Patent Description:
An inflatable packer can be used to isolate sections of an annulus from each other in a well. The annulus may be formed between two tubular strings (such as, a tubing string and a casing or liner string), or between a tubular string and an uncased or open hole wellbore. An inflatable seal element of the packer is internally pressurized, causing it to expand radially outward and thereby seal off the annulus.

It will, thus, be readily appreciated that improvements are continually needed in the arts of designing, constructing and utilizing inflatable well packers. Such improvements can be useful in a wide variety of different well environments and configurations.

<CIT> and <CIT> disclose tools that are useful for understanding the invention.

The invention provides a system for use with a subterranean well as claimed in claim <NUM>.

Representatively illustrated in <FIG> is a system <NUM> and associated method which can embody principles of this disclosure. However, it should be clearly understood that the system <NUM> and method are merely one example of an application of the principles of this disclosure in practice, and a wide variety of other examples are possible. Therefore, the scope of this disclosure is not limited at all to the details of the system <NUM> and method described herein and/or depicted in the drawings.

In the <FIG> example, a tubular string <NUM> is positioned in a wellbore <NUM> lined with casing <NUM> and cement <NUM>. In other examples, the tubular string <NUM> could be positioned in a section of the wellbore <NUM> that is uncased or open hole. In addition, the wellbore <NUM> is not necessarily vertical, but could instead be horizontal or otherwise deviated from vertical.

The tubular string <NUM> may be any of the types known to those skilled in the art as tubing (such as, segmented production tubing) or coiled tubing (substantially continuous tubing). The tubular string <NUM> may be made of any material or combination of materials (such as, steel, plastics, composites), and may include any combination of well tools connected therein. Thus, the scope of this disclosure is not limited to any particular details of the tubular string <NUM> as described herein or depicted in the drawings.

In the tubular string <NUM> example of <FIG>, an inflatable packer assembly <NUM> is connected in the tubular string below (as viewed in <FIG>) a check valve <NUM>. The check valve <NUM> permits fluid flow <NUM> from surface downward through the tubular string <NUM>, but prevents fluid flow in an opposite longitudinal direction toward the surface. The check valve <NUM> may be of the type known to those skilled in the art as a "pump-off" check valve, but other types of check valves may be used, and use of the check valve is not necessary, in keeping with the principles of this disclosure.

The packer assembly <NUM> includes an inflatable seal element <NUM> that is outwardly extendable into sealing engagement with a well surface <NUM>. In this example, the well surface <NUM> is an interior surface of the casing <NUM>, but if the wellbore <NUM> is uncased, the well surface could be an interior wall surface of an earth formation <NUM> penetrated by the wellbore. In other examples, the well surface <NUM> could be an interior surface of another type of tubular string (such as, a production tubing string or a liner string).

When the seal element <NUM> is sealingly engaged with the surrounding well surface <NUM>, an annulus <NUM> outwardly surrounding the tubular string <NUM> is sealed off. Fluid communication between upper and lower sections 30a,b of the annulus <NUM> is prevented by the seal element <NUM>.

To enable the packer assembly <NUM> to be set and unset multiple times in a single trip of the tubular string <NUM> into the wellbore <NUM>, the packer assembly includes a flow controller <NUM>. The flow controller <NUM> can be operated to inflate the seal element <NUM> using pressure in an internal longitudinal flow passage <NUM> of the tubular string <NUM>, or to deflate the seal element by venting pressure in the seal element to the internal flow passage of the tubular string.

As depicted in <FIG>, the packer assembly <NUM> is in a set configuration. The seal element <NUM> is inflated, so that it is outwardly extended and sealingly engages the well surface <NUM>, thereby isolating the upper annulus section 30a from the lower annulus section 30b. Inflation pressure in the seal element <NUM> is isolated from the flow passage <NUM> and is otherwise prevented from venting by the flow controller <NUM>.

As described more fully below, the flow controller <NUM> also isolates the upper annulus section 30a from the flow passage <NUM> in the set configuration. The upper annulus section 30a may be placed in fluid communication with the flow passage <NUM> in an inflate configuration (in which the flow controller <NUM> admits fluid from the flow passage <NUM> into the seal element <NUM>) and in a deflate configuration (in which pressure in the seal element is vented to the flow passage <NUM>).

In the method performed with the system <NUM>, the packer assembly <NUM> is connected in the tubular string <NUM>, and is installed with the tubular string into the wellbore <NUM> in the deflate configuration. In this configuration, the seal element <NUM> is not inflated, and is vented to the interior of the tubular string <NUM>.

When the packer assembly <NUM> is appropriately positioned in the wellbore <NUM> and it is desired to set the packer assembly, a flow rate of the fluid flow <NUM> through the flow passage <NUM> is increased until it is at or above a predetermined level. The flow rate may be increased from no flow, or from a lower flow rate (such as, circulation flow through the tubular string <NUM>), to the predetermined flow rate level.

When the flow rate reaches the predetermined level, the flow controller <NUM> places the flow passage <NUM> in communication with an interior inflation chamber <NUM> of the seal element <NUM> (not visible in <FIG>, see <FIG>). A flow path from the flow passage <NUM> to the inflation chamber <NUM> is opened, thereby inflating the seal element <NUM> in this inflate configuration.

When the seal element <NUM> is satisfactorily inflated, the flow controller <NUM> isolates the inflation chamber <NUM> from the flow passage <NUM>, thereby maintaining inflation pressure in the inflation chamber. The flow controller <NUM> is operated to this set configuration in response to longitudinally compressing the flow controller (e.g., by slacking off on the tubular string <NUM> at the surface, so that a weight of the tubular string is applied to the flow controller).

In the set configuration depicted in <FIG>, a variety of different well operations may be performed which rely on the upper annulus section 30a being isolated from the lower annulus section 30b. For example, an integrity of the casing <NUM> below the seal element <NUM> can be tested by pressurizing the flow passage <NUM> (e.g., using a pump at the surface), with the flow passage <NUM> being in communication with the lower annulus section 30b.

After the lower annulus section 30b has been pressurized, a pressure decrease (detected, for example, by monitoring pressure in the flow passage <NUM> at the surface) can indicate leakage from the casing <NUM> below the seal element <NUM>. Other tests, and other types of well operations, may be performed with the packer assembly <NUM> in the set configuration, in keeping with the principles of this disclosure.

The packer assembly <NUM> can be returned to the deflate configuration, for example, in order to permit conveyance of the packer assembly to another position in the wellbore <NUM>, or to allow the packer assembly to be retrieved from the wellbore. The flow controller <NUM> is operated to the deflate configuration in response to longitudinally extending the flow controller (e.g., by picking up on the tubular string <NUM> at the surface, so that the weight of the tubular string is lifted from the flow controller).

Referring additionally now to <FIG>, a cross-sectional view of an example of the inflatable packer assembly <NUM> is representatively illustrated. For convenience and clarity, the description herein of the packer assembly <NUM> relates to its use in the <FIG> system <NUM> and method, but it should be clearly understood that the packer assembly may be used in other systems and methods in keeping with the principles of this disclosure.

In the <FIG> example, the packer assembly <NUM> includes upper and lower connectors 40a,b for connecting the packer assembly in a tubular string (such as, the tubular string <NUM>). As depicted in <FIG>, the connectors 40a,b are threaded for coupling to similarly-threaded connectors of the tubular string <NUM>, but other types of connectors (such as, latches, quick couplers, etc.) may be used in other examples.

The lower connector 40b is connected to the flow controller <NUM> with an internal tubular mandrel <NUM>, such that the flow passage <NUM> extends through the seal element <NUM> between the flow controller <NUM> and the lower connector 40b. The inflation chamber <NUM> is formed radially between the seal element <NUM> and the mandrel <NUM>.

When a pressure differential is created from the inflation chamber <NUM> to an exterior of the seal element <NUM> (e.g., the annulus <NUM> in the <FIG> system <NUM>), the seal element is inflated and extends radially outward. When the pressure differential is subsequently relieved, the seal element <NUM> deflates and retracts radially inward. Thus, by controlling the pressure differential across the seal element <NUM> (between the inflation chamber <NUM> and the exterior of the seal element), the packer assembly <NUM> is changed between its deflate, inflate and set configurations.

Another internal tubular mandrel <NUM> connects the upper connector 40a to the flow controller <NUM>, such that the flow passage <NUM> extends through an actuator <NUM> and a flow director <NUM> of the flow controller. A lower end of the mandrel <NUM> is slidingly and sealingly received in the flow director <NUM>. In addition, the lower end of the mandrel <NUM> has a flow restrictor <NUM> therein that restricts the fluid flow <NUM> from an upper section 36a of the flow passage <NUM> to a lower section 36b of the flow passage.

As described more fully below, a position of the mandrel <NUM> in the flow director <NUM> determines whether fluid communication is permitted: between the upper flow passage section 36a and the inflation chamber <NUM>, between the lower flow passage section 36b and the inflation chamber <NUM>, and between the lower flow passage section 36b and the exterior above the seal element <NUM> (e.g., the upper annulus section 30a in the <FIG> system <NUM>).

Referring additionally now to <FIG> & <FIG>, cross-sectional views of the flow controller <NUM> and the flow director <NUM> are representatively illustrated apart from the remainder of the packer assembly <NUM>. In <FIG> & <FIG>, the flow controller <NUM> is depicted in an example of the deflate configuration, in which the seal element <NUM> (not shown in <FIG> & <FIG>, see <FIG>) is inwardly retracted and the packer assembly <NUM> can be conveyed into, displaced between locations in, or retrieved from, the wellbore <NUM>.

To prevent a pressure differential from being created from the interior to the exterior of the seal element <NUM> in the deflate configuration, the inflation chamber <NUM> is placed in fluid communication with the lower flow passage section 36b via the flow director <NUM>. In the <FIG> & <FIG> example, a deflate flow path <NUM> is in communication with the inflation chamber <NUM>, and is also placed in communication with the lower flow passage section 36b via ports <NUM> in the flow director <NUM> (see <FIG>).

The ports <NUM> are positioned between internal seals <NUM> capable of sealingly engaging an exterior of the mandrel <NUM>. With the mandrel <NUM> positioned as depicted in <FIG> & <FIG>, the ports <NUM> and the deflate flow path <NUM> are open for flow between the inflation chamber <NUM> and the lower flow passage section 36b.

If the mandrel <NUM> is displaced downward relative to the ports <NUM>, so that the mandrel is sealingly engaged by both of the seals <NUM>, the ports <NUM> and deflate flow path <NUM> will be closed to such flow. Thus, the ports <NUM>, seals <NUM> and mandrel <NUM> comprise a valve <NUM> of the flow director <NUM> for selectively permitting and preventing flow through the deflate flow path <NUM> between the inflation chamber <NUM> and the lower flow passage section 36b.

Another valve <NUM> comprises ports <NUM>, internal seals <NUM> and the mandrel <NUM>. The ports <NUM> and a flow path <NUM> provide for fluid communication between the lower flow passage section 36b and the exterior of the packer assembly <NUM> above the seal element <NUM> (as viewed in <FIG>).

In the deflate configuration of <FIG> & <FIG>, the valve <NUM> is open, thereby permitting flow through the ports <NUM> and flow path <NUM> between the lower flow passage section 36b and the exterior of the packer assembly <NUM> (e.g., the upper annulus section 30a in the <FIG> system <NUM>). However, if the mandrel <NUM> is displaced sufficiently downward, so that both of the seals <NUM> sealingly engage the exterior of the mandrel, the ports <NUM> and flow path <NUM> will then be closed to such flow.

Another valve <NUM> comprises ports <NUM> formed through the mandrel <NUM> above the flow restrictor <NUM>, and internal seals <NUM> carried in a poppet sleeve <NUM>. In the <FIG> & <FIG> deflate configuration, the valve <NUM> is closed, with flow through the ports <NUM> being prevented by the seals <NUM> and poppet sleeve <NUM>.

Yet another valve <NUM> comprises the poppet sleeve <NUM> and an external seal <NUM> carried on the poppet sleeve. In the deflate configuration depicted in <FIG>, the seal <NUM> is sealingly engaged in a seal bore <NUM> formed in a housing <NUM> of the flow director <NUM> and, thus, flow is prevented from the upper flow passage section 36a to an inflate flow path <NUM> in communication with the inflation chamber <NUM>. In the deflate configuration, such flow is also prevented by the closed valve <NUM>. Thus, fluid communication is permitted from the upper flow passage section 36a to the inflation chamber <NUM> via the inflate flow path <NUM> when the valves <NUM>, <NUM> are open, and fluid communication between the upper flow passage section and the inflation chamber via the inflate flow path is prevented when either or both of the valves <NUM>, <NUM> is closed (in this example, the valve <NUM> will not be open unless the valve <NUM> is open).

Note that the fluid flow <NUM> through the flow passage <NUM> creates a pressure differential across the flow restrictor <NUM>. Specifically, with the fluid flow <NUM> in a downward direction as viewed in the drawings, the upper flow passage section 36a will have a greater pressure therein relative to pressure in the lower flow passage section 36b.

In this example, the flow restrictor <NUM> comprises a reduced diameter orifice. In other examples, other types of flow restrictors (such as, bluff bodies, surface textures, tortuous flow paths, etc.) may be used to produce the pressure differential in response to the fluid flow <NUM>.

In the <FIG> system <NUM>, the lower flow passage section 36b is in relatively unrestricted fluid communication with the annulus <NUM> external to the packer assembly <NUM>. Thus, in this example, the pressure differential from the upper flow passage section 36a to the lower flow passage section 36b is substantially the same as a pressure differential from the upper flow passage section to the exterior of the packer assembly <NUM>.

As described more fully below, this pressure differential can be used to inflate the seal element <NUM> by placing the inflation chamber <NUM> in communication with the upper flow passage section 36a. As discussed above, the valves <NUM>, <NUM> are opened to permit such fluid communication. Displacement of the mandrel <NUM> downward relative to the poppet sleeve <NUM>, so that the ports <NUM> are no longer positioned between the seals <NUM>, will permit flow through the ports to a chamber <NUM> below the poppet sleeve <NUM>.

The flow controller <NUM> includes the actuator <NUM> for producing such relative displacement of the mandrel <NUM>. The actuator <NUM> includes a piston <NUM> with an upwardly facing piston area exposed to pressure in the upper flow passage section 36a via ports <NUM>, and a downwardly facing piston area exposed to pressure external to the packer assembly <NUM> via ports <NUM>. Thus, substantially the same pressure differential created across the flow restrictor <NUM> by the fluid flow <NUM> is also applied across the piston <NUM>.

When the flow rate of the fluid flow <NUM> is increased to the predetermined level, a sufficient biasing force is created by the pressure differential acting across the piston <NUM>, so that the actuator <NUM> displaces the mandrel <NUM> downward relative to the housing <NUM> of the flow director <NUM> (or, viewed differently, displaces the housing upward relative to the mandrel).

Referring additionally now to <FIG> & <FIG>, cross-sectional views of the flow controller <NUM> and the flow director <NUM> are representatively illustrated in an example of the inflate configuration. In this configuration, the flow rate through the flow passage <NUM> has been increased to at least the predetermined level and, in response, the actuator <NUM> has displaced the housing <NUM> upward relative to the mandrel <NUM>.

The valve <NUM> is now closed, with the mandrel <NUM> sealingly engaged with both of the seals <NUM>. Fluid communication between the lower flow passage 36b and the inflation chamber <NUM> via the ports <NUM> and the flow path <NUM> is prevented.

The valve <NUM> is now open, permitting fluid communication between the upper flow passage section 36a and the chamber <NUM> below the poppet sleeve <NUM>. This exposes a lower side of the poppet sleeve <NUM> to the pressure in the upper flow passage section 36a, while an upper side of the poppet sleeve is exposed to pressure in the seal element <NUM> via the flow path <NUM>.

The poppet sleeve <NUM> is biased downward in this example by a biasing force exerted by a biasing device <NUM> (depicted as a compression spring in the drawings). When the pressure differential from the lower side to the upper side of the poppet sleeve <NUM> is great enough to overcome the biasing force exerted by the biasing device <NUM>, the poppet sleeve will displace upward, at least until the seal <NUM> is no longer sealingly engaged in the seal bore <NUM>. At that point, the valve <NUM> is opened, and fluid communication is permitted between the upper flow passage section 36a and the inflation chamber <NUM> via the ports <NUM>, chamber <NUM> and flow path <NUM>.

As described above in relation to <FIG> & <FIG>, in the deflate configuration the inflation chamber <NUM> is pressure equalized with the lower flow passage section 36b, which is also in fluid communication with the upper flow passage section 36a via the flow restrictor <NUM>. In the <FIG> & <FIG> inflate configuration, the inflation chamber <NUM> is no longer pressure equalized with the lower flow passage section 36b, but is instead in communication with the upper flow passage section 36a. At least a predetermined pressure differential is created from the upper flow passage section 36a to the lower flow passage section 36b, due to the increased flow rate through the flow restrictor <NUM>.

The increased pressure communicated from the upper flow passage section 36a to the inflate flow path <NUM> will, thus, cause the seal element <NUM> to inflate and extend radially outward. In the <FIG> system <NUM>, the seal element <NUM> when inflated extends radially outward and sealingly engages the well surface <NUM>. Frictional contact between the inflated seal element <NUM> and the well surface <NUM> will also prevent, or at least inhibit, displacement of the packer assembly <NUM> relative to the well surface.

Note that the valve <NUM> is in some respects similar to a pressure relief valve, in that it opens only when the pressure differential across the poppet sleeve <NUM> (from the chamber <NUM> to the inflate flow path <NUM>) is greater than a predetermined level. The predetermined level is determined by factors including a piston area of the poppet sleeve <NUM> and the biasing force exerted by the biasing device <NUM>.

Thus, the valve <NUM> permits only one-way flow from the upper flow passage section 36a to the inflate flow path <NUM> in the inflate configuration. If the flow rate through the flow passage <NUM> is subsequently decreased, so that pressure in the upper flow passage section 36a decreases, the seal element <NUM> will not deflate, since the closed valve <NUM> will prevent release of pressure from the inflation chamber <NUM> to the upper flow passage section 36a.

The valve <NUM> remains open in the inflate configuration of <FIG> & <FIG>. Thus, fluid communication is permitted between the lower flow passage section 36b and the upper annulus 30a in the <FIG> system <NUM>.

Referring additionally now to <FIG> & <FIG>, cross-sectional views of the flow controller <NUM> and the flow director <NUM> are representatively illustrated in an example of the set configuration. In this configuration, the flow rate through the flow passage <NUM> has been decreased, and the flow controller <NUM> has been longitudinally compressed (for example, by slacking off on the tubular string <NUM> at the surface).

The longitudinal compression of the flow controller <NUM> causes the mandrel <NUM> to displace downward relative to the housing <NUM>. The valves <NUM>, <NUM>, <NUM> are closed, and so the inflation chamber <NUM> is isolated from both of the upper and lower flow passage sections 36a,b.

Fluid communication is prevented between the inflation chamber <NUM> and the upper flow passage section 36a via the inflate flow path <NUM>, and fluid communication is prevented between the inflation chamber <NUM> and the lower flow passage section 36b via the deflate flow path <NUM>. Thus, fluid is prevented from being released from the inflation chamber <NUM>, and the seal element <NUM> is thereby maintained in its inflated condition.

The valve <NUM> is closed in the set configuration of <FIG> & <FIG>. Thus, fluid communication is prevented between the lower flow passage section 36b and the upper annulus 30a in the <FIG> system <NUM>.

Tests, treatments and other types of well operations can now be performed with the packer assembly <NUM> in its set configuration. In the <FIG> system <NUM>, the seal element <NUM> isolates the upper annulus 30a from the lower annulus 30b in the set configuration.

Note that the ports <NUM> are positioned below the seals <NUM> in the set configuration, so that the fluid flow <NUM> can bypass the flow restrictor <NUM> (see <FIG>). In this manner, the resistance to the fluid flow <NUM> through the flow passage <NUM> is substantially reduced.

The packer assembly <NUM> can be returned to its deflate configuration (see <FIG> & <FIG>) by longitudinally extending the flow controller <NUM> (e.g., by picking up on the tubular string <NUM> at the surface). In this manner, the mandrel <NUM> will be displaced upward in the flow director <NUM>, until the valve <NUM> is opened (as depicted in <FIG>). This places the inflation chamber <NUM> in fluid communication with the lower flow passage section 36b, thereby allowing pressure in the inflation chamber to vent into the lower flow passage section 36b.

The lower flow passage section 36b is also in communication with the upper annulus section 30a in the deflate configuration. In this manner, elevated pressure in the wellbore <NUM> below the packer assembly <NUM> can be vented to the upper annulus section 30a, and will not act to maintain the seal element <NUM> in its inflated condition (e.g., as might otherwise occur with the elevated pressure applied to the inflation chamber <NUM>).

Note that the lower flow passage section 36b remains in fluid communication with the upper flow passage section 36a via the flow restrictor <NUM> in each of the deflate, inflate and set configurations of the packer assembly <NUM>. The packer assembly <NUM> changes from the deflate configuration to the inflate configuration in response to a flow rate increase in the flow passage <NUM>, the packer assembly changes from the inflate configuration to the set configuration in response to longitudinal compression of the flow controller <NUM>, and the packer assembly changes from the set configuration to the deflate configuration in response to longitudinal extension of the flow controller. These configuration changes may be performed any number of times during a single trip of the packer assembly <NUM> into the wellbore <NUM>.

It may now be fully appreciated that the above disclosure provides significant advances to the arts of designing, constructing and utilizing inflatable packer assemblies. In examples described above, the packer assembly <NUM> can be deflated downhole by venting the inflation chamber <NUM> to the lower flow passage section 36b, in a manner allowing the inflation chamber to be subsequently pressurized by producing a pressure differential across the flow restrictor <NUM>.

The above disclosure provides to the art an inflatable packer assembly <NUM> for use in a subterranean well. In one example, the inflatable packer assembly <NUM> can include an inflatable seal element <NUM> having an internal inflation chamber <NUM>, a flow passage <NUM> extending longitudinally through the inflatable packer assembly <NUM>, a flow restrictor <NUM> between first and second sections 36a,b of the flow passage <NUM>, and a flow controller <NUM> that selectively permits and prevents fluid communication between the inflation chamber <NUM> and each of the first and second flow passage sections 36a,b. The flow controller <NUM> changes from a deflate configuration to an inflate configuration in response to a flow rate increase through the flow passage <NUM>.

The flow controller <NUM> may include first and second valves <NUM>, <NUM>, <NUM>. The first valve <NUM>, <NUM> prevents fluid communication between the inflation chamber <NUM> and the first flow passage section 36a, and the second valve <NUM> permits fluid communication between the inflation chamber <NUM> and the second flow passage section 36b, in the deflate configuration.

The first valve <NUM>, <NUM> may permit fluid communication between the inflation chamber <NUM> and the first flow passage section 36a, and the second valve <NUM> may prevent fluid communication between the inflation chamber <NUM> and the second flow passage section 36b, in the inflate configuration.

The first valve <NUM>, <NUM> may prevent fluid communication between the inflation chamber <NUM> and the first flow passage section 36a, and the second valve <NUM> may prevent fluid communication between the inflation chamber <NUM> and the second flow passage section 36b, in a set configuration.

The flow controller <NUM> may change from the inflate configuration to the set configuration in response to longitudinal compression of the flow controller <NUM>. A resistance to flow from the first flow passage section 36a to the second flow passage section 36b may be reduced in response to the longitudinal compression of the flow controller <NUM>.

The flow controller <NUM> may change from the set configuration to the deflate configuration in response to longitudinal extension of the flow controller <NUM>.

Fluid communication may be permitted between the first and second flow passage sections 36a,b via the flow restrictor <NUM> in each of the deflate and inflate configurations.

The first flow passage section 36a may be placed in fluid communication with the inflation chamber <NUM> in response to the flow rate increase.

The first flow passage section 36a may be in communication with the inflation chamber <NUM> in the inflate configuration, the second flow passage section 36b may be in communication with the inflation chamber <NUM> in the deflate configuration, and the inflation chamber <NUM> may be isolated from the first and second flow passage sections 36a,b in a set configuration.

The first and second flow passage sections 36a,b may be in communication with each other in the deflate, inflate and set configurations.

A method of operating an inflatable packer assembly <NUM> in a subterranean well is also provided to the art by the above disclosure. In one example, the method can comprise connecting the inflatable packer assembly <NUM> in a tubular string <NUM>, so that a longitudinal flow passage <NUM> of the tubular string <NUM> extends through the inflatable packer assembly <NUM>, and a flow restrictor <NUM> restricts flow between first and second sections 36a,b of the flow passage <NUM>; and inflating an inflatable seal element <NUM> of the inflatable packer assembly <NUM> while fluid flows from the first flow passage section 36a to the second flow passage section 36b via the flow restrictor <NUM>.

The inflating step may include sealingly engaging the seal element <NUM> with a well surface <NUM>, thereby isolating an upper annulus section 30a from a lower annulus section 30b. The upper annulus 30a may be in fluid communication with the second flow passage section 36b after the isolating step. The method may include deflating the seal element <NUM> while the upper annulus section 30a is in fluid communication with the second flow passage section 36b.

The method may include conveying the inflatable packer assembly <NUM> in the well while an inflation chamber <NUM> of the seal element <NUM> is in communication with the second flow passage section 36b.

The inflating step may include increasing a flow rate from the first flow passage section 36a to the second flow passage section 36b. The flow rate increasing step may include closing a flow path <NUM> between the second flow passage section 36b and an inflation chamber <NUM> of the seal element <NUM>.

The method may include longitudinally extending the inflatable packer assembly <NUM>, thereby opening the flow path <NUM> between the second flow passage section 36b and the inflation chamber <NUM>.

A first flow path <NUM> between the first flow passage section 36a and an inflation chamber <NUM> of the seal element <NUM> may be open, and a second flow path <NUM> between the second flow passage section 36b and the inflation chamber <NUM> may be closed, in the inflating step. The method may include setting the inflatable packer assembly <NUM>, with the first and second flow paths <NUM>, <NUM> being closed in the setting step.

The method may include conveying the inflatable packer assembly <NUM> through the well, with the second flow path <NUM> being open in the conveying step.

The setting step may include longitudinally compressing the inflatable packer assembly <NUM>. The setting step may include decreasing a restriction to flow from the first flow passage section 36a to the second flow passage section 36b.

A system <NUM> for use with a subterranean well is also described above. In one example, the system <NUM> can include a tubular string <NUM> having an inflatable packer assembly <NUM> connected therein, so that a flow passage <NUM> of the tubular string <NUM> extends longitudinally through the inflatable packer assembly <NUM>. The inflatable packer assembly <NUM> is configured to block flow through an annulus <NUM> surrounding the tubular string <NUM> in response to inflation of a seal element <NUM> of the inflatable packer assembly <NUM>. The inflatable packer assembly <NUM> includes a flow restrictor <NUM> between first and second sections 36a,b of the flow passage <NUM>, a first selectively openable and closeable flow path <NUM> between the first flow passage section 36a and an inflation chamber <NUM> of the seal element <NUM>, and a second selectively openable and closeable flow path <NUM> between the second flow passage section 36b and the inflation chamber <NUM>.

The seal element <NUM> may separate an upper section 30a of the annulus <NUM> from a lower section 30b of the annulus <NUM> in a set configuration of the inflatable packer assembly <NUM>. The first and second flow paths <NUM>, <NUM> are closed in the set configuration.

The upper annulus section 30a may be in communication with the second flow passage section 36b in a deflate configuration of the inflatable packer assembly <NUM>.

The second flow path <NUM> may be open in the deflate configuration. The first flow path <NUM> may be closed in the deflate configuration.

The first flow path <NUM> may be open in an inflate configuration of the inflatable packer assembly <NUM>. Fluid communication may be permitted between the first and second flow passage sections 36a,b in the inflate configuration.

The first flow path <NUM> may open in response to an increase in flow rate from the first flow passage section 36a to the second flow passage section 36b.

Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example. Instead, any of the features described above and/or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.

Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.

It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.

In the above description of the representative examples, directional terms (such as "above," "below," "upper," "lower," "upward," "downward," etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.

The terms "including," "includes," "comprising," "comprises," and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as "including" a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term "comprises" is considered to mean "comprises, but is not limited to.

Claim 1:
A system (<NUM>) for use with a subterranean well, the system comprising:
a tubular string (<NUM>) having an inflatable packer assembly (<NUM>) connected therein, so that a flow passage (<NUM>) of the tubular string (<NUM>) extends longitudinally through the inflatable packer assembly (<NUM>), the inflatable packer assembly (<NUM>) being configured to block flow through an annulus (<NUM>) surrounding the tubular string (<NUM>) in response to inflation of a seal element (<NUM>) of the inflatable packer assembly (<NUM>), in which the seal element separates an upper section of the annulus from a lower section of the annulus in a set configuration of the inflatable packer assembly; and
the inflatable packer assembly (<NUM>) including a flow restrictor (<NUM>) between first and second sections (36a, b) of the flow passage (<NUM>), a first selectively openable and closeable flow path (<NUM>) between the first flow passage section (36a) and an inflation chamber (<NUM>) of the seal element, and a second selectively openable and closeable flow path (<NUM>) between the second flow passage section (36b) and the inflation chamber (<NUM>), characterized by the upper annulus section being in communication with the second flow passage section in a deflate configuration of the inflatable packer assembly.