MXPA06009261A - Method and actuator device - Google Patents

Abstract

A method and a device in connection with an actuator (7) intended for use in connection with a fluid flow or fluid reservoir, in particular an actuator that is designed to be used in connection with a drainage pipe (8) for the production of oil and/or gas in an oil and/or gas reservoir. An osmotic cell (9) is used to operate the actuator (10). The osmotic cell is placed in the fluid flow, whereby the necessary force and motion for the actuator (10) to adjust or drive a fluid control device or valve are achieved by utilising the osmotic pressure difference between the solution in the cell (9) and the external fluid flow/reservoir in relation to the cell.

Description

METHOD AND ACTUATOR DEVICE Field of the Invention The present invention relates to a method and device connected to an actuator, in particular a pressurized actuator that is designed to be used in connection with drainage pipes for the production of oil and / or gas in a reservoir. of oil and / or gas. Background of the Invention Drainage pipes of the above type are normally divided into a number of sections with one or more restriction devices of the admission that regulate the admission to the drain pipe. The specifications of US Pat. Nos. 4,821,801, 4,858,691 and 4,577,691 and the patent specification GB No. 2169018 describes prior art devices for extracting gas or oil in long horizontal and vertical wells. These prior art devices comprise a perforated drain pipe with, for example, a filter for controlling the sand around the pipe.

A major disadvantage of the devices of the prior art in relation to the production of gas or oil in highly permeable geological formations is that the pressure in the supply pipe increases exponentially in the upstream direction as a consequence of the friction ref.174805. flow in the pipeline. When the pressure difference between the reservoir and the drainage pipe is reduced upstream as a consequence of this, the amount of admission of the oil and / or gas from the reservoir to the drainage pipe will also be reduced accordingly. The total production of gas and / or oil will therefore be low with such a solution. For thin oil zones and high permeability in the geological formation, there is a risk of conicity, ie the admission of undesirable water or gas into the downstream drainage pipe, where the velocity of oil flow from the deposit to the pipeline is the biggest one. To avoid such conicity, production must therefore be reduced further. A somewhat higher production than with the previous prior art solutions is achieved using the Stinger method, which is described in the Norwegian patent application? O. 902544. This consists of two drainage tubes, of which the external tube is perforated, and an internal tube (Stinger) without perforation, which extends towards the external tube to a desired position. The pressure profile and therefore the productivity of the Stinger method is somewhat better than for the other methods of the prior art. In thin oil zones with high permeability, however, unwanted water or gas conicity can also occur with this method, with reduced productivity as a result. World Oil, vol. 212, N. 11 (11/91), pages 23-78, describes a method of dividing a drainage pipe into sections with one or more restriction devices of the intake in the form of displaceable sleeves or throttling devices. However, this publication is mainly related to the control of admission to restrict admission from the upstream areas in the pipeline to prevent tapering of water and gas. WO-A-9208875 shows a horizontal production pipe comprising a number of production zones, each of which is connected to the mixing chambers which have a larger internal diameter than the production zones. The production areas comprise an external perforated pipe, which can be considered as a filter. However, the sequence of sections that have different diameters is unfortunate because it creates turbulence of flow through the pipe and prevents the use of equipment that is normally introduced by means of tractors for the bottom of the drilling or "pipeline" systems. rolled up". The technology for drilling horizontal wells has been known since 1920, but many still consider it a pioneering technology. In the last twenty years, development work has been carried out continuously to drill horizontal wells in an effective, safe way. The current state of technology is that drilling safety is high, and that costs are approximately 50% higher than for vertical wells, but horizontal wells produce three to four times the amount, depending on the characteristics of the well. Deposit . It has been shown that horizontal wells are a financial precondition for exploration, for example, oil in geological formations where the oil zone is thin, permeability is high and the undesirable conicity of water or gas frequently occurs. It is expected that horizontal wells will be even more relevant in the pipeline for the exploitation of oil or gas fields, small and, in financial terms, marginal. EP Patent No. 0 588 421 of the applicant itself describes a method for improving the profile of the pressure in the drainage pipe beyond what is known from the previous solutions by the introduction of restrictions restricting the pressure difference between the reservoir and the annulus outside the drainage pipe and consequently the balance of the pressure profile along the well immediately outside the drainage pipe. This is done by the admission restriction devices for each pipe section that are arranged so that their inlets are connected to an annulus between the geological formation and the drain pipe or to an annulus between a filter and the drain pipe and the outlet is connected to the flow compartment of the drain pipe. This solution comprises admission restriction devices with a fixed setting (fixed through-flow), which is a disadvantage. When well drilling technology was developed, the requirements for reservoir drainage technology also increased. The drainage technology of the current prior art does not have satisfactory solutions for controlled drainage from the deposit, which is always adapted to the admission of existing water from the deposit. Brief Description of the Invention The present invention represents a solution that provides such control, in which the admission for each section or area of the drainage pipe is automatically adjusted in relation to the amount of water that is flowing, maintaining the production of water at a minimum level. The method according to the present invention is characterized by, for the operation of the actuator, an osmotic cell, placed in the fluid flow, is used, whereby the force and movement necessary for the actuator to activate or adjust a valve or Admission control device are achieved using the difference of the osmotic pressure between the solution in the cell and the external fluid flow or the fluid reservoir in relation to the cell, as specified in appended claim 1. The independent claim associated with the device in relation to the actuator according to the present invention is further characterized by the actuator comprising an osmotic cell which is designed to be placed in the fluid flow, whereby the force and movement necessary for the actuator to activate or Adjusting a valve or admission control device are achieved using the difference of the osmotic pressure between the solution in the cell and the external fluid flow or the fluid reservoir with respect to the cell, as specified in appended claim 4. The dependent claims 2-3 and 5-9 indicate the advantageous features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in the following with further detail with reference to the appended figures, wherein: Figure 1 shows a schematic diagram of a membrane cell separating the two solutions and indicating the principle of the present invention.

Figure 2 shows a schematic diagram of a solution in which an actuator according to the present invention is used in a manner related to an intake restriction device or valve device in a drainage pipe for the extraction of oil and gas from the formations (a well) under the surface of the earth. Detailed Description of the Invention The present invention is based on the principle of using the difference of the osmotic pressure in the cell as the "pulse mechanism" or drive unit for an actuator. More precisely, the present invention is based on an osmotic cell that is used to operate the actuator. The osmotic cell is placed in the flow of the fluid, whereby the force and movement necessary for the actuator to activate or adjust, for example, a valve or admission control device, are achieved by the use of the osmotic pressure difference between the solution in the cell and the external fluid flow related to the cell. The fundamental method of operation of a cell according to the present invention can be illustrated as shown in figure 1 with a "closed" container 1 with two chambers 2, 4, in which one of the walls consists of a semi-membrane -permeable 3. The semi-permeable membrane 3 is permeable in relation to the solution, conveniently a water / salt solution, located in a chamber 2, but impermeable in relation to the dissolved medium, conveniently a salty medium. The water can thus move freely from the chamber 2 in the cell, once the membrane 3 has been passed to the water or an aqueous solution with a lower salt level in the other chamber 4. The water transport once it is has passed the membrane will cause a difference in pressure through the membrane. This is called the difference of osmotic pressure. The thick line in each of the chambers 5, 6 indicates the liquid levels in them. The osmotic pressure can be defined by means of classical thermodynamic equations in which an equilibrium is assumed across the membrane. The chemical potential of the solution will be the same on each side of the membrane when equilibrium is achieved, assuming isothermal conditions. With reference to figure 1, the chemical potential for the two phases in chambers 2 and 4 respectively will be given by: μd ,? = μ ° i,! + RT nai,! + v ± Pi (1) μ?., 2 = μ ° i, 2 + RTLnai, 2 +? P2 (1) where R is the universal constant of gases, T is temperature, V is the molar volume, P is the pressure is already the concentration of the solution. The molecules of the solution in the diluted phase have a higher chemical potential (more negative) than the molecules in the concentrated phase. This chemical imbalance causes a flow of molecules from the solution (water) from the less concentrated phase to the more concentrated phase. This flow continues until the osmotic equilibrium has been achieved and all the parameters in the expression for the chemical potential (equations 1 and 2 above) can be changed, for example the temperature, concentration and pressure. In other words, with reference to a salt / water solution, the water will move quickly to the more concentrated side to dilute the solution, while the salt will quickly try to move in another direction to try to increase the concentration. The transport of the salt will be carried out only if the membrane is not a perfectly semi-permeable membrane. By the combination of equations (1), (2) and (3), we have the following: RT (ln ai / 2 - lnaifl) = (Pi - P2) Vi =? P V¿ (4) The difference of the hydrodynamic pressure (Pi - P2) is called the difference of the osmotic pressure? p = p? - p2. If only a pure solution (water) is used in phase 2 (a?, 2 = 1 in chamber 4), equation (4), the pressure, becomes: p = - RT lna., 1 Vi As was established previously, Figure 2 shows a schematic diagram of a solution in which an actuator 10 according to the present invention is used in relation to a drain pipe 8 for the extraction of oil and gas from the formations (a well, not shown) under the surface of the earth. In the example shown here, the actuator is an integrated part of a valve or restriction device of the intake in the drain pipe. As shown in Figure 2, the actuator 10 consists of a housing 7 with an internal osmosis cell 9. The housing 7 with the cell 9 is located inside and fastened to the right pipe 8 opposite a hole 11. The oil, The gas and / or the water are designed to flow from the formation to the pipe 8 through the hole 11, once the cell 9 has been passed and through the openings or holes 12 in the housing, once it has been past a closure plate or the like 13 and towards the pipe 8. The cell 9 consists, in turn, of a hollow body or chamber of which the end face turned towards the tubular wall of the pipe 8 consists of a semi-permeable membrane 14, while the wall on the opposite side consists of a waterproof, flexible membrane 15. The closure plate 13, which is located opposite the holes 12, is fastened to the flexible membrane 15. Inside the cavity, the cell 9 is provided with a solution of salt / water, and salt blocks 16 are provided to keep the solution saturated all the time. The actuator with cell 9 works as follows. When only the flow of oil and / or gas passes to the membrane 14, the flexible membrane 15 with the closure plate 13 will be compressed and the fluid will be able to pass between the holes 12 and the closure plate (open). When the water begins to flow once the membrane is passed with the oil / gas, the water will gradually pass through the membrane 14 into the chamber, causing the volume of the solution inside the chamber to increase and the membrane flexible 15 with the plate 13 moving outwards and gradually closing the flow through the holes 12. If there is a puddle of water, for example in the case of the conicity of the water, as mentioned in the introduction, the flexible membrane With the plate will move completely out and completely stop the flow through. In this way, the actuator according to the present invention can be used to regulate the admission of oil and / or gas partially or totally, depending on the amount of the accompanying water. Note that the present invention as defined in the appended claims is not limited to the example shown above. For example, a cylinder / piston device in which the piston moves the closure plate can be used in place of a flexible membrane. Or a solution for a needle / nozzle in which the needle is moved by a flexible membrane or piston can be used in place of a solution 12, 13 for an orifice / plate. The present invention is not limited to its use in relation to the extraction of oil and / or gas as described above. It can be used in any situation in which there are liquids or solutions where the principle of osmosis can be used. Otherwise, the present invention can be used as an advantage in relation to an admission restriction device as shown in the EO patent No. 0 588 421 of the applicant himself. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (8)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. 1. A method that is related to an actuator that is connected to a fluid flow or a fluid reservoir, in particular an actuator that is designed to be used in connection with a drainage pipeline for the production of oil and / or gas in an oil and / or gas field, characterized in that an osmotic cell is used to operate the actuator and is placed in the fluid flow, whereby the force and movement necessary for the actuator to activate or adjust a valve or device Admission control, are achieved by using the osmotic pressure difference between the solution in the cell and the reservoir / external fluid flow related to the cell.
2. 2. A method according to claim 1, characterized in that a salt / water solution is used as the solution in the cell.
3. 3. A method according to claims 1 and 2, characterized in that the actuator is used to operate a valve that regulates the admission of fluid through the intake openings in the drain pipe.
4. 4. An actuator device related to a fluid flow, in particular an actuator that is designed to be used in connection with a drainage pipe for the production of oil and / or gas in an oil and / or gas field, characterized in that the actuator comprises an osmotic cell which is designed to be placed in the flow of the fluid, whereby the force and movement necessary for the actuator to activate or adjust a valve or admission control device are achieved by the use of the difference of the osmotic pressure between the solution in the cell and the reservoir / external fluid flow related to the cell.
5. 5. A device according to claim 4, characterized in that the solution in the cell is a water / salt solution.
6. 6. A device according to claims 4 and 5, characterized in that the actuator is an integrated part of a valve or admission control device, whereby the cell is placed in a housing that is fastened to the internal wall of the valve. the drainage pipe connected to a hole in the wall of the pipe, whereby the fluid from the outward formation of the drain pipe is designed to flow through the hole (s), or through the housing and out through the openings therein, and a valve plate is designed to close or open the openings by means of the cell.
7. A device according to claim 6, characterized in that the valve plate is designed to be moved by means of a flexible membrane that makes up all or part of a wall of the cell.
8. 8. A device according to claim 6, characterized in that the valve plate is designed to be moved by a piston and the cell consists of a piston / cylinder arrangement in which a wall is designed as a movable piston in a piston. the cell housing. . A device according to previous claims 5-8, characterized in that salt blocks are provided inside the cell.