Patent Publication Number: US-9410398-B2

Title: Downhole system having compressable and expandable member to cover port and method of displacing cement using member

Description:
BACKGROUND 
     In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common. The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for CO2 sequestration. A tubular inserted within the borehole is used for allowing the natural resources to flow within the tubular to a surface or other location, or alternatively to inject fluids from the surface to the borehole. Opening perforations through the wall of the tubular to allow fluid flow there through after deployment of the tubular within the borehole is not uncommon. One method of opening such perforations is through ignition of ballistic devices, referred to as perforation guns. Due to the explosive nature of the guns, the art would be receptive to alternate methods of opening perforations in tubulars that do not require guns. 
     SUMMARY 
     A downhole system includes a tubular having a wall with at least one port there through; and at least one member arranged to cover the at least one port in a compressed condition thereof, and configured to at least partially displace cement pumped on an exterior of the tubular in a radially expanded condition of the at least one member. 
     A method of non-ballistically opening ports in a tubular of a downhole system, the method includes covering at least one port in the tubular with an initially compressed radially extendable member; inserting the tubular within a borehole; cementing an annular space between the tubular and the borehole; allowing the radially extendable member to expand from heat of curing cement; and, at least partially displacing the cement with the radially extendable member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings wherein like elements are numbered alike in the several Figures: 
         FIG. 1  is a partial quarter cross-sectional view of an exemplary embodiment of a downhole system with a radially extendable member in a non-extended condition; 
         FIG. 2  is a partial quarter cross-sectional view of the downhole system of  FIG. 1  depicting a cementing operation; 
         FIG. 3  is a partial quarter cross-sectional view of the downhole system of  FIG. 1  with the radially extendable member in a partially extended condition; 
         FIG. 4  is a partial quarter cross-sectional view of the downhole system of  FIG. 1  with the radially extendable member in a fully extended condition; 
         FIG. 5  is a partial quarter cross-sectional view of the downhole system of  FIG. 1  with a sleeve shifted and a foam attacking agent introduced; 
         FIG. 6  is a partial quarter cross-sectional view of the downhole system of  FIG. 1  with the radially extendable member removed and a fracture procedure initiated; and, 
         FIG. 7  is a partial quarter cross-sectional view of another exemplary embodiment of a downhole system with a radially extendable member in a non-extended condition. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     Referring to  FIGS. 1-6 , an exemplary embodiment of a downhole system  10  is illustrated. The system  10  is a non-ballistic tubular perforating system employable as a completion system within a borehole  12  extending through a formation  14 . The borehole  12  has a wall  16  that may be fractured to enhance the extraction of natural resources from the formation  14 . The system  10  includes a tubular  18  having a wall  20  with flow ports  22  there through. While only one section  24  of the tubular  18  is illustrated, it should be understood that several zones within the borehole  12  may be operated thereon using the system  10  by connecting the section  24  of the tubular  18  to other sections  24 , such as by using the threaded connections  26 ,  28  shown at the uphole and downhole ends  30 ,  32 , respectively, of the section  24 , or by connecting the section  24  to other sections  24  with other pieces of tubular (not shown) positioned there between. Cement  34  (shown in  FIGS. 2-6  only) is positionable radially of the tubular  18  in an annular space  36  between the wall  20  of the tubular  18  and the wall  16  of the borehole  12 , as will be further described below. At least one radially extendable member  38  is positioned radially outwardly of the tubular  18  in locations covering the ports  22 . As illustrated, the ports  22  are elongated apertures in the wall  20  that that are radially distributed about the tubular  18 , although other shapes and arrangements of the ports  22  may also be included in the system  10 . For operating within different longitudinally spaced zones of the borehole  12 , longitudinally spaced ports  22  can be provided, such as by the interconnection of two or more of the sections  24  of the tubular  18 . The member  38  can be provided at discrete locations to block each individual port  22 , or a single member can wrap around the outer periphery of the tubular  18  to cover several ports  22 , such as all the ports  22  within a particular section  24  of the tubular  18 . The members  38  may be provided entirely or partially within each port  22 , or radially exteriorly of the ports  22 . The members  38  are configured to cover the peripheries of their associated ports  22 . 
     The radially extendable member  38  is a foamed shape memory polymer (“SMP”) that can increase radially while surrounding the ports  22  of the tubular  18 . The system  10  employs foamed shape memory polymer, such as, but not limited to, Morphic™ technology, a shape memory polymeric open-cell foam available from Baker Hughes, Inc., as a volumetric masking agent to limit the amount and quality of cement  34  delivered to certain areas within the borehole  12 . 
     With reference to  FIG. 1 , the members  38  are initially provided in a compressed state on the outer diameter of the tubular  18 . The members  38  are mounted on the outer diameter, or within the ports  22 , in such a way that they surround, enclose, or fill at least the perimeter and area of the flow ports  22 . The members  38  are engineered such that they will remain compacted during deployment of the system  10 .  FIG. 1  shows the system  10  with the members  38  in the compressed state while being run in the borehole  12 . The members  38  will deploy to the uncompacted shape substantially surrounding/enclosing the flow ports  22  of the system  10  upon exposure to heat (such as that generated by curing cement  34 , or by a chemical reaction between a material in or around the members  38  with a fluid circulated in front of the cement  34 ). 
     The introduction of cement  34  is shown in  FIG. 2 . The cement  34  is pumped in a downhole direction  40  through the tubular  18 . At an end of the tubular  18  (not shown), after the cement  34  escapes the tubular  18 , the cement  34  moves in an uphole direction  42  through the annular space  36  between the tubular  18  and the borehole wall  16 . Radially extending the radially extendable member  38  after the cement  34  is pumped allows the cement  34  to be pumped through the annular clearance  44  between the wall  16  of the borehole  12  and the radially extendable member  38 . After-which radially extending of the radially extendable member  38  displaces some more of the cement  34  as the radially extendable member  38  radially extends into contact with the wall  16 . The members  38  will deploy to the un-compacted shape substantially surrounding/enclosing the flow ports  22  of the system  10  upon exposure to heat (such as that generated by curing cement  34 ). This is shown in  FIG. 3 , with the members  38  being deployed and displacing the green cement  34  (cement  34  that has not yet cured). The expanding foam of the members  38  will extend from the outer diameter of the tubular  18  out to the inner diameter of the borehole wall  16 , and contact and conform to this wall  16 , as shown in  FIG. 4 . The porosity and stiffness of the foam of the members  18  is engineered so that as the foam expands it displaces uncured cement  34  from the area into which it deploys. The displacement of the uncured cement  34  may be complete, or may include only enough liquid and particulate to severely degrade the quality of any cement  34  remaining in the area once cured. If necessary the cement may be retarded somewhat to align cure rate with foam deployment. The radially extendable member  38  establishes essentially a cement free pathway from the interior  46  of the tubular  18  through the ports  22  and through the radially extendable member  38  to the earth formation  14 . 
     Once the cement  34  has at least substantially cured in the unmasked areas (the areas not containing the deployed members  38 ), the system  10  is activated to move sleeves  48  and expose the ports  22  through a series of ball drops. As shown in  FIG. 5 , after cement  34  has cured, fracturing operations can begin from the pressure activated toe-sleeve by pressuring up the system  10  to open the sleeve  48 , and pumping an agent  50  that attacks the shape memory polymer foam in the area surrounding the outer diameter of the now-open pressure activated sleeve  48 .  FIG. 5  demonstrates one exemplary embodiment for opening the sleeve  48 , which includes the landing of a plug, such as a ball  52 , on a ball seat  54 . Seating the ball  52  allows pressure built against the ball  52  to move the ball  52 , ball seat  54  and attached sliding sleeve  48  in a downhole direction  40 . Movement of the sliding sleeve  48  in the downhole direction  40  reveals the ports  22  and the deployed member  38 , which are otherwise sealed from the interior  46  of the tubular  18  via seals  58 ,  60  that seal the sleeve  48  relative to the wall  20  of the tubular  18 . That is, once the sliding sleeve  48  is moved, the interior  46  of the tubular  18  is fluidically connected to the ports  22  and deployed member  38 . The sliding sleeve  48  may include ports (not shown) that are misaligned with ports  22  in the tubular  18  in a non-activated condition of the sleeve  48 , and aligned with the ports  22  in the tubular  18  when the sliding sleeve  48  is moved into an open condition of the ports  22 . Alternatively, the sliding sleeve  48  may be imperforate and moved completely away from the ports  22  in the tubular  18  to provide direct access between the interior  46  of the tubular  18  and the members  38 . Agent  50 , which may attack or remove the member  38 , and may include a solvent, such as but not limited to dimethylformamide and ethylene glycol monobutyl ether, may be pumped at the lead of each stage intended to undermine the strength of the member  38 . Treating the members  38  with the agent  50  has the effect of maximizing the area available to flow for fracturing treatment and limiting tortuosity, while maintaining the integrity advantages of a cemented liner. 
     Once the cement  34  has cured and the member  38  removed, the result is a substantially cemented completion system  10  with a cement sheath that is absent or severely compromised in the areas adjacent to any of the flow ports  22  as a result of the foam deployment. Removal of the members  38  result in large sections of exposed formation  14  ideal for stimulation. As shown in  FIG. 6 , once the agent  50  has degraded the member  38  in the area exposed by the displaced sleeve  48 , pump rate can increase and the first fracture stage can be completed. The ports  22  can be divided up into one or more zones, with just a single one of the zones being illustrated herein and the sliding sleeves  48  prevent simultaneous pressuring up of all zones located along the system  10 . Subsequent stages can be completed by dropping the appropriate ball size and landing the ball  52  while pumping more of the agent  50  for attacking the shape memory polymer foam, substantially increasing the area available to flow through the ports  22 . The fracture treatment will follow, and the pattern will continue until all sleeves  48  are opened. In this manner all of the stages in the system  10  benefit from the large flow area unfettered by tortuous perforation tunnels or cement, yet most of the completion is cemented in place, maximizing wellbore integrity. 
     Removal of the member  38  allows fluidic communication between an interior  46  of the tubular  18  and the earth formation  14 . This fluid communication allows treating of the formation  14 . Such treatments include fracturing, pumping proppant and acid treating, for example. Additionally, the system  10  would allow for production of fluids, such as hydrocarbons, for example, from the formation  14 . The system  10  enables the use of pre-formed ports  22  within the tubular  18 , as opposed to perforating the tubular  18  with perforations while within the borehole  12 . 
     While  FIGS. 1-6  depict the downhole system  10  in conjunction with a ball-activated sleeve  48 , it should be understood that the system is also usable with other types of frac sleeves  56 , such as, but not limited to, pressure actuated sleeves, hydraulically actuated sleeves, electrically actuated sleeves, and sleeves operable by downhole tools such as wireline devices, shifting tools, and bottom hole assemblies. An exemplary sleeve  56  not actuated by a ball  52  is shown in  FIG. 7  with the member  38  in a compressed condition. With the exception of the sleeve  56  being movable by a means other than the ball  52 , the system  100  shown in  FIG. 7  may be operated in a manner similar to the system  10  shown in  FIGS. 1-6 . Other arrangements for blocking the fluid communication between the interior  46  of the tubular  18  and the annular space  36 , as well as alternate arrangements for zonal isolation are also within the scope of the arrangements and the sleeves  48 ,  56 , and ball and ball seats  52 ,  54  are described for exemplary purposes. 
     While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.