Abstract: A linear indexing apparatus and associated methods of using same provide convenient operation of tools in a subterranean wellbore. In a preferred embodiment, a linear indexing apparatus has an outer tubular housing and a tubular mandrel axially slidably disposed within the housing. Two sets of slips are utilized to incrementally displace the mandrel relative to the housing. A piston associated with one of the sets of slips permits the mandrel to be incrementally indexed in response to a series of repeated applications of a predetermined differential pressure.

Abstract: A repositionable apparatus for perforating and gravel packing an underground well uses gravity or other means to reposition the apparatus instead of a conventional wireline or work string attached to a rig. Perforating and packing can be accomplished without a rig after the apparatus is initially placed and set in the well. One embodiment of the inventive apparatus uses a perforating gun assembly, a connected ported sub above the gun assembly, a translating annulus packer above the ported sub, a circumferential screen located above the packer, blank pipe connected above the screen, an openable port above the blank tubular pipe, and a second translating annulus packer attached to the blank tubular.

Abstract: A plug apparatus is provided which includes a dispersible plug member and a fluid barrier. In one embodiment described herein, a fluid barrier is utilized to prevent contamination of fluid contained in a plug apparatus. The fluid is thus available for use in dispersing a plug member of the plug apparatus, regardless of the types of other fluids present in a well in which the apparatus is installed. Various configurations of fluid barriers are also provided.

Abstract: A method and apparatus are disclosed which allow isolation of a plurality of zones for treatment, particularly sand fracturing. The lowermost barrier can be pumped through tubing and anchored in cased or open holes. In the preferred embodiment, the pumped plug has a visco-elastic member which contains a particulate aggregate mixture, such as described in U.S. Pat. No. 5,417,285. The visco-elastic material is subjected to a force which changes its shape so that the material obstructs the wellbore. The shape change also accomplishes dehydration of the material within the visco-elastic enclosure by virtue of fluid displacement, resulting from a volume reduction, hardening it so that a plug using the visco-elastic material is formed. Thereafter, a packer on the tubing string is set to isolate the zone for sand fracturing. The process can be repeated without tripping out of the hole as additional plugs are pumped through tubing and the process is repeated.

Abstract: A radially deformable inflatable tubular sleeve for tubing or obturating a well (P) or a pipe. The sleeve includes a tube and a series of breakable restraining rings positioned along the tube. The rings are arranged so that each ring breaks one after the other in the longitudinal direction of the sleeve when the tube is inflated by an internal fluid under pressure. As a ring breaks, liquid (B) present in the well is moved progressively forward so as to prevent pockets forming on the outside of the tubing.

Abstract: A bidirectional disappearing plug member and plug assembly is capable of blocking pressurized fluid flow from opposing axial directions in a flowbore. In a preferred embodiment, the plug member, which blocks flow through the flowbore, may be readily and at least partially dissolved through the application of at least one pressurization and depressurization within a tubing string above the plug assembly. Construction of the plug assembly permits the plug member to be conveniently emplaced in a fluid-filled wellbore by permitting fluid flow around the plug member during the emplacement process. The plug member may then be secured within the plug assembly to block fluid flow from either axial direction.

Abstract: A plug launching device for use in cementing operations in the construction of oil and gas wells, the device having, in certain embodiments, a tubular member with an upper section and a lower section which can accommodate at least a bottom plug and a top plug, the upper section having a floor and the lower section movable relative to the upper section so that when a first dart is pumped into the upper section by cement, the cement is diverted to raise the lower section to release the bottom plug, and when a second dart is pumped into the upper section by hydraulic fluid, it lands on the first dart and the hydraulic fluid is diverted to raise the lower section to further release the top plug.

Abstract: A plug is provided which is specially adapted for statically setting a plug portion within an internal profile formed in a wellhead. In an illustrated preferred embodiment, the plug portion is set by application of fluid pressure to a running tool portion. When set in. the profile, the plug portion is secured statically relative to the profile, thereby permitting advantageous utilization of a metal-to-metal seal on the plug portion. The plug portion includes features which maintain its set configuration in the profile. The running tool portion includes multiple pistons which enhance operation of the running tool portion. A disclosed verification tool provides an indication that the plug portion has been properly set.

Abstract: A device for plugging horizontal or vertical wells in oil or similar drillings includes a fluid-inflatable elastic packing element, which readily expands by the introduction of fluid therein, to fill an interior portion of the well to seal the well.

Abstract: The present invention relates to tools for use in wellbores which are actuated by means of actuating balls. The invention provides a method of actuating a tool located in a wellbore, the method comprising the sequential steps of: (a) locating a frangible actuating ball (2) on a seat, the seat being provided in the tool for receiving the actuating ball (2); (b) pumping fluid down a tubing string attached to the tool so as to apply a force to the seat and thereby actuate the tool, the force being transmitted to the seat through the actuating ball (2); and (c) breaking the actuating ball (2) to permit fluid to flow through the seat. The invention has the advantage over the prior art of providing means for actuating a downhole tool with an actuating ball (2) so that the actuating ball (2) does not form an undesirable obstruction once the tool has been actuated.

Abstract: A tool for clamping against the interior of a chimney flue having a scissors jack mechanism for adjustably clamping into various size chimneys. A seal plate for sliding over the shaft of the clamping device and for tightly sealing against the interior chimney flue walls. A cleaning brush mechanism affixed to the end of a tubular member, sized to slide over the clamping shaft for cleaning the interior of a chimney.

Abstract: An apparatus for sealing non-regular holes in a perforation in a wall, including a sealing member configured to be forcibly pressed into an inner surface of the perforation, an expandable member for forcing the sealing member against the inner surface of the perforation, and an expander member for causing the expandable member to force the sealing member against the inner surface of the perforation.

Abstract: A linear indexing apparatus and associated methods of using same provide convenient operation of tools in a subterranean wellbore. In a preferred embodiment, a linear indexing apparatus has an outer tubular housing and a tubular mandrel axially slidably disposed within the housing. Two sets of slips are utilized to incrementally displace the mandrel relative to the housing. A piston associated with one of the sets of slips permits the mandrel to be incrementally indexed in response to a series of repeated applications of a predetermined differential pressure.

Abstract: A mine shaft closure plug which is created by a self-expanding plastic foam on a platform positioned within the mine shaft. Multiple expansion foam containers are used to provide the foam. Each expansion foam container has two closed waterproof pouches, an inner pouch and an outer pouch, each containing a separate component of the foam. The inner pouch is contained within the outer pouch. Upon breaking the inner pouch, the separate foam components combine within the outer pouch to form a complete expansion foam. The foam expands slowly enough to provide sufficient time for the container to be placed on the platform. Once in position, the expansion foam bursts the outer pouch to form the expansion foam plug above the platform. Either the platform or the expansion foam containers may be lowered into place by attached tethers.

Abstract: A bidirectional disappearing plug member and plug assembly is capable of blocking pressurized fluid flow from opposing axial directions in a flowbore. In a preferred embodiment, the plug member, which blocks flow through the flowbore, may be readily and at least partially dissolved through the application of at least one pressurization and depressurization within a tubing string above the plug assembly. Construction of the plug assembly permits the plug member to be conveniently emplaced in a fluid-filled wellbore by permitting fluid flow around the plug member during the emplacement process. The plug member may then be secured within the plug assembly to block fluid flow from either axial direction.

Abstract: A method and apparatus for establishing and substantially destroying a fluid-type plug which is substantially dissolvable in fluid. A means for selectively opening a fluid port to the plug member is described which causes dissolution of the plug to occur. The plug member is maintained within a plug housing which also contains the fluid port. The plug housing is received within an annular sleeve which serves to seal the plug housing port against fluid intrusion into the plug housing port. The sleeve also contains an aperture which will become generally aligned with the plug housing port as the plug housing is axially separated from the annular sleeve. Axial separation of the plug housing and sleeve is accomplished by selectively pressurizing and depressurizing the flowbore containing the plug assembly to remove support for the plug housing.

Abstract: A wellbore is at least partially obstructed with a partition or obstruction member. A fluid slurry of an aggregate mixture of particulate matter is pumped into the wellbore adjacent the partition or obstruction member. The aggregate mixture of particulate material contains at least one component of particulate material, and each of the at least one particulate material components has an average discrete particle dimension different from that of the other particulate material components. Fluid pressure then is applied to the aggregate material and fluid is drained from the aggregate material through a fluid drainage passage in the partition or obstruction member. The fluid pressure and drainage of fluid from the aggregate mixture combined to compact the aggregate mixture into a substantially solid, load-bearing, force-transferring, substantially fluid-impermeable plug member, which seals a first wellbore region from fluid flow communication with a second wellbore region.

Abstract: A hollow body is provided with a seal by which it may be sealed within a nipple profile included in a tubing string. The body allows a wireline to be passed through it while maintaining a substantial seal. During running-in lower collet fingers engage a stop ring mounted on the body. When the plug becomes seated in the nipple profile by the weight of a logging tool also suspended on the wireline, fingers are disengaged by inward movement of external collet fingers and rollers. Consequent downward movement of the fingers allows the rope socket to push them outwardly and allows the logging tool to be lowered. An equalizing sleeve can be pulled up by the socket head from the sealing position to a raised position which allows pressure equalization above and below the plug to facilitate withdrawal thereof. Profiles on the fingers act to trap the socket head should the wireline pull out or break.

Abstract: A borehole decking plug which is created by a self-expanding plastic foam. Two closed waterproof pouches, an inner pouch and an outer pouch, each contain a separate component of the foam. The inner pouch is contained within the outer pouch, and both are contained within a third open external pouch having a tether attachment. Upon breaking the inner pouch, the separate foam components combine within the outer pouch to form a complete expansion foam. The foam expands slowly enough to provide sufficient time for the device to be lowered via the tether down a borehole to a preselected position. Once in position, the expansion foam bursts the outer pouch and escapes upward through the external pouch to form a deck plug at the preselected position.

Abstract: A method and apparatus for establishing a fluid plug within a well bore which can then be substantially destroyed upon demand to permit reestablishment of the well within a short period of time thereafter. Increased pressure actuates a plug rupture mechanism which destroys the integrity of the plug and allows the plug to be substantially eliminated from the wellbore within a short period of time thereafter. In described preferred embodiments, the plug is comprised of a salt and sand mixture which is highly resistant to fluid compressive forces but is subject to destruction under shear tension forces. The plug may be encased within a plug sleeve which is, in turn, encased within a plug housing which may be disposed within the well bore. The sleeve is associated within the housing so that fluid may be displaced about the plug sleeve as the housing is disposed into the well bore.

Abstract: Perforations and cracks in wellbore liners or casings may be temporarily or permanently covered by a radially-expansible, coiled sleeve member formed by a sheet of elastically-deflectable material such as stainless steel which is coiled and placed in a cylinder which may be conveyed into a well to a working position for deployment of the sleeve to expand into engagement with the casing wall to block the perforations or cracks. The cylinder includes a sleeve ejecting piston which may be urged to rapidly eject the sleeve from the cylinder by pressure fluid conveyed to the cylinder by coilable tubing or by a gas-generating charge material electrically connected to an E-line which also may be used to deploy the cylinder into its working position in the well.

Abstract: A locking cap for securing the open end of a well pipe to prevent contaminants from entering the well comprising a cap member adapted to be disposed over the open end of a well pipe casing to be locked, an outer flange downwardly extending from the cap member and integral therewith, the outer flange adapted to fit over the exterior surface of the well pipe casing to be locked, inner flange downwardly extending from the cap member and integral therewith, the inner flange adapted to fit about the interior surface of the well pipe casing to be locked, the inner flange including a series of parallel slots extending longitudinally inward from the end of the inner flange and towards the cap member to provide a series of radially expandable gripping fingers positioned along the perimeter of the well pipe casing interior surface, a cam disk positioned coaxially adjacent the inner flange, the cam disk being selectively movable against the fingers to radially expand each of the fingers into binding engagement against t

Abstract: A wellbore is at least partially obstructed with a partition or obstruction member. A fluid slurry of an aggregate mixture of particulate matter is pumped into the wellbore adjacent the partition or obstruction member. The aggregate mixture of particulate material contains at least one component of particulate material, and each of the at least one particulate material components has an average discrete particle dimension different from that of the other particulate material components. Fluid pressure then is applied to the aggregate material and fluid is drained from the aggregate material through a fluid drainage passage in the partition or obstruction member. The fluid pressure and drainage of fluid from the aggregate mixture combined to compact the aggregate mixture into a substantially solid, load-bearing, force-transferring, substantially fluid-impermeable plug member, which seals a first wellbore region from fluid flow communication with a second wellbore region.

Abstract: A sub-surface release plug assembly for use in cementing an outer casing annulus around a well casing. The plug assembly comprises non-metallic materials, and in particular, high-strength engineered plastics. A method of drilling out the plug assembly using a drill bit with no moving parts is also disclosed.

Abstract: A sub-surface release plug assembly for use in cementing an outer casing annulus around a well casing comprising a top plug releasably connected to a drill string by a collet mechanism and a bottom plug releasably attached to the top plug by a sleeve assembly extending through the top plug. The assembly further comprises primary and secondary release means for releasing said plugs thereby ensuring that the plugs are released in said casing during cementing operations.

Abstract: An anti-rotation device for use in a well tool, for example a top plug or a bottom plug, has a tapered male member having a corrugated outer surface which can enter a corresponding recess in another well tool to inhibit relative rotation therebetween.

Abstract: A well servicing assembly utilizes a plug mechanism for preventing fluid loss into a formation. The assembly includes a string of tubing which carries a packer, a perforating gun, a running tool, and a latch assembly. After perforating, the operator pulls the tubing upward, leaving the packer in place. The latch assembly engages the packer. The latch assembly has a plug contained therein which prevents downward flow of fluid through the packer as the tubing string is retrieved to the surface. After removing the perforating gun, the tubing string may be again lowered and re-engaged with the latch assembly. The latch assembly may be then repositioned below the packer.

Abstract: Cementing plugs for use in the cementing of casing in oil and gas wells. The cementing plugs are well-suited for use with a polycrystalline diamond compact drill bit.

Abstract: A casing packer apparatus includes a mandrel having a mandrel exterior, a longitudinal mandrel bore defined therethrough, and a power port defined in the mandrel communicating the mandrel bore with the mandrel exterior. A packer element is concentrically received about the mandrel. An annular piston is concentrically received about the mandrel and has an annular differential pressure area defined thereon and communicated with the mandrel bore through the power port. The annular piston and packer element are operably associated so that the packer element is set by sliding motion of the piston in response to increased fluid pressure in the mandrel bore. Either a compression set packer element or an inflatable packer element may be utilized.

Abstract: Inflatable devices configured for use particularly in large diameter boreholes and in blasting applications such as vertical cratering, the invention finds utility in blast removal of earth formations wherein the inflatable devices act to suspend explosives and/or stemming materials and the like within a borehole prior to detonation of explosives within said borehole. The inflatable devices are of various shapes and comprise an inner, relatively stretchable inflatable bag enclosed by an outer, relatively non-resilient bag, the inner bag having a valve to allow a fluid such as air to be pumped thereinto with the inner bag expanding to contact inner walls of the outer bag and force the outer bag into contact with walls of the borehole to exert forces against the borehole walls and thus "plug" the borehole at a desired location along the length thereof. Explosive materials and/or stemming materials can thus be suspended at desired locations within the borehole.

Abstract: A well-head (W) having a casing (C) through which a fluid flows. Apparatus (10) for controlling the flow of fluid has an output shaft (14) insertable into a sleeve (18), sleeve (18) being insertable into the casing at its fluid outlet end (E). The sleeve extends from a hub (12) which is placeable into the outlet end of the casing and extends down into the casing. The output/draw shaft (14) extends up through the sleeve, and has a draw nut (34) and a shut-off valve (16). The valve (16) allows fluid flow through the output/draw shaft during installation of the sleeve but shuts off flow thereafter. The sleeve has a circular wall (22), defining a longitudinal bore (24) having an inner diameter (D1) which gradually increases from the upper to the lower end of the sleeve. Circular wall (22) thus has a tapering thickness along the length of the sleeve. The output/draw shaft (14) is inserted up through the sleeve and has a tapered external diameter corresponding to the internal taper of the sleeve.

Abstract: Well apparatuses with device for preventing their relative rotation with respect to adjacent well apparatuses and anti-rotation devices for well apparatuses, including, but not limited to, plugs, float shoes, float collars, jars, and clutch devices for packers. In one embodiment self-aligning non-rotation devices are provided with body members having protrusions extending from recesses therein, the protrusions and recesses configured and disposed so that two opposed devices which initially misalign will co-act to align themselves. In another embodiment an intentional "sloppy fit" is provided between two opposed devices to facilitate device contact and co-action. In various embodiments unwanted separation of two devices is prevented due to the configuration of protrusions.

Abstract: Cementing plugs for use in the cementing of casing in oil and gas wells. The cementing plugs are well-suited for use with a polycrystalline diamond compact drill bit.

Abstract: There is disclosed an assembly of parts for use in cementing a casing string in a well bore comprising a float collar connectible as part of the string, a cement plug lowerable onto the collar, and a wiper plug lowerable onto the cement plug, the lower end of the cement plug having threads for limited make-up with threads on the upper end of the collar and the lower end of the wiper plug having threads for limited make-up with the cement plug, so as to limit rotation between them.

Abstract: In accordance with an illustrative embodiment of the present invention, a positively operable stop collar for providing a bridge in a well casing that prevents reverse flow of cement slurry includes a tubular body having upper and lower stop rings positioned in upper and lower recesses therein, seal rings between the recesses, and a bevel on the upper stop ring that is engaged by an inclined surface on the drive plate of a displacement plug to expand the upper stop ring and allow the drive plate to pass through the upper stop ring and to be locked in engagement with the seal rings.

Abstract: A tubular body containing a sleeve actuated safety valve is attachable to the top end of a hurricane plug. A running tool has a floating nut connection with the tubular body and a tubular extension on the running tool effects the opening of the safety valve while connected to the tubular body. After setting the hurricane plug, the running tool is disconnected from the tubular body by setdown weight, followed by rotation. A retrieving tool has an external threaded section which is threaded through an internal threaded section in the tubular body to engage the actuating sleeve for the safety valve, and effect the opening of the safety valve. Further rotation of the running tool engages the retrieving tool with the tubular body to effect the unsetting of the hurricane plug and permit the removal of the tubular body, hurricane plug and depending tool string from the well by the retrieving tool.

Abstract: An inflatable packing element for an inflatable packer or bridge plug utilized in subterranean wells comprises a tubular elastomeric sleeve which is surrounded by a plurality of circumferentially overlapping flexible metal ribs. The opposite ends of the ribs are respectively welded to an external surface provided on a force transmitting sleeve. The sleeve is provided with a shoulder having an abutting relationship with an internally projecting shoulder provided on the tubular mounting structure for the inflatable element.

Abstract: Well apparatuses with device for preventing their relative rotation with respect to adjacent well apparatuses and anti-rotation devices for well apparatuses, including, but not limited to, plugs, float shoes, float collars, jars, and clutch devices for packers. In one embodiment a non-rotation device has a main member with a recess on which are disposed a plurality of teeth with a load member adjacent the teeth for bearing a load put on the device and for isolating the teeth from the load, the teeth extending beyond the recess. In one embodiment the teeth are configured, disposed, and profiled to facilitate their interengagement with other teeth and to contain between them foreign objects which might impede proper interengagement. In various embodiments plugs are provided with such anti-rotation devices. In various embodiments the load member is a continuous circular ring disposed about the apparatuses outer periphery or around the opening of a channel through the device.

Abstract: A logging plug for suspension on a wireline comprises a hollow body provided with packers for sealing it to a nipple included in a tubing string, and a flow tube through which the line may slide with minimal leakage. A sliding equalizing tube in the lower position shown blocks communication across the packers. When moved upwards by striking it with a hammer or logging tool, communication is allowed via ports in the equalizing tube and in the hollow body, the annular passage around the wireline and an axial bore in the lower part of the hollow body. Any pressure differential across the packers is thus equalized, allowing the logging plug to be easily withdrawn.

Abstract: An easily drillable non-metallic, non-rotating plug set for use in well cementing operations.

Abstract: A geothermal wellhead repair unit including a mechanically set packer to isolate the wellhead for removal and repair thereof. The packer is run into the well string using a running tool. The packer is set by placing tension on the mandrel to set the packing elements and the slip assembly. Once the packer is set, the running tool can be disengaged without fear of collapsing the packer and the wellhead removed for repair or replacement. Upon replacement of the wellhead, the running tool can be used to unset and retrieve the packer.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of exposives into a borehole in order to produce desired blast results acording to the several methods of the invention.

Abstract: An invention relating to method and apparatus for the running of various tools and devices used to service oil and gas wells in combination with coiled tubing units that permits the application of a sudden downward force of predetermined magnitude.

Abstract: Well apparatuses with device for preventing their relative rotation with respect to adjacent well apparatuses and anti-rotation devices for well apparatuses, including, but not limited to, plugs, float shoes, float collars, jars, and clutch devices for packers. In one embodiment a non-rotation device has a main member with a recess on which are disposed a plurality of teeth with a load member adjacent the teeth for bearing a load put on the device and for isolating the teeth from the load, the teeth extending beyond the recess. In one embodiment the teeth are configured, disposed, and profiled to facilitate their interengagement with other teeth and to contain between them foreign objects which might impede proper interengagement. In various embodiments plugs are provided with such anti-rotation devices. In various embodiments the load member is a continuous circular ring disposed about the apparatuses outer periphery or around the opening of a channel through the device.

Abstract: A geothermal wellhead repair unit including a mechanically set packer to isolate the wellhead for removal and repair thereof. The packer is run into the well string using a running tool. The packer is set by placing tension on the mandrel to set the packing elements and the slip assembly. Once the packer is set, the running tool can be disengaged without gear of collapsing the packer and the wellhead removed for repair or replacement. Upon replacement of the wellhead, the running tool can be used to unset and retrieve the packer.

Abstract: A system and a plug for plugging a well conduit. The plug includes a lock mandrel and a valve. There is a prong releasably connected in the plug. A running tool is adapted to releasably connect to the plug lock mandrel and prong. After the plug is lowered into a well conduit and installed in a landing nipple, upward releasing force on the running tool moves the prong upwardly closing the valve and plug to flow and the prong locks in valve closed position. Later, the prong may be disconnected and raised from the plug to surface, permitting pressure outside and inside the plug to equalize for retrival of the plug.

Abstract: A high confidence tube plug for sealing the bore of a tube against fluid flow has an elastomeric sleeve for sealing the tube. An axially aligned hydroscopic disk swells when contacted with water to frictionally grip the tube. The sleeve and the disk are fastened together by a bolt and nut arrangement.

Abstract: An apparatus for setting and retrieving a bridge plug of the type which may be passed through a small diameter tubing, and may be sealed against a relatively large diameter casing by pressured fluid to inflate an elastomeric packing element carried by the bridge plug. The running tool is engagable with a valve housing by a J-slot connection and an axially shiftable, pressure balanced valve plug cooperates with the valve housing to open or close the fluid passageway therethrough extending to the inflatable elastomeric packing element. Upward movement of the running tool followed by left hand rotation effects the closing movement of the valve plug and the disengagement of the running tool. Downward movement of the running tool, while engaged with the valve housing, effects an opening of the plug valve.

Abstract: A retrievable bridge plug and packer apparatus. The tool includes a packer settable by right-hand rotation and vertical manipulation of the tool string and a bridge plug also settable by right-hand rotation and vertical manipulation of the tool string. A disabling tool is provided to disable the packer during setting of the bridge plug so that the packer is not prematurely set. After setting of the bridge plug below the formation, the packer and disabling tool may be disengaged from the bridge plug. At this point, the disabling tool is disengaged so that the packer may be set above the formation. The packer is unset by pulling on the tool string, and the packer and disabling tool may be reconnected to the bridge plug. Again lifting on the tool string unsets the bridge plug so that the apparatus may be retrieved or reused. A method of treating a well formation is also disclosed.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of explosives into a borehole in order to produce desired blast results according to the several methods of the invention.