Abstract:
Methods and apparatuses for installing lateral wells in an underground. The methods and apparatuses allow for efficiency in a milling and installation process for the lateral well. More specifically, tools and techniques are detailed which allow for controllably guided installation of a whipstock and/or subsequent production deflector hardware at locations adjacent lateral legs of a well to allow for such enhanced milling, installation and production efficiencies.

Description:
BACKGROUND 
     In the oilfield industry, it is common to install wells that extend laterally from a primary (sometimes vertical) well. These lateral wells extend into the underground formation surrounding the primary well and therefore increase the effective drainage area around the primary well. 
     Several techniques are currently used to drill and complete lateral wells. In cased primary wells, lateral wells are typically drilled through windows provided in the casing. These windows are often milled through the casing after it has been cemented in the primary well. In order to cut a window in the casing, a device that includes a packer and a whipstock is inserted into the primary well. The packer is set at a location that is immediately downhole of the desired location of the window and in such an orientation that the concave face on the whipstock faces the window. Thereafter a milling device is inserted into the primary well and the concave face on the whipstock deflects the milling device laterally towards the casing and thus facilitates milling at the desired location for the window. 
     SUMMARY 
     The applicant has found that known methods and apparatuses for setting a packer and whipstock device for milling a window in a casing of a primary well are not as efficient as desirable. For example, according to known methods and apparatuses it can be very difficult to properly orient the rotational position of the whipstock so that the window is milled at the desired location. Also, known whipstocks are difficult to retrieve once the milling operation is complete. In addition, applicant has found that current apparatus and methods for drilling and completing lateral wells require too many steps and specifically too many production runs into the primary well, thus resulting in inefficiency. 
     The present application derives from the applicant&#39;s efforts to provide improved methods and apparatuses for drilling and completing lateral wells. More specifically, the present application derives from efforts to provide more economical and effective methods and apparatuses for setting a packer and whipstock at a desired orientation in a primary well. The application also derives from efforts to provide more economical and effective methods and apparatuses for retrieving the whipstock from the primary well to thereby allow for further completion or production activities. 
     In one example, a method of installing a lateral well that deviates from a primary well at a predetermined radial location is provided. The method includes the steps of: (a) installing a downhole assembly in the primary well, the downhole assembly comprising (i) a first part of an orienting device comprising one of an orienting profile and an orienting key; (ii) a packer located downhole of the orienting device; (iii) an isolation device located downhole of the packer and forming a seal that prevents fluid flow through the downhole assembly; (iv) a running tool comprising a measuring device, a circulating device, and a second part of the orienting device comprising the other of the orienting profile and the orienting key, wherein operation of the circulating device and isolation device causes the packer to set; (b) operating the measuring device to identify the rotational orientation of the packer; and (c) operating the circulation device to set the packer. 
     In another example, the method further includes the step of comparing the identified rotational orientation of the packer to the predetermined radial location and then rotating the packer to orient it relative to the predetermined radial location prior to step (c). 
     In another example, the running tool includes a milling whipstock having a profiled surface and milling assembly configured to mill a section of well casing at the predetermined location. The method can further include the step of running the milling whipstock along a profiled surface on the whipstock and operating the milling device to mill a window in the casing for the lateral well at the predetermined radial location after step (c). 
     In another example, a second running tool including a production deflector having a through bore is coupled to a third part of the orienting device comprising the other of the orienting profile and the orienting key. The second running tool is inserted into the primary well and moved towards the downhole assembly, and the third part of the orienting device engages the first part of the orienting device to rotate the second running tool into a rotational position wherein a profiled surface of the production deflector faces the window. 
     In another example, an apparatus for installing a lateral well that deviates from a primary well is provided. The apparatus includes: a downhole assembly comprising (i) a first part of an orienting device comprising one of an orienting profile and an orienting key; (ii) a packer located downhole of the orienting device and adapted to seal an annular space between the downhole assembly and the primary well; (iii) an isolation device located downhole of the packer and forming a seal that prevents fluid flow through the downhole assembly; (iv) a running tool comprising a measuring device, a circulating device configured to provide a supply of fluid to the downhole assembly, and a second part of the orienting device comprising the other of the orienting profile and the orienting key; wherein operation of the circulating device and isolation device causes the packer to set. The measuring device is operable to identify the rotational orientation of the packer relative to the desired milling location of the window. The circulation device is operable to set the packer. 
     In another example, the running tool includes a milling whipstock having an orienting face and a milling device. 
     In another example, a second running tool is provided that includes the other of the orienting profile and orienting key and a production deflector having a through bore through which production fluid can flow. When the second running tool is moved towards the packer, the orienting profile and orienting key are engaged and cause the second running tool to rotate into a rotational position wherein the orienting face of the production deflector will direct production equipment into the well of the lateral well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a primary well. 
         FIG. 2  is a first example showing a schematic view wherein a packer and orienting device and circulation device are run into the primary well. 
         FIG. 3  is a plan view of one example of an orienting device suitable for use in the example shown in  FIG. 2 . 
         FIG. 4  is a schematic view of a milling whipstock, with a milling device being run into the primary well and aligned to mill a window at a desired location. 
         FIG. 5  is a second alternative example wherein a packer, orienting device, circulation device and milling whipstock are run into the primary well. 
         FIG. 6  is a schematic view of a lateral well extending from the primary well. 
         FIG. 7  is a schematic view of a retrieval device for retrieving the milling whipstock from the primary well. 
         FIG. 8  is a schematic view of an orienting device coupling a production deflector and by pass sub to the packer to open an isolation device. 
         FIG. 9  is a schematic view of production equipment for completing the lateral well. 
     
    
    
     DETAILED DESCRIPTION 
     In the present description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different apparatus and method steps described herein may be used alone or in combination with other apparatus, systems and method steps. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims. 
     As used herein, a primary well is generally shown as vertical, but can extend at any angle relative to the surface and is shown vertically for descriptive purposes only. Likewise, a lateral well is generally shown as horizontal for descriptive purposes only; it may extend at any angle that is different than that of the primary well at the point of deviation from the primary well. 
       FIG. 1  depicts a primary well  10  extending into an underground reservoir  12 . The well  10  can be any length and includes a casing  14 . A lower completion assembly  16  is disposed in the well  10  for producing and pumping fluids such as hydrocarbons from the surrounding underground reservoir  12  to the surface. The well  10  is shown as having a substantially vertical section  18  and a substantially horizontal section  20  into which the lower completion assembly  16  extends. 
       FIG. 2  depicts apparatus for installing a lateral well that deviates from the primary well  10  above the lower completion assembly  16 . The apparatus includes a packer  22  that is attached to the uphole end portion of a base pipe and configured to seal an annular space  26  between the base pipe  24  and the interior surface of the casing  14 . The actual configuration of the packer  22  can vary from that shown. Preferably however, the packer  22  is capable of being hydraulically set, such as for example a step bore hydraulic set packer. In the depicted example, an isolation device  28  is located downhole relative to the packer  22  and is configured to form a seal that prevents fluid flow through the interior of the base pipe. In the depicted example, the isolation device  28  comprises a ball valve; however, it is recognized that the isolation device can consist of any one of a number of sealing devices such as a plug, flapper valve, disc, or the like. A first running tool  30  is located uphole of the isolation device  28  and packer  22  and includes a circulating device  32 , such as for example an auto fill circulating valve and measuring device  34 , such as for example a measurement while drilling (MWD) tool. The purpose and function of these devices will be further described herein below. 
     An orienting device  36  is disposed in the primary well bore  10  between the packer  22  and the first running tool  30 . Preferably, the orienting device  36  includes a first downhole orienting part  38  connected to the uphole end portion of the packer  22  and a second uphole orienting part  40  connected to the downhole end portion of the first running tool  30 . The orienting device  36  can be any one of a number of commercially available devices that allow for adjustment of the rotational relationship between the uphole tool (in this case  30 ) and the downhole equipment (in this case packer  22 ). This application describes one of the many available options for the orienting device  36 . 
       FIG. 3  depicts the one example of the orienting device  36  in greater detail. In the example shown, the first orienting part  38  is an orienting head  42  that has an open end  43  for receiving the first running tool  30 . The orienting head  42  also has a profile surface  44  on its upper end. The profile  44  surface slopes towards a slot  46 . The downhole end of the orienting head  42  is connected to the uphole end of the packer  22 . The second orienting part  40  of the orienting device  36  includes an orienting key  48  extending outwardly from the downhole end portion of the first running tool  30 . The orienting key  48  is sized to engage and slide along the profile surface  44  and to sit in the slot  46  on the orienting head  42  when the first running tool  30  is moved towards the packer  22 . A sealing device  50 , which in the example shown in  FIG. 2  includes sealing rings, creates a seal between the outer circumference  29  (see  FIG. 3 ) of the lower end portion of the first running tool  30  and the inner circumference  31  (see  FIG. 3 ) of the orienting head  42  when the first running tool  30  is inserted into the orienting head  42  and the orienting key  48  seats in the slot  46 . A sealed annular space  35  is thus created between the isolation device  28  and the circulating valve  32  when the first orienting part  38  of the orienting device  36  engages the second orienting part  40  of the orienting device  36 . 
     The uphole end portion of the second part  40  of the orienting device  36  is threaded for engagement with a corresponding threaded portion (not shown in  FIG. 3 ) of the first running tool  30 . The orienting key  48  extends outwardly from an outer surface of mandrel  52  and includes beveled edges  54  for engaging and sliding along the profile surface  44  of the orienting head  42  on the first part  38  of the orienting device  36 . The orienting key  48  has a width that is slightly smaller than the width of the slot  46  in the orienting head  42 . As shown schematically in  FIG. 3  by arrow  47 , when the first part  38  is moved towards the second part  40 , the orienting key  48  contacts and slides along the downwardly sloped profile surface  44  and engages in or seats in the slot  46 . Movement of the second part  40  towards the first part  38  causes rotational movement of the second part  40  about its longitudinal axis  41  and thus changes the rotational orientation of the second part  40  relative to the first part  38 . Once the orienting key  48  is seated in the slot  46 , further rotation between the first part  38  and second part  48  is prevented. In the preferred example, the sloped profile surface  44  has a helical shape, which encourages the aforementioned sliding movement of the orienting key  48  into the slot  46  and rotational movement of the second part  40  relative to the first part  38 . 
     The second part  40  of the orienting device  36  also includes a shearable anchor latch  56 , which in the example shown includes a plurality of shear screws  58  spaced apart around the outer circumference of the second part  40  and a plurality of locking dogs  60  spaced apart around the outer circumference of the second part  40 . Each locking dog  60  has an outwardly extending foot  62  having a lower beveled surface  63  and an upper beveled surface  65 . Each locking dog  60  is separated from adjacent dogs in the plurality by a slot  61 . In this example, when the second part  40  of the orienting device  36  is moved towards the first part  38  of the orienting device  36 , the lower beveled surface  63  of each dog  60  is biased inward when it engages the interior surface of the orienting head  42 . The locking dogs  60  thus slide along the interior surface  31  of the orienting head  42  as the orienting key  48  slides along the profile surface  44  toward the slot  46 . When the orienting key  48  is seated in the slot  46 , the feet  62  of the locking dogs  60  reach an annular collar  64  in the first part  38  of the orienting device  36 . The resiliency of the cantilevered dogs  60  causes the feet  62  to spring back into a normal unbiased outwardly extending position, wherein the feet  62  engage the inner concave surface of annular collar  64 . In this engaged position, the dogs  60  help prevent longitudinal movement (e.g. removal) of the second part  40  relative to the first part  38 . In this example, if a certain predetermined force is applied to pull the second part  40  of the orienting device  36  out of the first part  38  of the orienting device, the shear screws  58  will shear off and thus permit release of the shearable anchor latch  56  and removal of the second part  40  of the orienting device  36  from the first part  38  of the orienting device  36 . During removal of the second part  40 , the dogs  60  will be biased inwards along the interior surface of the orienting head  42  when the upper beveled surface  65  moves out of the collar  64  and until the feet  62  clear the profile surface  44 . 
     During installation, the running tool  30 , orienting device  36 , packer  22  and the isolation device  28  are installed in the primary well  10 . While running into the primary well  10 , the circulating valve  32  is operated (or opened by default) to provide circulation of completion fluid to uphole assembly components, per conventional methods. The circulating valve  32  is operated to fill the annular space  26  and allow for measurement by the measuring device  34 . The measuring device  34  is configured to identify the rotational orientation of the packer  22  and/or associated orienting device  36  relative to a desired milling location for a proposed window for a lateral well. For example, the measuring device  34  identifies the location of the slot  46  on the orienting head  42  relative to the desired milling location. This orientation information is communicated to the operator by the measuring device  34  according to conventional methods, such as an electrical communication line or other wired or wireless communication link. Thus, it is possible to operate the measuring device  34  to identify the current orientation of the packer  22  to allow for adjustment of the orientation of the packer  22  to facilitate milling a window in the casing  14 . It can also be possible for the operator to adjust the orientation of the packer  22  from the surface so that the orienting profile surface  44  is in a convenient orientation relative to the intended location of the window for the proposed lateral well. 
     At or after the step of measuring the orientation of the packer  22  (and possibly adjusting the orientation of the profile surface  44 ), the circulating device  32  is operated to increase the fluid pressure inside the annular space  35  and to thereby cause the packer  22  to hydraulically set against the interior surface of casing  14 . This will effectively lock the first part  38  of the orienting device  36  and packer  22  in a particular orientation, which can be identified and logged by the measuring device  34 . Because the orientation of the packer  22  is known from the measurements taken by the measuring device  34 , and the desired location of a window to be milled in the casing  14  is known, it is possible to set the packer  22  at a known location that will provide for convenient or efficient milling operations, as discussed above. Thereafter, the first running tool  30  can be removed from the primary well  10  by pulling upwardly on the first running tool  30  by a force great enough to shear the screws  58  and allow for separation of the shearable anchor latch  56 . 
       FIG. 4  depicts further apparatus for installing the lateral well bore. A second running tool  66  is inserted into the primary well bore  10  and moved towards the packer  22 . The second running tool  66  includes a milling device  68 , a milling whipstock  70  and a rotatably adjustable device including an indexing mechanism or adjustment device  72  that connects the milling whipstock  70  to a third part  74  of the orienting device  36 . In the example shown, the third part  74  of the orienting device  36  including the adjustment device  72  is configured the same as the example depicted for the second part  40  of the orienting device  36 . 
       FIG. 5  depicts another preferred example, wherein the first and second tools  30 ,  36  are combined and the steps described with reference to  FIGS. 2 and 4  above are combined into one step. In this example, the running tool ( 30 ,  66 ), includes the measuring device  34 , circulating device  32 , milling device  68 , milling whipstock  70 , rotatably adjustable device including an indexing mechanism or adjustment device  72 , and third part  74  of the orienting device  36 . The entire assembly, including the aforementioned structures and the first orienting part  38 , packer  22 , and isolation device  28 , are run in hole simultaneously. As the run is made, a circulation device  32  and measuring device  34  are operated, as described above, to determine the orientation of the packer  22  with respect to a desired location for a window in casing  14 . In this manner, the number of trips required to orient and set the packer  22 , orient the milling whipstock  70  and conduct milling and installation procedures described below are decreased. This enhances efficiency and allows for fewer trips into the well bore. 
     Because the packer  22  is already set at a known orientation relative to the desired location of a window to be milled in the casing  14 , and typically the rotational position of the milling deflector  70  to the third part  74  of the orientation device  36  is known, it is possible to run the second tool  66  into the primary well bore  10  and achieve a desired orientation of the milling whipstock  70  relative to the desired location for a window  84 . Alternatively, adjustment of the adjustment device  72  can be made at the surface, as follows. 
     Referring to  FIG. 3 , the adjustment device  72  is encased by opposing uphole and downhole cylinders  78 ,  80  which are mounted concentrically on the uphole portion of the mandrel  52 . The downhole cylinder  80  is connected to the uphole cylinder  78  by a threaded connection  83 . The adjustment device  72  includes an adjustable spline that includes a series of seventy two interlocking teeth  75  mounted at five degree increments around the outer circumference of the mandrel  52  and a corresponding series of seventy two interlocking teeth  77  mounted around the inner circumference of the uphole cylinder  78  and designed to engage with the teeth  75  on the mandrel  52 . To access the adjustment device  72 , the downhole cylinder  80  is rotated to the left (relative to the view shown in  FIG. 3 ) and the threaded connection  83  releases to move the downhole cylinder  80  downwardly along the mandrel  52 , as shown by arrow  79 . The orienting key  48  on the mandrel  52  and the uphole cylinder  78  can then be rotatably oriented relative to each other by interlocking the teeth  75 ,  77  at a desired five degree increment. Thereafter the downhole cylinder  80  is moved back up the mandrel  52  (i.e. in a direction opposite the direction of arrow  79 ) and the threaded connection  83  is remade. A stop ring  85  on the uphole cylinder  78  engages a shoulder  87  on the mandrel  52  to hold the uphole cylinder  78  and mandrel  52  together via the threaded connection  83 . Operation of the adjustment device  72  thus allows for rotation of the location of uphole portions of the running tool  66 , including the milling whipstock  70  relative to the location of the orienting key  48  and fixably positioning the milling whipstock  70  at predetermined rotational intervals relative to the orienting key  48 . 
     Thus, as a contingency, prior to running the second running tool  66  (or  30 ,  66 ) into the primary well  10 , it is possible to operate the adjustable device  72  to index the rotational orientation of the milling whipstock  70  relative to the third part  74  of the orienting device  36 . Preferably, the milling whipstock  70  and third part  74  are rotationally indexed apart from each other at an angle such that when the second running tool  66  is run into the primary well  10 , the milling whipstock  70  will be rotated by the orientation device  36  into a position wherein the profiled or curved face  71  of the milling whipstock  70  faces a desired milling location for a window  84  for the proposed lateral well. For example, if it is determined by the measuring device  34  that the slot  46  on the first part  38  of the orienting device  36  is rotated a distance of 30 degrees from the desired window location, the orienting key  48  on the third part  74  of the orienting device  36  can be indexed at a rotational orientation that is 30 degrees apart from the curved surface  71  of the milling whipstock  70 . Thus, when the second running tool  66  is inserted into the primary well  10 , the key  48  will seat in slot  46  and because the key  48  and the curved face  71  of the milling whipstock  70  are rotationally spaced apart at an angle of 30 degrees, the milling whipstock  70  will automatically rotate 30 degrees away from the slot  46  and thus face the desired milling location for the window  84 . 
       FIG. 6  shows the primary well  10  after a window  84  has been milled and drilling equipment inserted to drill a lateral well bore  86 . The milling device  68  is separated from the second running tool  66  and run downhole along the curved surface  71  towards the casing  14  to mill the window  84  and the further conventional drilling procedures can be entertained. 
     Once milling and drilling procedures for the lateral well bore  86  are complete, the milling device  68  can be removed from the lateral well  86  and primary well  10 . Referring to  FIG. 7 , the milling whipstock  70  includes a slot  73  configured to engage with a retrieval hook  88  to facilitate retrieval of the milling whipstock  70  from the primary well  10 . The retrieval hook  88  is inserted into the primary well bore  10  and engaged in the slot  73 . An upward force is applied to the retrieval hook  88  that is sufficient to shear the shear screws  58  on the orienting device  36  and thus separate the third part  74  of the orienting device  36  from the first part  38  of the orienting device  36 , according to the process described regarding the second part  40 . The retrieval hook  88 , milling whipstock  70 , adjustment device  72  and third part  74  of the orienting device  36  can therefore easily be removed from the primary well  10  by the retrieval hook  88 . It will be recognized by those skilled in the art that the example of the retrieval hook  88  is one of many potential configurations for retrieving the milling whipstock  70 . 
       FIG. 8  depicts additional apparatus for further completing the lateral well  86 . A third running tool  92  includes a production deflector  94 , a rotatably adjustable device  96  that connects the production deflector  94  to a fourth part  98  of the orienting device  36 . In the example shown, the fourth part  98  of the orienting device  36  is configured the same as the second part  40  of the orienting device  36  shown in  FIG. 3 . The adjustment device  96  can be configured the same as the adjustment device  72  shown in  FIG. 3  and facilitates rotation of the production deflector  94  relative to the fourth part  98  of the orienting device  36  and more specifically relative to the orienting key  48 , if necessary. Prior to running the third running tool  92  into the primary well  10 , the adjustment device  96  can optionally be operated to index the orientation of the production deflector  94  relative to the fourth part  98  of the orienting device  36  to achieve the same offset angle determined to exist between the first part  38  of the orienting device and the window  84 . As such, when the third running tool  92  is inserted into the primary well  10 , the orienting key  48  on the fourth part  98  engages the profile surface  44  and seats in the slot  46  thereby rotating the third running tool  92  into a predetermined rotational position wherein the production deflector  94  faces the window  84  for the lateral well  86 . Further production equipment  102  inserted into the primary well  10  can thus be deflected into the lateral well  86 , as shown in  FIG. 9 . 
     The third running tool  92  also includes a opening device  100 . The opening device  100  is adapted to open the seal formed by the isolation device  28  as the third running tool  92  is coupled to the packer  22  and more specifically as the orienting key  48  is engaged in the slot  46 . In the example shown, the opening device  100  may include a conventional device for unseating a ball valve or unsealing a plug or flapper valve. In another example, the opening device  100  can be a shoe that breaks a disc of the isolation device  28 , thereby allowing fluid flow through the base pipe  24 . 
     The production deflector  94  includes a through-bore  102  through which production fluid from downhole portions of the primary well  10  can flow towards the surface. Therefore, once the third running tool  92  is fully inserted into the primary well  10  such that the fourth part  98  of the orienting device engages with the first part  38  of the orienting device, production from downhole portions of the primary well  10  and other associated lateral wells can commence. A bypass sub  110  located below the production deflector  94  allows for utilization of the casing ID for production and thereby to limit the small ID most likely created by the production deflector  94 . This aspect allows for a small production deflector, while limiting high flow and erosion, and increasing longevity of the well, especially in a sand control scenario. 
     Once the production deflector is installed, the remainder of third running tool  92  is pulled up and further well completion apparatus  102  inserted into the lateral well bore  86 , as shown in  FIG. 9 .