Inflatable packer & method

CROSS-REFERENCE TO RELATED APPLICATIONS

P-0001[0001] This invention claims priority pursuant to 35 U.S.C. § 119 of U.S. Provisional Patent Application Serial No. 60/374,077, filed on Apr. 17, 2002. This Provisional Application is hereby incorporated by reference in its entirety.

BACKGROUND OF INVENTION

P-0002[0002] 1. Field of the Invention

P-0003[0003] The present invention relates to well completion. More specifically, the invention relates to apparatus and methods for isolation of multiple zones of interest in a wellbore.

P-0004[0004] 2. Background Art

P-0005[0005] It is often desirable to isolate portions of a well. For example, separate zones may be isolated from one another in order to separately control production from the zones or portions of a zone may be isolated to prevent or reduce production of water.

P-0006[0006] Isolation in an open hole is typically accomplished with external casing packers (ECP), which are inflatable packers. In a typical completion operation, the ECP is run with a completion string downhole. An inflate service tool may be run with the ECP or on a separate trip. Cement, mud, or some other type of fluid is then pumped into the packer for inflation. The fluids pumped into the packer are trapped inside the packer, which is a closed chamber once the inflation port is shut off.

P-0007[0007] Generally, the inflation pressure trapped in the packer is initially higher than the formation pressure in order to maintain positive contact with the wall of the well. However, the inflation pressure may decrease for various reasons such as cooling down during injection or production, an increase in the borehole size as a result of formation depletion or borehole wall deterioration, or a leak in the packer. In these cases, the packer may lose contact with the borehole wall and stop providing the desired isolation.

P-0008[0008] With current packer systems, a loss of seal between the packer and the casing or formation wall may not be repairable or may require numerous remedial trips into the well, resulting in increased risk of blow out, loss of production, or increased damage to zones of interest due to long or repetitive shut-in. Remedial operations are extremely expensive and time-consuming. A need, therefore, exists for improved methods and apparatus for providing isolation and other functionality in a well.

SUMMARY

P-0009[0009] In one aspect, embodiments of the invention relate to a completion assembly for use in a well. A completion assembly in accordance with one embodiment of the invention includes at least one inflatable packer, at least one control line, and at least one source of pressurized fluid wherein the at least one source of pressurized fluid is in fluid communication with the at least one inflatable packer via the at least one control line.

P-0010[0010] In another aspect, embodiments of the invention relate to a completion assembly for use in a well. A completion assembly in accordance with one embodiment of the invention includes an upper completion assembly including at least one control line, and a seal mechanism, and a lower completion assembly including at least one inflatable packer adapted to be in fluid communication with a source of pressurized fluid via the seal mechanism and the at least one control line.

P-0011[0011] In another aspect, embodiments of the invention relate to a completion assembly for use in a well. A completion assembly in accordance with one embodiment of the invention includes an upper completion assembly including at least one control line and at least one inflatable packer adapted to be in fluid communication with a source of pressurized fluid via the at least one control line, and a lower completion assembly comprising at least one expandable packer adapted to isolate two adjacent formation zones when the at least one inflatable packer is inflated to push the at least one expandable packer against a wall of the well.

P-0012[0012] In another aspect, embodiments of the invention relate to a completion assembly for use in a well. A completion assembly in accordance with one embodiment of the invention includes at least one inflatable packer adapted to be energized by a downhole energy source selected from the group including a mechanical spring, a gas accumulator, a compressible liquid accumulator, a nitrified gel, a material that swells when it comes in contact with a formation or injection fluid, or a downhole motor and pump.

P-0013[0013] In another aspect, embodiments of the invention relate to a completion assembly for use in a well. A completion assembly in accordance with one embodiment of the invention includes an upper completion assembly comprising at least one inflatable packer adapted to be energized by a downhole energy source selected from the group including of a mechanical spring, a gas accumulator, a compressible liquid accumulator, a nitrified gel, a material that swells when it comes in contact with a formation or injection fluid, or a downhole motor and pump, and a lower completion assembly comprising at least one expandable packer adapted to isolate two adjacent formation zones when the at least one inflatable packer is inflated to push the at least one expandable packer against a wall of the well.

P-0014[0014] Other aspects of the invention will become apparent from the following description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

P-0015[0015]FIG. 1 illustrates a completion assembly according to one embodiment of the present invention.

P-0016[0016]FIGS. 2A and 2B illustrate completion assemblies according to certain embodiments of the present invention.

P-0017[0017]FIG. 3 illustrates a completion assembly according to one embodiment of the present invention.

P-0018[0018]FIG. 4 illustrates a lower portion of a completion assembly according to one embodiment of the present invention.

P-0019[0019]FIG. 5 illustrates an upper portion of a completion assembly according to one embodiment of the present invention.

P-0020[0020]FIG. 6 illustrates an upper completion assembly with an inflatable packer according to one embodiment of the present invention.

P-0021[0021]FIG. 7 illustrates an upper completion assembly with an inflatable packer according to one embodiment of the present invention.

P-0022[0022]FIG. 8 illustrates a method according to one embodiment of the present invention.

P-0023[0023]FIG. 9 illustrates a method according to one embodiment of the present invention.

DETAILED DESCRIPTION

P-0024[0024] Embodiments of the present invention relate to methods and apparatus for isolation in a well. A completion system in accordance with certain embodiments of the invention allows for monitoring of various characteristics to ensure isolation integrity, provides for a continuing source of energy to a packer such that the packer may maintain a positive contact with the borehole wall to ensure isolation, and/or allows the packer to be de-energized among other embodiments.

P-0025[0025]FIG. 1 illustrates one embodiment of the present invention in which the well has an upper cased section <b>12</b> and a lower completion assembly which includes a production tubing string <b>13</b> and an external casing packer <b>36</b>. Herein the terms external casing packer, ECP, inflatable packer, isolation packer, inflatable isolation packer, and the like are used interchangeably. In the embodiment shown, a control line <b>29</b> extends from the surface of the well, through production packer <b>18</b>, to the ECP <b>36</b>. Pressurized fluid provided through the control line <b>29</b> may be used to control the inflation pressure within the ECP <b>36</b>, which provides isolation in the well. As used herein, the term “control line” includes passageways formed in various well components. In one alternative embodiment, a fiber optic line is provided to monitor the isolation packer <b>36</b>. The fiber optic line may be provided as part of the control line <b>29</b> or as a separate line in the well. For example, the fiber optic line may provide a distributed temperature reading, pressure information, and other measurements for monitoring of the isolation packer <b>36</b>. FIG. 1 also shows a sensor <b>17</b> adapted to measure a characteristic indicative of the inflation of the isolation packer <b>36</b>. In this embodiment, the sensor <b>17</b> communicates with control line <b>29</b> that may incorporate an electric line therein.

P-0026[0026]FIG. 2A illustrates one embodiment of the present invention in which the control line <b>29</b> extends from a device <b>33</b>, through production packer <b>18</b> to ECP <b>36</b>. Device <b>33</b> is positioned downhole as part of the completion. Device <b>33</b> may be any suitable device (e.g. a pump, a compressed fluid source, etc.) to provide an energy source to inflate ECP <b>36</b>. FIG. 2B shows an alternative embodiment in which the device is positioned adjacent to the inflatable packer <b>36</b>.

P-0027[0027]FIG. 3 illustrates a completion system <b>200</b> according to one embodiment of the present invention. In this embodiment, a hydraulic control line <b>29</b> is run from the surface passing through a seal mechanism <b>11</b> (e.g., a straddle seal assembly that includes an upper element <b>37</b> and a lower element <b>39</b>), which isolates the packer inflate port <b>35</b> from the wellbore <b>45</b>. A seal mechanism <b>11</b> may be a straddle seal assembly as shown or any other suitable structure. The hydraulic control line <b>29</b> establishes communication with the control line fluid source (not shown) at surface or downhole, enabling the pumping of fluid through the hydraulic control line <b>29</b> to inflate the isolation packer <b>36</b>. The pressure inside the packer <b>36</b> may then be monitored and/or controlled by pumping additional fluid into the packer <b>36</b> (or extracting fluid to prevent bursting of the packer in the event that heating or reduction in borehole size occurs). This allows for monitoring or confirming the integrity of isolation and for maintaining a proper pressure inside a packer.

P-0028[0028] A pressure regulator (not shown) at the surface (or downhole) allows for maintenance of constant pressure in the packer <b>36</b> thus providing positive contact between the packer <b>36</b> and the wellbore <b>45</b> at all times. In this description, increasing pressure in an inflatable packer is referred to as “energizing” the packer, while decreasing pressure is referred to as “deenergizing.”

P-0029[0029] One or more packers may be run in the hole to provide isolation in the well (e.g. zonal isolation). In addition, these packers may be used in tandem to provide isolation redundancy. All packers may be inflated or energized with the same control line (shown as <b>29</b> in FIG. 2) or with multiple control lines, which can be run through a packer inflate portal seal assembly in order to engage multiple packers. Alternately, a pressure distributor may be run downhole to divert the flow of pressurized fluid to each selected isolation packer. In this case, a single control line from the surface is run to the pressure distributor and then an individual control line is run from the pressure distributor to each packer. This will allow pressure in each packer to vary according to the pressure required to maintain positive contact with the wellbore.

P-0030[0030] In a smart well, at least one downhole flow control valve (choke) controls the flow from at least one zone. Multiple valves may be used to independently control the flow from multiple zones. In some cases, sensor lines are also used to monitor temperature and pressure or other measurements in each zone. Chemical injection lines may also be run for scale prevention or other requirements. Completion of a smart well generally requires multiple runs and, therefore, requires some type of wet connect to connect various sensor and control lines between surface and downhole, particularly when the well is gravel packed. Some embodiments according to the present invention allow for a multiple zone completion assembly to be installed in a smart well in a single trip. Other embodiments of the present invention may alternatively be installed in a two-stage operation with a wet connect of the type used, known or appreciated by one skilled in the art. A two-stage installation may be necessary in the event that reservoir stimulation, gravel packing or some other procedure is required prior to final installation of sensor and control lines, flow tube, flow control valve, etc. Embodiments of the present invention may be used in both smart wells and normal wells.

P-0031[0031] The completion system <b>200</b> illustrated in FIG. 3 is a single trip completion assembly. After installation of the isolation packer and expandable screens (collectively referred to as the lower completion assembly), the upper completion assembly may be installed in the well in a single trip, thus eliminating the need for a wet connect. The upper completion may comprise one or more of a sensor and control lines, flow tube, downhole flow control valve, and other conventional and smart completion equipment. Although FIG. 3 illustrates the invention used in connection with expandable sand screens, it should be noted that conventional sand screens may be used. Additionally, the isolation provided by the inflatable packer <b>36</b> makes it useful for other applications in which no screens are present.

P-0032[0032] As shown in FIG. 3, a lower completion assembly (shown as <b>300</b> in FIG. 4) may comprise an upper screen <b>25</b>, a lower screen <b>31</b>, and an inflatable packer <b>36</b>. The screens <b>25</b> and <b>31</b> may be a wire-wrapped screen, an expandable screen, a gravel pack screen, a slotted screen, or other types of screens. The lower completion assembly (for sand face completion) is adapted to run in the well on a service tool (not shown) to a position below the liner hanger packer <b>34</b>. In the illustrated embodiment, a formation isolation valve (FIV) <b>28</b> is located between the upper screen <b>25</b> and the liner hanger packer <b>34</b>. The inflatable isolation packer <b>36</b> is typically in a deflated state while the lower completion assembly <b>300</b> is placed in the well. The inflatable packer <b>36</b> is disposed between the upper screen <b>25</b> and the lower screen <b>31</b> for the isolation of two or more zones <b>30</b> and <b>32</b>.

P-0033[0033] In accordance with one embodiment of the invention, once the lower completion assembly is placed in the well, an upper completion assembly may then be run in the well to engage the lower completion assembly in a single trip. As shown in FIG. 5, the upper completion assembly may include, for example, a multiport production packer <b>18</b>, a fluid loss control device <b>21</b>, a multi-valve system <b>20</b>, a slotted pup joint <b>38</b>, FIV shifting tool <b>50</b>, hydraulic control line <b>29</b> for energizing the inflatable isolation packer, control line <b>52</b> for actuating flow control valves in the multi-valve system <b>20</b>, control line for pressure and temperature sensors <b>24</b>, chemical injection line <b>27</b>, and other lines for other sensors and various functions. The lower completion assembly (shown as <b>300</b> in FIG. 4) and the upper completion assembly (shown as <b>400</b> in FIG. 5) are for illustration only. One of ordinary skill in the art would appreciate that an upper completion assembly may include fewer or more components, depending on a particular operation.

P-0034[0034] The upper completion assembly (shown as <b>400</b> in FIG. 5) may be run in the hole as a single system. When the upper completion assembly (shown as <b>400</b> in FIG. 5) is in place, a seal mechanism <b>11</b> (e.g., a straddle seal assembly having an upper sealing element <b>37</b> and a lower sealing element <b>39</b> as shown) isolates the packer inflation port <b>35</b> from the wellbore fluid. When the upper completion assembly (shown as <b>400</b> in FIG. 5) engages the lower completion assembly (shown as <b>300</b> in FIG. 4), the seal mechanism <b>11</b> forms a fluid conduit linking the inflatable packer <b>36</b>, via the packer inflation port <b>35</b>, with the control line <b>29</b>, which in turn connects to a source of pressurized fluid for energizing the inflatable packer <b>36</b>. Thus, the inflatable packer <b>36</b> may be energized by pumping pressurized fluid from the source at the surface (or downhole) into the control line <b>29</b>. The pressure in the control line <b>29</b> will rise as the inflatable packer <b>36</b> is energized. The pressure will rise rapidly once the inflatable packer <b>36</b> makes a contact with the wellbore <b>45</b>, giving an indication that a contact has been made. At this point, further controlled increase in the inside pressure of the inflatable packer <b>36</b> will provide positive isolation between two zones <b>30</b> and <b>32</b>. The pressure inside the inflatable packer <b>36</b> may be monitored at the surface or downhole. The pressure inside the inflatable packer <b>36</b> may be continuously or periodically monitored to maintain the isolation between zones <b>30</b> and <b>32</b>.

P-0035[0035]FIG. 3 further illustrates that after the multiport production packer <b>18</b> and the fluid loss control device <b>21</b> are set in casing <b>12</b>, the inflatable isolation packer <b>36</b> is inflated, the FIV <b>28</b> is opened, and the seal mechanism <b>11</b> (e.g., the straddle seal assembly <b>37</b> and <b>39</b>) is set in place, the annular space <b>46</b> selectively communicates with zone <b>30</b> allowing selective flow from zone <b>30</b> through the multi-valve system <b>20</b>. When flow tube <b>26</b>, connected to production tubing <b>14</b>, is also in place, annular space <b>47</b> selectively communicates with zone <b>32</b>, allowing selective flow from zone <b>32</b> as well.

P-0036[0036]FIG. 4 illustrates a lower completion assembly <b>300</b> according to one embodiment of the present invention. In this embodiment, a liner hanger packer <b>34</b> is adapted to sealingly mount to the lowermost section of casing <b>12</b>. A formation isolation valve <b>28</b> is mounted between the liner hanger packer <b>34</b> and the upper screen <b>25</b>. The inflatable isolation packer <b>36</b> is mounted between the upper screen <b>25</b> and the lower <b>31</b> in order to establish isolation of two adjacent zones. In operation, the screens <b>25</b>, <b>31</b> and the inflatable isolation packer <b>36</b> are set in wellbore <b>45</b> proximate the zones of interest. When the upper completion assembly (shown as <b>400</b> in FIG. 5) engages the lower completion assembly <b>300</b>, the seal mechanism (shown as <b>11</b> in FIG. 3 and FIG. 5) forms a fluid conduit linking the inflatable packer <b>36</b>, via the packer inflation port <b>35</b>, to the control line (shown as <b>29</b> in FIG. 3 and FIG. 5), thus allowing for monitoring, energizing, and/or deenergizing (or deflating) the isolation packer <b>36</b>. As noted above, the lower assembly is typically run in the well with the inflatable isolation packer <b>36</b> in its deflated state.

P-0037[0037]FIG. 5 illustrates an upper completion assembly <b>400</b> according to one embodiment of the present invention. The upper completion assembly <b>400</b> shown in FIG. 5 may be run in the well as a single system (i.e., a single trip system). In a typical operation, the upper completion assembly <b>400</b> is run in on the end of production tubing <b>14</b>. Then, the upper completion assembly <b>400</b> is set in casing by deploying the multiport production packer <b>18</b> and the flow loss control device <b>21</b>. A multi-valve system <b>20</b> is disposed between the production tubing <b>14</b> and a flow tube <b>26</b> to allow for selective flow of multiple zones. Control line <b>52</b> is adapted to operate the flow control valves in the multi-valve system <b>20</b>. A slotted pup (or pipe) joint <b>38</b> is located below the seal mechanism to allow for flow from a zone isolated below the inflatable isolation packer (shown as <b>36</b> in FIG. 3). Also, the slotted pipe <b>38</b> allows an operator to run and clamp various control lines outside the slotted pipe in the zone of interest, e.g. to deploy a fiber optics cable (not shown) for distributed temperature sensing, a chemical injection line <b>27</b>, an electric line (not shown) etc. This configuration may be repeated for additional zonal isolation deeper in the well.

P-0038[0038] When the upper completion system <b>400</b> is in place (i.e., engages the lower completion assembly shown as <b>300</b> in FIG. 3), the seal mechanism <b>11</b> (e.g., the straddle seal assembly <b>37</b> and <b>39</b>) isolates the packer inflation port (shown as <b>35</b> in FIG. 4). The inflatable isolation packer (shown as <b>36</b> in FIG. 4) is inflated or energized by pumping fluid, from the surface or downhole, through control line <b>29</b>. The pressure inside the packer may be monitored by a pressure sensor <b>40</b>, which, for example, may be located between the straddle sealing assembly elements <b>37</b> and <b>39</b>. While the pressure sensor <b>40</b> is shown to be located downhole, one of ordinary skill in the art would appreciate that the pressure sensor <b>40</b> may be located anywhere along the control line <b>24</b> (or on the hydraulic control line <b>29</b>) or on the surface. Alternatively, the back pressure, inside the packer, may be monitored at the surface via the sensor control line <b>24</b>. Additionally, other sensors, for example a temperature sensor, may be included. Pressure inside the inflatable isolation packer <b>36</b> may be energized or de-energized to maintain or interrupt zonal isolation. In other embodiments according to the present invention, the control lines may be adapted to run through the seal mechanism <b>11</b> in order to communicate with additional inflatable isolation packers (not shown) that might be set deeper in the well. A chemical control line <b>27</b> may be adapted likewise to reach deeper zones.

P-0039[0039] The prior discussion describes an exemplary completion system in accordance with one embodiment of the invention. In the embodiment shown, an inflatable packer is included in a lower completion assembly and adapted to be in fluid communication with a control line in the upper completion assembly to permit maintaining/monitoring the pressure inside the inflatable packer to ensure a tight seal against the borehole wall. One of ordinary skill in the art would appreciate that other modifications to the embodiment shown are possible without departing from the scope of the invention. For example, FIG. 6 shows an alternative completion system <b>500</b> in accordance with another embodiment of the invention. In this embodiment, the inflatable packer <b>36</b> is included as part of an upper completion assembly, instead of a lower completion assembly.

P-0040[0040] As shown in FIG. 6, a lower completion assembly may include an external seal or expandable packer <b>55</b> disposed between the upper screen <b>25</b> and the lower screen <b>31</b>, on the exterior thereof. An expandable packer <b>55</b> is a packer comprising an expandable tubing and a seal thereon. The upper screen <b>25</b> and the lower screen <b>31</b> may refer to two separate screens in some embodiments and to separate portions of a contiguous screen in other embodiments. For example, the screens <b>25</b>, <b>31</b> and expandable packer <b>55</b> may be a contiguous assembly of expandable tubing products with portions having a screen material thereon and other portions having a seal thereon. The expandable packer <b>55</b> is adapted to form a tight seal with the wall of the borehole <b>45</b> to isolate the adjacent production zones or to prevent flow between the outside of the expandable packer and the wellbore. Note that the expandable packer <b>55</b> may be formed as an integral part of the screens <b>25</b> and <b>31</b>. Alternatively, the expandable packer <b>55</b> may be an intermediary linking two separate (upper and lower) sections of the screen. In order to form a tight seal with the wall of the borehole <b>45</b>, the expandable packer <b>55</b> is preferably made of a flexible material, such as a rubber, an elastomer, or any similar synthetic or natural material that can provide the desired seal.

P-0041[0041] In the completion system <b>500</b> shown in FIG. 6, the inflatable packer <b>36</b> is part of an upper completion assembly. Because the inflatable packer <b>36</b> is part of the upper completion assembly the hydraulic control line <b>29</b> can be run directly to the inflatable packer <b>36</b> in order to control the pressure inside the inflatable packer <b>36</b> without the need of a seal mechanism (e.g., the seal assembly <b>11</b> shown in FIG. 5). Similarly, the sensor control line <b>24</b> or other lines (e.g., chemical injection line <b>27</b> shown in FIG. 5) may be run past the inflatable packer <b>36</b> without a sealing assembly.

P-0042[0042] In operation, the lower completion assembly is lowered into the wellbore until the expandable packer <b>55</b> is positioned and expanded between the two adjacent zones to be isolated or at any other desired point of isolation. Then, the upper completion assembly is lowered and the inflatable packer <b>36</b> is positioned at the same axial depth as the expandable packer <b>55</b>. According to one embodiment of the present invention, a pressurized fluid may then be pumped, either from the surface or from a downhole source, via the hydraulic control line <b>29</b> to inflate the packer <b>36</b>. The inflated packer <b>36</b> pushes the expandable packer <b>55</b> against the wall of the borehole <b>45</b> to form a tight seal to isolate the two zones in the formation. In certain alternative embodiments, the pressure inside the packer <b>36</b> can then be monitored, either continuously or periodically, with a sensor (not shown) via the sensor control line <b>24</b>, or, alternatively, by the control line <b>29</b>. The alternative completion system <b>500</b> shown in FIG. 6 has the advantages of simple construction (no need for a sealing assembly) and the ease to service or repair the inflatable packer <b>36</b>, should it fail. For example, in some cases in an expandable packer <b>55</b> may tend to relax after expansion in that the diameter of the expandable packer <b>55</b> becomes slightly reduced. In other cases the expandable packer <b>55</b> may not sufficiently engage the well after expansion to form a seal. The isolation packer <b>36</b> provides a force to maintain the desired seal and prevent relaxation of the expandable packer <b>55</b>. The isolation packer <b>36</b> may also expand the expandable packer <b>55</b>, either fully or partially (e.g., from an expanded state to a further expanded state). A standard isolation packer <b>36</b> may be used in combination with an expandable packer <b>55</b>. In some embodiments, however, the isolation packer <b>36</b> has the other features described herein, such as a constant pressure source and/or monitoring to ensure the proper pressure is applied. These added features ensure that the seal from the expandable packer <b>55</b> is maintained. The isolation packer <b>36</b> provides isolation inside the outer completion.

P-0043[0043] During completion, it is sometimes desirable to maintain communication between zones of interest in the initial stages of a completion or production and then, at a later stage, to establish isolation. For example, it may be desirable to initially commingle production from two zones and then later to isolate the zones subsequent to the onset of water production in one of the zones. Likewise, it may be desirable to isolate a portion of a zone to prevent or reduce water production from the zone or for other reasons. Furthermore, it may be desirable to isolate zones initially and then break isolation at a later stage of the completion for various reasons: for example, to balance varying flow rates from multiple zones, to improve oil production from one zone by commingling with gas production from another zone, in the event one of the valve assemblies in the downhole flow control valve fails, or for other reasons. Therefore, it is desirable to have packers that can be deflated when necessary. Embodiments of the invention described above permit monitoring of the pressure inside a packer, reenergizing the packer, or de-energizing the packer when desired. In addition, the isolation packer can be energized continuously by continuous pumping of fluid, from the surface, in the event a leak develops in the packer (as long as the rate of pumping is greater than the rate of the leak). Also, a liquid sealant can be pumped through the control line or provided in a local reservoir in order to seal a leak. In the various described embodiments of the present invention, the liquid sealant is a pressure-activated sealant similar to that carried by companies such as Seal-Tite International. The sealant carries monomers and polymers in suspension. Such sealants are traditionally pumped downhole when a leak develops in the downhole tools, in the downhole equipment, or in the tubing. When the sealants flow out of a leak with a relatively high surface area to leak ratio, the monomers and polymers “coagulate” in a cross-linking mechanism across the leak, and cause it to “heal.”

P-0044[0044] Monitoring the pressure inside the isolation packer, may not be required in some situations. FIG. 7 illustrates a completion system <b>600</b>, which uses an alternative isolation packer in accordance with one embodiment of the present invention. Rather than inflating or energizing the isolation packer via a control line, a downhole energization system may be used to inflate the isolation packer <b>36</b>. A downhole energization system, for example, may comprise a gas accumulator, compressible liquid accumulator, mechanical spring energization, a specially formulated rubber or other material, appreciated by one of ordinary skill in the art, that swells and provides additional energy when it comes in contact with a formation fluid or an injection fluid, or a downhole motor and pump powered by a source including a downhole battery, a downhole fuel cell, a downhole generator driven by flowing formation or injection fluid, or an electric line to the surface. The downhole energization system maintains continuous pressure outward on the formation and therefore monitoring pressure via a control line is not required. FIG. 7 shows one embodiment having an expandable packer <b>55</b> provided with two sections of expandable screen <b>25</b> and <b>31</b>, whereby the expandable packer <b>55</b> is disposed between the completion and the wall of the wellbore. As the isolation packer <b>36</b> is energized by downhole power source <b>33</b> (e.g., a pump and motor), it forms a seal with the expandable packer <b>55</b>, and the expandable packer <b>55</b> forms a seal with the wall of the wellbore. FIG. 7 shows schematically a sensor <b>602</b> in device <b>33</b>. The sensor measures one or more characteristics, such as pressure, temperature, flow, etc., indicative of the inflation of the isolation packer <b>36</b>. A downhole controller <b>604</b> receives the data from the sensor <b>602</b> and operates the downhole power source <b>33</b> to ensure proper inflation of the isolation packer <b>36</b>. For example, in the case of a downhole pump and motor powered by a power line to the surface or from a downhole power source, the controller <b>604</b> could turn the pump on and cause the isolation packer <b>36</b> to inflate as desired.

P-0045[0045]FIG. 8 illustrates a method according to one embodiment of the present invention. First, a lower completion assembly including an inflatable packer is lowered into a well (shown as <b>80</b>). Next, an upper completion assembly is lowered to sealingly connect with the lower completion assembly, thus allowing for fluid communication between the inflatable packer and a pressurized source of fluid via a control line (shown as <b>81</b>). Then, the isolation packer is inflated with pressurized fluid via the control line to establish isolation (shown as <b>82</b>). In some embodiments, the pressure inside the isolation packer may then be monitored (shown as <b>83</b>). If required, the pressure inside the inflatable packer can be energized to maintain a seal with the formation (shown as <b>84</b>), or, the inflatable packer can be deenergized (or deflated) in order to break isolation (shown as <b>85</b>). In some situations, it may be desirable to reestablish the isolation by reenergizing the isolation packer to form a seal with the formation. Once the completion is in place the isolation packer can be inflated, energized, de-energized (or deflated) and reenergized whenever required to optimize production levels in the well.

P-0046[0046]FIG. 9 illustrates an alternative method according to one embodiment of the present invention. First, an expandable screen or tubing is lowered into the well, wherein the expandable screen has an expandable packer attached to its exterior (shown as <b>91</b>). A completion assembly is then lowered into the well and positioned inside the expandable screen or tubing (shown as <b>92</b>). The isolation packer may be connected to a source of pressurized fluid via a control line. Then, the isolation packer is inflated with the pressurized fluid via the control line to establish isolation of the two zones between which the inflatable packer is disposed (shown as <b>93</b>). The pressure inside the isolation packer may be monitored (shown as <b>94</b>). If required, the pressure inside the inflatable packer may be energized to maintain a seal with the formation (shown as <b>95</b>), or, the inflatable packer can be de-energized (or deflated) in order to break isolation (shown as <b>96</b>). In some situations, it may be desirable to reestablished isolation by reenergizing the isolation packer to form a seal with the formation (shown as <b>97</b>). Once the completion is in place the isolation packer can be inflated, energized, deenergized (or deflated) and reenergized whenever required to optimize production levels in the well.

P-0047[0047] Note that in either method (shown in FIGS. 8 and 9) a downhole energization system instead of the pressured fluid on the surface may be used to inflate the isolation packer.

P-0048[0048] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.