EP4041983A1

EP4041983A1 - Arrangement for extracting oil and gas from oil and gas wells

Info

Publication number: EP4041983A1
Application number: EP20797372.8A
Authority: EP
Inventors: Juan Carlos Marie Arlandis
Original assignee: Hoerbiger Service Inc
Current assignee: Hoerbiger Service Inc
Priority date: 2019-10-10
Filing date: 2020-10-02
Publication date: 2022-08-17
Also published as: PE20220057A1; WO2021069318A1; AR116630A1

Abstract

An arrangement (1, fig.l) for oil and gas extraction in oil and gas wells which increases oil extraction by reducing the internal pressure of the well generated by the gas, the gas also being extracted and sent together with the oil for further treatment and commercial use.

Description

ARRANGEMENT FOR EXTRACTING OIL AND GAS FROM OIL AND GAS

WELLS

STATE OF THE ART OF THE INVENTION

Field of the invention

The present invention relates to an arrangement used in oilfield wells for the extraction of hydrocarbons, and more particularly it relates to an arrangement for the extraction of both liquid and gaseous hydrocarbons, avoiding gas leaks, increasing fluid extraction and reducing the internal gas pressure in the well.

Description of the prior art

In the oil industry, more particularly in the production of oil and gas, the so-called low-pressure or semi-depleted wells are known, which are wells that in the course of time and their exploitation contain an amount of oil and a pressure of gas that imposes the use of special equipment and techniques to be able to extract these products still remaining in the well. One of the solutions to the problem of extracting the remaining gas and oil is disclosed in US Patent Document 8,496,050, belonging to the same owner of the present invention. Said patent refers to an arrangement for the extraction of hydrocarbons comprising an extraction assembly consisting of a container, bucket or fluid collecting hose and an extraction pipe, and housed inside a well casing. The extraction pipe extends along the collecting hose, which has an open upper end, through which the upper section of the extraction pipe passes which end is attached to a draw wire of the aforementioned assembly. In turn, the hose has a closed lower end by means of a one-way check valve that allows fluid to enter the space between the hose and said pipe. The upper section that projects beyond the upper end of the collecting hose has a fluid discharge hole laterally formed. The operation of the device is based on the fact that the “hose/extraction pipe” assembly is lowered into the oil mass and once the oil has filled the container or hose the assembly is raised by the action of the draw wire until it reaches the end of its stroke. There, said discharge hole is positioned in a sealed chamber of the wellhead defined between a pair of sealing rings, so as to allow the discharge of the fluid by means of the suction of a pump that generates vacuum and, when internal pressure is available in the well, with the help of the gas pressure that exists in the interior defined by the jacket or casing.

US Patent 6,854,518 is also known which discloses a method that reduces the pressure of the upper section of a well, aiding in the production of gas and oil. The device is comprised of a production pipe housed within a casing. The method consists of reducing the pressure of the upper section of the well by means of a pump in order to reduce the pressure on the surface of the fluid. Pressure reduction at the bottom of said production pipe is generated; an increase in the pressure difference between the ground and the inside of the casing is caused. At the same time, the pressure is reduced through the production pipe that reduces the density of the fluid column it contains. This effect also reduces the pressure in the production pipe until it reaches a balance. It is clear that in the case of oil production wells where depths reach thousands of meters, suctioning fluid through a pipe from the surface requires excessive power to generate necessary pressure differences.

Patent US 6.464.012 discloses an oil extraction system that has a cylindrical container, suitable for being inserted into the casing. The container is attached to a wire to make it descend into the oil which enters through the bottom of the container that has a sphere that sits on a hole in said container, so as to allow the entry but not the exit of oil. The cylindrical container in its upper part has a hole on which a pressurized air supply line lays when the container moves up and is positioned against an air injector nozzle. The fluid that is in the container travels through a suction pipe by means of some holes made thereon in its lower part. The air supply line simultaneously supplies pressurized air which enters the container by pushing the oil through the suction pipe thereby emptying the container and supplying oil through a discharge port that the apparatus has on one of its sides. The supply of pressurized air is achieved through a tank containing this pressurized fluid which generates maintenance costs of high pressure values without taking into account the risk of explosion that can imply injecting air into a container with hydrocarbon.

US Patent 6,497,561 disclosing a fluid pumping apparatus for a well, comprising a tubular pump plunger for use with string of suction pipes reciprocally moving with said plunger. It also comprises a pumping container that includes a rod on one of the surfaces of the suction pipe string and a valve mounted at the bottom of the vessel container. The operation of this apparatus is based on a tubular member constructed to form a seat with the container, having a length that extends outside the container with a diameter smaller than that of the rod and also including a discharge valve mounted on the bottom of said tubular member. This tubular member is moved down into the container so that the fluid is pumped and pushed out of the container.

On the other hand, as mentioned above, crude oil is accompanied by water and gas in the field. However, under normal conditions the gas in the well can be a big problem for oil extraction. This may occur due to excessive gas pressure inside the well, more particularly in the annular space between the casing and the pipe. The presence of excessive gas pressure significantly decreases oil production. As a result of the foregoing, some provisions have been developed that allow gas to be extracted from the annular space of the well in order to reduce the pressure of the formation and allow and increase the production of crude oil. At present, beam compressors are used in mechanical pumping for the transfer of gas which are assembled and operated together with the AIB rod pumps, using a large piston and the extraction of gas depending on the number of strokes performed by the AIB.

Under the current state of the art available for the extraction of hydrocarbons, it would be very convenient to be able to reduce the gas pressure existing in oil wells not only to facilitate the extraction of the hydrocarbon, but also to extract and deliver the gas and oil to a network for refinement and subsequent treatments where oil and natural gas are used. In this way, the resources that are present in an oil field are better exploited, avoiding unnecessary and unproductive venting of gas into the atmosphere.

BRIEF DESCRIPTION OF THE INVENTION

It is therefore an object of the present invention to provide an arrangement for the extraction of hydrocarbons in an oilfield well that allows reducing the energy present in said well in the form of gas pressure in order to increase oil extraction.

It is also an object of the present invention, an arrangement for the extraction of hydrocarbons that uses the energy of the well in the form of gas pressure to perform the extraction of oil.

It is yet another object of the present invention to provide an arrangement for the extraction of hydrocarbons that allows the gas present in an oilfield well to be extracted and supplied to a main discharge line for future treatment.

It is still another object of the present invention to provide an arrangement for oil and gas extraction in oil wells, being of the type that has a wellhead and an extraction assembly that moves inside the well, defined within a well casing, said extraction assembly being formed by a fluid collecting container and an extraction pipe, which can be operated by suction or discharge pressure within the collecting container, wherein the extraction pipe extends inside said fluid collecting container, the extraction assembly being connected to a draw wire, for being raised and lowered within the well, said extraction pipe having an open bottom end inside the collecting container and an upper end having at least one discharge opening and said fluid collecting container having an open upper end and a lower end that can be closed or can include a one- way valve, said arrangement comprising at least one gas chamber defined in said wellhead between a lower seal and a middle seal; at least one oil chamber suitable for receiving the oil contained in the collecting container, the oil chamber being defined in said wellhead and between said middle seal and an upper seal; at least one oil pipeline connected to said oil chamber; and at least one gas suction/injection pump having a gas inlet line connected to the well and at least one gas outlet pipeline that branches into a first gas outlet line connected to said oil pipeline and a second gas outlet line connected to said gas chamber to push oil into the oil chamber and from there to the oil and gas pipeline.

BRIEF DESCRIPTION OF DRAWINGS

For greater clarity and understanding of the object of the present invention, it has been illustrated in several figures, in which the invention has been represented in one of the preferred embodiments, all by way of example, wherein:

Figure 1 shows a sectional view corresponding to a preferred embodiment of the arrangement of the present invention;

Figure 2 shows a sectional and enlarged view of a portion of the wellhead of the present invention;

Figure 3 shows a cut-away and sectional view in different sections of an extraction assembly according to the present invention, wherein the upper, intermediate and lower part thereof can be viewed;

Figure 4 shows a sectional and partial view of a second preferred embodiment of the invention, wherein it can be seen that the wellhead has a series of rubber seals to facilitate sealing, a spring to aid in unlocking the assembly, and a draw wire in accordance with the present invention; and Figure 5 shows a sectional and partial view of a coated draw wire according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures, it is seen that the invention consists of an arrangement 1 for the extraction of hydrocarbons that is incorporated into the surface of an oil well. Along the depth of said well, a casing 2 or jacketed pipe is housed, which is cemented around to obtain a fixed and rigid support position with respect to the ground. Said pipe reaches a depth such that it comes into contact with the hydrocarbons that it is desired to extract. Said hydrocarbons are present in a liquid state with solid particles and in a gaseous state at a certain pressure. All wells and especially those with low production need extraction systems to be able to extract the oil, which may be low cost systems, and it would be very convenient to have equipment that allows reducing the gas pressure to increase the extraction of fluid. These wells, that may be somewhat depleted or semi-empty require pumping devices and systems to be able to extract the remaining oil. The present invention not only manages to extract the fluid in question but also reduces the internal pressure of the gas present in the well to pump oil, and also manages to take advantage of the gas present so that it can be used later as natural gas or other derivatives thereof.

In a first preferred embodiment, the arrangement 1 of the present invention has a wellhead 3 arranged on the surface of said well, a spool (not shown) where the draw wire 5 is wound and a pulley 4 through which the draw wire passes 5 which is connected to the upper end of an extraction assembly 6 formed by a collecting container 7 and an extraction pipe 8 arranged within the container 7. Said assembly 6 is transferred vertically inside the well, defined by the casing 2, reaching a depth Z such that it comes into contact with the oil and submerges into it. The fluid collecting container 7 has an open upper end 9 and a closed lower end 10, which preferably has a one-way check valve 11 that allows the entry of the liquid into said fluid collecting container 7 and the extraction pipe 8 which is housed inside. This assembly is already sufficiently described in US Patent Document 8,496,050 of the same owner, cited above, whereby no further reference to the assembly shall be made.

The extraction pipe 8 has an open lower end 13 and an upper end 12 that crosses the open upper end 9 of the collecting container 7, said upper end 12 of the extraction pipe 8 being connected to the draw wire 5 which passes through the pulley 4. The upper end 12 of the extraction pipe 8 has a series of discharge holes 14 on its lateral surface, through which the discharge of liquid, that is to say of the oil collected in the container 7, is performed, as it will be explained later on. The extraction pipe 8 and the container 7 shall be joined together by any means, whether by radial joints, welding joints, etc. that may allow the collecting container 7 to have its upper end 9 open, in this way the extraction assembly is raised and lowered entirely.

The wellhead 3 includes, according to the invention, two sealed chambers, an oil chamber 15 defined between an upper seal 16 and a middle seal 17, and a gas chamber 18 defined between said middle seal 17 and a lower seal 19. The chamber 15 is hydraulically adapted to receive the liquid hydrocarbon fluid and is connected to an oil pipeline 20 which may or may not have a flow regulating valve 21 in its middle section. The valve 21 can operate in the form of opening and closing the oil passage.

According to a first embodiment of the invention, pipeline 20 is connected on one side to the oil chamber 15 and on the other side it branches into a pipeline 20a connected to an oil suction pump 25 and a pipeline 20b connected to a main discharge line 26 which continues into other stages of oil treatment which will not be illustrated due to lack of relevance in the operation of the present invention. The pump 25 in turn transfers fluid to the main discharge line 26 through an oil outlet line 36. It is noted that both pipeline 20b and the oil outlet line 36 have respective one-way valves 37. An electrovalve 39 may be arranged in the branch line that goes to the oil suction pump, that is line 21a, so as to isolate the pump 25 when it is not used to extract oil by suction, as will be described later in relation to a second embodiment of the invention. For its part, the gas chamber 18 is pneumatically adapted so that gas can enter it from a suction/injection pump 27 in order to improve the extraction of liquid oil. Therefore, the gas chamber 18 is connected to the suction/injection pump 27 which can be of the type disclosed in US Patent Application Publication 2018/0334894 of the same owner, or of another type that fulfills the function described herein. The suction/injection pump 27 takes the gas from the well through a main gas pipeline 22 and operationally recirculates it both to the gas chamber 18 helping with oil extraction, as well as the oil pipeline 20b allowing the reduction of pressure in the well. For this purpose, the suction/injection pump 27 has a gas outlet pipeline 28 which branches into a first gas outlet line 30 connected to said oil pipeline 20b and a second gas outlet line 38 connected to said gas chamber 18. It is noted that, the first and second gas outlet lines 30 and 38 have respective electrovalves 31 and 29 that allow gas to pass or stop.

In this way, the gas and oil are allowed to be transported together along the pipeline 26 and then separated and treated respectively. In turn, the reduction of the internal pressure of the well is allowed when the oil is not being extracted by the collector tube. By reducing the internal gas pressure in the well, but considering not to operate with negative pressures, the natural output or production of the oil from the formation is facilitated as mentioned above. The well pressure is sensed by a high-pressure sensor 23 and a low-pressure sensor 24 arranged in the main gas pipeline 22. These sensors 23 and 24 allow defining a minimum - maximum operating pressure range so that the pump extracts less or more gas according to said programmed range. The maintenance of the pressure from the formation shall guarantee the correct extraction of oil. The pump 27 can be regulated by a speed variator V1 which allows the speed of the pump to be modified depending on the amount of gas to be extracted or injected.

The novel and advantageous construction and operating features of the suction/injection pump 27 are sufficiently described in US Patent Application Publication 2018/0334894 and for such reasons we shall not go into descriptive details about it. However, the present invention is not limited to said gas suction/injection pump but other pumps, devices or related arrangements that allow gas pressure to be extracted and reduced can be used without any inconvenience.

The operation of this embodiment is based on being able to reduce the gas pressure present in the oil well and make the gas recirculate through the outlet pipelines both towards the gas chamber and the oil pipeline which in turn is connected to the main discharge line, allowing oil/gas extraction for further treatment and use. For this, there is a positioning sensor 33 that senses the position of a bushing 32 that is in operative contact with the upper end of the extraction assembly 6 when the latter is raised towards the wellhead 3. When the sensor 33 detects the position of the bushing 32, it sends a signal to a PLC 35 so that it activates the oil suction pump 25. When the pump 25 is extracting oil, the gas from the well is recirculated into the gas chamber 18 to help with the extraction of the collecting tube. When the extraction assembly 6 is lowered, the PLC 35 sends the cut-off signal to the pump 25 and the well gas is now injected into the main discharge line 26 through the oil pipeline 20b.

That is, in the first instance, the extraction assembly 6 drops to approximately 30 feet per minute and then accelerates to 280 feet per minute, reaching the place where the liquid is and sinking therein. At the moment in which the extraction assembly 6 touches the liquid, the existing torque varies, since a speed variator (not shown) connected to the spool detects said variation and sends the data to the PLC 35 to gradually slow down the lowering of the extraction assembly 6 to finally lower it 30 feet or the length of the collecting container 7 inside the mass of the fluid. Once the collector 7 is submerged 30 feet or the total length thereof, there is a waiting time below the level depending on the viscosity of the oil, thus allowing the mass of oil to enter into the collector 7 and waiting for it be loaded. This time is programmable. Once loaded, the loaded extraction assembly is raised and the upper end thereof pushes the rising bushing 32, it is positioned in front of the positioning sensor 33, which detects it, and sends the signal to the PLC 35 as mentioned above. The PLC sends the order to the spool motor to stop the wire from rising and simultaneously orders the oil pump 25 to start suctioning through the chamber 15 via the holes 14 of the extraction tube 8 and sending the oil to the pipeline 20.

Simultaneously with the lowering of the extraction assembly 6, the gas suction/injection pump 27 extracts the gas from the well through the main gas pipeline 22, passing through it and injecting it to the main discharge line 26 by means of the first gas outlet line 30, which has the open electrovalve 31 , and oil pipeline 20b. In this situation, the electrovalve 29 is closed preventing the circulation of gas into the gas chamber 18. When the extraction assembly is "up", that is, when the sensor 33 detects that the extraction assembly 6 is above by means of the position of the bushing 32, the signal is sent to the PLC so that it closes electrovalve 31 , opens electrovalve 29 and allows gas circulation to the gas chamber 18.

Thus, the suctioned gas is now conducted to the gas chamber 18 entering the collecting container 7, more particularly in the annular space between the collector 7 and the extraction tube 8 whereby the gas pressurized by the pump 27 helps the extraction and emptying of the collector 7. This extraction method allows the collector to be made of a greater length, much greater than the 10 meter suction capacity of any conventional liquid suction/injection pump. This is a great advantage over what is known, as it allows longer collectors with larger extraction volumes.

Indeed, as it is known, a surface pump could only suction a liquid up to a depth of 10 meters in the collector tube, that is to compensate for pressure of 1 bar. By the present invention, by injecting pressurized gas from well into the annular space between the collector tube or container 7 and the extraction tube 8, by means of the compressor or pump 27, it is possible to further suction 10 meters of liquid for each Bar or Kilos of gas pressure injected into the collecting container. For example, under normal conditions the pump suctions liquid up to 10 meters but if, according to the invention, 1 kilo or 14 PSI of gas pressure is injected, the pump can suction 20 meters of liquid, if 2 kilos or 28 psi are injected, it will suction 30 meters and so on. This reduces extraction times significantly and increases the equipment's extraction capacity.

Once the collector 7 has been emptied, the extraction assembly is lowered and the cycle begins again. While lowering, the gas pump continues to suction gas but now the PLC closes electrovalve 29 and opens electrovalve 31 so that the suctioned gas goes to the oil pipeline 20b and then to the main discharge line 26. This suction lowers the pressure in the well above the oil level, which promotes a greater supply of productive formation, that is to say more oil “comes out” than under normal pressure conditions. That pressure cannot be negative, that is, it must not generate a vacuum as mentioned above since this is counterproductive to the formation. This is already sufficiently described in US Patent Application 2018/0334894 of the same owner and for such reasons we will no go into further descriptive details.

Due to the above and to prevent the pressure from being negative, the main pipeline 22 has sensors 23 and 24 to provide a margin for the pump and thus "cut and start" within a preset pressure range which may be 0, or near zero but it is not advisable that it be negative. It is highlighted that, although two sensors have been described, it is clear that only one can be used to operate in the range described between a maximum and minimum pressure.

In brief, at the beginning of the tasks, the spool lowers the assembly 6 through the interior of the well until it reaches the depth Z corresponding to the level of the oil inside the casing 2, allowing it to submerge in the oil so that this enters the container 7. The fluid enters through the lower end 10, through the valve 11 , of the container 7, which can also be done through the open upper end 9 of said container 7, filling the interior of the extraction assembly 6. In this condition the assembly 6 is high and the weight of the fluid stored in the container 7 pushes the one-way check valve 11, closing the fluid passage and retaining it in the container. Said one-way check valve 11 can be comprised of a sphere that lays on a hole that has the collecting container 7 at its bottom, closing the flow passage when it has a certain weight of fluid on it. As mentioned above, during this operation the suction/injection pump 27 is suctioning gas, recirculating it towards the main discharge line and thus lowering the internal pressure, if required by the well.

The extraction assembly 6 is raised by means of the operation of the spool, not illustrated as it is known, which pulls the draw wire 5 connected to the upper end of the extraction pipe 8. The assembly 6 rises to a certain height at which it abuts against the bushing 32 to raise together until it is detected in one position by sensor 33 that sends the signal to PLC 35 so that it "stops" both the rise and the suction of gas towards the main discharge line 26. In said position, the upper end 12 of the extraction pipe 8 is positioned in the chamber 15 and the upper end 9 of the collecting container 7 is positioned in the chamber 18. In that position, the upper end 12 of the pipe 8 closes against the upper seal 16 and the holes 14 remain open towards the chamber 15, while the middle seal 17 closes the passage between the oil chamber 15 and the gas chamber 18 when closing on the outer surface of the extraction pipe 8. At that time, the electrovalve 29 is opened and the electrovalve 31 is closed, allowing the gas extracted from the well to recirculate towards the gas chamber 18 and to exert pressure on the column of liquid existing in the collector 7 so that it flows into the extraction pipe 8 thus helping with oil extraction. Once the collector 7 has been emptied, the extraction assembly 6 is lowered again repeating the described cycle.

In this way, the extraction of both gas and oil is allowed, which are transported through the main discharge line 26 for subsequent treatments. It is emphasized that, the extraction assembly may or may not be provided with at least one counterweight 34 in its lower part so as to allow submersion of the assembly in the oil. Counterweight 34 is well known in the field of the art and for such reasons we will not go into descriptive details about it. According to a second embodiment of the invention, the oil and gas extraction arrangement operates only with the suction/injection pump 27 of Figure 1, while the oil pump 25 is separated or isolated from the extraction arrangement or directly no being part of the extraction arrangement in which case the pump 25 and its pipelines 20a and 36 are eliminated, while pipelines 20, 20b and 26 remain in the extraction arrangement. Alternatively, the pump 25 can remain as a backup pump in which case line 20a is provided with the electrovalve 39, which shall be closed to isolate the pump 25 when it is not used to extract oil by suction, and the pump 27 is only used to extract the oil by impulse.

According to this second embodiment, the pipeline 20 is connected on one side to the oil chamber 15 and on the other side to the main discharge line 26. On the other hand, gas enters 18 through the gas chamber 18 from the suction/injection pump 27 that pushes the oil into the collector 7 so that it goes up the pipe 8 for the extraction towards line 26 as already explained in the first embodiment. The arrangement, connections, sensors and pipelines, inlet and outlet of the pump 27 remain the same in the first embodiment, so a new description of this shall not be made.

The operation of this embodiment is based on the operation of the pump 27 without pump 25. Therefore, electrovalve 39 must be closed in the event that the pump 25 is mounted on the extraction facility. If the extraction facility does not have pump 25, line 20a and valve 39 shall not exist. When the positioning sensor 33 detects the position of the bushing 32, it sends a signal to the PLC 35 so that it stops the rotation of the spool and, therefore, the rise of the cable, and activates the suction/injection pump 27 by recirculating the gas from the well to the gas chamber 18 to push the fluid that is in the container 7 and make it rise through the pipe 8. When the extraction assembly 6 is lowered, the PLC 35 sends the signal to close the valve 29 injecting gas into the pipe and to open the valve 31 to send the gas from the well to the main discharge line 26. The extraction assembly 6 descends into the well and collects fluid in the same manner as it does in the first embodiment of the invention. Once the fluid collecting container 7 is loaded, the extraction assembly is raised and when it reaches the wellhead, the upper end thereof pushes the rising bushing 32, it is positioned in front of the positioning sensor 33, which detects it, and sends the signal to PLC 35 as mentioned above. The PLC sends the order to the spool motor to stop the wire rising and simultaneously open valve 29 and close valve 31 so that it begins to push fluid into the pipe 8 which shall exit through the chamber 15 via the holes 14 of the suction pipe 8 and send the oil to the pipeline 26.

As already explained, simultaneously with the lowering of the extraction assembly 6, the gas suction/injection pump 27 extracts gas from the well through the main gas pipeline 22, passing through it and recirculating it towards the main discharge line 26 via the first gas outlet line 30, which has the electrovalve 31 open. In this situation, the electrovalve 29 is closed preventing the circulation of gas into the gas chamber 18. When the extraction assembly is "up", that is, when the sensor 33 detects that the extraction assembly 6 is above by means of the position of the bushing 32, the signal is sent to the PLC so that it closes electrovalve 31 , opens electrovalve 29 and allows gas circulation to the gas chamber 18.

Unlike the first described embodiment, which uses the pump 25 for the extraction of fluid, in the second embodiment the gas suctioned by the pump 27 is now taken to the gas chamber 18 entering the collecting container 7 and the suction pipe 8 whereby the gas pressurized by the pump 27 alone performs the extraction and emptying of the collector 7.

The advantage of this alternative form of extraction is that by pushing the fluid with the pressure of the gas, it allows to place the collector tube 7 of greater length since every 10 meters of the pipe it is required 1 kg/cm² to empty it, which is limited if It was performed by suction. Once the collector 7 has been emptied, the extraction assembly is lowered and the cycle begins again. While lowering, the gas pump continues to suction gas but now the PLC closes electrovalve 29 and opens electrovalve 31 so that the suctioned gas goes to the main discharge line 26.

Referring to Figure 2, in a third preferred embodiment, the wellhead 3 of the present invention may be comprised of a pair of rubber seals 101 which allow sealing against the draw wire 5 and thus avoiding gas venting to the surface. The draw wire 5 allows lifting and lowering of the extraction assembly 6 as mentioned above. The draw wire 5 is made of steel and is coated with a liner or coating layer of HYTREL or PIPELON 102 from the company DuPont. The HYTREL or PIPELON layer 102 has a percentage of additive that makes it antistatic and, in turn, provides the necessary seal to prevent gas venting.

Likewise, said wellhead 3 is provided with a spring 103 in a receiving chamber 104 in which the upper end 12 of the extraction assembly 6 is positioned. Said spring 103 is mounted on a lower seat 105 and receives the upper end 12 of the extraction assembly 6 to dampen its upward movement. When the upper end 12 rises up against the spring 103, the latter is mounted on said upper end and both parts together continue to rise so as to position themselves guided within an upper guide seat 106. The upper guide seat 106 in turn acts as a stop to the upstroke of the extraction assembly 6 while the spring 103 allows the upward movement to be damped. Likewise, when the downstroke of the extraction assembly is started, the spring 103 helps with the quick release of the upper end 12. Although, a portion of the wellhead 3 has been illustrated, it is understood that it also has both oil 15 and gas 18 chambers, as well as all the advantages and constructive characteristics mentioned in the first embodiment.

- As an example, but not limiting the invention, a well has randomly been selected in which the following problems have been detected:

- High back pressure in flow line.

- Reduction of the reservoir supply due to back pressure generated in the system. - Casing pressure increased from 10 to 40 psi.

- Increase of gas flow in the well due to low submergence.

Through the use of the hydrocarbon extraction arrangement of the present invention, it has been possible to lower the back pressure at the wellhead and improve the reservoir supply. Likewise:

- Wellhead pressure was reduced from 40 psi to 5 psi, achieving a production increase of 03 bopd to 08 bopd. - The level of submersion increased from 26 ft to 173 ft, thereby improving operating conditions by handling lower gas flow.

- Well currently producing 11 bopd with a constant submersion column of 173 ft. In this way, the arrangement for the extraction of hydrocarbons of the present invention is constituted and constructed, which allows the extraction of oil by reducing the internal pressure of the well generated by the gas, the gas also being extracted and delivered together with oil for further treatment and commercial use.

Claims

1. An arrangement for oil and gas extraction in oil and gas wells, the arrangement having a wellhead and an extraction assembly that moves inside a well defined within a well casing, said extraction assembly comprising a fluid collecting container and an extraction pipe extending inside said fluid collecting container, with an annular space being formed between the fluid collecting container and the extraction pipe, the extraction assembly being connected to a draw wire to raise and lower the extraction assembly inside the well, said extraction pipe having an open bottom end inside the collecting container and an upper end having at least one discharge opening, and said fluid collecting container having an open upper end and a lower end that may be closed, wherein the arrangement comprises: at least one gas chamber defined in said wellhead between a lower seal and a middle seal; at least one oil chamber suitable for receiving oil collected and contained in the collecting container, the oil chamber being defined in said wellhead, between said middle seal and an upper seal; at least one oil pipeline connected to said oil chamber; and at least one gas suction/injection pump having a gas inlet line connected though a main gas pipeline to the well and at least one gas outlet line that branches into a first gas outlet line connected to said oil pipeline and a second gas outlet line connected to said gas chamber.

2. An arrangement according to claim 1, wherein said oil pipeline bifurcates to connect to an oil suction pump and to a main discharge line, and said oil suction pump has a oil outlet line connected to the main discharge line, an electrovalve being arranged on the bifurcation that connects to the oil suction pump.

3. An arrangement according to claim 1, wherein said first and second gas outlet lines have respective electrovalves and said gas chamber is connected to said annular space existing between the collecting container and the extraction pipe when the collecting container is in an upper oil extraction position.

4. An arrangement according to claim 2, wherein said first gas outlet line is connected to the oil pipeline which in turn is connected to the main discharge line.

5. An arrangement according to claim 1, wherein said main gas pipeline has a high-pressure sensor and a low-pressure sensor.

6. An arrangement according to claim 1 , wherein said at least one oil pipeline has at least one one-way valve.

7. An arrangement according to claim 1 , wherein said wellhead has a bushing operatively receiving the upper end of the extraction assembly.

8. An arrangement according to claim 7, wherein a bushing position sensor is provided that is connected to a PLC.

9. An arrangement according to any of the preceding claims, wherein said PLC is operatively connected to at least one of a spool motor, the oil suction pump, the gas suction/injection pump and the electrovalves.

10. An arrangement according to claim 1, wherein said draw wire is made of steel coated with a coating layer in a manner that the draw wire is sealed against rubber seals arranged in said wellhead and is in contact and operatively held against a spring.