Patent Application
20140053917
1. Field of the Invention
This invention relates to the handling of flow back materials which occurs during the cleaning or preparation of oil or gas wells for long term production. The flow back material may include a mixture of water, gas, oil, sand, solid rocks or other solids, completion fluid and drilling mud for example. Various components such as filters, sand separators, chokes, liquid gas separators and tanks along with necessary valves, storage tanks and piping are currently used to process the flow back.
2. Description of Related Art
Currently the materials that are recovered during these flow back operations are considered to have little or no commercial value. In most cases the oil, gas, water and sand are all recovered into a common tank wherein the gas is allowed to vaporize to the atmosphere and the sand settles to the bottom of the tank with the oil and water being left to be disposed of or to be manually skimmed and separated during removal. During normal production operations of the well multiple units are used to separate the material from one another. These production separators however are not designed to handle a large amount of contaminates and can become damaged or plugged during this phase of the operation. Therefore the well must be cleaned up and these contaminates removed from the flow prior to the well being placed on long term production. To accomplish this, temporary equipment and facilities that can handle and separate these materials from the commercial commodities are set up. In the past these systems lacked the ability to reclaim or recover the oil and gas mixed with these materials during the flow back. However higher commodity prices and environmental concerns have pushed the oil and gas industry to recover these at much earlier stages during this production. This recovery helps to reduce carbon emissions while selling items that would otherwise be lost to the atmosphere during this stage. As the complexity of this separation process has increased so has the time and cost associated with the transport and set up of the temporary facilities. Before these facilities can be placed into operation the integrity as well as the functional operation of the equipment must be tested and certified as to their operating capabilities. On high pressure operations these rig up or set up operations can be complicated because the connections must be flanged and bolted together. In addition the higher pressure operations require connections and equipment that is much larger and heavier than standard operations to support the extreme pressure. This set up operation may take days to accomplish with each piece being transported to the well location on separate trucks because of their enormous size and weight. Once on location crews of men work with cranes and winch trucks to off load this equipment and precisely set the equipment the proper distance from one another so they may be connected together and pressure tested. Once all of the equipment has been brought in and assembled a truck screws anchors into the ground and each is load tested, then the piping that connects all of the individual pieces are tied to the anchors. This is done so that in the event that connection or pressure lines were to rupture during the operation the restraints would help to contain the release of pressure and energy. In addition spill containment must be put down to prevent oil and other contaminates from soaking into the ground. This entire operation may take several days to accomplish and many accidents, strains and injuries occur during this process. Therefore there is a need to design a system that can eliminate the complexity and reduce the manual labor while improving safety exists.
This invention allows for the on-site treatment of flow back materials through the use of a dual stage process. Additionally a unique diffuser is utilized to reduce the velocity in the high pressure flow back stream as it leaves the well head. A novel combination of separators and storage and containment vessels is utilized to separate the flow back material and the separated products may be further utilized or recycled.
Referring to
A number of manual dump valves 20, 21, and 22 for example are located in the bottom portion of pressure vessel 12 and are connected by conduits 24 and 25 to a conduit 23 which leads to an open top sand tank 27 which may be located in close proximity to the flow back system. Thus sand and other particulate material falling to the bottom of pressure vessel 12 may be directed to the tank 27 via the dump valves and conduits shown in
As shown in
Pressure vessel 32 may include one or more pressure relief valves 34, 35 and a gas conduit 36 connected to an upper portion of the vessel. Conduit 36 may lead to a sales conduit 37 or may be directed to a flare via conduits 38, 39. Tank 51 may also have an outlet to a conduit 59 which is connected to flare conduit 39. Pressure vessel 51 may also include one or more pressure relief valves 84, 85.
From the above description it can be seen that flow back fluid from a well treating process flows into diffuser 11 via conduit 10 which initially reduces the velocity of the fluid. Fluid then enters first pressure vessel 12 and begins to separate into its various components.
Gas will begin to form in the top portion while liquid and solids settle to the bottom. Some solids such as sand may initially be removed through manual dump valve 20, 21, and 22. Pressure vessel 12 is connected to a second pressure vessel 32 via gas conduit 31 and fluid conduit 30. Water and oil separate out due to weir baffle 55 in vessel 32. Gas exits pressure vessel 32 at 36. Sand and particulate material can be further separated through manual dump valves 42-44 to sand tank 27.
Water and other chemicals dissolved in the water are withdrawn from the pressure vessel 32 through mechanical dumps valves 40, 41 to tank 51. Oil can be removed from area 57 of pressure vessel 32 via a mechanical dump valve 62 to a holding tank or production equipment.
According to another aspect of the invention, a major portion of the system shown in
Specifically, diffuser 11, pressure vessels 12 and 32, and tank 51 along with the associated valves, conduits and connectors can all be preassembled on a trailer and tested and certified in advance in the manner described in pending U.S. patent application Ser. No. 12/953,197 filed Nov. 23, 2010, the entire contents of which is hereby incorporated herein by reference thereto.
A novel diffuser in accordance with another aspect of the invention will now be described with reference to
The diffuser 11 includes an outer housing 61 which may be cylindrical and an inner sleeve 62 positioned within and in contact with housing 61. A first connection member 76 with bores 71 is secured to the housing 61 for attaching the diffuser to the inlet of a pressure vessel 12 as shown in
The details of the diffuser pipe are shown in
Pipe 64 is closed at end portion 66. The pipe can be secured within the housing by suitable supports if desired.
As flow back fluid enters the diffuser through inlet 65, a portion of the fluid is deflected outwardly by the baffles while a portion of the fluid continues to flow within the pipe 65 until it impinges a subsequent baffle. This process continues until all the fluid exits the pipe into the chamber 82 formed between the sleeve 62 and the pipe 64. The velocity of the fluid from the well is thus reduced as it now enters pressure vessel 12.
By virtue of this design, should either the central pipe 64 or sleeve 62 wear out due to the abrasive nature of the flow back fluid, these parts may be easily replaced on site thus saving time and money.
Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.
