WO2016024210A2 - Anti-gas-lock check valve - Google Patents

Abstract

The invention relates to an anti-gas-lock check valve for subsurface pumps in mechanical pumping technologies (formed by a surface unit, a rod string, and a subsurface pump), which eliminates gas lock, reduces fluid pound and prevents sticking due to solids in the subsurface pumps. The anti-gas-lock check valve is formed by four main parts: a nut; a spring; a bell; and a body with production holes. During the downward movement of the travelling valve or in the event of the system stopping, the spring which is supported on the nut constantly exerts a downward force on the bell, forcing the bell to sit on the body, thereby closing the production holes. Consequently, the anti-gas-lock check valve prevents the pressure of the hydrostatic column inside a well from being exerted on the travelling valve of the subsurface pump during the downward movement of the system or in the event of the system stopping.

Description

 ANTI LOCK GAS CHECK VALVE

SUMMARY OF THE INVENTION

 The invention corresponds to a check valve against gas blocking for subsoil pumps in mechanical pumping technologies (consisting of a surface unit, a string of rods and a subsoil pump), which eliminates gas blocking, decreases the blow of fluid and prevents binding by solids in subsoil pumps.

The gas check check valve consists of four main parts: a nut, a spring, a bell and a body with production holes. During the downward movement of the traveling valve or before a system stop, the spring that rests on the nut constantly exerts a downward force on the bell, forcing the bell to settle on the body, closing the production holes. As a result, the gas check check valve prevents the pressure of the hydrostatic column, inside a well, from being exerted on the traveling valve of the subsoil pump during the downward movement of the system or before a system shutdown.

FIELD OF THE INVENTION

 The present invention corresponds to an anti-block gas check valve that prevents gas blockage, reduces fluid shock and protects solids (sands) to subsoil pumps that are used, in mechanical pumping technologies, for the production of hydrocarbons. .

The oil industry has multiple types of technologies, known as artificial lifting technologies, which are used for the production of hydrocarbons. One of these artificial lifting technologies is known as mechanical pumping. Mechanical pumping requires a subsoil pump for hydrocarbon production. However, these subsoil pumps are blocked by the presence of high percentages of gas in oil. Additionally, the fluid blow and the presence of sands generate damage to the subsoil pump components, decreasing the reliability and useful life of the system. The present invention has applicability in oil wells where mechanical pumping is used as artificial lifting technology.

BACKGROUND OF THE INVENTION

 Mechanical pumping is an artificial lifting technology widely used in the world to extract hydrocarbons from the underground to the surface. This technology consists of a system consisting of a surface unit, a string of rods and a subsoil pump. The subsoil pump is composed of a cylindrical sleeve and two check valves, a traveler and a stationary one. The cylindrical volume limited to the inner diameter of the jacket and the variable length between the traveling valve and the stationary valve is the chamber that is flooded with fluid coming from the well. When the surface unit is operated, it raises and lowers the string of rods that connects the surface unit with the traveling valve of the subsoil pump. This movement generates the displacement of the traveling valve into the subsoil pump. When the traveling valve rises, it closes as a result of the load exerted by the hydrostatic column that generates the fluid that is being produced. At the same time the stationary valve opens allowing fluid to enter the chamber. When the traveling valve lowers, it opens allowing the passage of the fluid contained in the chamber towards the surface. At the same time, the stationary valve is closed supporting the load exerted by the hydrostatic column that generates the fluid that is being produced. This cycle is repeated several times a day, producing hydrocarbons.

 Subsoil pumps lose efficiency as a result of the high presence of gas in the hydrocarbon. This loss of efficiency is known as gas blockage in the subsoil pump. This phenomenon occurs inside the subsoil pump chamber, when the gas separates from the oil being located between the oil and the traveling valve. Since the pressure exerted by the hydrostatic column of the production fluid, which is located on the traveling valve, is greater than the pressure of the gas that is below the traveling valve, the gas will be compressed during the downward movement until the Gas pressure exceeds the pressure of the hydrostatic column, opening the traveling valve and allowing the passage of fluid to the surface. As a result, the subsoil pump chamber is not filled to one hundred percent thus decreasing the pump's filling efficiency. Finally, after several cycles, the pump ends up presenting an accumulation of one hundred percent of gas in the chamber preventing the pumping of hydrocarbons towards the surface.

 Another problem that subsoil pumps have is the fluid blow. This phenomenon (fluid blow) occurs when the subsoil pump chamber is not completely filled by any fluid (gas, oil or water), usually due to the low fluid intake of the well. When the chamber is partially full and the traveling valve drops, it suddenly collides with the surface of the fluid inside the chamber, causing premature deterioration in the components of the artificial lift system, especially the rod string and the traveling valve.

Finally, a third problem faced by subsoil pumps in mechanical pumping is pump jamming due to the presence of sands. It is common that the fluid provided by a mechanical pumping well has a low sand content. Usually the sand normally travels to the surface with the rest of the fluid. However, when the mechanical pumping system is stopped for any reason, the sand present in the fluid decays to the subsoil pump increasing the likelihood of clogging. In cases where the subsoil pump gets stuck, the well is usually intervened in order to change it. This intervention generates production losses and increases in operation costs. DESCRIPTION OF THE INVENTION

 The present invention is a gas check check valve for subfloor pumps in mechanical pumping technologies. This technology is composed of a surface unit, a string of rods and a subsoil pump. The gas check valve is installed by threading the lower thread 9 into the upper stop of the subfloor pump, and it is traversed by the shaft that connects the rod string with the traveling valve of the subsoil pump.

The operation of the mechanical pumping systems is based on the opening and closing of the check valves (traveling and stationary) that contains the subsoil pump. Additionally, these pumps have a cylindrical sleeve that limits the diameter of the internal volume of the subsoil pump. Thus, the size of the chamber (the internal volume of the subfloor pump) depends on the length between the check valves of the subsoil pump and the internal diameter of the jacket. During the production of hydrocarbons, the chamber is expected to be completely flooded with liquid fluid in order to take advantage of the maximum possible volume of the subsoil pump.

 When the surface unit is operated, it raises and lowers the string of rods that connects the surface unit with the traveling valve of the subsoil pump. When the rod string rises, the traveling valve closes and rises, while the stationary valve opens allowing the passage of fluid from the reservoir into the subsoil pump chamber. Likewise, when the string of rods falls, the traveling valve opens and falls, while the stationary valve closes allowing the passage of the fluid, contained in the chamber, towards the surface. In this way, when the traveling valve is closed, it supports the load produced by the hydrostatic column on it. Similarly, when the stationary valve is closed, it supports the load produced by the hydrostatic column on it. It is precisely these loads that allow the check valves of the subsoil pump to be closed. Finally, the cycle is repeated several times a day thus allowing the production of hydrocarbons.

 The gas check valve is characterized by having a nut 1, an external pressure retaining gasket 2, an oring 3, an internal pressure retaining gasket 4, a spring 5, a bell 6, a body 7, which can be visualize in figure 1.

 When the traveling valve of the subsoil pump is in the upward path, it displaces the production fluid into the body 7 of the gas check valve. This increases the pressure inside the body 7, raising the bell 6 and compressing the spring 5, as shown in Figure 3. This is possible because the internal pressure retaining gasket 4 prevents the passage of fluid between the hole for shaft 10 of body 7 and the shaft that connects the rod string with the traveling valve of the subsoil pump. In this way the fluid is forced to pass through the production holes 8 of the body 7 in the direction of the surface. When the traveling valve of the subsoil pump is in the downward path, the bell 6 descends by the expansion of the spring 5 and sits on the body 7 closing the production holes 8, as shown in Figure 2. Of this shape, the pressure exerted by the hydrostatic column, during the downward movement of the traveling valve, is applied on the bell 6 and the external pressure retaining gasket 2 that is located inside the nut 1. This means that the traveling valve , from the subsoil pump, is isolated from the pressure exerted by the hydrostatic column during the downward movement. Finally, the oring 3 is installed as a safety measure to prevent the retaining gaskets from losing their sealing capacity due to possible fluid content between the nut 1 and the body 7.

The gas check check valve assembly is carried out by inserting the bell 6, and the spring 5 in the body 7. Subsequently, the nut 1 is threaded and fixed on the upper thread 1 1 of the body 7. In this way, the nut 1 provides support to the spring 5 so that it moves the bell 6 by seating it on the body 7, closing the production holes 8. As can be seen in figure 2. Gas blockage in the subsoil pumps occurs when the traveling valve withstands the pressure exerted by the hydrostatic column of the fluid, which is located above it, and that exceeds the pressure of the gas cushion of the fluid contained inside the chamber , just below the traveling valve. This prevents the traveling valve from opening during the downward movement in order to allow the fluid contained in the chamber to pass to the surface. With the increase in the number of opening and closing cycles of the subfloor pump check valves, the size of the gas mattress increases (up to 100% chamber volume) reaching the point where the traveling valve does not open, thus blocking the subsoil pump. However, if the system has the gas check check valve, the hydrostatic pressure of the fluid column, during the downward movement of the system, will be supported by the bell 6, the external pressure retaining gasket 2 and the oring 3 That is, the traveling valve is isolated from the pressure exerted by the hydrostatic column. This allows the pressure of the gas mattress to always be sufficient to open the traveling valve, allowing the fluid contained in the chamber to pass through the traveling valve and be confined to the volume formed by the bell 6, the body 7, the internal diameter of the subsoil pump sleeve and the subsoil pump travel valve. In other words, as long as the reservoir provides fluid, the traveling valve will have sufficient pressure to open.

 Another problem that subsoil pumps have is the fluid blow. This phenomenon (fluid blow) occurs when the subsoil pump chamber is not completely filled by any fluid (gas, oil or water), usually due to the low fluid intake of the well. When the chamber is partially full and the traveling valve drops, it suddenly collides with the surface of the fluid inside the chamber, causing premature deterioration in the components of the artificial lift system, especially the rod string and the traveling valve. However, if the system has the gas check check valve, the hydrostatic pressure of the fluid column, during the downward movement of the system, will be supported by the bell 6, the external pressure retaining gasket 2 and the oring 3 , thus isolating the traveling valve from the hydrostatic load of the fluid column. This allows the traveling valve, which is not supporting the hydrostatic column, to open gently when it comes into contact with the level of fluid contained in the subsoil pump chamber, reducing the fluid stroke.

Finally, a third problem faced by underground pumps in mechanical pumping is the clogging of the pump due to the presence of sands. Typically, clogging occurs when the surface unit is stopped allowing solids contained and distributed in the fluid column to rush into the subfloor pump and settle on the traveling valve. However, if the system has the gas check check valve and the surface unit stops, the spring 5 will expand by placing the bell 6 on the body 7, preventing the passage of sands into the subsoil pump. In other words, the solids will settle on the bell 6 and not on the traveling valve of the subsoil pump.

REIVINDICATORY CHAPTER

 Claims:

 1. Check valve anti gas block characterized by having a bell 6 that sits on a body 7 in order to prevent the pressure of the hydrostatic column of a well is exerted on the traveling valve of a subsoil pump.

 2. Gas check valve, characterized by having a body 7 with a lower thread 9 used to install said valve in the upper stop of a subsoil pump.

 3. Gas check check valve characterized by having an external pressure retaining gasket 2 that prevents the passage of fluid between the nut 1 and the shaft that connects the rods to the traveling valve of the subsoil pump.

 4. Gas check check valve characterized by having an internal pressure retaining gasket 4 that prevents the passage of fluid between the body 7 and the shaft that connects the rods to the traveling valve during the upward movement of the traveling valve of the pump of subsoil.

 5. Gas check block valve characterized by having a spring 5 which exerts a downward force on the bell 6 so that the gas block valve remains normally closed.

 6. Gas check valve, characterized by having a nut 1, a spring 5 and a bell 6, concentric to a body 7.

 7. Gas check valve, characterized by having a nut 1, a spring 5 and a bell 6, concentric to a body 7, where the nut 1 is screwed into the upper thread 1 1 of the body 7.

 8. Gas check valve, characterized by having a nut 1, a spring 5 and a bell 6, concentric to a body 7, where a bell 6 moves axially on the body 7.

9. Gas check valve, characterized by having a nut 1, a spring 5 and a bell 6, concentric to a body 7, where the nut 1 can be unscrewed from the upper thread 11 to allow the installation of the bell 6 and the spring 5.

REFERENCE LIST:

 one . Nut.

 2. External pressure retainer gasket

3. Oring.

 4. Packing internal pressure retainer.

5. Spring.

 6. Bell

 7. Body

 8. Production holes.

 9. Bottom thread.

 10. Shaft hole.

1 1. Upper thread.

DESCRIPTION OF THE FIGURES:

 Figure 1: Explosion view of the gas check check valve.

 Figure 2: Section view of the gas check check valve, normally closed position.

 Figure 3: Section view of the gas check check valve, open position.

Claims

1. Gas check check valve characterized in that it comprises a bell 6 that sits on a body 7 and prevents the pressure of the hydrostatic column of a well from being exerted on the traveling valve of a subsoil pump. 2. Gas check check valve characterized in that it comprises a body 7 with a lower thread 9 that houses said valve in the upper stop of a subfloor pump. 3. Gas check check valve characterized in that it comprises an external pressure retaining gasket 2 that prevents the passage of fluid between the nut 1 and the shaft that connects the rods to the traveling valve of the subsoil pump. 4. Gas check check valve characterized in that it comprises an internal pressure retaining gasket 4 that prevents the passage of fluid between the body 7 and the shaft that connects the rods to the traveling valve during the upward movement of the traveling valve of the pump of subsoil. 5. Gas check block valve characterized in that it comprises a spring 5 that exerts a downward force on the bell 6 so that the gas block valve remains normally closed. 6. Gas check valve, characterized in that it comprises a nut 1, a spring 5 and a bell 6, concentric to a body 7. 7. Gas check check valve characterized in that it comprises a nut 1, a spring 5 and a bell 6, concentric to a body 7, where the nut 1 is screwed into the upper thread 1 1 of the body 7. 8. Gas check valve, characterized in that it comprises a nut 1, a spring 5 and a bell 6, concentric to a body 7, where a bell 6 moves axially on the body 7. 9. Gas check check valve characterized in that it comprises a nut 1, a spring 5 and a bell 6, concentric to a body 7, where the nut 1 can be unscrewed from the upper thread 1 1 to allow the installation of the bell 6 and the spring 5.