Abstract:
The Invention is to be applied for selective injection of fluids in different formations, keeping the casing isolated from fluid pressure. “Fluid” is used in its widest sense: gases or liquids. It is hydraulically driven by the injection fluid. A single operator must only handle surface standard valves. It consists of five assemblies: Surface, Transport, Free Mandrel, Fixed Bottom Hole and Complementary. The Free Mandrel is the dynamic main device that carries all the Injection valves together, one for each formation, from the Bottom Hole to the Surface in 30′ and viceversa. As this operation is performed many times in the well lifetime, it allows a cumulative time and money saving. Workover equipment is only used for installing the system and for fixing packers. Formation Pressure is kept when the system is installed or when it is pulled up. Changes can be made at any time when they are needed.

Description:
[0001]    This invention is related to elements employed in the petroleum industry in general, but it particularly refers to a free mandrel system with protected casing. Its main specific purpose is to be applied to petroleum exploitation for the selective injection of fluids in different formations of a specific well. 
       SUMMARY OF THE INVENTION 
       [0002]    According to the characteristics of the invention, its main purpose is to achieve a free mandrel system which enables the setting up and simultaneous lifting of all Injection Valves from the surface by operating the valves of a surface component of the invention. This process is performed by only one operator without any kind of help, assistance or tool. 
         [0003]    More precisely, this invention has as its main goal the embodiment of a free mandrel system with protected casing created to allow selective injection in several well formations. Consequently, the free mandrel assembly has as many Injection Valves as formations a specific well may have. In the present explanation for the embodiment of the invention, the system is applied to a 139.5 mm (5″½) casing and it has been simplified to only two formations, an upper and a lower one, to facilitate the explanation and comprehension of its constructive layout structure. 
         [0004]    Said system is based on a dynamic main assembly, a Free Mandrel, through which Injection Valves are transported from the surface to their location on the bottom hole by means of injection fluid and an ordered surface valve handling. To this purpose, the Fixed Bottom Hole Assembly only allows fluid circulation from the annular to Tubing ( 9 ) in order to make the free mandrel return to the surface where all valves are placed, and remove them. Consequently, the purpose of the invention is achieved by an essential layout which comprises: 
         [0000]    (A) A Surface Assembly (SA) made up of an installation Mast, a Lubricator with a Catcher to release and catch the Free Mandrel Assembly, Conventional Valves and the Impeller which enables it to operate.
 
(B) A Transport Assembly (TA) made up of a Fishing Neck which contains a Retention Valve, two Rubber Cups which slide over a central tube and a Lower Connector which allows it to be bound to the next assembly.
 
(C) The Free Mandrel Assembly (FMA), which is the dynamic element of the device, is made up of a mandrel for every formation to be selectively injected (only two in this simplified case), where each mandrel lodges its corresponding Injection Valve.
 
(D) A Fixed Bottom Hole Assembly (FBHA), which is the device that is screwed to the bottom of the 73.026 mm (2″⅞) tubing string and over the On Off. When the Free Mandrel Assembly is inserted into the Fixed Bottom Hole Assembly, the FMA complements the hydraulic circuits they both contain to accomplish selective injection in every formation.
 
(E) A Complementary Assembly (CA), which is screwed to the lower part of the Fixed Bottom Hole Assembly (D) and comprises, in its interior part, the Telescopic Union screwed to the central and lower part of the Fixed Bottom Hole Assembly (D); the Injector Tube; the Injector Plug and the Rupture Disc passage.
 
In its exterior part, the Complementary Assembly (E) is made up of the upper part of the On Off screwed to the outer and lower part of the Fixed Bottom Hole Assembly (D). The lower part of the On Off is screwed to the upper end of the Upper Packer while the Injector Plug is screwed at its lower end with the Rupture Disk passage. To complete the installation, the 60.325 mm (2″⅜) tubing string is screwed to the lower part of the Injector Plug to fix the Lower Packer in the adequate position to separate both formations.
 
         [0005]    One or two 60.325 mm (2″⅜) tubings are placed below the Lower Packer, and the Shear Out is placed on its end. 
         [0006]    Some of the elements described in the above three paragraphs are commonly used in the industry, but they are essential for the operation of this invention. 
         [0007]    Said Free Mandrel (C) runs together with all well valves from the Lubricator to its insertion in the FBHA, employing the Catcher of the Lubricator to remove or replace the Injection Valves during the upstroke or removal. For that purpose, its valve system is designed to allow fluid passage from the Annular to the tubing string, blocking the passage of the fluid from the tubing string to the Annular with the purpose of protecting the Casing even when this Free Mandrel is not inserted into the FBHA. In other words, it will keep the Casing totally isolated from the pressure and the contact of the injection fluid. This also facilitates protective fluid circulation (fresh water with germicide) in the Annular to fill it or use it during the upstroke of the Transport (B) and Free Mandrel (C) Assemblies. 
         [0008]    Each of these elements has its special own characteristics to achieve the purpose of the invention. 
       BACKGROUND INFORMATION 
       [0009]    In the search for background information, several embodiments have been found. Some of the documents are transcribed below: 
         [0010]    US2004238218 (A1): Injecting a Fluid into a Borehole Ahead of the Bit, applied by Runia Douwe Johannes, Smith David George Livesey, Worrall Robert Nicholkas; Shell Oil Company. 
         [0011]    It describes a method and system for introducing a fluid into a borehole, in which there is arranged a tubular drill string including a drill bit, wherein the drill bit is provided with a passageway between the interior of the drill string and the borehole, and with a removable closure element for selectively closing the passageway in a closing position, and wherein there is further provided a fluid injection tool comprising a tool inlet and a tool outlet, the method comprising passing the fluid injection tool outlet through the drill string to the closure element, and using it to remove the closure element from the closing position; passing the fluid injection tool outlet through the passageway, and introducing the fluid into the borehole from the interior of the drill string through fluid injection tool into the borehole. 
         [0012]    It does not collide with the purpose of the present description. 
         [0013]    US2005011678 (A1): Method and Device for Injecting a Fluid into a Formation. Applicant: Akinlade Monsuru Olratunji (NL), Lightelm Dirk Jacob (NL), Zisling Djurre Hans, Shell Oil company. 
         [0014]    A method of injecting a stream of treatment fluid into an earth formation in the course of drilling a borehole into the earth formation, using an assembly comprising a drill string provided with at least one sealing means arranged to selectively isolate a selected part of the borehole from the remainder of the borehole, the drill string further being provided with a fluid passage for the stream of treatment fluid into the selected part of the borehole. The method involves: operating the drill string and stopping the drilling operation when a zone for which treatment is desired is arranged adjacent to the part of the selected part of the borehole; isolating the selected part of the borehole using the sealing means so as to seal the drill string relative to the borehole wall; and, pumping the stream of treatment fluid via the fluid passage into the selected part of the borehole and, from there, into the treatment zone. 
         [0015]    The mentioned characteristics that identify this embodiment do not give rise to a concrete antecedent of this invention. 
         [0016]    U.S. Pat. No. 4,050,516 (A): Method of Injecting Fluids into Underground Formations. Applicant: Dresser Ind. 
         [0017]    A method of injecting fluids into underground formations such as oil wells, and particularly advantageous for treating low-pressure formations having bottomhole pressures below normal tubing hydrostatic pressure, utilizes the steps of lowering into the borehole a tubing string, locating near the formation to be treated a partially pressure-balanced valve adapted to support a column of fluid in the string of tubing, and applying pressure to the column of fluid in the tubing to inject fluid through the valve into the formation. 
         [0018]    It does not interfere with the invention either. 
         [0019]    U.S. Pat. No. 4,433,728 (A): Process for selectively reducing the fluid injection or production rate of a well. Applied by Marathon Oil Co (US). 
         [0020]    This process improves the real conformance of fluids injected into or produced from a subterranean formation via a multi-well system wherein significantly greater amounts of fluid than desired are injected into or produced at least by one well of the multi-well system, in relation to other wells of the system. An aqueous caustic solution and an aqueous solution containing a polyvalent cation dissolved therein are caused to mix near the well bore environment of said one well, thereby forming an insoluble precipitate which reduces the permeability of the well bore environment substantially over the entire well bore interval. It has different characteristics that move it away from the embodiment being compared. 
         [0021]    U.S. Pat. No. 4,433,729 (A): Process for selectively reducing the fluid injection rate or production. Applicant: Marathon Oil Co (US). 
         [0022]    This patent is similar to the previous one. It utilizes a permeability-reducing chemical compound. 
         [0023]    CA2086594 (A1): Selective Placement of a permeability-reducing material to inhibit fluid communication between a near wellbore interval and an underlying aquifer. Applicant: Marathon Oil Co. (US). 
         [0024]    It&#39;s also based on injection of a permeability-reducing material. 
         [0025]    FR 2855552 (A1): A hydraulic fracturing method for operating e.g. oil wells, includes sequential, pressure-controlled phases of fluid, and ballast injection with pause for relaxation or formation. Applicant: Despax Damien (Fr). 
         [0026]    The method complies nine successive phases. Fracturing fluid loaded with ballast, ballast-free fluid, ballast mixed with fibers or coated adherents is used in the different phases. 
         [0027]    It is clearly shown that there is no interference with this invention. 
         [0028]    GB1179427 (A): Equipment for Injecting Fluids into an Underground Formation. Applied by Shell Int. research (NL). 
         [0029]    Fluid injected into a well is directed into one or two formations of different resistances to injection and separated by impermeable formation The “soak process” of oil Transport is carried out in a well. Steam injected into the well through a tubing is used to make oil flow into the tubing. Packers and labyrinth seals are alternatively used. 
         [0030]    These characteristics do not appear in this invention. 
         [0031]    RU2002126207 (A): Oil Well. Method for Oil Extraction from the Well and Method for Controllable Fluid Injection into Formation through the Well. Inventors: Stedzhemejer D. L., Vajngar K. D., Bernett R. R., Sevendzh V. M., Karl F. G. M, Khersh D. M. 
         [0032]    Well has casing pipe with a plurality of perforated sections and production string located inside the casing pipe. An alternating current source electrically linked with at least one of casing pipe and production string is located on ground surface and serves to conduct alternating current from ground surface into well. Controlled well section is also provided and it includes communication and control unit electrically linked with at least one of casing pipe and production string, having sensing means and electrically operated valves connected thereto. Communication and control unit is adapted to regulate flow between outer and inner production string parts. 
         [0033]    It is unnecessary to go on describing in detail this patent structure as it evidently does not collide with the object of this invention. 
         [0034]    U.S. Pat. No. 4,462,465 (A): Controlling injection fluids into wells. Applicant: Otis Eng. Co. (US). 
         [0035]    In this patent, a Side Pocket Fix Mandrel is described. It consists of a constructive variable of mandrels fixed to the bottom of conventional wells. 
         [0036]    In fact, the device is parallel with the main bore. A lateral side port communicates the receptacle with the exterior of the side pocket of the mandrel. A flow control assembly includes a sliding sleeve valve and a control valve, both designed to be removed from the receptacle. The sleeve valve is movable within the receptacle between a closed position and an open position relative to the side port, and includes collet fingers having outwardly projecting latching lugs for engagement in a receptacle latching recess in the closed position. The bore of the receptacle is slightly larger below the latching recess than it is above the recess, so that limited inward movement of the latching lugs, restrained by an insert within the sleeve valve, will permit movement of the valve downward to the open position but will not allow movement of the valve upward from the closed position, so long as the insert is in place. A control valve, to be selectively placed within the receptacle and latched with the sleeve valve includes a nose which is received within the sleeve valve and limits the inward deflection of the collet finger latching lugs. The control valve includes a latching lug for latching in another receptacle latching recess, when the sleeve valve has been moved to the lower open position. The control valve and sleeve valve have a coating latching mechanism so that when control valve is withdrawn, it lifts the sleeve valve to the closed position and then disengages from the sleeve valve. The sleeve valve includes an internal latching recess to enable withdrawal of the sleeve valve from the receptacle by a suitable pulling tool. 
         [0037]    To conclude, U.S. Pat. No. 4,671,352 (A): Apparatus for selectively injecting treating fluids into earth formations. Applicant: Arlington Automatics Inc. (US). 
         [0038]    The formation-treating apparatus described herein, is adapted to be dependently supported in a well bore from a pipe string and which includes upper and lower telescoped body members adapted to be selectively moved between upper and lower operating positions for controlling the injection of treating fluids into one or more earth formations traversed by the well bore. A pair of spaced packer elements are mounted on the lower member above and below a discharge port and cooperatively arranged for isolating a well bore interval that is to be treated by discharging one or more treating fluids in the pipe string from the port. To control the injection of treating fluids, retrievable valve means are also cooperatively arranged within the body members and adapted to be alternatively seated on upper and lower full-bore valve seats in the upper and lower bodies in response to movement of the bodies to their operating positions. In this manner, whenever the upper body member is moved to one of its operating positions, the valve means will be seated on the lower valve seated n the lower valve seat and unseated from the upper valve seat to open fluid communication between the pipe string and the treating tool. On the other hand, whenever the upper body member is moved to its other operating position, the valve means will be seated on the upper valve seat to trap treating fluids in the pipe string and discharge any unused fluids into the well bore. 
         [0039]    According to the background information found, it is evident that in known conventional pieces of equipment, to which the analyzed variables refer, all of them use fixed installations in the bottom hole. Consequently, when it is necessary to repair or replace any of the valves placed inside the mandrel, they have to be brought up to the surface. 
         [0040]    This necessarily demands the presence of specialized equipment at the well site to raise the mandrel by means of a cable or wire, and a jar socket or also other pieces of equipment used in the industry. 
         [0041]    In order to perform this operation, production has to be stopped, the device has to be raised from the bottom hole, necessary replacements are made, it has to be lowered and then, production is resumed. This produces costs in personnel, down time (during which the well is not operating) and lead time (between order and delivery of the equipment) at the oil field. 
         [0042]    This is the procedure for the maintenance of mechanical systems for conventional fixed installations. 
         [0043]    With this invention, all these problems are advantageously solved because the complete mandrel installation is raised. The mandrel is not fixed to the bottom hole because it is free. This results in an important time and extra hand work advantage because it can be operated by only one person from the surface by simply handling the valve set provided by the invention. 
         [0044]    To summarize, among other advantages of the invention described herein, the following can be mentioned: 
       1. Operational Advantage: 
       [0045]    Fluid injection is continuous and it is not interrupted in any of the operational stages as the formations are kept constantly pressurized. That is to say, the fundamental purpose of fluid injection (secondary recovery) is to pressurize the formations to achieve a larger formation volume in the surrounding or adjacent producing wells. 
       2. Economic Advantages: 
       [0046]    Minor investment or cost in initial equipment. 
         [0047]    No additional equipment is required, as wireline or slikeline or external personnel because valve setting up or removal, and all operations to fix both assemblies are performed in a significantly shorter time. This results in reduced time for equipment use. 
         [0048]    The operation is performed by control personnel of injector wells (either the operator or field supervisor) from the surface by handling the well head manifold valves. The change is immediately performed the moment it is required. 
         [0049]    Consequently, for example, for 2500 m deep installations, the FMA described herein, reaches the surface with all valves installed in about 30 minutes and requires a slightly shorter time in the downstroke. Both strokes are attained with the same injection fluid. This process will be indicated in the operational relation by means of the attached figures. 
         [0050]    This also implies that the installations are active during lead time and the time employed by the equipment to pull up every valve from the bottom hole and replace it for another. This operation is performed after the well is depressurized. This advantage is utilized several times while the well is producing, thus, accumulatively, adding a significant value. —It is worth noting that while the equipment is expected to reach the location and while the operation is being performed, the formation pressure is lost and so is its influence on the producing wells. 
         [0051]    A blind plug (not shown in Figures) is provided so that the tubing tightness may be verified at the initial, intermediate and final stage of the installation. 
         [0052]    Strokes can be performed to verify the accumulated depositions and in increasing periods, that is to say, beginning with short periods and increasing them in order to define the most suitable one for each well without depressurizing the formations, and with no additional equipment costs or external personnel. 
         [0053]    The inhibited fluid lodged in the Annular can be changed for maximum Casing protection in case of long injection periods without replacing injection valves or employing pulling equipment to disconnect the On Off ( 43 ). 
         [0054]    Besides, it can block any formation, examine or stimulate others. This is achieved by removing the FMA (C), leaving the formation circuit in service and blocking the other one. This also allows determining if there is any interference between any of the formations by injecting fluid in one and placing Amerada® Gauge, an instrument to measure pressure in the bottom hole, inside another mandrel to verify pressure variation in different injection flows. 
         [0055]    In order to make this invention, a free mandrel with protected casing, more comprehensible so that it can be put into practise easily, a detailed description of a preferable embodiment will be given in the following paragraphs. 
         [0056]    This will refer to the accompanying illustrative figures as a demonstrative example but not limiting the invention. Its components will be able to be selected among diverse equivalents without moving away from the invention principles as established in these documents. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0057]    The main invention components are schematically represented in different views in the Figures which accompany the present technical and legal description. As the component parts have a great length but a relatively small diameter, the Figures have been deliberately deformed so that the component parts can be distinguished to be explained. In some of the Figures hydraulic flow circulations, which are necessary for its operation, are identified with different conventional symbols: 
           [0000]    +=Injection fluid, provided by the Power Plant with the highest pressure flowing into all injection valves to be regulated according to the conditions of every formation.
 
#=Controlled fluid to be injected in the upper formation. It comes out through the lower end of the upper valve.
 
*=Controlled fluid to be injected in the lower formation. It comes through the lower end of the lower valve.
 
x=Fluid injected at low pressure through the Annular (e 1 ) to achieve the return of the Free Mandrel Assembly.
 
           [0058]    The pressure is approximately 2 to 3 kg/cm 2 . (Obviously the higher the pressure, the faster the return speed, but the mentioned pressure is the recommended one). Again, 30 minute return time is achieved in a 2500 m deep installation. 
           [0000]    --=Fluid removed from the tubing as the Free Mandrel assembly moves up to the surface. Its pressure is slightly lower than the one that pushes up the Free Mandrel Assembly. 
           [0059]    =White/empty space=Settled fluid or only with hydrostatic pressure (for example, in the annular between the casing and the tubing during the injection process). 
           [0060]    As an operative example of the invention, the simplest embodiment applied to purge water injection of only two formations: an upper and a lower one will be described hereinafter, as informed above. 
           [0061]    In this description, the Fluid concept will be taken in its widest sense, that is to say, referring to any type of liquid or gas. 
           [0062]    The invention equipment is essentially made up of the following operative assemblies. 
         A—Surface Assembly (SA) 
       B—Transport Assembly (TA) 
       C—Free Mandrel Assembly (FMA) 
       D—Fixed Bottom Hole Assembly (FBHA) 
       E—Complementary Assembly (CA) 
         [0063]    The Figures are as follows: 
           [0064]      FIG. 1  is an elevational longitudinal sectional view of the general layout of the invention. Here the position of a series of cross sections, numbers I to VIII, is shown to facilitate the functional explanation of the device. 
           [0065]      FIG. 2  is an enlarged partial view of one section of  FIG. 1  where the Surface Assembly (A), component of the invention, is shown in detail. 
           [0066]      FIG. 3  is a detailed view of the Transport Assembly (B), component of the invention. When operating, the only fluid that circulates (+) is the one that comes in through 73.025 mm (2″⅞) tubing ( 9 ) (i), goes through the Fishing Neck ( 11 ) and connects with the Upper Free Mandrel (C). 
           [0067]      FIG. 4  is an elevational sectional view where the characteristics of the Free Mandrel Assembly (C) and fluid circulation are shown. 
           [0068]      FIG. 5  shows both Transport (B) and Free Mandrel Assembly (C) as they run through the well from the Lubricator ( 3 ) to the Fixed Bottom Hole Assembly (D) in their downstroke, and from the Fixed Bottom Hole Assembly (D) to the Lubricator ( 3 ), in their upstroke. Different fluids are shown inside both assemblies, the incoming one (+), the one to be injected (#) in the upper formation and the one to be injected (*) in the lower formation. 
           [0069]      FIG. 6  is an elevational sectional view of the Fixed Bottom Hole Assembly (D) with its essential components. 
           [0070]      FIG. 7A  represents the Fixed Bottom Hole Assembly (D) in connection with the Free Mandrel (C) and Transport (B) Assemblies. The (+) fluid entering through the 73.025 mm (2″⅞) Tubing ( 9 ), the Upper Free Mandrel, the outcoming (#) fluid through the Middle Plug ( 17 ) radial passage ( 19 ), to be injected in the Upper Formation, in the plane of said Middle Plug radial passage ( 19 ). 
           [0071]      FIGS. 7B and 7A  are the same Figures but, in  7 B, the sectional plane is perpendicular to passage ( 19 ). The incoming fluid (+) path is shown. This reaches the lower valve through the middle plug ( 17 ) longitudinal passages (C 1 ) to be injected in the lower formation (*). 
           [0072]      FIG. 8  shows the Fixed Bottom Hole Assembly (D) screwed to the Complementary Assembly (E). The Transport Assembly (B) is inserted inside it with the Free Mandrel Assembly (C) during simultaneous injection in both formations. Fluids are also shown as they circulate through different passages. 
           [0073]      FIG. 9  only shows the injection in the upper formation (#) of the invention layout. The Transport (B), Free Mandrel (C), Fixed Bottom Hole (D) and Complementary Assemblies (E) are represented while showing operative hydraulic paths. 
           [0074]      FIG. 10 , a transverse sectional view on line III-III ( FIG. 1 ), shows the Upper Formation injection fluid in the Middle Plug ( 17 ) axial passage plane ( 19 ), the Fixed Bottom Hole Assembly (D), vertical passages (C 1 ) (+) and (C 2 ) (#) and Casing ( 10 ). The Annulars (e 2 ) (white space) and (e 6 ) (#) are also shown. 
           [0075]      FIG. 11  shows the injection in the Lower Formation (*) of the invention layout. In this Figure, The Transport (B), Free Mandrel (C), Fixed Bottom Hole (D) and Complementary (E) Assemblies are represented while showing operative hydraulic paths. 
           [0076]      FIG. 12 , a transverse cross-sectional view on line IV-IV ( FIG. 1 ), shows lower formation (*) fluids flowing out of the Lower Injection Valve ( 21 ) and fluids involved in lower formation injection. As in the previous Figure the Casing ( 10 ), the Fixed Bottom Hole Assembly (D) and the Lower Plug ( 22 ) are also shown together with (C 2 ) (white space) and (C 3 ) (white space) passages, and the Annular (e 2 ) (white space). 
           [0077]      FIG. 13  shows simultaneous injection in both formations. The incoming plant fluid (+) is controlled by the corresponding valves for Upper (#) and Lower (*) Formation injection. 
           [0078]    The Transport (B), Free Mandrel (C), Fixed Bottom Hole and (D) and Complementary Assemblies (E) are represented while showing operative hydraulic paths with the above mentioned symbols (+, #, *). 
           [0079]      FIG. 14 , a transverse cross-sectional view on line V-V ( FIG. 1 ), corresponds to Upper and Lower Formation simultaneous injection at the height of the Casing Protective Valve ( 36 ) of the Fixed Bottom Hole Assembly (D) lower end. Upper Formation injection fluid (#) goes through the Annular (e 9 ) defined by the FBHA (D), inner diameter and the outer diameter of the inner body of the Telescopic Union ( 37 ) and the (*) fluid through the inside of the Telescopic Union ( 37 ). 
           [0080]      FIG. 15 , a transverse cross-sectional view on line VI-VI ( FIG. 1 ), corresponds to the lower part of the Fixed Bottom Hole Assembly (D) below the Casing Protective Valve ( 36 ) with the simultaneous injection fluids (e 9 ) acting in the Upper (#) and Lower Formations (*) through the inside of the Injection Tube ( 40 ). 
           [0081]      FIG. 16 , a transverse cross-sectional view on line VII-VII ( FIG. 1 ), shows Upper and Lower Formation fluid injection, and fluid circulation in the Injector Plug ( 41 ) plane through the Rupture Disc passage ( 42 ). Casing Upper Perforations ( 49 ), Injection Tube ( 40 ) and the Injector Plug ( 41 ) together with Annulars (e 3 ) (#) and (e 11 ) (#) can also be seen. Lower Formation fluid (*) circulates through the inside of the Injection Tube ( 40 ). 
           [0082]      FIG. 17 , a transverse cross-sectional view on line VIII-VIII ( FIG. 1 ), only shows Lower Formation injection (*) and fluid circulation in the Shear Out ( 48 ) passage plane and Casing Lower Perforations ( 50 ) in that area. Annular (e 5 ) (*) and the Shear Out inner passage (*) (C 4 ) are also shown. 
           [0083]      FIG. 18  represents fluid distribution during the Free Mandrel Assembly (C) upstroke and when the System injects in both formations without flow control and with low pressure (x). It is only when the Free Mandrel Assembly (C) hooked in the Transport Assembly (B) is inserted in its position inside the Fixed Bottom Hole Assembly (D) that the injection in both formations is controlled. 
           [0084]    The resulting hydraulic circuits can be identified with the symbols that represent the operating pressures. In the Annular (e 1 ) (x) and in the 73.026 mm (2″⅞) tubing ( 9 ) (i) (--). 
           [0085]      FIG. 19  shows a transverse cross-sectional view on line I-I ( FIG. 1 ) with fluid circulation in simultaneous injection process in both formations. This takes place at the Well Head ( 8 ). The Casing ( 10 ) and the 73.026 mm (2″⅞) Tubing ( 9 ) (i) are shown. There is only hydrostatic pressure (white space) in the annular between them (e 1 ). There is (+) in the inside of the Tubing ( 9 ). 
           [0086]      FIG. 20 , a transverse cross-sectional view on line II-II ( FIG. 1 ), shows fluid circulation in the Free Mandrel Assembly upstroke, (--) flowing inside the 73.026 mm (2″⅞) Tubing ( 9 ) (i), and (x) through (e 1 ). 
       
    
    
     DESCRIPTION OF THE INVENTION COMPONENTS 
       [0087]      FIGS. 1-20  above, specially developed for this description, will be taken as reference. In these Figures, the main details of all the parts of the essential assemblies that make up the invention have been taken into account. 
         [0088]    These parts are the following:
     1 —Pipeline from Water Power Plant     2 —Catcher     3 —Lubricator     4 —Mast     5 —Impeller     6   1 —V1 (Standard Valve)     6   2 —V2 (Standard Valve)     6   3 —V3 (Standard Valve)     6   4 —V4 (Standard Valve)     6   5 —73.026 mm (2″⅞) conventional full passage Injection Valve     7 —Retention Valve     8 —Well Head     9 —73.026 mm (2″⅞) Tubing   i—Tubing ( 9 ) Interior (Direct)   e 1 —Annular between 9 and 10     10 —Casing     11 —Fishing Neck     12 —Retention Valve     13 —Rubber Cups     14 —Lower Connector     15 —Outer Jacket     16 —Seal Ring     17 —Middle Plug     18 —Upper Formation Injection Valve     19 —Middle Plug radial passage     20 —Seal Ring     21 —Lower Formation Injection Valve     22 —Lower Plug     23 —Seal Ring     24 —Upper Body     25 —Upper Packer Collar     26 —Seal Ring     27 —Lock Nut     28 —Lower Body     29 —Seal Ring     30 —Spacer     31 —Spacer Injection outlet Perforation     32 —Lower Packer Collar     33 —Seal Ring     34 —Seat     35 —Seal Ring     36 —Casing Protective Valve     37 —Telescopic Union inner body     38 —Seal Ring     39 —Telescopic Union outer body     40 —Injection Tube     41 —Injector Plug     42 —Rupture Disc passage     43 —On Off     44 —Upper Packer     46 —Lower Packer     47 —60.325 mm (2″⅜) Tubing     48 —Shear Out     49 —Casing Upper Perforations—Upper Formation     50 —Casing Lower Perforations—Lower Formation   
 
         [0144]    In  FIGS. 10 ,  12 ,  14 ,  15 ,  16 ,  17 ,  19  and  20 , which correspond to different transverse cross sectional views of the Casing, there are vertical passages and Annulars determined by different parts coupled together in the installation. Injection fluids circulate through these vertical passages: 
         [0000]    C 1 —It is placed in the Middle Plug ( 17 ). They are passages in the Free Mandrel Assembly (C) central body.
 
C 2 —The Annular (e 6 ) where the regulated pressure (#) is discharged through the Upper Formation Injection Valve ( 18 ) and conducted to the Annular (e 9 ) placed between the Telescopic Union inner body ( 37 ) and the interior of the Fixed Bottom Hole Assembly (D). C 2  are eccentric vertical passages in the FBHA (D) which connect (e 6 ) with (e 9 ).
 
C 3 —Vertical passage containing Valve ( 36 )
 
C 4  Shear Out inner passage
 
         [0145]    Note: Annular space or Annular is the space between the inner diameter of an exterior tube and the larger diameter of an interior tube. Both tubes can or cannot be concentric. There are several Annulars in this invention layout: 
         [0000]    e 1  Between the Casing ( 10 ) and the 73.026 mm (2″⅞) Tubing ( 9 )
 
e 2  Between the Casing ( 10 ) and the FBHA (D)
 
e 3  Between the Casing ( 10 ) and the Injector Plug ( 41 )
 
e 4  Between the Casing ( 10 ) and the 60.325 mm (2″⅜) Tubing ( 47 )
 
e 5  Between the Casing ( 10 ) and the Shear Out ( 48 )
 
e 6  Between the Middle Plug ( 17 ) and the FBHA (D)
 
e 7  Between the Upper Mandrel Jacket ( 15 ) and the Upper Injection Valve ( 18 )
 
e 8  Between the Lower Valve ( 21 ) and the FBHA (D) interior
 
e 9  Between the Telescopic Union inner body ( 37 ) and the inside of the FBHA (D)
 
e 10  Between the Telescopic Union outer body ( 39 ) and the On Off ( 43 )
 
e 11  Between the Injection Tube ( 40 ) and the Injector Plug ( 41 )
 
         [0146]    As all components and their characteristics have been defined, here follows their layout and existing relationships among them. 
         [0147]    According to  FIG. 1 , the equipment is composed of A, B, C, D, and E Assemblies. In this Figure, transverse cross-sectional lines are indicated (I-VIII) to facilitate the comprehension of the structures of said assemblies. Only some components are indicated to facilitate the comprehension of the invention structure: 
         [0000]      9 —73.026 mm (2″⅞) Tubing
 
i—Tubing ( 9 ) Interior. (Direct)
 
         10 —Casing 
       [0148]      37 —Telescopic Union inner body 
         38 —Telescopic Union Seal Rings 
       [0149]      39 —Telescopic Union outer body 
         40 —Injection Tube 
       41 —Injector Plug 
       [0150]      42 —Rupture Disc passage 
         43 —On Off 
       44 —Upper Packer 
       46 —Lower Packer 
       [0151]      47 —60.325 mm (2″⅜) Tubing 
         48 —Shear Out 
       49 —Upper Formation Casing Perforations 
       50 —Lower Formation Casing Perforations 
       [0152]      FIG. 2  corresponds to Surface Assembly (A) made up of: 
         [0000]      1 —Pipeline from Water Power Plant 
         2 —Catcher 
       3 —Lubricator 
       4 —Mast 
       5 —Impeller 
       6   1 —V1 (Standard Valve) 
       6   2 —V2 (Standard Valve) 
       6   3 —V3 (Standard Valve) 
       6   4 —V4 (Standard Valve) 
       [0153]      6   5 —73.026 mm (2″⅞) conventional full passage Injection Valve 
         7 —Retention Valve 
       8 —Well Head 
       [0154]      9 —73.026 mm (2″⅞) Tubing 
       I—Tubing Interior ( 9 ) (Direct) 
       [0155]    e 1 —Annular between 9 and 10 
         10 —Casing 
       [0156]      FIG. 3  corresponds to Transport Assembly (B) made up of: 
         11 —Fishing Neck 
       12 —Retention Valve 
       13 —Rubber Cups 
       14 —Lower Connector 
       [0157]    In this Figure the injection fluid provided from the Plant is represented by the (+) symbol which crosses it all over. 
         [0158]      FIG. 4  corresponds to the Free Mandrel Assembly (C) made up of: 
         15 —Outer Jacket 
       16 —Seal Ring 
       17 —Middle Plug 
       18 —Upper Formation Injection Valve 
       [0159]      19 —Middle Plug radial passage 
         20 —Seal Ring 
       21 —Lower Formation Injection Valve 
       22 —Lower Plug 
       23 —Seal Ring 
       [0160]    Incoming injection fluid is represented here with the (+) symbol. 
         [0161]    It is divided into two streams: 
         [0000]    1—It enters through the upper part of the Injection Regulating Upper Valve ( 18 ) which delivers the already controlled fluid (#) to be injected in the upper formation through the Middle Plug ( 17 ) radial passage ( 19 ).
 
2—It circulates through the Annular (e 7 ) to guide the fluid through the Middle Plug ( 17 ) vertical passages (C 1 ) (not shown in this view) and feed with injection fluid (+) the Lower Injection Valve ( 21 ) which delivers the controlled fluid (*) to inject in the Lower Formation through the Lower Plug ( 22 ).
 
         [0162]    In  FIG. 5 , the fluid (+) goes through the Transport Assembly (B) and the Free Mandrel Assembly (C) and enters the injection fluid inlet (+) in its upper part. The controlled fluid (#) continues towards the Upper Formation by the lower part of the Upper Injection Valve ( 18 ) and comes out through the Middle Plug passage ( 19 ). Injection Fluid (+) continues through the vertical passages, not shown in this view, until it feeds the Lower Injection Valve ( 21 ) in its upper part and, from here, the controlled fluid (*) comes out to inject the Lower Formation through the Lower Plug ( 22 ). 
         [0163]      FIG. 6  represents the Fixed Bottom Hole Assembly (D) made up of: 
         24 —Upper Body 
       25 —Upper Packer Collar 
       26 —Seal Ring 
       27 —Lock Nut 
       28 —Lower Body 
       29 —Seal Ring 
       30 —Spacer 
       [0164]      31 —Spacer Injection outlet Perforation 
         32 —Lower Packer Collar 
       33 —Seal Ring 
       34 —Seat 
       35 —Seal Ring 
       36 —Casing Protective Valve 
       10 —Casing ( 10 ) 
       [0165]    e 2 —Annular
 
C 2 —Vertical passage
 
C 3 —Vertical passage
 
         [0166]    In  FIGS. 7A and 7B , injection fluid (+) enters through 73.026 mm (2″⅞) ( 9 ) (i) Tubing into the Assembly (B) upper end, goes through the Transport Assembly (B), then goes into the Free Mandrel Assembly (C) through the upper end of the Upper Injection Valve ( 18 ) and comes out already controlled (#) towards the Upper Formation going through the Annular (e 6 ) and the Spacer Injection outlet Perforation ( 31 ). Then it goes through vertical passages (C 2 ) of the FBHA (D) and the Annular (e 9 ). Simultaneously, the other injection fluid stream (+) coming into the Upper Mandrel flows through the Annular (e 7 ), the vertical passages of the Middle Plug (C 1 ), (only shown in  FIG. 7B ) until it reaches the upper end of the Lower Injection Valve ( 21 ), which controls the fluid to be injected in the Lower Formation (*). Said injection fluid (+) stream goes through the Lower Plug ( 22 ) and continues through the Telescopic Union ( 37 ). 
         [0167]      FIG. 8  corresponds to the B, C, D and E Assemblies. In addition to the already defined components and so as not to fall into repetitions, these are the remaining ones: 
         [0000]      37 —Telescopic Union inner body
 
 39 —Telescopic Union outer body
 
         40 —Injection Tube 
       41 —Injector Plug 
       [0168]      42 —Rupture Disc passage 
         43 —On-Off 
       44 —Upper Packer 
       [0169]    In this Figure, the injector circuits of both formations are represented. The injection fluid (+) enters through 73.026 mm (2″⅞) Tubing ( 9 ) (i), goes through the Transport Assembly (B), gets into the Free Mandrel Assembly (C) through the upper end of the Upper Injection Valve and comes out as controlled fluid (#) towards the Upper Formation through the Middle Plug radial passage ( 19 ). It passes through the Annular (e 6 ) and the Spacer Injection outlet Perforation ( 31 ). Then it channels through the FBHA (D) vertical passages (C 2 ), the Annulars (e 9 ), (e 10 ) and (ell), and the Rupture Disc passage ( 42 ). 
         [0170]    Simultaneously, the other injection fluid stream (+) that goes into the Upper Mandrel, flows through the Annular (e 7 ), the Middle Plug ( 17 ) vertical passages (C 1 ) until it reaches the upper end of the Lower Injector Valve ( 21 ) which controls the fluid to be injected in the Lower Formation. (*). It goes through the Lower Plug ( 22 ) and continues through the inside of the Telescopic Union ( 37  and  39 ), the Injection Tube ( 40 ) and the Injector Plug ( 41 ). Meanwhile the Annular (e 1 ), (e 2 ) and the vertical passage (C 3 ) are kept without pressure (white space). 
         [0171]    In  FIGS. 9 ,  11  and  13 , the invention components that have not been mentioned follow below. 
         46 —Lower Packer 
       [0172]      47 —60.325 mm (2″⅜) Tubing 
         48 —Shear Out 
       [0173]      49 —Casing Upper Perforations—Upper formation
 
 50 —Casing Lower Perforations—Lower formation
 
         [0174]    In  FIG. 9 , it can be observed that there is no pressure in the Annulars (e 1 ), (e 2 ) and in the passage (C 3 ) (white space). The Upper Formation Injection is the only one represented, that is, the Upper Injection Valve ( 18 ) is regulating the flow (#) and the lower one ( 21 ) is blocked. So, the lower valve ( 21 ) is represented as if it were a solid body that blocks fluid passage. For that reason, the central passage (corresponding to the Lower Formation circuit) is shown without pressure or fluid (white space). Consequently, the Injection Plant pressure (+) acts through 73.026 mm (2″⅞) Tubing ( 9 ) (i), as the regulated fluid (#) is injected to the Upper Formation through the Casin Upper Perforations ( 49 ). Through the Annular (e 1 ), (e 2 ) and the passage (C 3 ) there is no fluid circulation. There is only hydrostatic pressure (white space). 
         [0175]    In  FIG. 10 , a transverse cross-sectional view on line ( FIG. 1 ), the Annulars (e 2 ) are marked as empty (white space). The Plant injection fluid circulation (+) goes through the Middle Plug ( 17 ) vertical passages (C 1 ) and comes out regulated (#) through the Middle Plug ( 17 ) transversal (radial) passage ( 19 ) to the Annular (e 6 ) and through the vertical passages (C 2 ) (#). 
         [0176]    In  FIG. 11 , it can be observed that in the Annulars (e 1 ),(e 2 ) and the passage (C 3 ) there is no pressure (white space) as only the Lower Injection Formation is represented. The injection fluid (+) that enters through 73.026 mm (2″⅞) ( 9 ) (i) goes through the Transport Assembly (B) and comes into the Free Mandrel Assembly (C) through the upper end of the blind Upper Injection Valve (it does not allow fluid passage and it is represented as a solid). The Annular (e 6 ), Spacer Injection outlet Perforation, the FBHA (D) vertical passages (C 2 ), the Annulars (e 9 ), (e 10 ) and (e 11 ) and the Rupture Disc passage ( 42 ) have no pressure. No fluid circulation is observed in the figure. 
         [0177]    At the same time, the other injection fluid stream (+) coming into the Upper Mandrel flows through the Annular (e 7 ) and the Middle Plug vertical passages (C 1 ) until it reaches the upper end of the Lower Injector Valve ( 21 ), which controls the fluid to be injected in the Lower Formation (*). Said injection fluid stream (*) goes through the Lower Plug ( 22 ) and continues through the interior of the Telescopic Union ( 37  and  39 ), Injection Tube ( 40 ), Injector Plug ( 41 ), 60.325 (2″⅜) ( 47 ) Tubings, Lower Packer ( 46 ), the 60.325 mm (2″⅜) ( 47 ) and Shear Out ( 48 ). 
         [0178]    Meanwhile, the Annulars (e 1 ) and (e 2 ), and the vertical passages (C 2 ) and (C 3 ) are kept without pressure (white space). 
         [0179]      FIG. 12 , a transverse cross-sectional view on line IV-IV ( FIG. 1 ), shows the controlled fluid (*) circulation to be injected in the Lower Formation through the Lower Plug ( 22 ) central passages. Meanwhile the Annular (e 2 ) and the vertical passages (C 2 ) and (C 3 ) are kept without pressure (white space). 
         [0180]      FIG. 13  shows that in the Annulars (e 1 ) and (e 2 ), and passage (C 3 ) there is no pressure as simultaneous Injection in the Upper (#) and Lower (*) Formations with regulated fluids are represented here. Valves ( 18 ) and ( 21 ) are regulating injection fluids in both formations. Consequently, the injection fluid (+) enters the 73.026 mm (2″⅞) Tubing ( 9 ) (i), goes through the Transport Assembly (B) and flows into the Free Mandrel Assembly (C) through the Injection Valve upper end ( 18 ) to the upper formation (#) and in the lower one (*), going out through perforations ( 49 ) and ( 50 ). To complete the regulated fluid circuit to be injected in the Upper Formation as shown in  FIG. 9 , this fluid course is added as it comes out of the Rupture Disc passage ( 42 ) until it gets into the chamber delimited as follows: 
         [0000]    1. In the upper part by the lower side of the Upper Packer ( 44 )
 
2. In the outer part by the Casing ( 10 )
 
3. In the inner part by the Telescopic Union ( 37  and  39 ), Injection Tube ( 40 ) and Injector Plug ( 41 )
 
4. In the lower part by the upper side of the Lower Packer ( 46 )
 
         [0181]    That is to say, the regulated fluid (#) is forced to go through the Casing Upper Perforations ( 49 ) and enter the Upper Formation. 
         [0182]    To complete the regulated fluid circuit to be injected in the Lower Formation (*) as shown in  FIG. 11 , this fluid course is added as it comes out of the Injector Plug central passage ( 41 ), 60.325 mm (2″⅜) Tubings ( 47 ), Lower Packer ( 46 ), 60.325 mm (2″⅜) Tubings ( 47 ), and Shear Out ( 48 ), until it gets into the chamber delimited as follows: 
         [0000]    1. On the upper part by the lower side of the Lower Packer ( 46 )
 
2. On the outer part by the Casing ( 10 )
 
3. In the inner part by the 60.325 mm (2″⅜) Tubings and the Shear Out ( 48 )
 
4. On the lower part by the bottom hole
 
         [0183]    That is to say, the regulated fluid (*) is forced to go through the Casing Lower Perforations ( 50 ) and enter the Lower Formation. 
         [0184]      FIG. 14 , a transverse cross-sectional view on line V-V ( FIG. 1 ), shows that there is no fluid circulation through the Annular (e 2 ) and the white (C 3 ) passage, that is to say, no fluid circulation is observed within them. Through the interior of the Telescopic Union ( 37 ) inner body, the controlled fluid (*) is conducted to the Lower Formation (*), and the controlled fluid (#) for the Upper Formation is conducted through the Annular (e 9 ). 
         [0185]      FIG. 15 , a transverse cross-sectional view on line VI-VI ( FIG. 1 ), represents the Lower Formation injection fluid (*) circulation through the Injection Tube ( 40 ) central passage and the Upper Formation controlled fluid (#) through the Annular (e 9 ) while there is no circulation through the Annular (e 2 ). 
         [0186]      FIG. 16 , a transverse cross-sectional view on line VII-VII ( FIG. 1 ), represents the Upper Formation fluid injection (#) that comes through the Annular (e 11 ), goes through the Rupture Disc passage ( 42 ), fills the Annular (e 3 ) and goes through the Casing Upper Perforations ( 49 ) until it gets to the Upper Formation. The Lower Formation injection fluid (*) goes through the Injection Tube ( 40 ) interior. 
         [0187]      FIG. 17 , a transverse cross-sectional view on line VIII-VIII ( FIG. 1 ), shows injection fluid (*) flowing to the Lower Formation through the Shear Out ( 48 ) central passage (C 4 ) and the Annular (e 5 ), coming out through Casing Lower Perforations ( 50 ) until it (*) reaches the Lower Formation. 
         [0188]      FIG. 18  represents the recovery chamber where it can be seen how low pressure fluid (x) is injected through the annular to recover el TA (B) and the FMA (C). Their upstroke is shown. Fluid (x) with the necessary pressure to perform the TA and FMA upstroke has too be injected through the annular (e 1 ). This fluid enters through the Casing Protective Valve ( 36 ). This makes the TA (B) and the FMA (C) move to the surface where they will finally insert into the Catcher ( 2 ). Fluid (---) with a pressure slightly lower than injection pressure flows over these assemblies. Low pressure (x) pressurizes both formations. This particularity has already been mentioned as a technical operational advantage of the invention. It is advantageous because the formations are never depressurized. 
         [0189]      FIG. 19 , a transverse cross-sectional view on line I-I ( FIG. 1 ), shows how Injection Fluid (+) coming from the Water Plant (not shown here) is injected through 73.026 mm (2″⅞) Tubing ( 9 ) Interior (i) (Direct), whereas the annular (e 1 ) between the 73.026 mm (2″⅞) Tubing ( 9 ) and the Casing ( 10 ) shows no fluid circulation. 
         [0190]      FIG. 20 , a transverse cross-sectional view on line II-II ( FIG. 1 ), shows that the dislodged fluid (---) returns through Tubing  9  (i) (Direct) due to the FMA (C) upstroke. Low pressure fluid (x) is injected through the annular (e 1 ) between ( 9 ) and ( 10 ) when the FMA (C) upstroke is required. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0191]    According to the scheme represented in  FIG. 1  of the Free Mandrel System, Protected Casing, the invention layout is composed of: 
       A—Surface Assembly (SA) 
     B—Transport Assembly (TA) 
     C—Free Mandrel Assembly (FMA) 
     D—Fixed Bottom Hole Assembly (FBHA) 
     E—Complementary Assembly (CA) 
       1 —(A)—Surface Assembly (SA) 
       [0192]    It is schematically represented in  FIG. 2 . It is the assembly of conventional parts such as valves ( 6   1 ), ( 6   2 ), ( 6   3 ), ( 6   4 ), ( 7 ) and ( 8 ) properly laid out to perform the required operation of the Free Mandrel System, Protected Casing, with additional parts specially designed to complement this operation. These parts are the Lubricator ( 3 ) with the Catcher ( 2 ), the Mast ( 4 ) to release and recover the Free Mandrel (C) and the Transport (B) Assemblies together by using the Mast ( 4 ) and the Impeller ( 5 ) to make the system work. The SA is screwed over the Well Head ( 8 ) in the 73.026 mm (2″⅞) Full Passage Conventional Injection Valve ( 6   5 ). The Lubricator ( 3 ) with the Mast ( 4 ) and the Catcher ( 2 ) in its lower end is screwed on Valve ( 6   5 ). Injection Fluid comes from the Pipeline ( 1 ) into the well through Valve ( 6   1 ). When this Valve is open, the well can inject simultaneously in all Formations. When it is shut, it does not allow the injection fluid flow and the well does not operate. (Stand-By stage). 
         [0193]    The Pipeline ( 1 ) diverges into a second branch and Valve ( 6   2 ) is shut during that operation. When it is open, it allows the injection fluid to flow to the Impeller ( 5 ). This injects at low pressure in the Annular (e 1 ) to perform the FMA (C) upstroke which is required to recover all installed Injection Valves. 
         [0194]    This procedure is used to drive the Impeller ( 5 ) Circulation Pump, which uses this fluid as driving power. 
         [0195]    The Valve ( 6   3 ), placed at the upper end of the Lubricator ( 3 ) is kept closed during the injection. It is only opened to retrieve the FMA (C) (upstroke). 
         [0000]    The Impeller ( 5 ) allows the injection fluid to circulate from the Casing ( 10 ) to the 73.026 (2″⅞) Tubing ( 9 ) (i), through the Casing Protective Valve ( 36 ) for the FMA (C) upstroke to the surface. 
         [0196]    It is clarified that the Impeller is a low pressure pump, with no movable parts. It uses the Plant fluid as power fluid and injects it in the Annular (e 1 ) with the fluid it sucks from 73.026 (2″⅞) Tubing ( 9 ) (i). 
         [0197]    This operation enables low pressure circulation to drive the Transport Assembly (B) and the Free Mandrel Assembly (C) in their upstroke from the FBHA (D) until it is trapped in the Catcher ( 2 ). 
         [0198]    The Valve ( 6   1 ) is kept open for the downstroke whereas Valves ( 6   2 ), ( 6   3 ) and ( 6   4 ) are kept shut. The injection fluid push and the FMA (C) weight will insert the FMA (C) into the FBHA (D) while automatically beginning the selective injection in the Formations. 
         [0199]    For this operation, a flow, not larger than 400 m 3 /a day, is recommended to go through Valve ( 6   1 ) to prevent the FMA (C) from inserting into the FBHA (D) with excessive impact. In most downstrokes, the Operator opens Valve ( 6   1 ). Then, he can leave the location as the operation is completely automatic. 
         [0200]    Only in injected flows over 400 m 3 /a day, it is necessary for the Operator to liberate the flow completely after 30 minutes to leave the well in ideal operating conditions. 
         [0201]    The above-mentioned Surface Assembly (A) is screwed to the Well Head ( 8 ). Its hydraulic circuit consists of conventional valves and the Impeller with a feeding line coming from the Water Plant. 
         [0202]    The Pipeline separates into two branches. The first one goes into the SA (A) central passage through a first Valve ( 6   1 ) and the second branch connects with the Impeller ( 5 ) through a second Valve ( 6   2 ). The Impeller connects to the Annular (e 1 ) through the Well Head ( 8 ). 
         [0203]    The third Valve ( 6   3 ) is placed at the Lubricator ( 3 ) outlet and is closed while operating. When it is open, it allows the 73.026 (2″⅞) Tubing ( 9 ) (i) fluid to re-circulate to the Annular (e 1 ) for the FMA (C) upstroke. 
         [0204]    The 73.026 mm (2″⅞) Full Passage Injection Valve ( 6   5 ), connected to the Well Head ( 8 ), allows the FMA (C) to run in both strokes and the injection and return fluids flow to retrieve the FMA (C). 
         [0205]    The Valve ( 6   4 ) is used to recover the FMA (C) without the Impeller ( 5 ) assistance or when it does not work properly. This process works by opening Valve ( 6   2 ) to let a small volume of injection fluid flow, keeping the Annular (e 1 ) pressure below 5 kg/cm 2 , and making the fluid circulate through Valve ( 6   4 ). A tank truck is used to collect the fluid coming from the FMA (C). 
         [0206]    As a reference, it can be stated that for the mentioned depth, that is, 2,500 m, the fluid volume is approximately 7500 liters. 
       2—(B)—TRANSPORT ASSEMBLY—TA 
       [0207]    It is schematically represented in  FIG. 3 . It is one of the dynamic components that moves with the Free Mandrel Assembly (C) from the Surface Assembly (A) to its insertion in the Fixed Bottom Hole Assembly (D) during the FMA (C) downstroke or vice versa, upstroke. It consists of a Lower Connector ( 14 ), a Retention Valve ( 12 ) for the upstroke, Rubber Cups ( 13 ) and the Fishing Neck ( 11 ) screwed together. The Transport Assembly (B) is used to transport the Free Mandrel Assembly (C). 
         [0208]    Obviously, said Assembly (B) is specially designed according to the operating requirements of the invention device. 
         [0209]    It is essential in the FMA (C) upstroke as the Rubber Cups ( 13 ) expand against the 73.026 mm (2″⅞) Tubing ( 9 ) taking the utmost advantage of its volume when they receive the upward injection fluid push. This push also closes the Retention Valve ( 12 ) for the greatest fluid efficiency. 
         [0210]      FIG. 5  shows the Transport Assembly (B) screwed to the Free Mandrel Assembly (C) upper end. 
         [0211]    The TA ends in its upper extreme in a normalized Fishing Neck ( 11 ), according to API (American Petroleum Institute) specifications, which allows it to be trapped by the Catcher ( 2 ) ( FIG. 2 ) at the end of the upstroke and detached from it at the downstroke start. 
         [0212]    In case of any inconvenience, TA (B) and FMA (C) can be trapped by means of Slickeline equipment. 
         [0213]    The TA (B) ends in its lower extreme in the Lower Connector where it is screwed to the Free Mandrel Assembly (C). 
         [0214]    The assembly of (B) and (C) is schematically represented in  FIG. 5 . 
       3 (C)—Free Mandrel Assembly—FMA: 
       [0215]    It is schematically represented in  FIG. 4 . It is the main dynamic component that travels from SA (A), in its downstroke, and is inserted into the FBHA (D) to begin selective injection in different Formations. 
         [0216]    In its upstroke, it moves injector valves to be examined or removed. 
         [0217]    It is one of the five Assemblies composed of totally new parts. It has been graphically represented in  FIGS. 4 ,  5 ,  7 A,  7 B,  8 ,  9 ,  11 ,  13  and  18 . 
         [0218]    It has been specially designed for the operation of the system applied to selective injection in different Formations. As it has been above-mentioned, it can be applied to several formations but in this specific explanation, it has been reduced to only two formations to facilitate the explanation. 
         [0219]    Every Mandrel contains an Injection Valve in its interior, except the Lower one which is only integrated by an Injection Valve specially designed for this purpose. 
         [0220]    In  FIG. 4 , a Free Mandrel Assembly to inject in two formations is schematically represented. 
         [0221]    The difference between the Upper Mandrel which contains an Upper Formation Injection Valve ( 18 ) in its interior and the Lower Mandrel composed only by a Lower Formation Injection Valve ( 21 ) specially designed, can be observed in  FIG. 4 . 
         [0222]    The Upper Free Mandrel is screwed at its upper end to the Transport Assembly (B) by the Outer Jacket ( 15 ). This closes with the FBHA (D) Upper Packer Collar ( 25 ) through the Seal Ring ( 16 ). It contains the Upper Formation Injector Valve ( 18 ) in its interior. It is screwed to the Middle Plug ( 17 ) in its lower end. 
         [0223]    The Middle Plug ( 17 ) closes with the FBHA (D) Lower Packer Collar ( 32 ) with Seal Ring ( 20 ). 
         [0224]    The Injection Valve ( 21 ) is screwed to the Middle Plug ( 17 ) lower end. This valve corresponds to the Lower Formation which ends in the Lower Plug ( 22 ). It closes with Seal Rings ( 23 ) in the Seat ( 34 ) in  FIG. 6  of the Fixed Bottom Hole Assembly (D). 
         [0225]      FIG. 4  shows the incoming fluid (+) which comes out regulated (#) from the Upper Formation Injection Valve lower end to fulfill the upper formation required conditions. Whereas, the incoming fluid (+) moves through the annular (e 7 ) limited on the outside by the Upper Mandrel Jacket ( 15 ), goes through the Middle Plug ( 17 ) passages (C 1 ) (not shown in this Figure), reaches the Lower Mandrel and is admitted by the Lower Formation Injection Valve ( 21 ) which transforms the fluid into (*). 
         [0226]    As it has been previously described, the Upper Mandrel, which contains the Upper Formation Injection Valve ( 18 ), receives the Plant fluid (+) and the regulated fluid for upper formation (#) required conditions finally comes out from the Upper Injection Valve lower end. 
         [0227]    The incoming fluid (+) moves through the annular (e 7 ) limited on the outside by the Upper Mandrel Jacket ( 15 ) and on the inside by the Upper Formation Injection Valve ( 18 ). This (+) fluid reaches the Lower Mandrel through the Middle Plug ( 17 ) passages (C 1 ) (not shown in  FIG. 4 ) and is admitted by the Lower Formation Injection Valve ( 21 ). That is to say, the Lower Formation Injection Valve ( 21 ) receives the incoming fluid (+) and transforms it into the fluid with the necessary conditions to be injected in the Lower Formation (*). 
       4—(D)—Fixed Bottom Hole Assembly—FBHA: 
       [0228]    It is schematically represented in  FIG. 6 . This Assembly is static. The Workover Equipment installs it with its lower end screwed to the On Off ( 43 ) upper end, and its upper end to the first 73.026 (2″⅞) Tubing ( 9 ) (i) lower screw of the string that communicates it with the Well Head ( 8 ). 
         [0229]    The FBHA (D) lodges the FMA (C) so that hydraulic circuits are completed. They allow the Upper Packer ( 44 ) and the Lower Packer ( 46 ) to be fixed from the surface without having to resort to Slickeline equipment or similar ones. Then Selective Injection is performed in every Formation. 
         [0230]    The FMA (C) seals the Upper Packer Collar ( 25 ) with Seal Ring ( 16 ) ( FIG. 4-6 ) and separates the injection fluid (+) contained in the 73.026 mm (2″⅞) Tubing ( 9 ) (i) that enters the Upper Mandrel through the Transport Assembly (B). 
         [0231]    The Upper Free Mandrel is provided with a Middle Plug ( 17 ) in its lower end. ( FIG. 4 ). This Middle Plug seals the Lower Packer Collar ( 32 ) with Seal Ring ( 20 ) ( FIG. 4-6 ) and prevents the fluid regulated by the Upper Formation Injection Valve from passing to the FBHA (D) lower chamber. 
         [0232]    The Lower Formation Injector Valve ( 21 ) receives Injection fluid (+) through the Middle Plug ( 17 ) vertical passages (C 1 ), regulates the flow that is required for the Lower Formation Injection, and channels it through the Lower Plug ( 22 ) ( FIG. 4 ) and to the Injection Tube ( 40 ) through the Telescopic Union ( 37 ). 
         [0233]    The Casing ( 10 ) Protective Valve ( 36 ) is located in this lower chamber. It allows fluid passage to go through the Annular (e 1 ) to 73.026 (2″⅞) Tubing ( 9 ) (i) Interior (Direct) but prevents the fluid from passing from the 73.026 mm (2″⅞) Tubing to the Annular (e 1 ). This keeps the Casing ( 10 ) totally isolated from injection fluid pressure and contact. 
         [0234]    In the upstroke, it impulses the Free Mandrel Assembly (C) to remove injection valves. 
         [0235]      FIGS. 7  A and B represent the TA (C) assembled with the FMA (C) inserted in the FBHA (D) in operating position, that is to say, ready to inject selectively in both Formations. 
       5—(E)—Complementary Assembly—CA: 
       [0236]    It has been schematically represented in  FIG. 8  where it is screwed in the lower part of the FBHA (D). 
         [0237]    It is composed of specific parts that correspond to the invention equipment design. They are complemented by other parts of common use in Petroleum Industry. 
         [0238]    On the outside, the lower part of the FBHA (D) screws in the upper part of the On Off ( 43 ) which, in its lower part screws in the Upper Packer upper end ( 44 ). (Both are common use parts). The Injector Plug ( 41 ) screws in the Upper Packer lower part. This Plug lodges the passage where the Rupture Disc is located ( 42 ). Both are specific parts of this equipment. This Rupture Disc is used to fix the Upper Packer ( 44 ) and, once it has been fixed, the pressure is raised until it bursts and enables the circuit to perform Upper Formation Injection. 
         [0239]    The Telescopic Union Inner Body ( 37 ) is screwed to the FBHA (D) internally and in a concentric pattern. It slides and seals inside the Telescopic Union Outer Body ( 39 ). 
         [0240]    The Telescopic Union has two functions: 
         [0000]    I) When the Upper Packer ( 44 ) fixes, there is a longitudinal displacement that is absorbed by the Telescopic Union.
 
II) It allows On Off ( 43 ) rotation and longitudinal displacement to remove the FBHA (D) with the tubing string.
 
         [0241]    The Injection Tube ( 40 ) is screwed in the lower part of the Telescopic Union Outer Body ( 39 ) and is screwed in the Injector Plug ( 41 ) in its lower end. 
         [0242]    The 60.325 mm (2″⅜) ( 47 ) Tubings that connect the Injector Plug ( 41 ) with the Lower Packer ( 46 ) are schematically represented in  FIG. 9 . The required quantity of 60.325 mm (2″⅜) ( 47 ) to separate both packers are screwed in the lower part of the Injector Plug ( 41 ) and the Lower Packer ( 46 ), in its upper part. 
         [0243]    Other sections of 60.325 mm (2″⅜) ( 47 ) Tubings connect the Lower Packer ( 46 ) with the Shear Out ( 48 ). 
         [0244]    The 60.325 mm (2″⅜) ( 47 ) Tubing is screwed in the lower part of the Lower Packer ( 46 ) and, at the other end, in the upper part of the Shear Out ( 48 ) which is also used to fix the Lower Packer ( 46 ). This circuit is closed by the Shear Out ( 48 ) interior ball. This allows a pressure increase in the 60.325 mm (2″⅜) Tubing ( 47 ). Once the Lower Packer ( 46 ) is fixed, pressure continuous being increased until the Shear Out ( 48 ) ball is displaced. This enables the circuit to perform the Lower Formation Injection. 
       6—Assembly Sequence for the Invention Equipment Installation 
       [0245]    The assembly sequence at the well head is the following: 
         [0000]    I) The Shear Out ( 48 ) ( FIG. 9 ) is assembled, ball included, in the 60.325 mm (2″⅜) (47) tubings.
 
II) The 60.325 mm (2″⅜) ( 47 ) Tubing is screwed with the Lower Packer ( 46 ).
 
III) The 60.325 mm (2″⅜) Tubings ( 47 ) required for the separation between the Formations to be injected are screwed to the upper end of the Lower Packer.
 
IV) The Injector Plug ( 41 ) ( FIG. 8 ) is screwed to the last 60.325 mm (2″⅜) Tubing ( 47 ). The FBHA (D), screwed to the CA (E) ( FIG. 8 ), is delivered already assembled, including the Rupture Disc and the proper torque so that the Workover Equipment screws the Injector Plug ( 41 ) on the 60.325 mm (2″⅜) Tubing upper end ( 47 ), required by the well to comprise the distance of the Upper Formation Perforations ( 49 ).
 
V) The required quantity of 73.026 mm (2″⅞) Tubings ( 9 ) to reach the surface and screw in the Full Passage Conventional Injection Valve is assembled to the FBHA (D) upper end.
 
VI) The Lubricator ( 3 ) will be installed on the 73.026 mm (2″⅞) Tubing Full Passage Conventional Injection Valve ( 65 ).
 
VII) The Mast ( 4 ) can be left assembled in the Lubricator or will be placed whenever a change of the Free Mandrel Assembly (C) is necessary.
 
         [0246]    The rest of the SA (A) is assembled as indicated in  FIG. 2 . 
       7—Description of the Equipment Operation 
       [0247]    Once the different components of the invention embodiment have been determined and developed to explain their nature, the description is herein complemented with a summary of what has already been described about the functional and operative relationship of its parts and the outcome they provide. 
       Installation: 
       [0248]    According to the previous paragraphs and, in other words, for the operational description of the invention device, the following are the operations needed for its installation in a specific well: 
       1::1 Complete Verification of the Tubing String Water Tightness 
       [0249]    As the complete Tubing string is assembled, water tightness tests are performed using the Full Blind Plug Not illustrated. 
         [0250]    Once the 73.026 mm (2″⅞) Tubing ( 9 ) (i) has been assembled up to surface, its water tightness is tested. The Well Head pressure is increased up to 3000 psi; the valve is closed and, for 20 minutes, it is necessary to verify that it keeps constant. 
         [0251]    Once tubing water tightness testing has been satisfactory, the Full Blind Plug is removed. 
         1 :: 2  Lower Packer ( 46 ) Fixing 
       [0252]    The FMA (C) is lowered with the Blind Middle Plug, that is to say, the fluid pumped by the Workover Equipment is only injected through the Lower Mandrel. It pressurizes the Telescopic Union ( 37  and  39 ), the Injection Tube ( 40 ), the 60.325 mm (2″⅜) Tubings ( 47 ) and the Shear Out ( 48 ). (This circuit is closed). As the pressure is slowly increased, the Lower Packer ( 46 ) is fixed by cutting the pins. This is perceived by the impact of Jaws against the Casing ( 10 ). The proper fixing is verified according to the Packer supplier specifications. 
         [0253]    After that, the pressure is increased until the Shear Out ( 48 ) ball enables the Lower Formation Injection. Meanwhile, Formation admission tests are made according to the established program. Pressures and volumes are also checked. During this operation, the pressure in the circuit to fix the Upper Packer ( 44 ) is null (white space). 
       1::3 Upper Packer ( 44 ) Fixing 
       [0254]    The FMA (C) is removed with the Blind Middle Plug, and the Middle Plug ( 17 ) is placed. The Lower Plug is changed by a Blind Lower Plug. In this case, when the fluid is pumped through the 73.026 mm (2″⅞) Tubing ( 9 ), it is all directed to the Upper Formation Injection Circuit. This is blocked in the Injector Plug ( 41 ) by the Rupture Disc ( 42 ). 
         [0255]    When pressure is increased by the Workover Equipment Pump, the required pressure is reached by the rupture of the Upper Packer ( 44 ) pins and the Upper Packer is fixed. Its proper position is checked according to what has been recommended by the manufacturer. Thereon, the pressure continues to be increased until the Rupture Disc bursts and this enables the circuit to inject in the Upper Formation. 
         [0256]    Admission tests are performed at different pressures according to the defined program. 
         [0000]    1::4 Downstroke or FMA (C) insertion 
         [0257]    Open Valves ( 6   1 ) and ( 6   5 ). Keep all the other valves closed. The FMA (C) is normally assembled for simultaneous injection with the Middle Plug ( 17 ), the Lower Plug ( 22 ) and corresponding regulated Injection Valves according to the injection program. The Formation Selective Injection begins automatically when the FMA (C) arrives and inserts into the FBHA (D). 
         [0258]    After assembling the Well Head ( 8 ), the FMA (C) can be installed with the Workover Equipment Pump or with the Plant Injection Fluid. 
         [0259]    During the downstroke, fluid is injected in both formations without any type of control. In both cases, the fluid pushes the FMA (C) with the Upper and Lower Formation Injector Valves regulated according to the well Injection program until the FMA (C) inserts into the FBHA (D). At this moment, Selective Injection is automatically started in both formations according to what has been programmed. Once the downstroke has begun, the Operator does not need to wait for the FMA (C) to reach and insert into the FBHA (D) as it will be done in 20 or 25 minutes and Selective Injection will begin automatically. 
         [0260]    1::5 Upstroke to recover the FMA (C) on the surface 
         [0261]    Close ( 6   1 ) Valve ( FIG. 2 ) and partially open Valve ( 6   2 ) and completely open Valve ( 6   3 ). This allows Injection Fluid to flow into the Impeller ( 5 ). This component drives it through the Annular (e 1 ), opens the Casing Protective Valve ( 36 ), goes into the FBHA (D) lower chamber and drives the FMA (C) to the surface until it is hooked in the Catcher ( 2 ). The well is depressurized. The FMA (C) together with the TA (B) are removed by turning round the Catcher ( 2 ) and then, they are hoisted by the Mast ( 4 ). 
         [0262]    If the well is not depressurized, the Catcher ( 2 ) can not be turned round. For safety reasons, it is designed to block itself, even if there is low pressure. In this case, the Operator can leave and perform other activities. When the operator comes back, he will find the FMA (C) in the Catcher ( 2 ) and the Formations already pressurized. 
         [0263]    At the Well Head, the following components can be replaced:
       a) The Injector Valves by removing the used ones and placing new controlled units.   b) The FMA (C) with the valves already installed.       
 
         [0266]    In both cases the task will be performed by the operator. Obviously, FMA (C) replacement is faster with the valves already controlled. 
       1::6 Selective Injection Operation in Both Formations 
       [0267]    The Injection Fluid (+) reaches the Surface Assembly (A) along a Pipeline ( 1 ) fed from the Water Plant and enters the System through ( 6   1 ) Valve completely open. Valves ( 6   2 ), ( 6   3 ) and ( 6   4 ), shown in  FIGS. 1 and 2 , must be closed. 
         [0268]    The 73.026 mm (2″⅞) Injection full passage Conventional Valve ( 6   5 ) has to be open to allow the FMA (C) to get through. The injection fluid, which enters the well through Valve ( 6   1 ), fills the Lubricator ( 3 ) (+) ( FIG. 2 ) and the fluid flows through 73.026 (2″⅞) Tubing ( 9 ) (i) (+), goes through the TA (B) (+) and enters the Upper Mandrel (+). 
         [0269]    In the Upper Mandrel, the Upper Formation Injection Valve ( 18 ) ( FIGS. 4 ,  5 ,  7 A,  7 B,  8  and  9 ) takes the (+) fluid and regulates the flow (#) that must be injected in that Formation by guiding it through the Middle Plug ( 17 ) passage ( 19 ). 
         [0270]    This regulated fluid (#) fills the chamber limited in the upper end by the Seal Ring ( 16 ) that blocks the Upper Packer Collar ( 25 ). In the lower part, it is limited by the Seal Ring ( 20 ) with the Lower Packer Collar ( 32 ). 
         [0271]    The already regulated fluid is compelled to go through the Annular (e 6 ) to the FBHA (D) inner side passage (C 2 ) ( FIGS. 7A ,  7 B and  8 ) through which it successively discharges into the Annulars (e 9 ), (e 10 ) and (e 11 ). On the outside, they remain limited with the On Off ( 43 ) interior and the Upper Packer ( 44 ). On the inside, it is limited by the Telescopic Union exterior ( 37  and  39 ) and the Injection Tube ( 40 ). In the lower end, the limit is the Injector Plug. ( 41 ). The fluid goes out through the Rupture Disc passages ( 42 ) ( FIGS. 8 and 9 ). 
         [0272]    The fluid, which is regulated (#) by the Upper Injector Valve ( 18 ) ( FIG. 4 ), is oriented through the Injector Plug ( 41 ) Rupture Disc passage ( 42 ) ( FIGS. 8 and 9 ) to the chamber limited by: 
         [0000]    I) The Upper Packer ( 44 ) lower side in the upper end ( FIG. 9 )
 
II) The Well Casing ( 10 ) on the outside ( FIG. 9 )
 
III) The Telescopic Union ( 37  and  39 ) and the Injector Tube ( 40 ) in the inside ( FIG. 9 )
 
IV) The Lower Packer ( 46 ) upper side in the lower end ( FIG. 9 )
 
         [0273]    The Fluid (#) regulated by the Upper Formation Injection Valve ( 18 ) ( FIG. 4 ) is then pushed to inject in the Upper Formation through the Casing Upper Perforations ( 49 ) ( FIGS. 9 and 13 ). 
         [0274]    This is the course taken by the regulated fluid to go into the Upper Formation ( FIG. 16 ). The Injection fluid (+) takes up the Upper Formation Injection Valve outer chamber (e 7 ) in the Upper Mandrel. The fluid flows through the Middle Plug ( 17 ) vertical passages (C 1 ) ( FIGS. 4 ,  7 B,  8  and  9 ). These passages run into a chamber and the fluid (+) is taken by the upper part of the Lower Formation Injection Valve ( 21 ) ( FIGS. 4 ,  7 B and  11 ), which regulates the flow (*) to be injected in the Lower Formation. This already regulated fluid (*) to be injected in the Lower Formation is conducted through the Middle Plug inner part ( 22 ), Telescopic Union ( 37  and  39 ) inner part, Injection Tube ( 40 ), Injector Plug inner part ( 41 ), 60.325 mm (2″⅜) Tubings ( 47 ) and Lower Packer ( 46 ), and finally unloaded through the Shear Out ( 48 ) ( FIGS. 1 ,  9 ,  11  and  13 ) into the chamber limited by: 
         [0000]    I) Lower Packer ( 46 ) lower side in the Upper end ( FIGS. 9 ,  11  and  13 )
 
II) The Well Casing ( 10 ) on the outside ( FIGS. 9 ,  11  and  13 )
 
III) The bottom hole in the lower end
 
         [0275]    The Lower Formation regulated fluid (*) is introduced through the Casing Lower Perforations ( 50 ) in the above-mentioned Formation ( FIGS. 11 ,  13  and  17 ). 
         [0276]    This is the course taken by the regulated fluid (*) to go into the Lower Formation. 
         [0277]      FIGS. 7A and 7B  show two sections of the Transport Assembly (B) screwed in the upper end of the FMA (C) inserted into the FBHA (D) and injecting selectively in both formations. Both sections show the circuits that drive fluids to every formation. The Plant Fluid (+) is taken to be regulated by the Upper Formation Injection Valve ( 18 ) for the Upper Formation (#) and the Lower formation Fluid (*) is taken to be regulated by the Lower Formation Injection Valve ( 21 ). 
         [0278]    In  FIG. 7A , section is parallel to the Middle Plug ( 17 ) Injection Passage ( 19 ). 
         [0279]    In  FIG. 7B , section is perpendicular to the Middle Plug ( 17 ) Injection passage ( 19 ). 
         [0280]      FIG. 4  shows the fluid that has been regulated for the Upper Formation required conditions. 
         [0281]    According to the previous detailed explanations and in order to reinforce the invention operational comprehension, here follows a summary of the fluid operative paths. This fluid is injected through the component parts of the invention structure in two formations: Upper and Lower Formations in the simplified model adopted as an example to perform one of the possible applications of the invention. 
         [0282]    Starting from the Surface Assembly (A), the symbol (+) is used to represent the fluid provided by the Plant through the pipeline ( 1 ), Valve ( 6   1 ). The fluid already regulated by the Valve ( 18 ) and to be injected in the Upper Formation is represented by (#) symbol. The fluid regulated by Valve ( 21 ) and to be injected in the Lower Formation is represented by the (*) symbol. 
         [0283]    The fluid that comes from the Plant goes into the Tubing ( 9 ) (i) (+) through the 2″⅞ conventional full passage Injection Valve ( 6   5 ). To make this operation possible, the Valve ( 6   1 ) must be open and the ( 6   2 ), ( 6   3 ), and ( 6   4 ) valves shut until the fluid reaches the Free Mandrel Assembly (C) ( FIG. 4 ) through the Transport Assembly (B) ( FIG. 3 ). Selective Injection is then performed in the two formations (#) and (*). 
         [0284]    In a downward description, it can be observed that two watertight chambers have been formed. They make it possible to direct the fluid to be injected: 
         [0000]    1—An upper chamber ( FIGS. 7A ,  7 B,  8 ,  9 ,  11  and  13 ) limited by the closure produced between the upper Seal Ring ( 16 ) that packs in the Upper Packer Collar ( 25 ), and the Plant pressure (+) contained in the Tubing string up to this location.
 
2—At the same time, an Upper Mandrel chamber will also be determined. This is contained between said closure produced by the upper Seal Ring ( 16 ) with the Upper Packer Collar ( 25 ) and the closure produced between the Middle Plug ( 17 ) Seal Ring ( 20 ) with the Lower Packer Collar ( 32 ). This chamber contains the fluid to be injected (#) in the Upper Formation with pressure regulated by Injection Valve ( 18 ) and channeled through the Middle Plug ( 17 ) passage ( 19 ). Both the Plant pressure (+) in the annular (e 7 ) and in the (C 1 ) passage and the Injection Pressure (#) in the Upper formation coexist in this chamber ( FIGS. 7A ,  7 B and  8 ).
 
         [0285]    The Free Mandrel Assembly (C) ( FIG. 4 ) lodges the upper Injection Valve ( 18 ) that regulates the Upper Formation Injection (#) and is screwed in the Middle Plug ( 17 ) in its lower part. The circuit that drives this already regulated fluid is identified by the symbol (#). It is driven ( FIGS. 7A ,  7 B and  8 ) through the Middle Plug ( 17 ) passage ( 19 ), Annular (e 6 ), FBHA (D) vertical passages (C 2 ) to Annulars (e 9 ), (e 10 ) and (e 11 ), Injector Plug ( 41 ) through Rupture Disc ( 42 ) passage to Annular limited by: 
         [0000]    I The Upper Packer lower part ( 44 ) ( FIGS. 8 ,  9  and  13 )
 
II The Lower Packer upper part ( 46 ) ( FIGS. 8 ,  9  and  13 )
 
III On the outside by the Casing ( 10 ) ( FIGS. 8 ,  9  and  13 )
 
         [0286]    The fluid to be injected goes through the Casing Perforations ( 49 ) and enters the Upper Formation. 
         [0287]    3—The Lower chamber ( FIG. 11 ) is determined by the closure of the Lower Packer Collar ( 32 ) and Middle Plug ( 17 ) Seal Ring ( 20 ) and Lower Plug ( 22 ) Seal Rings ( 23 ) with seat ( 34 ). The Lower Formation Injection Valve ( 21 ) admits the Plant Fluid (+) by its upper end and regulates it to be injected (*) in the Lower formation according to the established conditions. 
         [0288]    Between the Upper Mandrel Jacket ( 15 ) and the outside of the Upper Regulation valve ( 18 ), in the Annular (e 7 ), the Plant (+) fluid feeds the Lower Regulation Valve ( 21 ) through the Middle Plug ( 17 ) passages (C 1 ). Said Valve ( 21 ) transforms the pressure and the volume as requested for Lower Formation Injection. 
         [0289]      FIGS. 7A ,  7 B and  8  show, in the FBHA (D), the circuit that drives this regulated flow, identified by the symbol (*), to the Lower Formation. It must go through the Lower Plug ( 22 ), Telescopic Union ( 37  and  39 ), Injector Tube ( 40 ) through Injector Plug ( 41 ) central passage ( FIGS. 8 ,  11  and  13 ). In its end, the 60.325 mm (2″⅜) Tubings ( 47 ) are screwed. These tubings connect the Lower Plug ( 41 ) with the Lower Packer ( 46 ). The 60.325 mm (2″⅜) Tubings ( 47 ) and the Shear Out ( 48 ) are screwed to the Lower Packer lower end; the fluid (*) flows through the Casing ( 10 ) Lower Formation Perforations ( 50 ) ( FIGS. 1 ,  11 ,  13  and  17 ). 
         [0000]    4—Free Mandrel Assembly Recovery Chamber (x) ( FIG. 18 ) is the chamber limited by the outside of the Injection Valve Jacket ( 21 ) and the FBHA (D) inner diameter, Annular (e 8 ) ( FIGS. 7A ,  7 B and  8 ). The chamber is closed by the Casing Protective Valve ( 36 ). The fluid that fills it is at the pressure of the column that contains the Annular. 
         [0290]    In order to make the Free Mandrel Assembly (C) return to the surface, low pressure fluid is injected (x) through the Annular (e 1 ) and 73.026 mm (2″⅞) Tubing  9  (Direct) is depressurized. 
         [0291]    The Casing Protective Valve ( 36 ) opens and lets the fluid in. This fluid drives the Free Mandrel Assembly (C) until it is caught in the Catcher ( 2 ). To remove the Free Mandrel Assembly (C) together with the Transport Assembly (B), it is only necessary to operate the Surface Valves in the following way: 
       1—Close Valve ( 6   1 ). 
     2—Open Valve ( 6   2 ). 
     3—Open Valve ( 6   3 ). 
       [0292]      4 —Keep Valve ( 6   4 ) closed. 
         [0293]    With this configuration, the Plant Water enters through the Impeller ( 5 ) into the annular. This opens the Casing Protecting Valves ( 36 ) allowing the fluid to enter and produce the disconnection of the Free Mandrel Assembly (C) and the Transport Assembly (B) from the FBHA (D). From this moment on, the fluid produces the upward push that makes the Rubber Cups ( 13 ) expand and closes the Transport Assembly Valve ( 12 ) located in the Fishing Neck ( 11 ). 
         [0294]    The upward speed is proportional to the volume of the fluid injected in the Annular (e 1 ). The upstroke ends with the Free Mandrel Assembly (C) and the Transport Assembly (B) hooked together in the Catcher ( 2 ) located in the Lubricator ( 3 ). 
         [0295]    To remove them from the well: 
         [0000]    1) Turn the Catcher ( 2 ) eye-bolt until it adopts the “Catching” position. In this position, the Catcher cage retains the assemblies when they make an impact in their upstroke. 
       2) Close all Surface Assembly Valves ( 6   1 , 6   2 , 6   3 , 6   4 ). 
       [0296]    3) Wait until 73.026 mm (2″⅞) Tubing ( 9 ) (Direct) pressure reaches zero.
 
4) Turn the Catcher ( 2 ) 90° to remove it from the Lubricator ( 3 ).
 
5) Raise the Free Mandrel Assembly (A) and the Transport Assembly (B) with the Mast ( 4 ).
 
6) Lower the assemblies and unhook them for inspection or replacement.
 
         [0297]    To install the Free Mandrel Assembly (A) and the Transport Assembly (B), the reverse process has to be performed:
   1) All surface Valves must be shut. ( 6   1  to  6   4 ).   2) The two assemblies are hooked together, installed in the hoisting system and then introduced in the Lubricator ( 3 ).   3) The Catcher ( 2 ) is turned 90° to close the Lubricator ( 3 ).   4) The Catcher eye-bolt is turned to the releasing position so that the Free Mandrel Assembly (A) and the Transport Assembly (B) unhook from the Catcher ( 2 ) and start the downward movement.   5) Valve ( 6   1 ) is opened so that the fluid push makes the assemblies descend at a proper speed, according to the injected flow.   
 
         [0303]    A speed of about 70 to 85 meters/minute is considered reasonable for the downstroke. 
         [0304]    A greater downward speed is also possible. For example, 100 meters/minute (shorter downstroke) and when it is close to the FBHA (D), slow down the speed to 50 meters/minute so that the insertion is adequate. Once the two assemblies are engaged, the pressure begins to rise until it reaches the Pipeline pressure. In this moment, the system begins to inject selectively in the two formations. 
         [0305]    A manufacturing possibility, which leads to materializing this invention, and the way it works has been described. To complete the documents, here follows a synthesis of the invention contained in the claims which come next. 
         [0306]    (There appears a signature followed by a seal that reads “LUIS SALVADOR CUNEO. Industrial Property Agent. Registration Number 1409”.)