Abstract:
A manifold battery for hydrocarbon fields has an entrance manifold which is connected to a plurality of separators which are operatively connected through ducts and valve sets, with gas storage devices and a pair of circulating pumps. A purging chamber is also provided which is connected to the storage devices and to the separators. An auxiliary tank reduces the adverse impact to the environment, accidents, dangers and consequential risks of flammable, toxic and damaging substances concentration, as well as reducing the operative times and the related costs.

Description:
[0001]    This application is based on and claims the benefit of priority from prior Argentine Patent Application No. 2013 010713, filed Mar. 5, 2013, the entire contents of which are incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention is related to the field of means or dispositions employed for the temporary storage and treatment of hydrocarbons, more particularly, it refers to a manifold battery that, unlike traditional batteries, reduces the impact on the environment, the consequential accidents, dangers and risks of the flammable, toxic and damaging substances concentration, as well as the operative times and connected costs. 
         [0003]    Even when the present description refers more particularly to the technical and commercial advantages of its implementation as a manifold battery for hydrocarbon fields, it is clear that its use accommodates the pertinent environmental safety rules and cooperates with awareness for the environment. 
       BACKGROUND 
       [0004]    In order to better understand the purpose and scope of the present invention, it is convenient to describe the current state of the art regarding the traditional manifold tanks or batteries used and the drawbacks that occur. 
         [0005]    Manifold batteries are well known in the field of the art and it is well known that they receive the oil extracted from the wells, to treat the same in a first stage prior to its refining process. A battery is generally used in small plants constituted by a collector or “manifold”, such as it is known in the art, provided in the battery entrance to be connected to the plurality of wells available in the place, and to receive the oil which is simultaneously extracted from them. In turn, it is known that the oil comes accompanied by gas and water, among other components, for which a gas separator, a pair of heaters, a plurality of general production tanks (160 m3) and control tanks (40 m3), some pumps, flowmeters, liquid separators, etc. are provided. Thus, the oil, the water and the natural gas coming from the wells flow are separated in the mentioned tanks and separated by diverse methods, subsequently being prepared for the following treatments or purposes. 
         [0006]    In addition, the storage tanks are designed to store and handle great oil and gas volumes, being generally of big dimensions. The storage constitutes a valuable element in the exploitation of hydrocarbon services since it acts as a core zone between production and/or transportation to absorb the consumption variations. Known tanks comprise a cylindrical form with a flat bottom, vaulted top structure, being floating some times, so as to avoid flammable gas accumulation within them. The tanks may be or not be provided with a heating system. 
         [0007]    On the other hand, in case an extremely dangerous defect or drawback in the mentioned tanks occurs, there will be a containment pool surrounding each of them, in order for a rapid evacuation so as not to damage and impact the environment. 
         [0008]    However, the batteries&#39; infrastructure demands high economic investments. This occurs since the conditions in which both the oil and the gas have to be stored in such storage tanks are quite specific and, consequently, the materials used for their construction present very high costs. In turn, due to safety matters, such pools surrounding each of the tanks are built, leading to an additional cost. To this, the costs for the periodic controls carried out are added, as well as the facilities maintenance, more particularly the storage tanks, which generate high costs for the use of heavy machinery and time loss, which could be used to optimize production. So, the purchase, assembly, installation and maintenance of the storage tanks generate high costs which very few companies may bear. 
         [0009]    On the other hand, tanks which comprise big dimensions, store a great amount of oil and gas that may be dangerous in the event that they are not in optimal conditions, and due to various reasons, leaks or other types of drawbacks that occur endangering operators, the production zone and especially the environment. 
         [0010]    Considering the current state of the art available for manifold batteries, it would be advantageous to have a new manifold battery, constituted and constructed to reduce the impact on the environment, the accidents, dangers and consequential risks of the flammable, toxic and damaging substances concentration, as well as the operative times and the connected costs. 
         [0011]    Therefore, it is one of the purposes of the present invention to provide a new manifold battery which is constituted and constructed to reduce the impact on the environment, the accidents, dangers and consequential risks of the flammable, toxic and damaging substances concentration, as well as the operative times and the connected costs. 
         [0012]    Another purpose of the present invention is to provide a manifold battery which reduces the costs, as well as, the generation, accumulation and release of gases, thus achieving a greater operative security. 
         [0013]    Another purpose of the present invention is to provide a manifold battery which adjusts to the needs of individual circumstances, being able to adapt as a mobile battery to measure the wells, either in marginal, new or distant fields. 
         [0014]    Still another purpose of the present invention is to provide a manifold battery that reduces the environmental impact. 
       SUMMARY 
       [0015]    In keeping with one aspect of the present invention, a manifold battery for hydrocarbon fields includes an entrance manifold which connects to a plurality of separators, which are operatively interconnected through ducts and valve sets, with a disposition of gas storage devices and a set of circulating pumps. A purging chamber connects to the storage devices and separators. The manifold battery has three-way valves connected to at least a general line and at least a control line. The separators are connected to the general and control lines, and include at least two control separators and at least two general separators are connected among themselves, providing an auxiliary tank connected to those separators and to those circulating pumps through the respective ducts and valve sets, wherein one of the gas storage devices is a reserve gas vessel for instruments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    For a better understanding and clarity of the present invention purpose, the same has been illustrated in a unique drawing, in which the invention has been represented in one of the preferred performance forms, all at the example title, where: 
           [0017]      FIG. 1  shows a schematic diagram of the present manifold battery. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Referring to  FIG. 1 , a new manifold battery for hydrocarbon fields is constituted and constructed to significantly reduce adverse impact on the environment, avoid gas accumulation which may endanger the facility and operators, and particularly reduce the operative costs and times. 
         [0019]    The manifold battery for hydrocarbon fields of the present invention includes an entrance collector or “manifold”  1  constituted by a three-way valve disposition which present at least a general line  1 A and at least two control lines  1 B and  1 C, being interconnected to a plurality of separators by means of an entrance valve set  2 A,  2 A′ and  2 A″ respectively. All the production of a determined field derives to such three-way valve disposition, where the complete production flows through the general line  1 A, while the control lines  1 B and  1 C are used to evaluate the individual production of a determined well. 
         [0020]    The plurality of separators includes at least two general separators  3 A and at least two control separators  3 B. That is why the hydrocarbons coming from the manifold  1  through the general line  1 A pass through the entrance valves  2 A and enter the general separators  3 A, while the hydrocarbons flowing through the control lines  1 B and  1 C, pass through the valves  2 A′ and  2 A″ respectively, and enter the control separators  3 B. In the general  3 A and control  3 B separators, hydrocarbons are separated by decantation, remaining in the liquid phase in the bottom zone of them, while the gaseous phase is in the upper one. Once the general  3 A and control  3 B separators have accumulated a pre-established level, the opening of one of the control  2 B valves occurs for the case of separators  3 A, and of one of the control valves  2 B′ and  2 B″ for the case of  3 B separators, respectively, so as to send the fluid to a discharge line  4 , towards a circulating pump set  5 . In addition, the gas is evacuated from a set of exit valves  2 C in the case of general separators  3 A, while it is evacuated from control separators  3 B by a set of exit valves  2 C′ and  2 C″, towards a gas storage disposition device. 
         [0021]    Referring again to the circulation pumps  5 , the same comprise a first operation pump  5 A and a second auxiliary pump  5 B, where both circulating pumps are the type comprising a double effect piston, with a flow of at least 185 m3/h minimum at a maximum labor pressure of 75 kg/cm2, and a minimum suction pressure of at least 1 Kg/cm2. The circulating pump  5 A operates in a constant manner, evacuating the production, while, such circulation pump  5 B begins operating when pump  5 A is under preventive maintenance and/or under eventual fault. 
         [0022]    In regards to the gas storage devices, they include a gas separator  6  which allows the elimination of the liquid existing in the gas coming from the separators  3 A and  3 B, a burning ditch  6 A and a reserve gas vessel for instruments  6 B which feeds the facility instruments with gas. That is how gas evacuates from the separators  3 A and  3 B, passes primarily through a gas measuring bridge, and then resides in the gas separator  6  and/or in the burning ditch  6 A and/or in the reserve gas vessel  6 B. 
         [0023]    The excess gas is evacuated and directed to related motor compressor stations or treatment plants by means of a valve  6 C. In addition, the mentioned gas measuring bridge has a first pneumatic valve  6 D and a second pneumatic relief or venting valve  6 E. The first valve  6 D is connected to the general gas separator  6 , while said second valve  6 E is connected to the burning ditch  6 A. The latter is activated in case the pressure is higher than that established in the event of the gas pipeline break. 
         [0024]    It should be pointed out that the liquid that is separated from the gas within the gas separator  6 , is purged and discharged through a valve  6 F towards a purging chamber  7 , which receives all of the purges of all the process elements through the purging lines  4 A and which have an emergency pool and a level indicator. Generally, the gas captured in the batteries is for consumption, as heater fuel, explosion motors, instrument gas, while the excess gas is destined for sale. 
         [0025]    The manifold battery is provided with an auxiliary tank  8  connected to the separators  3 A and  3 B, and to the circulation pumps  5 A and  5 B, through the respective ducts and valve sets, where it has at least one entrance valve  8 A, a pneumatic control valve  8 B, at least an overflow pipe  11  and a pneumatic controller configured with a pressure lower than the separators&#39; working pressure. It is then that, in the case of fault in the facility, either by the separators or by the pumps, the hydrocarbon production enters the tank  8 , through the entrance valve  8 A which is activated by the pneumatic controller. When such production reaches a determined level within the tank  8 , it sends a signal to a remote terminal unit “RTU”, which controls the opening of the pneumatic valve  8 B and the closing of a pneumatic valve located between the pumps  5 A and  5 B. The remote terminal unit RTU is of the type that performs the collection of the information supplied by the sensors connected to the process, the command of final control elements and the communication with a control center. Thus, pump  5 B starts operating so that it evacuates the tank production  8 . On reaching a vacuum pre-established height level, it should close the pneumatic valve  8 B and stop pump  5 B. In the event that the tank  8  overflows, there is an overflowing pipe  11  provided with a pneumatic valve and a level sensor which opens and evacuates the production to the purging chamber  7  through the purging line  4 A, avoiding in this way leaks in the facility zones and the consequential environmental impact. 
         [0026]    On the other hand, each general separator  3 A has a level sensor  12  which acts when the interface level exceeds the point established activating the entrance pneumatic valve  2 A, closing and diverting the production to the other general separator  3 A. Moreover, it has a pressure sensor  13  which acts when the working pressure declines, activating the entrance pneumatic valve  2 A so that it closes and directs the production to the other general separator  3 A. In the event of fault in both general separators  3 A, either by level or by pressure, production is diverted to the tank  8  through a relief valve  10  that acts by pressure. In fact, each control separator  3 B also has a level sensor  14  which acts when the interface level exceeds the established point, activating a three way pneumatic valve which delivers the production through the individual line and through the general separators  3 A entrance. It also has a pressure sensor  15  which, when the separator working pressure  3 B is under the established point, activates the three way pneumatic valve closing the same, passing the production by individual line and by general separators entrance line. It may be pointed out that each of the separators  3 A and  3 B are provided with a level controller  16 , a sensor and pressure transmitter  17  and principally with a continuous level controller  18 , which prevents the pumps  5 A or  5 B from working in fault or being stopped due to fault of a minimum flow. In the event that all of the general separators  3 B and control separators  3 B start working in fault, control separators  3 B production is diverted through valves  2 A′ and  2 A″ to the entrance line of the general separators  3 A and afterwards, starting from them, diverting to tank  8  through relief valve  10 . 
         [0027]    It is thus that the hydrocarbons coming from the wells are primarily delivered to the battery through collector  1  which allows delivering them to different separators, having two control separators  3 B and two general separators  3 A, where the control separators  3 B allow determining the individual production of each well by mass sensor meters. In the general separators  3 A, the general production is passed and the liquid phase is separated from the gaseous phase by densities difference, where the gaseous phase is directed to the gas pipeline or gas separator  6  and the liquid phase is discharged to a suction pipe or discharge line  4  which otherwise goes directly to pumps  5 A or  5 B, which send the previously separated oil to the crude treatment plant. 
         [0028]    Thus, the manifold battery of the present invention reduces the impact to the environment, preventing gas accumulation which may endanger the facility or the operators, due to the fact that it prevents the use of the usual storage tanks in the traditional batteries, reduces the purchase, assembly and maintenance costs, and notoriously optimizes the operative times.