 45. An air-actuated butterfly valve 47 is located in inlet pipe 45 for selectively opening and closing each pipe as desired. The pump 37 is driven by engine 39, which may be an electric motor or a combustion engine, for example. 10 The control sides of the air-actuated butterfly valve 47 and the air-actuated gate valve 34 are respectively pneumatically coupled to the output of an air compressor 49, which is located on operating station platform 14. 15 A flare kit 51 is also positioned on operating platform station 15 and is electrically coupled to igniters located adjacent burner flutes 11 on the roof of the tank housing 5. In operation the tank 1 is towed to site by a prime mover. During towing it 20 assumes the in-transit attitude shown in Figure 11 as it rolls along on its wheels 13. Once at site a blooie line waste tube is connected to the main pipe 17 via inlet port 15. The main pipe 17 is of a larger diameter than the blooie line waste 25 tube which carries the product (gas, water and solids) from the well. This is so that the velocity of the gas, water and solids passing into the main pipe 17 is reduced. Preferably adapters are provided to transition between the two pipe diameters. The inlet side of pump 37 is connected to a water supply such as a tank or sump by means of supply pipe 40. 30 Waste solids water and gas then proceed through the main pipe 1-9 17 from inlet 15 and issue out through the pipe apertures 19. The solids and water fall into the hoppers 21 while the gas vents to the top of housing 5. An operator of the tank then makes use of the flare kit 51 to send a spark to the igniters 7 that are adjacent burners 11 and lighting a pilot flame. Gas rising up from the housing through openings 7 is ignited by the pilot flame and burns off. As further material enters the inlet port 15 of the main pipe 4-9 17, the level of 5 the solids and water in the hoppers 21 rises. The operator monitors a fluid level indicator (not shown but side wall mounted) from platform 4-5 14 which is coupled to a fluid level sensor or float within the tank that monitors the level. Once the solid and fluid level has risen to a predetermined level the operator starts engine 39 and compressor 49. Activating the compressor 49 opens any 10 or all of the butterfly valves 47 and the gate valves 34 on the inlet and outlet sides of the venturi pump T-piece 31. All valves may be separately controlled. Pump 37, which is powered by engine 39, then pumps water from supply line 15 40 and through hoses 43 so that the venturi pump nozzles 31 begin to spray a high velocity stream of water. The action of the pump nozzles 31 causes a venturi effect in the usual manner which sucks waste solids through the hopper outlet 27. The waste and water from nozzle 31 then passes through the open gate valve 34 and through waste outlet pipe 35. A tanker receives 20 the waste from outlet pipe 35 for storage and then transport to a waste disposal site. In a further embodiment of the invention dividing wall sections not reaching to the top of the housing can be added through the width of the tank. Air rams 25 can also be provided to close the main pipe 17. This is so that portions of the main pipe 17 can be closed off to stop fluids and solids travelling through the whole length of the pipe. In this way a volume of the fluids and solids may be restricted to one or more forward sections of the tank only. V-weirs can also be included in the dividing walls and be used to gauge the volume of flow from 30 one section into another in the normal manner. Where the tank is divided into sections multiple level indicators may be provided for each section in order to monitor the level in each section independently.

8 Mud gun wash lines may also be provided to assist in washing out the inside of the tank. In compliance with the statute, the invention has been described in language 5 more or less specific to structural or methodical features. For example, a mobile tank according to an embodiment of the invention has been described which has three separate vents formed in its housing. Other numbers, or a single, vent might instead be formed if desired. Indeed, the entire roof may be constructed as essentially open but covered with mesh suitable to allow gases 10 to pass through it and also to act as a load supporting platform. Furthermore, venturi pumps have been described for evacuating the hoppers of solid wastes. However, other types of pumps might be used in further embodiments of the invention. The preferred embodiment features conical hoppers however other types of receptacles, in the form of tanks or containers 15 of other shapes might be used in some instances. The drawings depict a straight vertical outlet at the bottom of the hopper however it may also be angled or curved to improve the venturi effect. It will therefore be realised that variations and further embodiments of the invention will be realised by those skilled in the art and are encompassed by the following claims. 20 The term "comprises" and its variations, such as "comprising" and "comprised of" is used throughout in an inclusive sense and not to the exclusion of any additional features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described 25 comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted by those skilled in the art.

Claims (18)

1. A solids collection tank including: a housing; an arrangement for collecting solids within the housing; at least one vent formed in the housing for emission therethrough of gases associated with the solids; and a controllable ignition means for igniting the gases.

2. A solids collection tank according to claim 1, including wheels for moving the tank from site to site.

3. A solids collection tank according to claim 1 or claim 2, wherein the arrangement for collecting solids within the housing includes a pipe formed with a series of apertures along its underside for said solids to fall therethrough.

4. A solids collection tank according to claim 3, including receptacles located beneath the apertures for collection of the solids.

5. A solids collection tank according to claim 4, wherein the receptacles comprise hoppers.

6. A solids collection tank according to claim 4 or claim 5, wherein a pumping assembly is provided for evacuating the solids from the receptacles when required.

7. A solids collection tank according to claim 6, wherein the pumping assembly comprises a venturi effect suction pump arrangement.

8. A solids collection tank according to claim 7, wherein the venturi effect suction pump arrangement is configured to use water as a working fluid. 10

9. A solids collection tank according to 8, wherein each receptacle includes an output port located above a corresponding venturi nozzle of the said suction pump arrangement.

10. A solids collection tank according to claim 9, wherein inlet sides of the venturi nozzles are interconnected.

11. A solids collection tank according to claim 10, including a pump in communication with the interconnected inlet sides of the venturi nozzles for forcing the water through the nozzles.

12. A solids collection tank according to any one of claims 9 to 11, wherein an outlet side of each of the nozzles is preferably placed in communication with one or more ports for evacuation of solids from said hoppers.

13. A solids collection tank according to claim 11 or claim 12, wherein the pump is located fast with the housing.

14. A solids collection tank according to claim 13, wherein the pump is located on a platform separable from the housing.

15. A solids collection tank according to claim 14, wherein a motor or engine is located on the platform and coupled to the pump for driving the pump.

16. A solids collection tank according to any one of claims 1 to 15, wherein the controllable ignition means includes at least one igniter associated with the at least one vent.

17. A solids collection tank according to claim 16, wherein said igniter is coupled to a control unit remote from said burner for operation thereof.

18. A solids collection tank substantially as described herein with reference to the drawings. * * *