Patent Publication Number: US-2018045022-A1

Title: Wellbore tubular and method

Description:
FIELD 
     The invention relates to wellbore structures and, in particular, nozzles and tubulars for wellbore fluid control. 
     BACKGROUND 
     Various wellbore nozzles and tubulars are known and serve various purposes. Tubulars are employed to both inject fluids into and conduct fluids from a wellbore. In some cases, nozzles are employed to control the flow and pressure characteristics of the fluid moving through the wellbore. 
     Wellbore tubulars with nozzles have failed in some challenging wellbore conditions, such as in steam or acid injection operations. Improved nozzled tubulars are of interest. 
     SUMMARY 
     In accordance with another broad aspect, there is a wellbore tubular comprising: a base pipe including a wall; a port through the wall providing access between an inner diameter of the base pipe and an outer surface of the base pipe; a nozzle in the port, the nozzle including an orifice; and a diffuser tube on the outer surface to receive fluid exiting the orifice, the diffuser tube including an inlet port opening to an inner diameter within a tubular wall of the diffuser tube, a fluid diffusing wall at a bend within the diffuser tube and a plurality of outlet ports from the diffusing tube. 
     In accordance with another broad aspect, there is a method for handling fluid in a wellbore comprising: forcing fluid flows through a nozzle orifice which extends from an inner diameter of a tubular to an outer surface of the tubular; and directing the fluid flowing from the nozzle orifice along the outer surface and into a diffuser tube to diffuse energy of the fluid flowing from the nozzle orifice before the fluid exits the tubular. 
     It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Drawings are included for the purpose of illustrating certain aspects of the invention. Such drawings and the description thereof are intended to facilitate understanding and should not be considered limiting of the invention. Drawings are included, in which: 
         FIG. 1  is a perspective view of a wellbore tubular; 
         FIG. 2  is a section along line I-I of  FIG. 1 ; 
         FIG. 3  is a section through line II-II of  FIG. 2 ; 
         FIG. 4  is an enlarged section through a nozzle installed in the wall of a tubular; 
         FIG. 5  is an exploded perspective view of the components of a nozzle to be installed in the wall of a tubular; 
         FIG. 6  is a perspective view of a nozzle seat; 
         FIG. 7  is an enlarged sectional view of a nozzle; 
         FIG. 8  is an enlarged section through a nozzle installed in the wall of a tubular; 
         FIG. 9  is an axial sectional view through a tubular with a diffuser therein; 
         FIG. 10  is a section along of  FIG. 9 ; 
         FIG. 11  is a section along IV-IV of  FIG. 10 ; 
         FIG. 12  is sectional view of another tubular, the sectional view being similar to that of  FIG. 10 , but passing through the nozzle; 
         FIG. 13  is a perspective view of the diffuser and nozzle arrangement of the tubular of  FIG. 12  with the shield removed; and 
         FIG. 14  is a section along V-V of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. 
     Referring to  FIGS. 1 to 3 , a wellbore tubular  10  is shown. The wellbore tubular is for conveying fluid into or out of a well and for permitting fluid to pass between its inner diameter and its outer surface. The tubular has a durable construction and may even accommodate the significant rigors presented by handling steam flows. The wellbore tubular may be formed using various constructions. For example, the ends  10   a  of the wellbore tubular may be formed for connection to adjacent wellbore tubulars. As will be appreciated, while the tubular&#39;s ends are shown as blanks, they may be formed in various ways for connection end to end with other tubulars to form a string of interconnected tubulars, such as, for example, by formation at one or both ends as threaded pins, threaded boxes or other types of connections. 
     Wellbore tubular  10  includes a base pipe  12  with one or more ports  14  through the base pipe wall. Fluids may pass through ports  14  between the base pipe&#39;s inner diameter ID defined by inner surface  12   a  and its outer surface  12   b . Depending on the mode of operation intended for the wellbore tubular, fluid flow can be inwardly through the ports toward inner diameter ID or outwardly through the ports from inner diameter ID to the outer surface  12   b.    
     The inner diameter generally extends from end to end of the tubular such that the tubular can act to convey fluids from end to end therethrough and be used to form a length of a longer fluid conduit through a plurality of connected tubulars. 
     The tubular may include a shield  16  mounted to base pipe  12 . The shield may be positioned to overlap the ports. Shield  16  may be spaced from outer surface  12   b  such that an annular space  18  is provided between the shield and outer surface  12   b.    
     There are openings from space  18  to the exterior of the tubular, which is the outer surface  12   b  exposed beyond the shield. For example, there may be openings  18   a  through the shield or at the end edges  16   a  of shield  16  where fluid can flow into or out of space  18 . In the illustrated embodiment of  FIG. 2 , shield  16  is spaced at at least some edges  16   a  from outer surface  12   b  such that there are openings  18   a  through which space  18  can be accessed at those edges. In some embodiments, as shown, the shield may be positioned to encircle base pipe  12  at the ports  14  and, therefore, may be shaped as a sleeve, as shown with space  18  formed as an annulus and with annular access openings  18   a  at both ends of the sleeve. 
     The openings may take other forms in other embodiments, depending on the form of the base tubular, sleeve, and mode of operation. For example, in one embodiment, the  118   a  openings may be formed in whole or in part by grooves  119  in the outer surface  112   b  of the base pipe ( FIG. 8 ). 
     Shield  16  may serve a number of purposes including, for example, protecting the ports from abrasion and diverting flow for fluid velocity control. For example, shield  16  diverts flow between the exterior of the tubular and ports  14 , such that it must pass along outer surface  12   b  of base pipe. Flow, therefore, cannot pass directly radially between the exterior of the tubular and inner diameter ID. In particular, because shield  16  overlaps the ports, ports  14  open into space  18 , flow between exterior of the tubular and the inner diameter changes direction at least once: at the intersection of port  14  and space  18 . While flow through the ports  14  is radial relative to the long axis xb of the tubular, flow between the ports and the exterior of the tool is through space  18  and that flow is substantially orthogonal relative to the radial flow through ports  14 . 
     Each port  14  has a nozzle assembly  20  installed therein. The nozzle assembly permits flow control through the port in which it is installed. With reference also to  FIG. 4 , nozzle assembly  20  includes at least a nozzle  22  and may include an installation fitting  24 . 
     Nozzle  22  includes an orifice  26  extending through the nozzle body through which fluid passes through the nozzle and therefore through the port. In particular, a nozzle  22  is installed in each port such that flow through the port is controlled by the shape and the configuration of orifice  26 . 
     Nozzle  22  is formed of a material that can withstand the erosive rigors experienced down hole such as via abrasive flows, high velocity flows, corrosive flows with acid and/or steam passing through orifice  26 . Nozzle  22  may, for example, be formed of a material different, for example, harder than the material forming base pipe  12 . The base pipe is, for example, usually formed of steel such as carbon steel and nozzle  22  may be formed of a material harder than the carbon steel of base pipe  12 . In some embodiments, for example, nozzle  22  may be formed of tungsten carbide, stainless, hardened steel, filled materials, etc. 
     Orifice  26  may be shaped to allow non-linear flow through nozzle  22 . In particular, orifice  26  defines a path through the nozzle, through which fluid flows, and the path from its inlet end to its outlet end is non-linear, including at least one bend or elbow that causes at least one change in direction of the fluid flowing through the orifice. This bend may affect fluid flows in a number of ways to redirect the flow to a more favorable direction, to cause impingement of the fluid against a nozzle surface or another flow to diffuse energy from the flow, to mitigate erosive damage to certain surfaces and/or to create an extra back pressure to slow or otherwise control flows of certain fluids autonomously through the nozzle. For example, the geometry of the nozzle orifice  26  can be selected to choke selectively gas, water, steam or oil. 
     For example with reference also to  FIG. 7 , orifice  26  may include a diverting bend at y that diverts flow through the nozzle from a first direction to a second direction which is offset, out of line from the first direction. With reference to the direction of flow depicted through the nozzle of  FIG. 7 , the first direction is shown by arrow Fa and the second direction is shown by arrow Fb. In one embodiment, the second direction is substantially orthogonal to the first direction. 
     Nozzle  22  is positioned in a port and will have one end open to the inner diameter ID of the tubular and the other end open to the outer surface  12   b . Generally, the nozzle is installed so that a base end  22   a  is installed adjacent and open to inner surface  12   a  and an opposite end  22   b  is installed adjacent and open to outer surface  12   b . Orifice  26  may be formed, therefore, to avoid straight through flow between base end  22   a  and opposite end  22   b . Orifice  26 , for example, may include a portion defining a main aperture  26   a  and a portion defining a lateral aperture  26   b . Main aperture  26   a  extends from an opening  26   a ′ at a base end  22   a  of nozzle  22  to an end wall  26   a ″ at an opposite end  22   b  of the nozzle. Lateral aperture  26   b  extends from the main aperture and connects main aperture  26   a  to another opening  26   b ′ adjacent opposite end  22   b . Lateral aperture  26   b  extends at an angle from the long axis of main aperture  26   a . The angular intersection of the axis of lateral aperture relative to the main aperture may be substantially orthogonal (+/−45°) and in one embodiment, for example, the apertures  26   a ,  26   b  intersect at y at substantially 90°. 
     The nozzle may be substantially cylindrical with ends  22   a ,  22   b  and substantially cylindrical side walls extending between the ends. In such an embodiment, the main aperture portion opens at an end and the pair of lateral aperture portions opens on the cylindrical side walls. 
     End wall  26   a ″, which can be flat (planar) or domed (concave), prevents straight through flow through the nozzle and acts to divert flow from the first direction in the main aperture to the lateral direction through lateral aperture  26   b . Impingement of fluid flows against wall  26   a ″ dissipates energy from the flow and concentrates erosive energy against wall  26   a ″ rather than surfaces beyond the nozzle. Orifice  26  is formed through the material of the nozzle and, thus, walls  26   a ″ and the other walls defining orifice  26  are of erosion-resistant material. Thus, the diverting bend and in particular end wall  26   a ″, can reliably accommodate the passage therethrough of erosive flows including that of steam. This foregoing description focuses on flow in only one direction through apertures  26   a ,  26   b , but it is to be understood that flow can be from opening  26   b ′ to opening  26   a ′ (i.e. with the flow moving in the opposite directions of arrows Fa and Fb), if desired. See for example,  FIG. 8  wherein flow arrows F through nozzle  122  pass in the opposite direction: from outer lateral aperture portions  126   b  to main aperture portion  126   a  of orifice  126 . 
     Orifice  26  may be further configured to control the flow characteristics of fluid passing therethrough. In one embodiment, apertures  26   a ,  26   b  may be sized to limit the volume of fluid capable of passing therethrough. For example, apertures  26   b  may be smaller diameter openings, sized to allow less flow, than aperture  26   a . For example, the total cross sectional area of apertures  26   b  may be less than the total cross sectional area of aperture  26   a , such that a back pressure is created when flow is in the direction of arrows Fa, Fb. Stated another way, the pressure drop is mainly across  26   b . The primary flow control through the nozzle is at lateral aperture  26   b , more so than  26   a.    
     Alternately or in addition, apertures  26   a ,  26   b  may be shaped to impart desired flow rate and/or pressure on the fluid passing therethrough. For example, lateral aperture  26   b , as shown, has internal shape with a jetting constriction to impart a jet effect, which generally includes a fluid acceleration and pressure change (i.e. drop), in the fluid passing therethrough. The shape of apertures  26   a  may change depending on whether the flow is intended to be with arrows Fb or against them or a bidirectional jetting shape may be employed with a symmetrical constriction similar to an hour glass. 
     In addition or alternately, there may be more than one main and/or lateral aperture. For example, as shown, orifice  26  may take the form of a T-shaped conduit with at least two lateral apertures  26   b  extending from the main aperture. However, while two lateral apertures  26   b  are shown, there may be only one or more than two such apertures. Generally, there will be an even number of lateral apertures with pairs substantially diametrically opposed across the circumference of the main aperture  26   a . The diametric positioning, with one lateral aperture  26   b  opening into main aperture  26   a  at a position substantially opposite another lateral aperture  26   b  (as shown in  FIG. 7 ), allows fluid impingement when flow is inwardly from apertures  26   b  to aperture  26   a . This impingement may create a desired back pressure on the flow through nozzle. 
     Nozzle  22  conveys fluid between openings  26   a ′ and  26   b ′ across the wall of the base pipe. One opening is exposed in the inner diameter of the base pipe and the other opening is exposed on outer surface  12   b . If shield  16  is employed, fluid when exiting from nozzle  22 , enters annulus  18 . The position of orifice  26   b ′ of lateral aperture  26   b  causes some fluid movement parallel to outer surface  12   b , rather than straight radially out from port  14 . 
     Nozzle  22  may be installed in any of various ways in its port  14 . If desired, nozzle assembly  20  may include installation fitting  24  to hold nozzle  22  in its port  14 . For example, if the material of nozzle  22  prevents reliable engagement to base pipe or is formed of a material different than the material of the base pipe, a fitting  24  may be employed to ensure a good fit of the nozzle in its port and may, for example, reduce the risk of nozzle  22  falling out of the port. 
     Installation fitting  24  may be formed to fit between the nozzle and the port. For example, the installation fitting may include a portion for being engaged in the port and a portion for securing nozzle. The portion for being engaged in the port may vary depending on the form and the shape of the port and the desired mode of installation in port  14 . In the illustrated embodiment, for example, installation fitting  24  includes a threaded portion  28  as that portion engageable in the port. The port may also include threads  30  into which fitting  24  may be threaded. 
     The portion for securing the nozzle may also vary, for example, depending on the form and shape of nozzle  22  and the desired mode of installation of nozzle  22 . For example, in one embodiment, nozzle  22  can be held rigidly by the fitting and in another embodiment, nozzle  22  may be installed to have some degree of movement relative to the fitting, while being held against becoming entirely free of the fitting. Thus, as an example, fitting  24  in the illustrated example includes a passage  32  into which nozzle  22  fits. Passage  32  passes fully through the fitting such that it is open at both ends of the fitting and, in other words, the fitting is formed as a ring. When nozzle  22  is installed in passage  32 , opening  26   a ′ is exposed at one end of the passage and opening  26   b ′ is exposed at the other end of the passage. 
     In this embodiment, nozzle  22  is secured rigidly into passage  32 . For example, nozzle  22  may be press fit and possibly mechanically shrunk fit, into passage  32 . In one embodiment, fitting  24  may be heated to cause thermal expansion thereof that enlarges the diameter across passage  32 , nozzle  22  may be fit therein and fitting  24  cooled to contract about the nozzle and, thereby, firmly engage it. In such an embodiment, fitting  24  may include features to modify the hoop stresses about the ring to best accommodate heating expansion for press fitting. For example, passage  32  and nozzle  22  may have a tapering diameter from end to end to facilitate press fitting these parts together. For example, nozzle  22  may have a tapering outer diameter from one end to the other and passage  32  may have a tapering inner diameter from one end to the other end. The nozzle  22  may then be inserted and forced into passage  32  with the narrow end of the nozzle wedged into the narrow end of the passage and the tapering sides of the parts in close contact. In addition or alternately, for modification of hoop strength, passage  32  may include notches  34  in the otherwise substantially circular sectional shape (orthogonal to the center axis x of passage  32 ). 
     In some embodiments, the material of nozzle  22  may have thermal expansion properties different than the material of base pipe  12 . As such, if nozzle  22  was installed directly into base pipe  12 , it may tend to become dislodged or damaged in use such as when in a high temperature (i.e. steam) environment. Generally, the materials most useful for the nozzle may have a low coefficient of thermal expansion, while the materials most useful for the base pipe  12  may have a reasonably high coefficient of thermal expansion and most often a nozzle firmly installed in a port at ambient temperatures may tend to fall out of a base pipe at elevated temperatures. To address issues caused by thermal expansion, installation fitting  24  may be formed of a material having a coefficient of thermal expansion selected to work well with both the nozzle and the base pipe. In one embodiment, installation fitting  24  is formed of a material having a coefficient of thermal expansion between those of the materials of the base pipe and the nozzle. In another embodiment, the coefficient of thermal expansion of fitting  24  is greater than that of base pipe  12 . As such, when undergoing thermal stress, fitting  24  will undergo thermal expansion ahead of base pipe  12  and fitting  24  stays firmly engaged in port. In such an embodiment, nozzle  22  and fitting  24  can be connected when the fitting is thermally expanded. 
     Shield  16 , if employed, may overlap the nozzle assembly to hold nozzle  22  in the port  14 . In one embodiment, nozzle  22  is fit in the port such that any movement to fall out of port is radially out towards outer surface  12   b . A controlled installation that tends to allow nozzle  22  to only move outwardly towards the outer surface may be achieved, for example, by tapering of the nozzle and the port/passage in which it is installed to have their wider ends radially outwardly positioned, for example closer to the outer surface of the base pipe. Shield  16  includes a plug  36  in a hole  38  that substantially radially aligns with port  14 . Plug  36  is removable to allow opening of hole  38  and access to port  14  and, thereby, installation of nozzle assembly  20  to port  14  through hole  38 . After nozzle  22  is installed, plug  36  may be reinstalled in hole  38  to overlie the nozzle. Plug  36  and hole  38 , for example, may be threaded to facilitate removal and reinstallation of the plug. 
     Plug  36  can ensure that nozzle  22  remains in position in port  14  even if nozzle  22  comes loose. For example, plug  36  can be formed to penetrate into hole  38  sufficiently to bear down on end  22   b  of the nozzle. If there are tolerances that may prevent reliable fitting of the plug against end  22   b  of the nozzle, a flexible spacer may be employed. For example, as shown, there may be a spring  40  between plug  36  and nozzle  22 . 
     Nozzle assembly  20 , in this embodiment including nozzle  22  and fitting  24  in port  14 , allows fluid to move between inner diameter ID and outer surface  12   b  through orifice  26 . The lateral orifice  26   b  directs fluid flows that are adjacent opening  26   b ′ to pass substantially parallel to outer surface  12   b  through annulus  18 . To facilitate flows through the annulus with minimal erosive damage to shield  16 , aperture  26   b  may be positioned such that flows therethrough pass somewhat parallel to the long axis xb of base pipe. For example, the nozzle  22  can be installed such that the axis xa of aperture  26   b  is within 60° and perhaps within 45° of long axis xb. In the illustrated embodiment, axis xa of aperture  26   b  is substantially aligned with long axis xb. 
     To install a nozzle assembly in such an embodiment, plug  36  can be removed from hole  38 , the nozzle assembly including at least nozzle  22  but possibly also fitting  24  can be inserted through hole  38  and installed in port  14  with openings  26   a ′ and  26   b ′ exposed in inner diameter ID and annulus  18 , respectively, and with axis xa of aperture  26   b  directed in a selected direction, for example toward the open edges  16   a  of shield  16 . Then plug  36  can be installed in hole  38  over nozzle  22 . If there is a spacer, such as spring  40 , it is positioned between nozzle  22  and plug  36 . In an embodiment where the nozzle assembly includes fitting  24  and nozzle  22 , these parts can be installed separately or may be connected ahead of installation. 
     Tubulars according to the present invention can take other forms as well. In one embodiment, as shown in  FIG. 8 , tubular  110  includes a screening apparatus  150 . Tubular  110  is primarily useful for handling inflows, since screening apparatus  150  removes oversize particles from the flows to opening  118   a . Grooves  119  in outer surface  112   b  extend under apparatus  150 , through openings  118   a  under an edge of the shield and into space  118  between outer surface  112   b  and shield  116 . Space  118  opens to nozzle. It is noted that tubular  110  illustrates a nozzle  122  without an additional installation fitting and, instead, nozzle  122  is secured directly into the material of base pipe. 
     During use of the tubular, fluid may pass through nozzle orifice  26  between inner diameter ID and outer surface  12   b . Nozzle  22  diverts flow such that it passes in a non-linear fashion between inner diameter ID and outer surface  12   b . Orifice  26  causes fluid flows to change direction as they pass through the nozzle including both: (i) substantially radially relative to the long axis xb of the base pipe and (ii) substantially parallel to the outer surface, which is possibly somewhat parallel to the long axis of the base pipe. This may direct flows through space  18  between outer surface  12   b  and shield  16  spaced from the outer surface. The fluid may flow through space  18 , along outer surface  12   b  through an opening  18   a ,  118   a  to the annulus about the tubular. 
     Flows outwardly tend not to cause formation damage, as the fluid jetting through the nozzle is diverted from a radially outward direction (through aperture  26   a ) to a lateral direction through aperture  26   b  and along the outer surface of the base pipe, which is parallel to the wellbore wall. As such, the force of the fluid passing from the tubular is dissipated at end wall  26   a ″ of the orifice, where the flow path diverts laterally. 
     In use, nozzle  22  may control fluid flows by accommodating and avoiding erosion through ports and controlling velocity and pressure characteristics of the flow. 
     For example, a method for accepting inflow of steam or produced fluids in a paired, heavy oil (such as oil sand), gravity drainage well may employ a tubular such as is depicted in  FIGS. 1 to 3  or  FIG. 7 . In paired well steam production, it is desirable that introduced steam create a steam chamber in the formation that heats the heavy oil and mobilizes it as produced fluids. The produced fluids are intended to flow into a producing well. Sometimes steam from an adjacent well may break through and seek to enter the producing well. Using a tubular, as described, steam may be restricted from passing into the tubular due to the form of the nozzle and the configuration of the nozzle in the tubular. In particular, the limited entry size of the apertures first limits the volume of produced fluids that can pass into the tubular. Also, the impingement of flows from the diametrically opposed apertures  26   b  tends to resist flows through the orifice  26  and creates a back pressure that limits flows through the nozzle. Also, the diverted flow path from aperture  26   b  to aperture  26   a  dissipates fluid force so that the tubular tends not to problematically erode. As such, a steam chamber may form outwardly of the tubular, even if a break through occurs from the steam injection well to the producing well. 
     During use, while forces may tend to act to dislodge nozzle from its position, the method may include holding the nozzle in place against the forces tending to move the nozzle into an inactive position. For example, the method may include holding the nozzle down into the port, for example, by a shield thereover. Alternately, or in addition, the method may include holding the nozzle against dislodgement by differences in thermal expansion, for example, by use of a fitting. A fitting may act between the nozzle and the base pipe to hold the nozzle in place. For example, the fitting may prevent the nozzle from passing into the inner diameter due to a taper in the parts and the nozzle may have a thermal expansion that holds the nozzle in place. 
     While the embodiment is described wherein nozzle  22  is rigidly installed in fitting  24 , the nozzle in some embodiments can be slidably mounted in the fitting. For example, nozzle can slide into and out of the fitting depending on the pressures against openings  26   a ′ and  26   b ′. As such, nozzle  22  can operate as a form of valve. 
     A nozzle, as described hereinbefore, may have an orifice shaped to restrict flow in one direction, but such an orifice may not restrict flow as much in the opposite direction. For example, with reference to  FIGS. 9 to 13 , a nozzle  222  may be installed in a tubular  212  intended to handle produced fluid flow, which is flow inwardly from the base pipe&#39;s outer surface  212   b  through the orifice of the nozzle. Specifically, with reference back to  FIG. 8 , inward, produced fluid flow may be through a lateral aperture  126   b  of the orifice and then into a main aperture  126   a  of the orifice, before entering the inner diameter ID of the tubular. In such an embodiment, each orifice lateral aperture  126   b  has a smaller diameter inner end (the end closer to main aperture  126   a ) and a larger diameter outer end (the end closer to space  118 ) and a flaring diameter from the inner end to the outer end. This orifice shape creates back pressure on the fluid passing therethrough in the direction of arrows F. 
     With such a tubular, flow in the opposite direction, outwardly from the inner diameter, ID through nozzle  122  to outer surface  112   b  may not be slowed by the orifice and may, in fact, be accelerated such that the fluid passing from nozzle  122 , out through lateral aperture  126   b  along outer surface  112   b  may have a high velocity and may be damaging to structures in the fluid path, especially if the fluid is steam or acid. 
     For example if it is desired to use tubular  110 , that is intended to control and slow inflow of produced fluids into the tubular inner diameter, instead to pump fluids through from the tubular into the formation (in a direction opposite arrows F), the fluids passing from nozzle  122  may damage structures including parts of the tubular such as shield  116 , base pipe outer surface  112   b , screening materials  150 , or the formation. Fluids, such as water, gas, steam or acid, passing from the nozzle orifice  126   b  may cause erosion-corrosion. 
     A tubular  210  that provides both controlled, low stress inflow and controlled, low stress outflow through a nozzle  222  may include an outflow diffuser  260  positioned to accept flow from the nozzle. The outflow diffuser  260  accepts flow and dissipates some of the energy therefrom before releasing the flow to exit and flow away from the tubular. The diffuser includes a wall positioned out of alignment, for example substantially orthogonally, to the axis xa (see  FIG. 7 ) of the orifice&#39;s lateral apertures  226   b.    
     The diffuser may be installed on outer surface  212   b  of the tubular wall to receive impingement from an outward flow from nozzle  222 , which will be through the orifice&#39;s lateral apertures  226   b . There may be a diffuser for each lateral aperture of the nozzle. The diffuser is positioned adjacent the nozzle and generally in a space such as an exterior fluid chamber  218  such as one defined between a shield  216  and outer surface  212   b . The exterior fluid chamber has an opening  218   a  to the exterior of the tool through which fluid enters or exits the chamber. When fluid is passing outwardly through nozzle  222 , it follows an exit path from nozzle to opening  218   a  where the fluid passes out from under the shield  216  to the exterior of the shield. Opening is part of the exit path for the fluid. The opening  218   a  may open directly to the exterior of the tool. Alternately, a filtering material  250  may be disposed across opening  218   a  to filter fluid passing through opening  218   a.    
     In one embodiment, the diffuser is a tube positioned and configured to accept fluids exiting the nozzle at lateral apertures  226   b  and redirect and slow the fluids before releasing them to continue along the exit path and flow from the tubular. The diffuser tube has a tubular construction with a tubular wall defining there within an inner diameter that provides a conduit for fluids to flow between an inlet port  262  to the tube and a plurality of outlet ports  264  from the tube. The inlet port may have a diameter larger than the diameter of each individual outlet port  264 . The diffuser tube may be formed with an elbow  266  along its conduit length such that flow passing therethrough is redirected and does not pass straight through. The elbow creates the wall positioned out of alignment, for example substantially orthogonally, to the axis xa (see  FIG. 7 ) of the orifice&#39;s lateral aperture  226   b . The tube in one embodiment is L or T-shaped with an inlet portion  270 , which is a length of the tube having the inlet port  262  at one end thereof and elbow  266  at the other end and one or more, such as for example two, arm portions  272  extending from the inlet portion at the elbow. Outlet ports  264  are positioned in the arm portions  272 , but are spaced from elbow  266 . The outlet ports may be holes through the tubular wall forming the arm portions and/or may be holes at the end of the arm portions. The inner diameter of the inlet portion opens at the elbow into the inner diameters of the arm portions. Thus, fluid passing through the conduit of the tube enters through the inlet port and impinges against an end wall  266   a  at the bend of elbow  266 . The end wall  266   a  causes the fluid to change direction and flow down arm portions  272 . 
     In one embodiment, the diffuser tube is T-shaped with inlet portion  270  connected to two arm portions at a T-shaped elbow. The diffuser tube may be substantially symmetrical about the inlet portion. 
     The diffuser is positioned on the outer surface of the wall of the tubular  212  adjacent the orifice of nozzle  222  to receive the fluid passing from lateral aperture  226   b . In one embodiment, inlet port  262  is positioned substantially aligned with lateral aperture  226   b . For example, inlet port  262  may be positioned such that its center point is axially aligned with axis xa of the nozzle&#39;s lateral aperture  226   b . Inlet port  262  may be flared and may taper across its inner diameter with depth into the inlet port. This flare causes the inlet port opening of the diffuser to be conically formed and creates a wider entry site to the diffuser. This ensures that most if not all of the fluid passing from lateral aperture  226   b  passes into the diffuser conduit  260 . 
     The arm portions  272  extend from inlet portion  270 . Since the diffuser is positioned on the wall of tubular  212 , arm portions  272  may be curved to substantially follow the circumferential curvature of the tubular&#39;s wall. In one embodiment, the long axis of inlet portion  270  extends substantially in alignment with long axis xb of the tubular body  212  and arms  272  are attached to the inlet portion and are curved to extend around the circumferential curvature orthogonal to the long axis xb of the tubular body. 
     As noted above, outlet ports  264  are positioned in the arm portions  272 . Ports  264  may be positioned in the end of the arm portions  272  and/or may be positioned spaced apart along the length of each arm portion. In one embodiment, the ports  264  are positioned to direct the fluid passing therethrough into a particular area of the tubular. In one embodiment, for example, ports  264  are positioned in arm portions  272  such that fluid exiting therefrom cannot flow directly along a straight line to the exit opening  218   a  on the tubular. For example, ports  264  can be positioned in arm portions  272  such that fluid passing from the ports must change direction to reach the exit opening  218   a . The ports, for example, may be oriented to face towards a blocking structure such as towards the outer surface, the shield or another diffuser. Alternately, the ports may be positioned to expel fluid into counter or cross flowing fluid path or along a path not directly parallel to the exit path leading to exit opening  218   a . For example, if there are two diffuser tubes in the tubular, they may be positioned such that their outlet ports  264  face each other. In the illustrated embodiment, for example, ports  264  are positioned in arm portions  272  on a side that faces away from the exit path of the fluid. The ports open towards another diffuser and, in particular, toward ports  264  on that other diffuser. Additionally, at least some ports are angled up toward shield  216  and/or angled down toward surface  212   b , which are the walls that define the upper and lower limits, respectively, of the exterior fluid chamber  218 . As such, ports  264  in the illustrated embodiment, are positioned to expel fluid away from opening  218   a  into a counter flowing fluid path generated by fluid expelled from the opposite diffuser and upwardly or downwardly at an angle to impinge against the upper or lower limits of the chamber in which they are installed. 
     While, the diffuser may be installed in the tubular to receive an outward flow from nozzle  222 , a bypass opening may be provided to permit produced fluid to bypass the diffuser and enter the nozzle without first passing through the diffuser. The fluid may, therefore, enter the nozzle directly to flow inwardly into the inner diameter without flowing through the diffuser. In the illustrated embodiment, diffuser conduit  260  is spaced from the nozzle such that there is an open space  280  between the nozzle and the inlet portion  270  of the diffuser. Produced fluid may flow through opening  218   a , into open space  280  and then enter nozzle directly to thereby flow inwardly into the inner diameter, while bypassing at least the arm portions and elbow, and possibly the entirety, of the diffuser. The bypass opening may take other forms such as large holes through the inlet portion, if the diffuser if attached directly adjacent the nozzle. 
     In addition, if desired, the diffuser may be mounted in chamber  218  with gaps  282  between the upper and/or lower surfaces of the arm portions  272  and the shield  216  and/or surface  212   b  such that produced fluid can pass above and below the diffuser to enter the nozzle&#39;s orifice without flowing through the diffuser. 
     In spite of these gaps  282  and open space  280 , diffuser  260  is installed to be held firmly in its position adjacent the nozzle. In one embodiment, there is a mounting block  286  that secures the diffuser in position between shield  216  and base pipe  212 . In  FIG. 11 , mounting block  286  is sandwiched and secured between the shield and the base pipe and in the tubular of  FIG. 12 , mounting block  286  is installed in a recess  288  in the shield. In any event, the mode of installation such as the use of mounting block  286  maintains gaps  282  and spacing at open space  280 , to secure the diffuser against being pushed away from the nozzle by the force of the fluid flow. 
     Diffuser  260 , especially at inlet port  262 , outlet ports  264  and elbow  266 , must withstand a lot of erosive fluid force. As such, diffuser  260  may be constructed of a durable material similar to those used for the nozzle. While the use of such material may be costly, the amount of this material required for nozzle  222  and diffuser  260 , may be small compared to the overall material requirements of the tubular. These parts, the nozzle and the diffuser can be installed in a tubular formed of standard construction materials. 
     The spacing between the diffuser and the nozzle may determine how much of the nozzle&#39;s flow is treated via the diffuser and the force at which the fluid enters the inlet portion. This spacing may be varied as desired in the construction of the tubular. 
     The tubulars of  FIGS. 10 and 13  differ in a few respects including the shape and mode of installation of the mounting portion  286 . These two embodiments also show two different installations for nozzle  222 , wherein  FIG. 10  shows the nozzle formed as an integral component of the base pipe and  FIG. 13  shows the nozzle as an insert installed through a capped port, such as is described in  FIG. 3 . 
     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. For US patent properties, it is noted that no claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”.