Abstract:
A tool and method based on proven technologies, to remove sand and other types of solid particulate materials and fluids from wellbores and conduits, resulting from well-drilling, well-production or both, and consequently to reactivate well production. As time passes, solid aggregates are consolidated, plugging the wellbore, so they can be removed following two stages: disintegration in small particles and its further transport to surface. The tool, modular, composed of different subsystems, is connected to the end of concentric coil tubing, operates promoting the aggregates disintegration by using a spiral jet to impact these solids and suctioning the small particles and well fluids, simultaneously or later, by using jet pumps based on a set of several venturis. Changes between different operation modes are imposed by modifying surface pump pressure levels and the tool does not need to be removed from the wellbore between different stages, reducing the overall operation time.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/358,947, filed on Jul. 6, 2016, which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to maintenance and cleaning of oil field and gas field wellbores. More specifically, this disclosure pertains to coiled tubing equipment and tools used for cleaning sand and other types of particulate materials out of wellbores. 
       BACKGROUND 
       [0003]    Concentric coil tubing, also commonly referred to as “endless tubing”, is widely used in the oil and gas service industries for conducting many different stimulation and or work-overs of newly drilled and older producing wells. Coil tubing generally comprises a continuously “spooled” indefinite length of tubing, usually constructed of steel although other materials have been used. 
         [0004]    Oil/gas service tools are commonly connected to a coiled tubing unit and inserted into wellbores for downhole cleaning or formation stimulation. Examples of such tools include wash nozzles and jetting nozzles. For example, a wash nozzle connected to the end of coiled tubing is inserted into a wellbore after which, a pressurized cleaning fluid exemplified by water, acids or nitrogen, and the like, is pumped into the coil tubing and exits through the wash nozzle in the vicinity of the area to be cleaned. Such wash nozzles are commonly used to remove sand plugs, wax, calcium or debris such as failed linings from within the coiled tubing unit. Accumulations of sand plugs and/or wax and/or calcium, and/or debris significantly reduce the well performance. Similarly, wash nozzles can be used to clean other confined and/or tubular spaces exemplified by sewer lines, industrial waste lines, and the like. 
         [0005]    Existing jetting tools may have static or moveable jetting nozzles. The first are more simple but its performance is limited to the areas of the conduit where the nozzle jet is directed, while the moveable nozzles have the advantage of sweeping the circumference of the tool but have a lower reliability due to the failure in moveable parts in contact with the well fluids and solids or even conduit surface, and the difficulties in the control of the nozzles spinning which causes the loss of energy of the jet. Some other jetting tools use alternatives to address these difficulties but result in a higher risk to the formation. 
         [0006]    An emerging jetting nozzle technology called Vortex Generating Washer Nozzles (PCT/CA2016/050751) uses an innovative system consisting on static nozzles which generate spiral currents thanks to a high-speed pulsatile and intermittent fluid flow covering a 360 degrees sweep of the circumference of the conduit. 
         [0007]    Downhole jet pumping is a common oil/gas process used to extract fluids inside the wellbore up to the surface, by means of the injection of a pressurized external fluid which passes through a venturi nozzle, creating a pressure drop at the venturi throat which sucks the wellbore fluids and to later pump them up to the surface. 
         [0008]    Existing coiled tubing servicing tools in the oil/gas have tested the effectiveness of the methods separately, by means of specialized tools for specific conditions of the wells or ducts, but with a lack of flexibility to be used in different well conditions, and with a poor integration between the two operating principles, making necessary having several specialized tools to satisfy the demand for services in fields having wells with different conditions, from depth and wellbore fluid pressure to different density and viscosity fluids. 
       SUMMARY 
       [0009]    The invention relates to the cleaning and removal of liquids and/or solids in a wellbore or conduits that may be obstructing well flow and tools entrance. Examples of which are sand, mud, small rock particles, scale, wax, and water which are results of well-drilling, well-production operations or both. These are typical production problems encountered with all wells whether drilled vertically, horizontally or, deviated, or a combination of. 
         [0010]    Applications of the invention relates to proven technologies and techniques for removal of particles otherwise obstructing well flow. 
         [0011]    Conventional methods for removing these obstructions may include, but are not limited to bailing, high pressure fluidizing, drilling, milling, and acidizing. However, the uses of some of these methods are not desirable as further damage to the well formation may be a result. 
         [0012]    The objectives of this invention include but are not limited to: 
         [0013]    1) Provide a simple and effective tool and method based on proven technologies to remove obstructions in wellbores and conduits that limit: (a) expected flow of fluids through the well or conduit; (b) tool entrance into the wellbore; and (c) flow of formation fluids flow into the wellbore in the case of oil and gas wells. 
         [0014]    2) Provide a simple and effective tool and method for recovering well fluids and solids to reactivate well production non harmful for the formation 
         [0015]    3) Provide a single, compact and modular tool able to be adapted to wells of different conditions by means of few hardware changes, mainly referring to different composition and properties of obstructing solids, different well fluid density and viscosity and different depth, pressure and directionality of the wells. 
         [0016]    4) Provide a simple and effective tool and method to accomplish the preceding tasks listed in objectives (1) and (2) using the same Bottom Hole Tool Assembly without removing it from the wellbore between tasks. 
         [0017]    5) Provide a tool or method that guarantees a prolonged life of the key components. 
         [0018]    6) Provide a tool and method that reduces the overall operation time when operating in the well or conduit 
         [0019]    7) Provide a tool with a highly reliable operation 
         [0020]    To accomplish these objectives, it is disclosed a Coiled Tubing Spiral Venturi Tool (CTSVT) which is a modular, compact tool assembly (also known as a Bottom Hole Assembly BHA), easily attachable to a concentric coiled tubing system, comprising basically a jet pump system or suction head, a jetting washing nozzle subsystem and a flow control subsystem, arranged in an innovative architecture that allows cleaning and removal of solid obstructions in wells and conduits as well as the reactivation of the production in oil and gas wells by means of the individual or simultaneous use of the jetting washing functions and the jet pumping function. 
         [0021]    The present invention is exemplified by a preferred embodiment of the tool assembly, with the components that better accomplish the stated objectives. However, as one of the objectives of this invention relates to easy adaptation to wells with different conditions it is also disclosed alternative embodiments of the tool to satisfy those conditions. The adaptability of the tool refers to the mechanical adjustment of specific control components and to the replacement, addition or removal of some specific purpose modules. 
         [0022]    The architecture of the tool from a functional perspective is composed of: (a) a jetting nozzle subsystem, which is located on the lower side of the tool and consists on a modular jetting nozzle assembly based on the Vortex Generating Washer Nozzle principle (PCT/CA2016/050751) or variations of it; (b) a jet pump subsystem or suction head located at the upper side of the tool with respect to the jetting nozzle subsystem, consisting of a modular hollow disc shaped arrangement of several venturis peripherally located on those discs around a central conduct (to allow the flow of the power fluid to the other conduits of the tool), and (c) a control subsystem which is located along the flow path of the power fluid, on the center conduct of the tool, consisting on an innovative series of pressure sensitive valves that block and divert the power fluid depending on its pressure level. The upper and lower directions refer to the part of the tool located closer to the surface or more distant from it respectively. 
         [0023]    The Coiled Tubing Spiral Venturi Tool is a hydraulically operated device using one or more hydraulic conduits where one or all of them are concentrically assembled in relation to each other to supply a high pressure power fluid to the Bottom Hole Assembly (BHA). The high pressure power fluid is pumped from a surface pressure unit down to the BHA through the internal conduct of concentric coiled tubing, and is then utilized to: 
         [0024]    a) Supply high pressure fluid to one or several jetting nozzle directed towards solid obstructions in the wellbore, breaking it down into smaller removable particles thereby unplugging the wellbore fluid flow. 
         [0025]    b) Supply high pressure fluid to a venturi assembly using jet pump principles to suction wellbore fluid and/or carried solids into the tool and then pressurize them to pump them up to the surface through the annular conduct of the coiled tubing. 
         [0026]    c) Remotely select whether to direct the high pressure fluid: to the jetting nozzles, to the jet pump, both at the same time or neither of them by means of the control subsystem valves activated by different pressure levels on the power fluid. 
         [0027]    The control subsystem is composed first by: (a) a hold down valve located upstream at the entrance of the power fluid to the tool, being a two position pressure sensitive valve in charge of stopping or allowing the flow into the tool; (b) a control valve, located downstream of the hold down valve, being a three position pressure sensitive valve, diverting the power fluid flow into the jetting nozzle assembly exclusively (position normally closed), to both the jetting nozzle assembly and the jet pump assembly (intermediate position), or to the jet pump assembly exclusively (position completely retracted), respectively depending on the pressure of the power fluid it faces. 
         [0028]    The four different positions of the two valves in addition to the possibility of movements upwards, downwards or no movement of the tool by the coiled tubing action, provide the tool with six differentiated operation modes, which can be activated in a continuous way once the tool is down into the wellbore without the requirement of taking the tool out to the surface, which can be combined in specific sequences providing effective methods to accomplish the solid removal and/or well stimulation within the same tool run into the well. 
         [0029]    In order to accomplish one of the objectives of the present invention referring to provide a compact tool, most of the components mentioned belonging to different subsystems are arranged in a constructive way that some of them get enclosed or being shared by other subsystem. The exemplified tool in the later description of this disclosure shows a preferred embodiment of the tool with the control valve totally embedded within the jetting nozzle assembly, with some components providing multiple functionality on both subsystems. The compact architecture is important not only because of the saving in components, but also from the perspective that the shorter the overall tool length, the better adaptability to the shapes of the well including the solid obstructions. 
         [0030]    In order to address the reliability objective of the device while running into the well two filtering systems are included, a common filter to all the embodiments of the device located in the jet pump suction of the wellbore fluid, and an alternative filter located at the entrance of the fluid power to the tool. Both filters prevent the flow ducts specially the smaller like nozzles from being clogged, limiting the operability of the tool. To increase tool reliability the system is also provided with a relief valve to ensure the proper seating of the control valve when different operation modes are set by means of changes in pressure of the power fluid. Other aspect of the operational reliability of the tool is aimed by the low number of components and the absence of relative movements between components. 
         [0031]    One of the main advantages of the present invention respect to other existing tools lays on the ability to easily adapt a single tool to the changing conditions found among wells, especially to those referring to high changes on the wellbore and formation fluid density and viscosity, types of obstructing solids and service to be provided (cleanout or well activation) which some well service providers can find in the same geographical area. This tool adaptability is achieved by means of the replacement, addition or removal of some specific purpose modules like different venturi arrangement in size, shape and number; adjustable mechanics to allow different operating pressure switching levels; mechanical compensation of suction pressure versus pumping pressure; easily exchangeable different geometry valve modules to change tool behaviour favoring jetting over suctioning or vice versa; a rupture mechanism to aid to release the tool in case of sediment stuck; internal and external filtering modules to avoid entrance of certain size solids into the tool with its respective downhole cleaning methods. Every addition or adaptation of the preferred embodiment of the tool with the mentioned modules is presented as a disclosed alternative embodiment of the present invention. 
         [0032]    The device utilizes materials specifically selected to provide longevity against damage incurred by removing the obstructive materials from the wellbore. 
         [0033]    The exemplary embodiments of the present disclosure pertain to coiled tubing spiral venturi tools for cleaning and maintenance of oil-field wellbores and/or gas field wellbores. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES: 
         [0034]    The present disclosure will be described in conjunction with reference to the following drawings in which: 
           [0035]      FIG. 1 a    is an isometric view of the assembled preferred embodiment of the coiled tubing spiral venturi tool indicating with schematic arrows the jetting flow, suctioning flow lines and tool orientation in the well; 
           [0036]      FIG. 1 b    is a partial isometric view of the assembled preferred embodiment of the Coiled Tubing Spiral Venturi Tool with the Vortex Generating Washing Nozzles Assembly placed inside of a sectioned conduit indicating the Spray Jetting and the spiral flow lines; 
           [0037]      FIG. 1 c    is a cross section view of the conduit with a plan view of the preferred embodiment of the Coiled Tubing Spiral Venturi Tool with the Vortex Generating Washing Nozzles Assembly with arrows indicating Spray Jetting over internal conduit surface; 
           [0038]      FIG. 2  is a longitudinal cross-section through one embodiment of a coiled tubing spiral venturi tool according to the present disclosure; 
           [0039]      FIG. 3  is an exploded isometric view of the coiled tubing spiral venturi tool shown in  FIG. 1 ; 
           [0040]      FIG. 4  is a further exploded isometric view of the coiled tubing spiral venturi tool shown in  FIG. 1 ; 
           [0041]      FIG. 5  is an exploded isometric view of an external connector component for sealingly mounting the coiled tubing spiral venturi tool to a concentric coiled tubing string; 
           [0042]      FIG. 6  is an exploded isometric view of a seal assembly component of the coiled tubing spiral venturi tool; 
           [0043]      FIG. 7  is an exploded isometric view of an internal connector component of the coiled tubing spiral venturi tool; 
           [0044]      FIG. 8  is an exploded isometric view of a venturi plate component of the coiled tubing spiral venturi tool; 
           [0045]      FIG. 9  is an exploded isometric view of a control valve assembly component of the coiled tubing spiral venturi tool; 
           [0046]      FIG. 10  is an exploded isometric view of a relief valve assembly component of the coiled tubing spiral venturi tool; 
           [0047]      FIG. 11  is an exploded isometric view of a venturi nozzle plate assembly component of the coiled tubing spiral venturi tool; 
           [0048]      FIG. 12  is an exploded isometric view of a Vortex Generating Wash Nozzle assembly (PCT/CA2016/050751) component of the coiled tubing spiral venturi tool; 
           [0049]      FIG. 13  is an isometric view of a venturi outlet transition component of the coiled tubing spiral venturi tool; 
           [0050]      FIG. 14A  is a bottom view of the venturi plate from  FIG. 11  showing the placement of venturis circumferentially about the centre of the venturi plate component; 
           [0051]      FIG. 14B  is a longitudinal cross-sectional A-A view from  FIG. 14A  showing a standard conical diffuser shape of a venturi in a first plane; 
           [0052]      FIG. 14C  is a longitudinal cross-sectional C-C view from  FIG. 14A  showing the conical diffuser shape of the venturi shown in  FIG. 17B  in a different plane; 
           [0053]      FIG. 15A  is a bottom view of another embodiment of a venturi plate component showing the placement of venturis circumferentially about the centre of the venturi plate component; 
           [0054]      FIG. 15B  is a longitudinal cross-sectional A-A view from  FIG. 15A  illustrating the non-standard conical diffuser shape of a venturi in first plane; 
           [0055]      FIG. 15C  is a longitudinal cross-sectional D-D view from  FIG. 15A  showing the non-standard conical diffuser shape of the venturi; 
           [0056]      FIG. 16 a    is a partial longitudinal section view of the zone of the Hold Down Valve of the preferred embodiment of the tool; 
           [0057]      FIG. 16 b    is a partial longitudinal section view of the zone of the Hold Down Valve seating with the Hold Down Valve assembly removed showing an alternative embodiment of the tool including the Inline Filter; 
           [0058]      FIG. 16 c    is a partial longitudinal section view of the zone of the Hold Down Valve seating with the Hold Down Valve assembly removed showing an alternative embodiment of the tool including the Inline Filter when recirculating the return fluids; 
           [0059]      FIG. 17  is a partial longitudinal section view of an alternative embodiment of the tool showing the zone of the Vortex Generating Washing Nozzle and the Control Valve Assembly, with an alternative Control Valve Piston placed on its closed position; 
           [0060]      FIG. 18 a    is a partial longitudinal view of an alternative embodiment of the tool showing a Rotative Vortex Generating Washing Nozzle assembly; 
           [0061]      FIG. 18 b    is a front view of the alternative embodiment of the tool as shown in  FIG. 18   a,  with arrows indicating the rotational movement of the Rotative Vortex Generating Washing Nozzle assembly; 
           [0062]      FIG. 19  is a partial longitudinal view of an alternative embodiment of the tool showing at least one Power Fluid Tube installed in the place of one of the Venturi Nozzles; 
           [0063]      FIG. 20 a    is a partial longitudinal view of an alternative embodiment of the tool showing the assembly of a primary and a secondary Venturi Transition Plate; 
           [0064]      FIG. 20 b    is an exploded isometric view of the primary and secondary Venturi Transition Plates; 
           [0065]      FIG. 21  is a partial longitudinal section view of an alternative embodiment of the tool with the Rupture Device installed with the internal fluid inside the tool flowing through the Rupture Nozzle; 
           [0066]      FIG. 22  is a longitudinal cross-section of the preferred embodiment of the coiled tubing spiral venturi tool located downhole in a wellbore illustrating the operation under the “Reset” mode; 
           [0067]      FIG. 23  is the longitudinal cross section of the preferred embodiment of the present invention shown in  FIG. 22 , illustrating the “Well Jet” operation mode; 
           [0068]      FIG. 24  is the longitudinal cross section of the preferred embodiment of the present invention shown in  FIG. 22 , illustrating the “Well Jet and Vacuum” operation mode; 
           [0069]      FIG. 25  is the longitudinal cross section of the preferred embodiment of the present invention shown in  FIG. 22 , illustrating the “Well Vacuum” operation mode; 
           [0070]      FIG. 26 a    is a partial longitudinal section view of the preferred embodiment of the present invention when the control valve piston is on its closed position in “Jet Only” operation mode, showing the relief valve components closed; 
           [0071]      FIG. 26 b    is a partial longitudinal section view of the preferred embodiment of the present invention when the control valve piston is shifted to its fully opened position in “Vacuum Only” operation mode, showing the relief valve components opened during transition; 
           [0072]      FIG. 26 c    is a partial longitudinal section view of the preferred embodiment of the present invention when the control valve piston is shifted to its fully opened position in “Vacuum Only” operation mode, showing the relief valve components closed after transition; and 
           [0073]      FIG. 27  is a scheme of a typical concentric coil tubing cleanout operation with the coiled tubing spiral venturi tool placed in the wellbore. 
       
    
    
     DETAILED DESCRIPTION 
       [0074]    The exemplary embodiments of the present disclosure pertain to a Coil Tubing Spiral Venturi Tool which is an attachable tool in concentric coil tubing systems, used to perform actions of removing and collecting restricting solids in conduits like oil well casings, gas well casings, production tubing, wellbores, industrial waste fluid lines, municipal waste fluid lines, and the like. The restricting solids may be depositional sediments, sand, mud, wax, scale, congregate, calcium and/or other types of debris from fluid-conveying conduits, which can represent total obstructions or plugins, like sand bridges or partial obstructions, limiting the normal flow of fluids through the conduit or well casing, reducing oil/gas well production, and increasing the risk for other coil tubing operations to be performed in such conduit or well. 
         [0075]    The invention disclosed herein use the operating principle of induced spiral flow generated by a Vortex Generating Washing Nozzle system or variation thereof (PCT/CA2016/050751), combined with the vacuum suction and pumping power of an innovative multi venturi downhole jet pump, which can be operated remotely, individually or together, in order to better adapt to the obstruction condition and increase the spiral flow effect. The operative capacity of at least four modes of remote operation is achieved thanks to a combined system of pressure-sensitive valves. 
         [0076]    The employment of Vortex Generating Washing Nozzles technology combined with the peripheral multi venturi suction capabilities make this invention advantageous over other existing tools employing similar physical principles in the matter of enhancing the solid obstruction removal effectiveness, as wells as the cost and time saving during coil tubing operations because of rapid responsiveness for changing modes of operation, the number of modes of operation available, and the tool ability to be adapted to different well conditions. 
         [0077]    The preferred embodiment of the invention described herein with its component arrangement represents an improvement in operational reliability and component life with respect to the existing coil tubing cleanout tools using similar physical principles, and provides advantages related with the adaptability of the tool by replacement, addition or removal of modules to better respond to different well conditions, shown as alternative embodiments of the invention. 
         [0078]    For the purpose of the present description, the terms Coil Tubing Spiral Venturi Tool Assembly (CTSVT) and Bottom Hole Assembly (BHA) are used indistinctly, referring to the same mechanical tool assembly herein disclosed identified with the number  1  in figures. The terms “Drive Fluid” and “Power Fluid” are used indistinctly and are identified in figures with number  81 . The terms Jet Pump assembly and Venturi Assembly are used indistinctly. The terms Jetting Nozzle assembly, Washing nozzle assembly are used indistinctly, and refers to the Vortex Generating Washing Nozzle Assembly when referring to the preferred embodiment of the tool. 
         [0079]    The exemplary assembly of the preferred embodiment of a Coiled Tubing Spiral Venturi Tool  1  according to the present disclosure is shown in  FIGS. 1 to 14 . The two basic functionalities of any embodiment of the assembled tool  1  while operating inside of a fluid conduit, wellbore or tubular casing  84  are shown in  FIG. 1 , being (a) jetting a power fluid to disintegrate solid deposits by means of direct impact of the power fluid jet or by inducing spiral current flow in the wellbore fluid represented by arrows  82   a,  which is performed by the Jetting nozzle subsystem  70 , and (b) suctioning/pumping up the well fluids surrounding the tool represented by arrows  82   b  with the released solid particles suspended on it, performed by the suction head or jet pump subsystem  30 . The tool can operate while moving downwards, upwards or while stationary at a fixed depth, with its axis oriented as the axis of the conduit. The tool is composed by multiple modular hollow disc shaped elements, aligned to specific positions that permit to connect internal fluid conduits. The external shape of the tool is cylindrical, with a smaller diameter than the conduit to allow the passage of fluids between the conduit walls and the tool, and to allow the tool  1  to move without friction into the conduit  84 , and as big as possible to allocate the bigger venturi diffuser diameters, which are peripherally located around a central fluid conduit. 
         [0080]    As stated above the Jetting Nozzle Subsystem  70  of the preferred embodiment uses the Vortex Generating Washing Nozzle (PCT/CA2016/050751) shown in  FIGS. 1 b    and  1   c,  consisting on conical shaped pulsating sprays coming out of the slotted nozzles  101   a  located on the Vortex Generating Washing Nozzle assembly  100 .  FIG. 1 b    shows the Coiled Tubing Spiral Venturi Tool  1  inside of the conduit  84  which has been partially broken for illustration purposes with the power fluid  81   a  coming out of the tool in the form of three partial conical deployed spray of non-uniform height. The spray jet may produce the plugged or sediment solids removal on the internal conduit surface by direct impact or by means of spiral forward currents  82   a  in the wellbore fluids generated by the effect of said power fluid jet  81   a  The simultaneous effect of the spray jet of power fluid  81   a  with the active suction produced by the jet pump system  30  induces spiral upwards currents  82   d  on the well fluid. There are at least three slotted nozzles  101   a  which are elongated non-concentric slots, allowing the Power Fluid  81   a  to impact in a 360 degrees sweep over the internal surface of the conduit  84 , represented by arrowed lines  81   a  in  FIG. 1   c.  A plan view of the Coiled Tubing Spiral Venturi Tool  1  inside a crossed sectioned conduit  84  is shown in  FIG. 1   c,  where it can be appreciated the distribution of the slotted nozzles  101   a.    
         [0081]    The physical principles behind the formation of the pulsating spray jet produced by the Vortex Generating Washing Nozzle (PCT/CA2016/050751) is out of the scope of this disclosure and is referred as a proven technology for this invention, being relevant for the present invention the innovative way how this assembly hardware interacts with the tool and the effects produced by the spray jet in conjunction with the particular use with this tool. 
         [0082]      FIG. 2  shows a longitudinal section view of the preferred embodiment of the tool comprising a Concentric Connector Assembly  10 , which connects the tool  1  with the coil tubing external conduit  14 , the Venturi Plate Assembly  110 , which center orifice serve as conduit for the pass of the power fluid being pumped from surface through the internal conduit of the coiled tubing  12 , to later be diverted by the Control Valve Assembly  120  either to the jetting nozzles assembly  70 , being finally jet sprayed out of the tool through the Vortex Generating Washing Nozzle assembly  100 , or to be directed towards the suction head assembly  30  ( FIGS. 2, 3 ) where the fluid is accelerated by the Venturi Nozzles  124  creating the pressure drop when passing through the convergent—divergent orifices of the Venturi Plate  114  which creates the suction of the wellbore fluids external to the tool through the slots in the Suction Head Housing  130 . The wellbore fluids and the power fluid are mixed and pumped when passing through the Venturi Diffuser  40 , and conducted to the surface as a return fluid through the annular conduit formed between the conduits  14  and  12  of the coiled tubing. The coiled tubing spiral venturi tool  1  is demountable and sealable, engage able with the concentric coiled tubing. 
         [0083]      FIG. 3  shows the easy assembly of hollow disc shaped components along to its axis of approximation. From top to bottom, first the Concentric Connector Assembly  10  is composed by the external connector top sub  22 , the external connector component  15 , external connector bottom sub  24  and external connector  17 . Right in the bottom of it, it encounters, the Suction Head Assembly  30 , composed by the Venturi Diffuser  40  and the Venturi Plate Assembly  110 , enclosed into the Crossover Sub  55  and the Slotted Suction Head Housing  130  with is correspondent Suction Screen  140 . All of the external longitudinal rectangular features as well as the small orifices located outside of the Concentric Connector Assembly  10  components and the Crossover Sub  55  are simply for exemplary purposes of features provided for wrenching and securing of the modular parts, being possible embodiments of the tools without any of those features. At the bottom of the tool it is located the Jetting Nozzle Subsystem  70  aligned with the suction Head Subsystem  30  by means of the Venturi Alignment Ring  116 , and is composed by the Vortex Generating Wash Nozzle assembly  100 , kept in place by the stop nut  150  and the valve stem lock nut  152  which secure the assembly with the thread of the jet shutoff valve stem. 
         [0084]    Demountable engagement of the coiled tubing spiral venturi tool to a concentric coiled tubing is shown in  FIGS. 4 and 5  wherein the concentric coiled tubing has an inner tubing  12  and an outer tubing  14  that is engaged by an outer tubing disconnect assembly  20 . The external connector top sub  22  of the outer tubing disconnect assembly  20  is slid over the outer tubing  14  of the concentric coiled tubing. A seal pack assembly  26  is slid over the outer tubing  14  and into the annular space between external connector top sub  22  and the outer tubing  14 . An inner disconnect roll-on assembly  32  is inserted into the concentric coiled inner tubing  12  and mechanically fastened in place. A venturi plate transition component  40  is slid over the inner disconnect roll-on assembly  32  into the annular cavity between the inner disconnect roll-on assembly  32  and the concentric coiled outer tubing  14 , thus centralizing the inner components of the coiled tubing spiral venturi tool with the outer components of the coiled tubing spiral venturi tool. Then, the external connector bottom sub  24  is slid over the venturi plate transition component  40  and the outer tubing  14  and is coupled to an external connector component  15  that is in turn, coupled to the external connector top sub  22 . The coupling together, using set screws  154  of the external connector top sub  22 , the external connector component  15 , and the external connector bottom sub  24  compresses a seal pack assembly  26  in the annular cavity between the concentric coiled outer tubing  14  and the outer tubing disconnect assembly  20  thereby sealing the coiled tubing spiral venturi tool to the concentric coiled tubing. Additional sealing of the connections between the components comprising the outer tubing disconnect assembly  20  is provided by use of O-rings  156 . It is within the scope of the present disclosure to vary the numbers of set screws used to couple together the components comprising the outer tubing disconnect assembly  20  to provide leak proof engagement of the coiled tubing spiral venturi tool with different types and diameters of concentric coiled tubings and for different types of wellbore applications. It is also within the scope of the present disclosure to provide set screws to break under specified shear stress levels to allow the coupled coiled tubing spiral venturi tool and concentric coiled tubing to separate under axial tension. 
         [0085]    An embodiment of a suitable seal pack  26  for use with the coiled tubing spiral venturi tool disclosed herein is shown in  FIG. 6 . A metal ring  26   a  is assembled in parallel with a series of sealing devices consisting of O-rings  26   b,  polypack cup seals  26   c,  and carbon fiber packings  26   d,    26   e  (the thickness of  26   d  is twice the thickness of  26   e ) to form a compressible seal pack capable of withstanding high fluid pressures. 
         [0086]    An embodiment of an inner tubing roll on connector assembly  32  for use with the coiled tubing spiral venturi tool disclosed herein is illustrated in  FIG. 7  wherein inner coil tubing upper connecter  32   a  and inner coil tubing lower connecter  32   b  are cylindrical bodies that are fastened together with multiple set screws  154 . The number of set screws  154  installed is dependent on the application of the coiled tubing spiral venturi tool in a wellbore. If so required, the set screws  154  are allowed to break under shear stress to allow the coupled coiled tubing spiral venturi tool and concentric coiled tubing to separate under axial tension. Sealing devices, i.e. O-rings  156  are installed over the “roll on” end of the upper connecter  32   a.    
         [0087]    An embodiment of a Venturi Plate Assembly  110  with the fluid column holding valve components for being used with the coiled tubing spiral venturi tool disclosed herein is illustrated in  FIG. 8 . The fluid column holding valve comprises a cylindrical flow tube  112  cooperating with a series of disc springs  117  assembled in series to support the holding valve plunge  118 , which is exposed to the drive fluid. The fluid column holding valve will be normally closed containing the column of drive fluid contained in the inner tubing string until the drive fluid pressure is increased up to a level capable of compress the springs  117  allowing the drive fluid to pass through. The venturi plate  114  is a cylindrical body with an array of venturi cavities placed circumferentially around the centerline. The venturi alignment ring  116  is a tabbed cylindrical ring that is used to align the venturi plate  114  with the venturi jet nozzle plate assembly  124  ( FIG. 11 ). O-rings  156  are used to seal pressure between threaded connections. Slotted spring pins  119  are fastening devices installed to align the venturi plate  114  with the venturi plate transition component  40 . 
         [0088]    An embodiment of a control valve assembly  120  cooperating with a Vortex Generating Wash Nozzle assembly  100  for being used with the coiled tubing spiral venturi tool disclosed herein is illustrated in  FIG. 9 . The control valve assembly  120  comprises a relief valve assembly  122  that contains a series of disc springs  129  assembled in series to support the control valve plunger called the “jet nozzle shift dart”  126 . The jet nozzle shift dart  126  remains closed during fluid flow passing through a ported set screw  127  that is installed into the jet nozzle shift dart  126 . Fluid flow will pass through the device and exit the Vortex Generating Wash Nozzle assembly  100 . The primary shift stop sleeves  128  are fluid passage rings that allow fluid to pass through the disc springs  129  without restriction. A jet nozzle plate alignment screw  125  is provided to align the jet nozzle plate assembly  124  and the relief valve assembly  122 . A swirl plate lock ring  102  is provided to prevent rotation of inner parts caused by fluid under pressure flowing through the Vortex Generating Wash Nozzle assembly  100 . O-rings  156  are provided to seal the connections. 
         [0089]    The relief valve assembly  122  from  FIG. 9  is shown in more detail in  FIG. 10  and generally comprises a venturi inlet sub  122   a  containing a series of disc springs  122   d  assembled in series to support a stainless steel ball  122   b  and a relief valve dart  122   c.  It is optional if so desired, to use coil springs instead of discs springs. Ported hex plug  127  is provided to adjust the spring tension and opening pressure of the relief valve assembly  122 . The stainless steel ball  122   b  will open under a predetermined pressure allowing fluid under pressure to re-enter the control valve assembly  120  through drilled ports and open the jet nozzle shift dart  126 . 
         [0090]    The jet nozzle plate assembly  124  from  FIG. 9  is shown in more detail in  FIG. 11  and generally comprises a first embodiment of a venturi jet nozzle plate  124   a  with a plurality of venturi jetting nozzles  124   b  installed into the venturi jet nozzle plate  124   a  circumferentially around its centerline. A plurality of screw plugs  124   c  are also installed into the venturi jet nozzle plate  124   a.  O-rings  156  are provided to seal pressure between threaded connections. 
         [0091]    An embodiment of a spiral Vortex Generating Wash Nozzle  100  for use with the coiled tubing spiral venturi tool disclosed herein is illustrated in  FIG. 12  and general comprises: (i) a Vortex Generating Wash Nozzle  104  that is a slotted cylindrical body to provide a high-pressure fluid jet stream to the front of the coiled tubing spiral venturi tool into a wellbore, (ii) a jet shutoff valve stem  108  that is a threaded hollow cylindrical shaft fitted with an ported set screw for use to adjust fluid flow through the Vortex Generating Wash Nozzle  104 , and (iii) a nozzle swirl plate  106  fitted with a ported hex screw  127 . The nozzle swirl plate  106  provides a non-parallel fluid flow to enter the Vortex Generating Wash Nozzle  104  thereby causing stainless steel ball  122   b  to rotate within the annular cavity defined by the Vortex Generating Wash Nozzle  104  and the jet shutoff valve stem  108 . The jet shutoff valve stem  108  may adjusted to divert fluid to the Vortex Generating Wash assembly and jet nozzle venturis. O-rings  159  are provided to seal the connections. 
         [0092]    The venturi plate transition component  40  from  FIG. 3  is shown in more detail in  FIG. 13 . As fluid exits the venturi plate assembly, the individual fluid paths are further expanded and transitioned to the full circular fluid flow of the annular cavity of the concentric tubing strings. 
         [0093]      FIG. 14A  shows an end view of the venturi plate  114  of the preferred embodiment of the tool from  FIG. 8 , with three conical venturis  114   a  equidistantly distributed around its diameter.  FIG. 14B  shows a cross section through the venturi plate  114  from  FIG. 14A  at A-A showing a conical shape, while  FIG. 14C  shows a cross section through the venturi plate  114  from  FIG. 14A  at C-C. 
         [0094]    One of the objectives of this invention is to have a tool that can be easily adapted to the different conditions of the wells where it will operate, mainly because of different types of fluids present in the well, depth and directionality of the well, type of work to be performed and type and composition of obstructions to be removed. In addition to the preceding figures which describe the typical components of the preferred embodiment of the invention and its basic functionalities,  FIGS. 15-21  describe the modules which can be replaced, added or removed before introducing the tool into the well to obtain the best performance and higher operational reliability while maintaining the main functionalities from  FIG. 1 , resulting each possible combination of the basic tool or preferred embodiment with one or many of these modules in a different embodiment of the invention. 
         [0095]      FIG. 15A  shows a different module of the venturi plate  115 , to replace plate  114  from  FIG. 14   a,  having non-symmetrical venturi orifices  115   a  spaced equidistantly around the diameter of the venturi plate  115 .  FIG. 15B  shows a cross section through the venturi plate  115  from  FIG. 15 b    at B-B showing an asymmetrical ovaled shape, while  FIG. 15C  shows a cross section through the venturi plate  115  from  FIG. 15A  at D-D. The purpose of the change in the conical shape between orifices  115   a  and  114   a  obeys to make a better flow transition and unification from the multiple venturi diffuser into the common discharge. It is within the scope of this disclosure to provide 2, 3, 4, 5, 6, 7, 8, 9, 10 conical or non-symmetrical oval shaped venturis, which can be equidistantly distributed around the diameter of a venturi plate or follow a different pitch between them not necessarily constant, in order to better adapt to the type of well fluids and solids to be suctioned. It is also considered in order to produce different effect on the suction properties, the use of different size or diameter venturis within the same plate. 
         [0096]      FIG. 16 a    shows a partial longitudinal section view of the preferred embodiment of the tool on the area of the column hold valve  118  with the springs  117 .  FIG. 16 b    shows an alternative embodiment of the tool (without showing the hold down valve  118  and springs  117  for clarification purposes) where an inline filter  113  is placed downstream to the regular column hold valve plunger position, which can be installed to avoid the entrance of solids being carried by the power fluid  81  into the small fluid conduits of the tool, especially the jetting nozzles and venturi nozzles, which could clog them and make them inoperative, reducing the performance of the tool even making the operation to fail. The inline filter  113  is intended to catch the solids produced by any working fluid clot or debris coming from the internal surface of the coil tubing, which cannot be filtered by the in-surface filtering unit. To prevent impurities captured by the filter from obstructing the passage of the fluid downstream when the tool is in the well, there is provided a self-cleaning method consisting of making consecutive opening and closing cycles of the fluid column valve or which causes a partial deformation and movement of the filter making the solids on it to rearrange and move to one side. The inline filter  113  can also improve reuse of the Power Fluid  81 . The filter is not provided as a default component on the preferred embodiment of the tool because it produces a drop in the pressure downstream which could reduce both the suctioning and the jetting power of the tool, and it is only included when suspected to be present the clogging risk. Alternative embodiments of the tool could comprise the complete removal of the hold down valve  118  and springs system  117  leaving only the inline filter  113 , with the disadvantage of eliminating the “Reset” operation mode of the tool and leaving no procedure for cleaning the filter. 
         [0097]      FIG. 16 c    represents one of the main advantages of the use of the inline filter  113 , which are filtering low treatment fluids at the entry of the tool in operations involving the recirculation of the return fluid  82   f  to be pumped down to the bottom hole assembly together with the non-used power fluid  81 . 
         [0098]    In order to increase the effectiveness of the jetting effect when removing hard solids like scales or when the wellbore fluids are at high pressure, it is required the tool to deliver a higher pressure jet, which requires operate a higher power fluid pressures on the “Jet Only” operation mode of the tool. For doing this, the control valve shift dart  126   FIG. 9  of the preferred embodiment of the tool can be replaced by a different shape shift dart  126   b  shown in  FIG. 17 , which length L is longer, have a bigger upstream area UA facing the power fluid in order to improve the sealing with the venture conduits, and a smaller downstream area DA facing the high pressure fluid on the nozzle area, to reduce the effect on the shift dart  126   b.  In order to reduce the DA area, it can be required to insert an adapter sleeve element  126   c.    
         [0099]    In order to enhance the tool capability in solid removal when certain well conditions like high viscosity wellbore fluids or high pressure is present, the Vortex Generating Wash assembly described for the preferred embodiment of the tool which is a static jetting module can be replaced by a Rotating Vortex Generating Wash assembly  100   b  as shown in  FIG. 18   a,  consisting on a Rotating Vortex Generating Wash Nozzle  104   b  capable of rotating concentric to the housing  101   b  by means of an axially restricted low friction slack fit between the cylindrical faces of both elements, with the fluid sealing adding sealing rings  103  to make it possible to rotate as shown by the arrows in  FIG. 18 b    with in order to aid to the spiral currents creation. This rotational assembly could represent a higher reliability risk for the tool while operating in the wellbore because of the failure of the sealing ring components and the progressive wearing of the mating faces, reasons why this is an alternative embodiment of the tool instead of the preferred one with the static Vortex Generating Washer Nozzle Assembly 
         [0100]    An alternative embodiment of the present invention for operations involving heavy or highly viscous wellbore fluids is shown in  FIG. 19  which is partial longitudinal section view on the area of the venturi assembly, where a long tubular element called Power Fluid Tube  124   d,  is assembled in replace of at least one of the venturi jetting nozzles  124   b  located over the venturi jet nozzle plate  124   a,  passing through the venturi plate  114 , with the function of supplying high pressure Power Fluid directly to the area of the venturi diffuser transition  40 , with the purpose of providing higher pressure to pump up to the surface those viscous or heavy wellbore fluids located in that zone of the tool. When the power fluid tube  124   d  is installed, the tool loses some of its suctioning capability due to the cancelling of at least one of its venturis being replaced, reason why this is an alternative embodiment of the tool instead of the preferred one. 
         [0101]    Other way to increase the pumping pressure of the suctioned wellbore fluid is to make the venturi diffuser transition plate as long as possible to increase the velocity to pressure conversion. To achieve the longest possible length in the diffuser it can be rearranged the typical tool assembly of the preferred embodiment to include additional venturi transition modules as shown in  FIG. 20 a    and  FIG. 20   b,  where it is added one secondary venturi transition plate  41  to the venturi transition plate  40 , being possible to add more than one secondary venture transition plates, all of them aligned between each other by means of the aligning features  42  and with respect to the mating components by means of locating features. When this tool rearrangement is made, it is also required to replace the external connector bottom sub  24  by a longer one  24   b,  which makes the total length of the tool longer. The reason to use a short venturi transition plate  40  in the preferred embodiment of the tool, instead of a long one or even the array of more than one as in  FIG. 20   a,  is because it also increases the total length of the tool assembly, which is something to be avoided considering that the longer the tool, the higher the risk of this tool to get stuck in the wellbore or conduit because of its greater rigidity compared to that of the coil tubing. 
         [0102]    To minimize the risk of the tool getting stuck in the conduit because of the built up solids around it during operation, it can be added a module called rupture device assembly  25  shown in  FIG. 21  which replaces the external connector bottom sub  24  ( FIGS. 4 and 5 ) of the preferred embodiment of the invention. The rupture device assembly  25  is composed by the rupture nozzles  251  which are conduits normally closed with an internal pressure sensitive mechanism to open when the internal pressure on the tool reaches the rupture pressure, which is higher than the maximum operating pumping pressure of the venturi jet pump in the area of the venturi transition plate  40   FIG. 1 a    and the annular conduct  14  of the coil tubing. To achieve the rupture device the tool must be operated in an special mode involving to pump down the Power Fluid  81  represented by black arrows through both the internal conduit  12  and the annular conduit  14  of the coil tubing, in order to create a pressure enough on the fluid located on the venturi transition plate, which will be a mixture of the Power Fluid  81  and the wellbore fluid  82  identified by the arrows  82   e.  Once the rupture pressure is reached, the jet produced by the rupture nozzles  251  can remove part of the obstructing solids external to the tool and also produce some lateral movement of the tool which can lead to the release of the tool accompanied by the pulling or pushing movement of the coil tubing. The typical embodiment of the rupture device assembly  25  comprises at least one rupture nozzle  251  aligned with each of the venturi conduits (three for the preferred embodiment of the tool), located on the rupture sleeve connector sub  252 . 
         [0103]    In a similar procedure that described in  FIG. 21  to activate the rupture device, it can be cleaned or unplugged the suction screen  140  and the slotted suction head housing  130 , by pumping down power fluid through both the internal conduit  12  and the annular space  14  of the coiled tubing, which increases the tool reliability and makes possible to perform continuous operation with the tool in the well without the need to remove it from the well. 
         [0104]    The tool described in this document for any of the presented embodiments can operate in four different theoretical modes associated to the four possible combination between the Hold Down Valve and the Control Valve, according to the type of action to be performed, some of them being done with the tool moving upwards, or downwards or while stationary.  FIGS. 22-25  show a longitudinal section view of an embodiment of the invention, located in an unspecified portion of a well, describing each of the basic modes of operation of the tool. The tool is immersed on the well fluids  82 , contained by a conduit or case  84  and at that unspecified portion of the well there are some obstructions  82   c  like those due to sedimentation. The principle used to switch between modes of operation is the variation on the pressure level of the drive fluid (DF) (pumped from a coil tubing pressure surface unit), described by arrow  81  passing through the inner tubing  12  of the concentric coil tubing system to which the tool is attached, and enters the coil tubing spiral venturi tool assembly (CTSVT)  1  via the inner coil tubing lower connecter  32   b.  The passage of this drive fluid  81  through the tool is conditioned to its pressure level can open internal pressure-sensitive valves, which allow to communicate the different work elements of the tool, so that different nozzles and venturis can act in a selective way to perform the different actions of cleaning and collection of the debris and residues inside the well or conduit. In order for the tool to be able to operate, the surface unit is required to pump the drive fluid into four different pressure ranges, which will be called the BP (base pressure) range, LP range (low pressure), MP range (medium pressure) and HP range (high pressure); there being no limits or physical values established for them, and these ranges vary depending on the configuration and adjustments made to the tool before entering it into the well or conduit. 
         [0105]      FIG. 22  describes the so called “Reset” operation mode of the tool, in which the drive fluid  81  is in the pressure range BP which is lower than the pressure required to overcome the resistance of the fluid column hold valve  118 , preventing the flow of the fluid to the control valve assembly  120  and the rest of the internal conduits, nozzles and venturis of the tool. No well fluid represented by wavy lines  82  or material on the outside of the tool is drawn by suction into the tool or pumped up to the surface through the annular space between the outer tubing  14  and the inner tubing  12 , and no drive fluid  81  leaves the tool to the well. This operation mode can be used, but is not limited to the downwards or upwards traveling stages of the tool, to downhole hold-on stops or switch between other operation modes of the tool, or for different operations like on surface equipment calibration or testing, having two main advantages, first to avoid loss in drive fluid when it is not performing some tool work cycle, representing energy and fluid savings, and second having always a base pressure level on the drive fluid  81  allowing to move rapidly from one operation mode to another, representing time saving and increasing tool effectiveness. 
         [0106]      FIG. 23-25  shows the additional modes of operation of the tool. When the drive fluid  81  pressure is intentionally raised from the BP level to a level higher to the pressure P 1  which is the minimum pressure required to overcome the resistance or closing force of the fluid column hold valve  118 , the fluid passes through said valve then through internal fluid conduit formed by the central hole of the venturi plate transition component  40  and venturi plate assembly  110 , and finally reach the control valve assembly  120 . The control valve assembly  120  for this particular embodiment acts as a normally closed valve (referring the term “closed” only to the extended position of the springs, not to the flow condition through the internal orifice on the piston), three position-two way pressure sensitive valve, which allows the drive fluid  81  to take any of the two ways depending on its pressure level. Each one of the three positions of the control valve assembly  120  will correspond to a different operation mode of the tool. As described earlier in  FIGS. 9 and 10  for this particular embodiment of the invention the control valve assembly  120  comprises the sliding jet nozzle shift dart  126  loaded by the disc springs  129  and a relief valve assembly  122 , but other embodiments of the present invention could comprise normally open valve or even an array of a different number of valves in order to achieve the desired three position—two ways of the flow. For this embodiment the three positions of the control valve  120  corresponds to: (a) the most extended length of the disc springs  129 , (b) the most comprised length of the disc springs  129 , and (c) an intermediate position between positions (a) and (b). 
         [0107]      FIG. 23  shows the so called “Well Jet” operation mode of this embodiment of the tool, which occurs when the pressure of the drive fluid  81  is in the LP range, meaning higher than pressure P 1 , but lower to the pressure P 2 , which is the pressure required to overcome the force of disc springs  129 , being called this pressure range LP range. While the drive fluid  81  is on LP range, the control valve  120  remains on its (a) position, meaning that the disc spring  129  is extended at its most possible length causing the outer side of the jet nozzle shift dart  126  to set against the inner walls of the venturi inlet sub  122   a,  preventing the drive fluid  81  to flow onto the venturi jetting nozzles  124   b,  allowing it only to flow through the inner opening of the jet nozzle shift dart  126  towards the Vortex Generating Wash nozzle  104  to become the jet fluid  81   a  coming out of the tool, with sufficient force to unplug or refine obstructive material exemplified by sand bridges, mud, wax, soft scale, congregate, and the like in the wellbore that would otherwise prevent further passage of the tool into the wellbore. The fluid jet produces spiral like currents  82   a  with the wellbore fluid, which makes the disintegration and fluidization of sediments  82   c  more effective than the single jet impact. The power fluid  81   a  being projected outward from the Vortex Generating Wash nozzle  104  follows a 360 degree spray pattern, producing an egressing fluid flow that is irregularly pulsatile and intermittent, producing a flow vortex, a swirl flow, and a helical flow of highly pressurized high-speed irrigation fluid which rotation can be controlled by reconfiguring the components within the wash nozzle assemblies, or by modulating the fluid flow pressure through the wash nozzle assemblies. Additionally, the intermittent, pulsing high-speed fluid flow directed over the entire circumference allows the tube or wellbore to be thoroughly cleaned at lower fluid pressures and fluid flow rates than static jet wash nozzles 
         [0108]      FIG. 24  describes the so called “Well Jet and Vacuum” operation mode of this embodiment of the tool, which occurs when the pressure of drive fluid  81  is raised intentionally to a level higher than P 2  pressure, but lower than the pressure P 3 , the later defined as the pressure that produces the full compression of the disc spring  129 . At this pressure range, the control valve  120  is set to position (c), resulting in the jet nozzle shift dart  126  being separated from the inner walls of the venturi inlet sub  122   a,  allowing the drive fluid to flow in two different paths, one through the inner opening of the jet nozzle shift dart  126  because of the gap with the tip of the shutoff valve stem  108 , which leads the drive fluid to be jet as fluid  81   a  as in the case of the operation mode described in  FIG. 23 , and a second flow path which conducts the drive fluid up to the venturi jet nozzle  124   b,  what is indicated by arrow  81   b.  As the drive fluid  81   b  passes through the venturi plate assembly  110 , the low pressure caused by the principles of the jet pump makes the wellbore fluid “WF”  82   a  carrying the removed solids to enter the device through slot openings of the slotted suction head housing  130 , which is covered by the suction screen  140  in order to prevent larger particles suspended in wellbore fluid  82   a  from entering the tool, causing the obstruction of conduits and venturi throats. The combination of the suctioned wellbore fluid  82   a  with the suspended solids  82   c  on it, plus the injected drive fluid  81   b  passing through the venturi assembly  46  and the venturi transition plate  40  is called the returning fluid RF  83 , and it is sent to the surface through the annular space between the outer coil tubing  14  and the inner coil tubing  12  because of the increase of pressure due to the conversion of the kinetic energy of the return fluid  83  into static pressure at the venturi diffuser section, as in any typical downhole jet pump systems. 
         [0109]    The simultaneous action of the drive fluid jet  81   a  generated by the Vortex Generating Wash Nozzle assembly  100 , and the suction generated by the venturi effect increases the spiral currents solids  82   c  of the tool, which enhances tool effectiveness for the removal of sediments and debris obstructing the wellbore. 
         [0110]      FIG. 25  shows the fourth operation mode so called “Vacuum Only Mode” of the same embodiment of the invention as shown on the preceding  FIGS. 22 to 24 . To achieve this operation mode, the drive fluid pressure  81  is raised up to a level equal or higher than P 3  pressure called the pressure range HP, which causes the control valve assembly  120  being set to position (b), consisting on the compression of the disc springs  129  to its minimum possible length when the tip of the jet shutoff valve stem  108  gets inserted into the inner orifice of the traveling jet nozzle shift dart  126  attached to the end of the disc springs  129 . Once occurs the occlusion of the internal bore of the jet nozzle shift dart  126  by the seating of the jet shutoff valve stem  108  against it, the drive fluid  81  (called  81   b  once it is diverted to flow towards venturi conduits) can only flow into the venturi nozzles  124   b  and the venturi assembly  110  as described for  FIG. 23 , being the flow into the Vortex Generating Wash Nozzle  104  completely blocked which ceases the spiral jet of drive fluid out of the tool. The return fluid  83  is composed by the power fluid  81  and the well bore fluids suctioned by the tool. 
         [0111]    The “Vacuum Only” is effective in the reactivation of the production zones of an oil well by the joint effect of removing the sediments  82   c  blocking the flow to the wellbore as by the stimulation of the reservoir  86  by the pressure differential created by the venturi effect. The present embodiment of the tool disclosed has an advantage regarding some existing tools because of the location of the multiple circumferential jet pump venturis which ensures an uniform 360 degree pressure differential around the tool regardless of the orientation of the tool. 
         [0112]    The results obtained by the tool operating in the theoretical four operating modes described above ( FIG. 22-25 ) may produce different effects and be better suited to different specific works, depending on the direction of movement of the tool. For this reason, we distinguish six different practical operating modes (called PO Modes) of the tool being: Reset Mode or PO mode A, which can be performed in any direction or stationary; Jet Only Downwards or PO mode B, Jet Only Upwards or PO mode C, Vacuum and Jet Downwards or PO mode D; Vacuum and Jet Upwards or PO mode E; Vacuum Only or PO mode F, which can be performed in any direction or stationary. 
         [0113]    The present document discloses not only the tool hardware and its embodiments but also the methods how it operates to successfully perform the different works it&#39;s been designed for. These methods are obtained from physical testing of the tool on real operations and consist on specific sequences of some of the six practical operation modes described above, for the main works on the area of wellbore solid obstruction removal and well stimulation, and they are: 
         [0114]    (Method 1) Tool Surface Calibration. Fluid power is pumped to the tool to adjust the spring force opening of the three valves at determined pressures, being the PO modes sequence PO mode A, PO mode B or C, PO mode D or E, PO mode F. The pressure levels stablished consider the hydrostatic pressure of both power fluid and wellbore fluid, type of each of those fluids, flow pressure loss, target depth, kind and composition of sediments to remove, and tool hardware configuration among other factors. 
         [0115]    (Method 2) CleanOut. Run the tool downwards in PO mode A until a depth above target depth, switch to PO mode D at the lower pressure in range LP, increasing pressure within LP range as closing to target depth. Continuous evaluation of the return fluid indicates when target depth is reached because of change of composition. Once target depth is reached increase pressure over P 3  to switch to PO mode F moving downwards and upwards. When pulling the tool out of the hole switch to PO mode E and after PO mode A upwards until reaching surface. 
         [0116]    (Method 3) Blockage Removal. Run the tool down into the hole in PO mode B, and once passed the suspected target depth switch into PO mode C upwards to ensure blockage disintegration. Run again in PO mode D downwards at the lower pressure in range MP as far above target depth and increasing up to the highest pressure within MP range until reaching target depth, then switch to PO mode F downwards and upwards up to a depth far above target depth. Then switch to PO mode E and finally to PO mode A up to the surface. 
         [0117]    (Method 4) Well Activation. Run the tool into the hole with PO mode D downwards to the target depth, then increase pressure to switch to PO mode F remaining at the same depth while evaluating the return fluid at surface. Once formation fluids are found at a certain rate in the return fluid, tool can be pulled in PO mode E upwards and after to PO mode A up to surface. 
         [0118]    The tool operation modes are not limited to the methods disclosed in this document, but those are the ones describing the main operation the tool has been designed for, mainly referred to oil/gas wells. 
         [0119]    To accomplish one of the objectives of the present invention regarding the optimization of the overall operation time of the tool, it is provided a relief valve associated to the control valve (as shown in  FIG. 10 ) which main purpose is to reduce the stabilization time of the tool when the switch between operation modes occurs.  FIGS. 26   a,    26   b  and  26   c  describe the function of the relief valve on the preferred embodiment of the tool which consists on relieving the pressure of the Power Fluid trapped on the conduits of the venturi nozzle and the ones on the jet nozzle which are at both sides of the control valve Jet nozzle shift dart  126 .  FIG. 26 a    describes the jet nozzle shift dart  126  in the seated position (Jet Only Operation mode position) closing the venturi nozzle conduits  121   a  and  121   b,  which makes that the pressure on those conduits be equal to the hydrostatic pressure of the wellbore fluid, lower than the one on the jetting nozzle conduits  121   c  at the power fluid  81  pressure. In that position, the relief valve ball  122   b  is in closed position (right most position in  FIG. 26 a   ), which maintains the pressure difference between the two conduits aiding the control valve shift dart to stay closed.  FIG. 26 b    shows the control valve shift dart  126  movement (right most position in  FIG. 26 b   ) when the power fluid  81  has been increased to switch into Venturi Only mode. As the Power Fluid now pressurizes the venturi nozzle conduits, the relief valve ball  122   b  opens (moving leftwards in  FIG. 26 b   ) because of the pressure difference between the remaining pressure of power fluid on the jetting nozzle conduits  121   c  which is higher than the now lower pressure in the venturi conduits  121   a  because of venturi effect. The high pressure on the jetting nozzle conduits  121   c  oppose to stabilize the position of the shift dart  126 , so when relief valve ball  122   b  moves allowing communication between the venturi conduits  121   a  and the jetting nozzle conduits  121   c,  the pressure on the latest is reduced, which makes to stabilize position of shift dart  126  (because of the higher pressure on the upstream side of it) and makes the relief valve ball  122   b  spring to overcome the force generated by the pressure difference between the two conduits, all of this described on  FIG. 26   c.  By the effect of the relief valve the time it takes the piston to settle in “Venturi Only Mode” position is lower, reducing the total time of operation 
         [0120]      FIG. 27  shows a typical concentric coil tubing cleanout operation in an oil/gas well using the invention herein disclosed. The tool  1  is attached to the concentric coil tubing  12  and  14  and located into the well section where the plugins and obstructions are located. The drive fluid  81  is pumped downhole through the inner coil tubing  12 , being pressurized by the hydraulic pressure surface unit  91 . When the tool operates in either of the two vacuum modes, the return fluid  83  is pumped to the surface by the jet pump effect through the outer coil tubing  14 , and it discharges at the surface into a collector tank  92 , where it is processed, filtered to remove the solid from the well bore, and conditioned to be recirculated and pumped down again. 
         [0121]    While the preferred embodiment and various alternative embodiments of the invention have been disclosed and described in detail herein, it may be apparent to those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope thereof.