MXPA06007572A - Inflate control system for inflatable straddle stimulation tool - Google Patents

Abstract

A method and apparatus for controlling inflation and deflation of spaced inflatable packer elements of a straddle stimulation tool within a well casing of a well. A straddle stimulation tool is positioned by tubing at a desired location within the well casing. Fluid is pumped through the tubing and tool at a rate inflating the spaced inflatable packer elements within the well casing and establishing an annulus interval. The inflation control retains pressure within the inflated packer elements and permits the flow of stimulation fluid into the annulus interval for stimulation of the formation. After completion of well stimulation, the packer element pressure control is moved to a packer equalizing position by tension applied via the tubing to equalize packer pressure with casing annulus pressure, deflating the packer elements and permitting conveyance of the straddle stimulation tool within the well casing by the tubing string.

Description

INFLATING CONTROL SYSTEM, FOR AN ALTERNATE STIMULATION INFLATABLE TOOL BACKGROUND OF THE INVENTION Field of Invention: The present invention relates, generally, to packing tools with alternating ends, for alternating and isolating a casing range within which well treatment operations, such as the fracture of the production formation, are typically driven. More particularly, the present invention concerns the packing tool with alternating ends having inflated gaskets spaced from each other, to be sealed within a well casing, to define a sealed casing range and having an inflated control system which is controllable from the surface for the inflation of the elements of the packaging, for the storage and release of the inflation pressure stored in the package and for the control of the different modes of operation of the tool. The present invention also concerns a method, controllable from the surface, for the responsive inflation of the flow of the packing elements, for storing the inflation pressure within the packing elements, and for the selectively activated deflation of the packing elements. packing elements, to allow the use of a tool with alternating ends for the treatment of the intervals and to facilitate the movement of the packing tool with alternating ends, in different locations of the sub-surface and to facilitate the removal and extraction of the tool.

Description of the Art Preview: The term "alternating stimulation tools" as used herein, is intended to refer to any well service tool having spaced packing elements and which is used within a well, to isolate a particular zone or intevalo of The sub-surface, which typically has a jacket with perforations, the tool has a fluid supply for the various well treatment operations, such as acid injection, fracturing the formation, with the injection of a propellant agent towards the inside of the fractures of the formation that develop during the fracture process, and any other type of service operation where the fluid is injected into a range of the jacket for any treatment character of the surrounding formation the jacketing interval. The term "element" as used herein is intended to refer to a packing element, particularly an inflatable packing element, which is mounted on a well stimulation tool. Two or more packing elements are held in spaced relationship by means of a well stimulation tool, and when sealed within the well jacket, they define a range of the casing within which the well stimulation fluid is pumped for treatment of a formation zone that is in communication with the jacket of the well, by means of perforations located in the jacket.

The production of a gas or oil well can often be improved by means of treatment by injection of treatment or stimulation fluids, directly into the formation (s), through the perforations located in the Jacketed Moreover, the benefits are often greater if, for a given well, multiple zones are isolated and treated separately. In order to isolate a particular area, it must be effectively sealed from the rest of the well. This can be achieved through the use of elastomeric packing elements that are sealed with the casing of the well and block the ring located between the casing of the well and the tool located at the bottom of the well.; The packing elements, when they are placed in position of altemability, are located above and below the perforations of the jacket, and in this way alternate a given area located within the jacket. The treatment fluid is then injected through a transport conduit and a fluid delivery mechanism, such as a spiral tubing, and the fluid is forced out of the tool, between the packing elements, and into the interior of the formation through the perforations of the jacket.

In many wells, the stimulation tool must pass through a small diameter production tube, before reaching the larger diameter casing. This requires the use of inflatable sealing elements that, when deflated and thus contracted to a small dimension, will pass through the production pipe and other restrictions and, after inflation, will have sufficient volume and mechanical integrity to fill and sealing the large ring that typically exists between the tool and the jacket wall. Additionally, the tool must be able to direct the fluid that is pumped from the surface, through different trajectories, in the various stages of the operation of the tool. For example, at certain times the fluid must be directed towards the packing elements for inflation of the package, on the upper sealing element, and between the elements for the treatment of the formation.

Inflatable stimulation tools with alternating ends, currently available in the market, require various degrees of manipulation by means of spiral tubes, in order to achieve deflation of the package and to move the tool from one position to another localized position inside the jacket of the well and to direct the fluid that is pumped from the surface. The difficulties inherent in achieving these properties, particularly in deep or deviated wells, result in tools with alternating ends that often turn out to be unreliable and difficult to operate.

COMPENDIUM OF THE INVENTION It is a main feature of the present invention to provide a novel well treatment or inflatable stimulation tool for the wells, where the tool has inflatable gaskets with alternating ends for sealing the locations spaced within the jacketed well, and this way, an isolated range of the jacket for which the treatment or stimulation is applied is defined.

It is another feature of the present invention to provide a novel well treatment or inflatable stimulation tool that has inflatable and spaced packing elements and that additionally has a control system for inflating the packing elements, storing and sealing the pressure in the packing elements, and direct the pumped fluid between the inflatable elements of the package and then deflate the packing elements to allow the movement of the tool to another location located inside the well, or to allow the removal and removal of the tool , from the well.

It is also a feature of the present invention to provide a novel well treatment tool or inflatable well stimulation, which establishes a flow path through an injection port and achieves inflation of the package without any type of requirement. movement by the tool, and achieve the deflation of the package by means of the simple application of a pushing force of predetermined magnitude.

It is another feature of the present invention to provide a novel tool for well treatment or well stimulation, which can be simply and efficiently operated from the surface, to achieve the various operational modes of the tool and to be able to make changes between the modalities operational.

Briefly, the various objectives and characteristics of the present invention are realized by means of a treatment or stimulation tool, which is introduced and withdrawn and extracted from the wells by means of a tube tape composed of spiral tubing or a tubing with a flexible joint, in this way allowing the tool to be introduced, displaced or extracted from the well-deviated or horizontal sections, as well as the vertical sections of the well. Especially when the spiral tubing is used for the transport of the tool and for the supply of the treatment fluid, it should be kept in mind that a significant tensile force could be applied to the spiral tubing, such as for withdrawal and extraction. of the spiral tubing and the tool with alternating ends, but only a limited amount of compression or thrust forces could be applied to the spiral tubing. When excessive thrust is applied, the spiral tubing will quickly deform by compression and will be damaged. When the tool packing elements with alternating ends are deflated and thus contracted, the spiral tubing can be easily pushed on the surface without any significant risk of compression deformation, to allow the tool to move downwards with alternating ends for the effects of the positioning of the tool, even under conditions in which the hole in the well has horizontal or highly deviated sections.

When used as part of an inflatable stimulation tool with alternating ends, a well stimulation tool incorporating the principles of the present invention will allow the operator located on the surface to inflate the packing elements, store and seal the pressure within the inflated elements of the package, for the purpose of storing and sealing the pressure located within the inflated packing elements, to maintain an effective seal within the well casing, to direct the flow path of the fluid supply through the injection port located between the packing elements, and then deflate the packing elements when the movement or removal of the stimulation tool is desired. The only type of spiral tubing handling that is typically necessary, will be required at the end of the formation or well stimulation procedure, to deflate and thereby remove the sealing of the packing elements. The device will also automatically establish its original position after deflation, so that the tool can be moved downwards or upwards, to additional zones, during the same trajectory in the well.

BRIEF DESCRIPTION OF THE DRAWINGS The manner in which the aforementioned characteristics, advantages and objectives of the present invention are achieved and can be understood in detail, a better and particular description of the invention, briefly summarized above, could be taken as a reference for the preferred embodiment of these, which is illustrated in the accompanying drawings, said drawings are incorporated herein as a part of the foregoing.

It should be noted, however, that the appended drawings illustrate only a typical embodiment of this invention and because of this they should not be considered as limiting in their field of action, since the invention may be adapted to other equally effective additions.

In the Drawings: FIGURE 1 is a sectional, longitudinal and schematic view of a packing tool with alternating ends, assembled with an inflation control system in accordance with the principles of the present invention; FIGURE 2 is a schematic, operational, block diagram illustration of the inflation control system of FIGURE 1, showing the operating sequence of the same within a well; FIGURE 3A, is a sectional, longitudinal and schematic view, similar to that of FIGURE 1 and showing the packing tool with alternating ends and the inflation control system with a well casing and illustrating the operation at a low level of flow rate; FIGURE 3B, is a sectional, longitudinal and schematic view, similar to that of FIGURE 3A and illustrating the operation at a low level of flow rate; FIGURE 4A, is a sectional, longitudinal and schematic view, similar to that of FIGURE 3A and illustrating the pumping of fluid through the tool and the inflation control assembly in the injection mode, to inject treatment fluid or of stimulation towards the interior of the formation that surrounds the perforations of the jacket; FIGURE 4B, is a sectional, longitudinal and schematic view, similar to that of FIGURE 4A and illustrating the condition where the packing tool with alternating ends and the inflation control assembly are in injection mode, but where no fluid injection occurs; FIGURE 5A, is a sectional, longitudinal and schematic view, similar to that of FIGURES 3A and 3B, and illustrating the application of a tension force directed towards the assembly of the tool by way of the pipe tape, then that equalization of the pressure with the pressure of the formation has occurred and with the packaging elements inflated; and FIGURE 5B, shows a sectional, longitudinal and schematic view, similar to that of FIGURE 5A, and illustrates the release of the inflation pressure of the spaced and inflated elements of the package, for the purpose of preparing the tool for replacement. or for its withdrawal and extraction.

DETAILED DESCRIPTION OF THE PREFERRED INCORPORATION This invention consists of an inflation control system (SCI) that is used as part of a packaging stimulation tool with alternating ends (inflation tool) for spiral tubing. The SCI does not control the entire operation of the inflation tool, only the process of inflating the elements, storing and releasing the stored pressure, and directing the pumped fluid into the ring located between the packing elements . Additional components are required, upstream of the ICS, to make the switch between a "circulation" mode, where the fluid is discharged from the tool and into the ring located between the tool and the casing before reaching the ICS. , and it is made to return to the surface, and an "inflation / injection" mode, where all the flow is forced into the SCI and is used to inflate the packing elements or to stimulate the formation. The SCI is operated with a minimum amount of manipulation of the spiral tubing and moves to most of its positions automatically, if the appropriate operating schedule of the pump is followed.

Referring now to the drawings and firstly to FIGURE 1, an inflation control system, generally shown at 10, and incorporating the principles of the present invention, is shown assembled with an inflated, well-stimulating tool with alternating ends, generally shown at 12. It should be borne in mind that the inflation control system and the inflated, wellbore stimulation tool assembly with alternating ends are only intended to be illustrative of the preferred embodiment of the present invention and It is not intended to limit the spirit and scope of the invention, in any way. If so desired, an integral, inflated packaging tool with alternating ends could be provided and incorporates an inflating control system of nature and for the purpose stated herein. The inflation control system 10 and the inflated tool with alternating ends 12, whether they are composed of connected sections of the tool or of an integral assembly of the tool, are here identified simply as the tool. The inflated, well stimulating tool with alternating ends 12, is provided with the inflated, packed and spaced elements 14 and 16, which have inflated ports 18 and 20, each of which is in communication with an inflated passageway. of flow 22 of the inflated packing tool and the inflation control system. Between the inflated and spaced packing elements, with alternating ends, 14 and 16, the inflated tool with alternating ends 12 defines an injection port 24 through which treatment fluid is flowed into the ring of an insulated or sealed interval. of the jacket 26 that is defined within the jacket and between the inflated elements of the packing with alternating ends 14 and 16, as shown in FIGURE 3B. The injection port 24 is in communication with a flow passage 28 which is provided within the packing tool with alternating ends 12 and the inflation control system 10.

At its upper end, the inflation control system 10 is provided with a pipe connector 30, by means of which a pipe tape 32, such as a spiral tubing or a tubing with flexible joint, is connected to the inflation control system 10. The pipe tape 32 extends through the hole in the well, to a pipe handling equipment located on the surface, by means of which the pipe tape is manipulated in order to operate the tool to a desired location inside the well, for the replacement of the tool in the well, after the treatment or stimulation of a zone or an interval, or to deflate and release the inflated packages with alternating ends, to allow the movement or removal and extraction of the tool of stimulation with alternating ends. It is visualized that during a single trip to the interior of the well, any desired number of formations or zones could be treated. It is simply appropriate to deflate and de-energize the inflatable elements of the package, after each stimulation treatment has been completed, and to use the spiral tubing to selectively position the tool in another perforated area or interval of the casing of the well, in where the stimulation treatment process is repeated.

The inflation control system 10 of the stimulation tool with alternating ends defines the housing of a tool 34 having an internal chamber 36. A displacement deflation member 38 to which the pipe connector 30 and the pipeline are assembled. 32, or to which a section of the tool is assembled, serves to connect the SCI to the rest of the tool flow control section, inflated, well stimulation with alternating ends 12. The displacement deflation member 38 it is connected to the SCI through a very rigid spring 42, which will yield significantly only when a tension force of predetermined magnitude is applied to the displacement deflation member, by the pipe tape 32. The deflation spring 42 connects the displacement deflation member 38 with the SCI. Thus, if the SCI is restricted in its movement (such as when the inflation tool is anchored by the inflated packing elements) and tension is applied to the displacement deflation member 38, the spring 42 will be compressed by the directed force upwards and the displacement deflation member 38 will move upwards. If the displacement deflation member 38 moves upwardly and the pressure piston of the element 50 is in the lower position, then the displacement deflation member 38 will mesh with the pressure piston of the element 50 and move it towards the "superior" position. Otherwise, however, the displacement deflation member 38 and the pressure pin of the element 50 will not engage.

The displacement deflation member 38 defines a dependent activation section 40 which extends into the internal chamber 36 and is sealed with respect to the tool housing 34 by means of an O-ring seal 41. The spring deflation 42 is located within the inner chamber 36 and is positioned with its upper end positioned in a meshed fashion and transmitting force with a downward facing shoulder 44, located within the tool housing, and with its lower end in a geared form and transmitting force with a shoulder facing upwardly 46 of an annular extension or flange 48 of the dependent activation section 40 of the displacement deflation member 38. The deflation spring 42 has a very high value of spring constant and thus requires the application of large tensile forces directed to the displacement deflation member or 38, for the purpose of compressing the deflation spring sufficiently to allow upward displacement of the displacement deflation member 38 relative to the tool housing 34.

A pressure piston of the element 50 is displaceable within the internal chamber 36 and defines a flow passage of the stimulation fluid 51, through it. The sole purpose of the pressure piston of the element 50 is to store and release the pressure in the inflatable packing elements. The pressure piston of the element 50 comprises, in part, a nozzle 64 having two positions, a nozzle position "upwards" and a nozzle position "downwards". In the nozzle up position, the packing elements 14 and 16 can be inflated through an inflated equalization port 100, but because the pressure piston of the element 50 is not sealed inside the tool housing in this position, the inflation pressure of the package can not be stored and will always equalize with the pressure of the spiral tubing. At the nozzle down position, the equalizing inflation port is blocked by the sealed bottom end of the element 50 pressure piston, and the high pressure fluid will not be allowed to exit the inflated packing elements yet after the pressure drops in the spiral tubing. The pressure piston of the element 50 is moved to the "downward" position of the nozzle, by means of a sliding ring 72, and is moved to the "upward" position by means of the displacement deflation member 38 and has a connecting housing with loss of movement 52 which establishes a connector housing 54, within which a Connection extension 56 of the dependent trigger section 40 of the displacement deflation member 38 is displaceable. An extension or flange 58 located at the lower end of the connection extension 56, defines an upward facing shoulder 60, which meshes so as to transmit force with an internal shoulder facing downward 62 when the deflation member of displacement 38 is displaced upwards against the force of the deflation spring 42. In the absence of this tension force, which is applied by way of a pipe tape 32, the pressure piston of the element 50 is essentially isolated from mechanically from the displacement deflation member 38.

The housing of the pressure piston connector 52 of the element 50 is provided with a nozzle member 64 that is normally positioned within an upper depression of the nozzle 66 of the tool housing, as shown in FIGS. 3A, and which is movable downward, as shown in FIGURE 3B, to a position where the nozzle member 64 is located within a lower nozzle receptacle 68. The pressure piston of the member 50 defines a generally elongated cylindrical section 70 around which a sliding ring 72 having external and internal seals 74 is positioned and 76, which hold the slide ring in sealed relation to the generally elongated cylindrical section 70, and an inner surface 78 of the tool housing 34. The sealed slide ring 72 is displaceable within the ring located between the generally cylindrical section 70 and the internal surface 78 of the tool housing 34 located within the limits defined by the downward facing shoulder 80 of the tool housing 34, and an upwardly facing shoulder 82 of an annular brake flange with a slip ring 84 of the generally cylindrical section 70 of the pressure piston of the element 50. The sliding ring essentially floats between the SCI housing and the pressure piston of the element, with an elastomeric seal located between each of them. The pressure of the spiral tubing acts on the slide ring 72 from the top, and the (annular) pressure of the well acts on the slide ring from the bottom. The slide ring 72 is essential for the operation of the pressure piston of the element 50, making it independent of the prevailing pressure conditions at the bottom of the well. In other words, if the pressure inside the ICS is greater than the cladding pressure, the resultant force of the slide ring 72 will act downward on the pressure piston of the element 50. If the pressure differential is high enough to overcome the nozzle retention force, the pressure piston of the inflatable packing element 50, will be moved to its "lower" position; this is the manner in which the pressure is stored in the inflatable elements of the packing 14 and 16. If the pressure in the well is greater than the pressure in the spiral tubing, the sliding ring 72 will not exert a force on the piston of pressure of the inflatable packing element 50. This means that, regardless of the conditions in the well, the sliding ring 72 will not be able to disconnect the pressure piston from the inflatable element of the package 50 and release the pressure of the packing element. Thus, the spaced elements of the inflatable gasket 14 and 16 will remain inflated and sealed to the jacketed well. The downward movement of the pressure piston of the packing element 50 is limited by an upwardly facing annular shoulder 86, located within the tool housing 34. An equalization passage 88 communicates the ring 90 located between the control system of inflation 10 and the casing of the well 92, with the internal chamber of the tool 94 that houses the pressure piston of the packing element 50.

At the lower end of the generally cylindrical section 70 of the pressure piston of the packing member 50, an annular sealing member 96 is provided which establishes a seal within a cylindrical lower section 98 of the internal chamber of the tool 94. An ignitable equalization port 100 is in communication with the inflation flow passage 22 and, with the pressure piston of the packing element 50 in the upward position shown in FIGURE 3A, the fluid pressure of the airflow tape of the tubes that is communicated through the displacement deflation member 38 and the pressure piston of the element 52, is communicated with the inflation flux passage 22 to the inflation packages 14 and 16, causing inflation of these for the sealing of the well stimulation tool located within the jacket of the well 92, in spaced locations that define a cladding range 102 which are typically perforated, as shown at 104, for communication with a production formation that surrounds the cladding range.

An inflation hole 106 is provided in the structure of the wall of the tool housing 34, and communicates the ring of the jacket 90 with the chamber of the piston 108 that is defined within the housing of the tool 34. The inflation orifice 106 It does everything possible to inflate the packing elements to a desired pressure differential, without actually knowing the well pressure in the tool. This is because a given flow rate along the entire inflation orifice 106 results in a known pressure drop. The drop in pressure is effectively independent of the absolute pressure values for each side of the hole. Additionally, by changing the properties of the hole, the operator can achieve different drops in pressure with the same level in the flow rate; This may be necessary, depending on the capabilities of the pump that is used.

An inflatable / injection piston 110 is displaceable within the chamber of the piston 108 and urged in a downward direction, by means of a compression spring member 112, referred to as an injection spring, and is sealed within the chamber of the piston. piston 108 by means of a piston sealing member 113. The inflatable / injection piston 110 directs the pumped fluid both to the entire area of the inflatable orifice 106 and outside the SCI, or blocks this path and directs the fluid down the SCI, and finally between the inflated elements of the packer and towards the interior of the formation. If the element pressure piston is in the upper position, then the inflatable / injection piston 110 will be balanced at its pressure level and forced down by means of the injection spring 112. Once the pressure piston of the element 50 move to the lower position as shown in FIGURE 1, and the packing elements are inflated, the inflatable / injection piston 110 will have a pressure of the elements acting from the bottom, and a pressure of the spiral tubing acting from the top When the pressure of the spiral tubing falls to a level below the element pressure, the inflatable / injection piston 110 will then move upward, compressing the injection spring 112 and sealing it against the body of the ICS. The inflatable / injection piston 110 is provided with a piston extension, or stem 107, that extends into the interior of the piston receptacle 109 and is sealed to the tool housing, by means of a sealing O-ring 111. With the inflatable / injection piston 110 in the position shown in FIGS. 3A and 3B, the fluid pressure that is injected through the inflation control system tool from the tube belt, in addition to acting within the Inflatable packaging elements, will also be ventilated through the inflation hole 106, to the jacket ring.

A vertical inflation movement valve 114 is located within a valve chamber 116 and is directed to a position that closes the passageway of the valve 118, by means of a spring of the valve 120. The valve of vertical movement of Inflation is, essentially, a check valve that will allow the fluid to flow from inside the spiral tubing, into the interior of the internal chamber 101 and up to the inflation port, but not from the spaced and inflatable gaskets through the passage 22, and to inner chamber 101. This feature causes the spaced elements of the inflatable packages to remain inflated and sealing the stimulation tool with alternating ends, with the casing, until the pressure of the packing element is subsequently equalized with the pressure of the pipe. During inflation, the fluid flows into the inflatable packing elements, through the equalization port, until the pressure piston of the element 50 moves to the lower position of FIGURE 3B. After the pressure piston of the packing element moves downward, packing inflation continues through the vertical movement inflation valve. When the pressure piston of the element 50 has moved downward, as shown in FIGURE 3B, to a position that closes the inflatable equalization port 100, the inflation pressure of the package will flow beyond the vertical movement valve and towards the interior of the inflation flow passage 22, to the inflatable packing elements 14 and 16. Because the vertical movement valve 114 is a unidirectional valve, that is, a check valve, the inflation pressure of the Inflatable elements of the gaskets will be trapped and the elements of the gaskets will remain inflated, even when the inflation pressure, upstream of the vertical movement valve has been lowered. Thus, with the inflatable elements of the inflated packages and sealing the tool located inside the casing, the pressure of the pipe could be reduced and the elements of the packages will remain inflated, so that the activities of stimulation of the well can be carried out in the interval of the cladding ring, between the spaced elements of the packing. When the pressure piston of the element 50 is in its upper position, as shown in FIGURE 3A, the inflatable packing elements may be inflated at a low level of flow rate, because the flow path from the tube tape to the inflation flow passage 22 is opened via the equalization inflation port 100. When the pressure piston of the element 50 is in its lower position, as shown in FIGURE 3B, the inflatable packing elements will be inflated at a high flow rate because the inflation pressure of the package is blocked from the equalization inflation port, and should be disconnected from the vertical movement valve 114, to flow into the interior from the passage of inflation flow 22 and towards the inflatable elements of packages 14 and 16.

The piston chamber, located below the inflatable / injection piston 110, is in communication with the inflation flow passage 22, via port 122, so that, under conditions of low fluid flow, inflation of the packing as shown in FIGURE 3A, the injection pressure from the pipe, act on the larger area of the upper surface of the inflator / injection piston 110, and act via the port 122. over a smaller area of the bottom surface of the inflatable / injection piston 110, in this manner - causing the inflatable / injection piston 110 to be directed downwards by the action of the pressure response force, as well as by the force of the compression member of the spring member 112. Thus, the inflatable / injection piston 110, when the inflatable packing elements are inflated at a low flow rate, as shown in FIGURE 3A and at a high flow rate, as shown in FIG. shown in FIGURE 3B, it will be positioned at its maximum level towards the entire downwardly directed extension, and the restricted orifice 106 will be opened for control of the inflation pressure, within the internal chamber 101.

The tool housing 34 defines a piston equalization chamber 124 having a cylindrical wall surface 126. A member of the equalization piston 128 is movable with the piston equalization chamber 124 and is sealed with respect to the surface of the piston. the cylindrical wall 126, by means of the seals of the annular piston 130. An equalization passage 132 is defined by the housing of the tool 34 and communicates the ring of the jacket 92 with the equalization chamber of the chamber 124 below of the equalization piston, when the equalization piston is in its extreme upper position. A piston spring 134 is located within the tool housing 34, below the equalizing piston, and imparts a spring force directed upwardly to the equalizing piston, and normally maintains the position of the equalizing piston thereon. communication port 132, as is evident from FIGURES 1, 3A, 3B, 4B, 5A and 5B. The equalization piston member 128 defines an internal flow passage 135 and has an internal flow restrictor 136 located there, which defines a restricted orifice 138. During the injection of the stimulation fluid, typically at high pressure, the fluid flow through the restricted hole 138 develops a resultant force on the equalization piston, forcing the equalizing piston downwardly and against compression of its piston spring 134. This downward response movement to the equalization piston compresses the piston spring 134 and causes the equalization piston member to block communication port 132, as shown in FIGURE 4A. The equalizing piston member 128 ensures that, unless the fluid is being pumped through the SCI and into the formation, the pressure will equalize within the ring located above and below the inflatable packing element 14. This It is important, both during inflation and during deflation, when a pressure imbalance can damage the inflatable elements of the package and possibly pose a threat to safety. If there is no fluid flowing through the equalizing piston member 128, the equalizing piston member will be forced upwardly by its piston spring 134, opening the communication or communication port 132, from the inside of the tool to the Jacket ring 90. However, once fluid flows through hole 138 in the equalizing piston member, the resulting pressure drop will force the piston down, closing communication port 132 and forcing all fluid to which moves under the tool, through the passage of fluid flow 28 and into the interior of the formation via the perforations of the jacket 104.

Operation of the Inflation Control System As mentioned above, the bul should be used in conjunction with the components that, when assembled upstream of the ICS, direct the pumped fluid 1) out of the tool before reaching the ICS, or 2) through the ICS . It is important to keep the SCI isolated from the flow, until the operator is ready to inflate the packing elements. Alternatively, the pressure differential stored in the packing elements by the SCI is directly related to the flow rate. Thus, it is equally important that when the SCI is operated, that all the pumped fluid is directed through the SCI before being discharged from the tool. The following description of the SCI operation assumes that all the pumped fluid is directed through the SCI, and that the operator has located the adequate depth for the alternation of the jacket perforations, and is ready to start the inflation of the element. of packaging. The operation of the SCI will be broken down into three main categories, each of which is described below. Also, as explained above, FIGURE 2 is a schematic illustration of a block diagram of the main steps in the operation of the CSl, and due to this exposes the various stages and inflation characteristics of the controlled packing element, the injection of fluid and the deflation of the packing element that allow the stimulation tool with alternating ends to be used for the treatment of a different number of sub-surface areas, without needing the removal and extraction of the tool from the well, after each treatment of the casing interval. 1. Inflate Once the tool is located in the proper depth in the well, and the inflatable and spaced elements of the packaging are alternating the area of interest, the operator begins to inflate the inflatable and spaced elements of the package. The inflation fluid is pumped through the SCI at a low flow rate, as indicated by the schematic block 140 of FIGURE 2. This process is also shown in FIGS. 3A and 3B, where the flow arrows show the trajectory of the pumped fluid. The only way the fluid can be discharged from the SCI is through the inflation hole 106. Inflation fluid is pumped slowly first, because the inflatable elements of the gaskets 14 and 16 can be damaged if inflated very quickly. Note that the inflation fluid can flow simultaneously through the inflation equalization port 100, to the inflating flow passage 22, and the inflatable elements of the package and through the inflation hole 106, to the ring 90. This means that the same drop in pressure through the inflation orifice 106, due to the pumping rate, is observed through the inflatable elements of the package. Thus, the packing elements will begin to inflate, even at a low flow rate; this is the reason why it is important to keep the SCI isolated from the flow, until it is time to inflate the package inflation elements.

After the inflatable elements of the package have had an adequate time to adjust to the pressure differential (this time varies with the magnitude of the differential) the flow rate is increased by some fixed amount,? Q, which results in a corresponding increase in the pressure differential of the packing element. Again, the operator must wait for the inflatable elements of the package to adjust to the change in pressure, before proceeding.

It is important to be aware that, if the pump stops for any reason before the inflation is completed, the inflatable / injection piston will be disconnected and will move upwards to a certain extent. This property makes it impossible to simply start pumping to continue to inflate, because some amount of the pumped fluid will not be directed through the orifice, but instead, it will move downstream of the injection path and below the inflatable / injection piston. However, the SCI is robust to situations where pumping stops inadvertently for any reason. The sliding ring will not displace the pressure piston of the element, until a minimum pressure differential has been reached (see FIGURE 3B). When stored in the inflatable elements of the package, this minimum pressure difference provides sufficient anchorage, so that the operator can pull on the surface and deflate the elements. Yes, on the other hand, the pump stops before the minimum pressure is reached and the pressure piston of the element has not been displaced, the operator will simply wait for any level of pressure that is stored in the elements, to equalize it through the nflable EQ port. After the pressure has been equalized in any situation, the inflatable piston / injection will be moved down to its inflation position, and the operator can then repeat the inflation process.

The operator continues the process of increasing the pumping rate progressively, and will allow the elements to respond until the target pressure differential level is reached. Note that the target pressure differential must always be greater than the minimum pressure stored by the element pressure piston; otherwise, the elements will simply deflate after the pumping stops. Once the target pressure differential is achieved, the operator stops pumping. As soon as the pumping is stopped, the pressure differential through the inflatable / injection piston causes it to move upwards, closing the discharge path through the inflation hole and opening the path through the rest of the ICS. From this point on, all fluid pumped through the SCI will flow through the bottom of the inflatable / injection piston and out of the injection port. 2. Invention Once the elements are inflated to the desired pressure difference, the stimulation fluid is pumped from the surface, through the SCI, and into the interior of the formation. In order for the stimulation fluid (often an acid) to reach the tool, the operator must first displace any amount of fluid in the spiral. The operator will do this by pumping the stimulation fluid, to force the unwanted amount of fluid out of the tool located on the ICS and up to the surface. Once the stimulation fluid has reached the tool, the operator will stop circulation to the surface, close the circulation path, and open the injection path that directs the fluid through the SCI.

Because the inflatable piston / injection is in the upward facing position, the stimulation fluid will not be able to exit the ICS through the inflation port, and instead will move through the lower portion of the ICS. At a low flow rate (approximately 0.25 bpm to 0.50 bpm), the stimulation fluid will generate a pressure drop through the equalization piston, which is sufficient to close the piston and seal the injection equalization port (see FIGURE 4A). As long as the stimulation fluid is pumped at or above this minimum flow rate, the only outflow path for the stimulation fluid is outside the injection port and into the formation interior.

As an alternative to the hole in the equalization piston, a unidirectional valve such as a check valve could be used. The check valve allows the flow of the surface to pass, after a nominal pressure differential has been achieved, but the valve does not allow the fluid to pass from the bottom. The changing pressure differential of the check valve for the pumped fluid is sized such that the equalization piston will move down to block the injection equalization port before the check valve opens. For example, if you require 50 psi (pounds per square inch) of differential pressure to displace the equalizing piston, the check valve could be designed to open with 100 psi differential. This feature ensures that all the pumped fluid can be moved out of the injection port, and not the injection equalization port.

When the pumping stops, the equalization piston returns to its original position and opens the injection equalization port (see FIGURE 4B). This allows flow through the injection equalization port in any direction, to balance the pressure above and below the upper packing element. This is an important characteristic of the SCI, especially during inflation and deflation, when a pressure differential around the upper packing element can damage the packing elements and generate enormous forces that may represent a safety hazard.

This invention relates to the flow control portion of an altemability tool, and not to the tool as a whole. Consequently, for the purposes of clarity in FIGURE 1 and in FIGURES 3-5, not all ports are shown in a typical alternate tool. For example, a bypass port is usually present and allows communication at all times from the lower part of the lower packing element to the upper part of the upper packing element. Thus, when the injection equalization port balances the pressure through the upper packing element, the pressure will also become balanced through the lower packing element. 3. Deflate The process of circulating the fluid to the tool and then into the formation can continue indefinitely, without deflating the packing elements. When the operator has finished the treatment of a particular area and wishes to deflate the packing elements, the operator simply must wait for a sufficient period of time for the pressure through the packing elements to equalize through the equalization port. injection 132. The amount of time required for this will vary depending on the characteristics of each zone.

Once the pressure through the packing elements is matched with the cladding pressure, the operator will apply tension to the tool through the spiral tubing, to achieve deflation of the packing. Because the displacement deflation member 38 is only connected to the SCI through the deflation spring 42, and the packing elements are anchored to the casing by means of the inflation pressure, the deflation spring will be compressed when the tension is applied. When the deflation spring 42 is compressed by the tension force of the pipe, the displacement deflation member 38 engages the pressure piston of the element 50, moving it to its upwardly directed position (see FIGURE 5A). The high-pressure fluid that is stored in the inflatable elements of gaskets 14 and 16 will now be released through the inflation equalization port 100 and into the internal flow passage of the SCI.

Once sufficient time has elapsed for the elements to equalize, the inflatable / injection piston member 110 will swing in its pressure and will return to its downward (start) position by the force of the spring 112. At this point, the SCI will be fully established and may be moved to another area. The previous process is repeated as required for each zone in the well.

In view of the above, it is evident that the present invention is well adapted to achieve all the objectives and characteristics that are established from now on, together with other objectives and characteristics that are inherent in the apparatus set forth herein.

As will be readily apparent to those skilled in the art, the present invention can easily be produced in other specific forms without departing from the spirit or essential characteristics. The present embodiment should be, in this way, considered as illustrative and not restrictive, the field of action of the invention is indicated by the claims instead of the foregoing description, and all the changes included within the meaning and range of The equivalences of the claims are intended to be considered.

Claims (15)

CLAIMS:

1) A method for the control of inflation and deflation of the irifiable and spaced elements of the packages of a stimulation tool with alternating ends and transported by tubes, located inside the casing of a well, the stimulation tool with ends alternating has a member to control the pressure of the package and is responsive to movement due to the pressure in the pipe and the pressure in the jacket, and is displaceable by a predetermined tension force and applied to the pipe, said method comprises: - develop the inflation pressure of the packing element located inside the stimulation tool with alternating ends, with the pressure of the pipe and with the inflatable and spaced packing elements, for the sealing of these inside the casing of the well and of define an isolated range of the jacket; - cause the responsive positioning of the pressure of the pipe of the member of control of the pressure of the packing, for the maintenance of the inflation of the inflatable and spaced elements of the packing; - injecting well stimulation fluid through the stimulation tool with alternating ends and into the isolated range of the casing; and - after completing the well stimulation, apply sufficient tension force to said stimulation tool with alternating ends through the pipeline, to move the packing pressure control member by a tension force applied to the pipe, and releasing the inflation pressure from the inflatable and spaced elements of the package and disconnecting the stimulation tool with alternating ends for transport by pipe, within the jacketed well.

2) The method of claim 1, in. where a displacement deflation member in movable assembly condition with the stimulation tool with alternating ends, and has a connection that applies a tension force to the packing pressure control member, the displacement deflation member is connected With the transport and fluid supply pipe, the step of said method of applying sufficient tension force comprises of: - equalizing the pressure of the jacket through the inflatable packing elements, and with the inflatable and spaced elements of the packing in inflation condition, apply sufficient tension force via a transport and fluid supply pipe, to move the displacement deflation member and to move the packing pressure control member to a position to equalize the pressure of the packing with the pressure of the pipe, in this way deflate the inflatable and spaced elements of the packaging.

3) The method of claim 1, wherein the pressure control member of the packing member and the displacement deflation member have a connection with loss of movement which causes the application of a tension force to the control member of the pressure of the packing element, only after a tension force has moved the displacement deflation member to force the application of a relationship with the package pressure control member, said method comprises of: - applying sufficient tension force to the displacement deflation member via a pipe tape, to establish a tension force that transmits a ratio of the displacement deflation member to the pressure control member of the packing member and to move the pressure control member from the packing to the deflation position of the packing element.

4) The method of claim 1, wherein a spring member is disposed in a force transmission relationship with the displacement deflation member and with the stimulation tool with alternating ends, and urges that said displacement deflation member towards a tension force and in the opposite direction, the pressure control member of the packing element applies a tension force to the pressure control member of the packing member, only after having overcome the force of the spring member, said method comprises of: - applying sufficient force of tensioning the displacement deflation member by way of a pipe tape, to overcome the force of the spring member and to move the pressure control member of the packing element towards the deflation position of the packing element.

5) A method to control the inflation and deflation of the inflatable and spaced packing elements of a stimulation tool with alternating ends, inside the jacket of a well, comprising: - with a pipe tape that supplies fluid and positioning the stimulation tool with alternating ends to a desired location within the casing of the well, the stimulation tool with alternating ends has a pressure control member of the packing element movable between an inflation position of the packing element and a pressure equalization position of the packing element; - cause the flow of fluid from the pipeline that supplies the fluid, through the stimulation tool with alternating ends, to an inflation rate of the spaced and inflatable packages and establish the inflatable and spaced elements of the package, inside of the casing of the well and to establish an isolated interval of the casing inside the casing of the well and between, the elements, inflatable and spaced, of the packing; - retain the pressure of inflation within the spaced and inflatable elements of the package; - causing the flow of the stimulation fluid through the stimulation tool with alternating ends and towards the interior of the ring interval, for the stimulation of the formation surrounding the anilio interval; - moving the element pressing member to an equalization position of the package and equalizing the packing pressure with the jacket ring pressure; and - after equalizing the packing pressure with the jacket ring pressure and deflating the inflatable packing elements, move the pipe tape and the stimulation tool with alternating ends into the jacketed well.

6) The method of claim 5, wherein moving the pressure control member of the element comprises: - applying a tension force to the pipe tape and moving the tape . pipe, the displacement deflation member and the element pressure piston are directed upwards and position the element pressure piston in the position of the pressure equalization piston.

7) The method of claim 5, wherein an internal chamber is located within the stimulation tool with alternating ends and which is in communication with the spaced and inflatable packages, and wherein a restricted orifice communicates the internal chamber with the ring located between the stimulation tool and the casing of the well, said method comprises: - with the pressure control member of the packing element in the inflation position of the packing element, causing the flow of fluid from the packing tape. pipe to the inside of the inner chamber, and from the inner chamber through the restricted orifice and to the ring, at a predetermined rate for inflation of the inflatable elements of the package; and - decreasing the flow of fluid from the pipeline and deflating the inflatable elements of the packing, by equalizing the packing pressure with the pipe pressure.

8) The method of claim 5, wherein an internal chamber is located within the stimulation tool with alternating ends and a valve member that controls the communication of the internal chamber and the inflatable spaced packages, and wherein an orifice Restricted communicates the internal chamber with the ring located between the stimulation tool with alternating ends and the casing of the well, said method comprises: - with the pressure control member of the packing element in the position of pressure retention and inflation of the packing element, causing the flow of fluid from the pipe tape into the inner chamber, and from the inner chamber through the valve member and from the inner chamber through the restricted orifice and up to the ring, to a predetermined rate for inflation of inflatable packaging elements; - decrease the flow of fluid from the pipe tape and into the internal chamber; - causing the valve member to retain the inflation pressure of the packing element located within the inflatable packing elements; and - after stopping the flow of the stimulation fluid into the ring range, with the pipe tape moving the pressure control member of the packing member to the pressure equalization position, and then deflating the nflatable and spaced elements of the packing by means of the pressure of the equalization pack with the pressure of the pipe.

9) The method of claim 5, wherein the alternating-end stimulation tool has a tool housing defining an internal chamber in communication with the pipe tape and having the member's pressure control member, at least partially movable in that position, and is in communication under pressure with the inflatable elements of the package, and a hole is present in the housing of the tool and in communication with the internal chamber, with the ring located between the housing of the tool and the casing of the well, said method comprises: - injecting pressurized fluid from the pipe tape, into the interior of the internal chamber; - communicate the injected pressure to the spaced and inflatable elements of the package; and - controlling the inflation pressure of the fluid located within the inner chamber and the spaced and inflatable elements of the package, by means of fluid flow from the internal chamber, through the orifice and up to the jacket ring.

10) The method of claim 5, wherein the alternating end stimulation tool defines an injection pressure equalization chamber and an injection pressure equalization port, and an injection pressure equalization piston having a passageway flow through them, and is movable within the injection pressure equalization chamber, between the injection position where the pressure equalization piston closes the pressure equalization port by injection, and an equalization position wherein the injection pressure equalization port is open, said method comprises: - causing sufficient flow velocity of the stimulation fluid through the flow passage, causing responsive movement to the flow of the pressure equalization piston through injection to the injection position; - continuing the flow of the stimulation fluid through the flow passage and maintaining the pressure equalization piston by injection in the injection position during the flow of the stimulation fluid and into the interior of the ring interval; and - after cessation of the flow of the stimulation fluid through the flow passage, move the pressure equalization piston by injection to the equalization position and the pressure of the equalization ring interval, with the ring pressure of the Jacketed

11) A stimulation tool with alternating ends to isolate and stimulate the selected formations in the wells, comprising: - a tool body having spaced and inflatable packing elements, and defining a fluid injection passage having a fluid injection port located between the spaced and inflatable packing elements, the tool body also defines a flow passage in fluid communication with the spaced and inflatable packing elements and defines an inflation control chamber and an equalization port of inflation in communication with the inflation flow passage, and the control chamber; - a pressure control member of the packing element defining a flow path of stimulation fluid, and being movable within the pressure control section, located between the pressure equalization position where the equalization port is located. it is open, and a pressure storage position in which the pressure control member of the packing element blocks the flow of fluid through the equalization port; - a unidirectional valve member is located within the tool body and allows the unidirectional flow of the stimulation fluid, from the inflation control chamber to the inflation flow passage, when the pressure control member of the packing element It is located in the pressure storage position; and a displacement deflation member that is movably relative to the tool body and having a pipe connector to which a conveyor and f supply pipeline is connected, the displacement deflation member causes the movement of the pressure control member of the packing element towards a pressure equalization position, after the application of a tension force of predetermined magnitude to the displacement deflation member, by means of the conveyor belt and f supply.

12) The alternating-end stimulation tool of claim 11, comprising: - the pressure control member of the packing member that is movable from the pressure equalization position to the pressure storage position, responsive to the inflation fluid pressure.

13) The alternating-end stimulation tool of claim 11, which comprises: - the pressure control member of the packing element defining a connection receptacle and an internal shoulder facing downwardly; - the displacement deflation member defines a flow passage in communication with the pipe tape and having a connector extension that is movable within the connector pocket, the extension of the connector defines a tension shoulder facing upwardly, and that establishes a gear that transmits force with the inner shoulder facing downwards, after the predetermined movement directed upwards of the displacement deflation member, by means of the pipe tape and then the further upward movement of the deflation member of displacement moving the pressure control member of the packing element to the pressure equalization position.

14) The alternating-end stimulation tool of claim 11, comprising: - the tool body defining an internal chamber, to which the pressure line is communicated; - an inflation control hole is mounted on the body of the tool and establishes the communication of the internal chamber with a ring located between the body of the tool and a jacket of the well; - An inflatable / injection piston that is movable inside the internal chamber and having an injection passage through them, the inflatable / injection piston has a first position that allows the flow of fluid through the control orifice. inflation and a second position that blocks the flow of fluid through the inflation control hole; and - a spring member that holds the inflatable / injection piston in the first position.

15) The alternating-end stimulation tool of claim 11, comprising: - the tool body defining an equalization piston chamber and defining an injection equalization port that communicates the equalization piston chamber with the jacketed well; - a member of the equalization piston that is movable within the equalization piston chamber, which is responsive to the force of the pressure differential and which has an equalization injection pressure located in normal position with the cladding pressure, EQ piston member has an injection position that blocks the injection equalization port that is responsive to the predetermined injection flow rate. SUMMARY OF THE INVENTION A method and apparatus for controlling the inflation and deflation of the inflatable elements of the packing of a stimulus tool with alternating ends, located within the casing of a well. A stimulation tool with alternating ends is positioned by the pipe in a desired location, inside the jacketed well. Fluid is pumped through the pipe and the tool, at a rate that inflates the inflatable and spaced elements of the packing, into the jacketed well, and establishes a ring span. The pressure control retains the pressure within the inflated packing elements and allows the flow of the stimulation fluid into the ring range for the effects of the formation stimulation. After completing the stimulation of the well, the pressure control of the packing element is moved to an equalization position of the packing, by means of the tension applied by the line of the pipe, to equalize the pressure of the packing with the pressure of the ring of the jacket, to deflate the packing elements and allow the transport of the stimulation tool with alternating ends, inside the jacket of the well, by means of the pipe tape. V5