Abstract: A device for generating pressure waves in a well or a wellbore. The device includes a housing containing an impact-generating mechanism for generating the pressure waves and a connector for connecting the housing to a conveyor for transporting the device to any desired location within the well or the wellbore. The device may be used for a number of downhole applications such as cleaning perforations, fracturing processes, vibration of a casing to prevent fluid flow in a cemented annulus, hydraulic jar operations for freeing stuck downhole objects, generating data to optimize pumping parameters and as an enhancement to percussion drilling techniques.

Abstract: An optical computing device and method for (1) determining and/or monitoring corrosion data in a given environment and (2) evaluating a downhole formation, both being accomplished in real-time by deriving the data from the output of an optical element.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to terminate sampling of fluid into one of a set of fluid sampling chambers sharing a common inflow sampling line by operating a set of closure mechanisms. Further activity may include initiating sampling of the fluid into another one of the set of fluid sampling 5 chambers, wherein the fluid sampling chambers are configured to sample the fluid in the sampling line in a selected sequence, such that filling a prior fluid sampling chamber as part of the sequence enables sampling in the next fluid sampling chamber as part of the sequence, and wherein the closure mechanisms comprise individual check valves 10 and a common diversion valve or individual diversion valves. Additional apparatus, systems, and methods are disclosed.

Abstract: Systems and methods include an extreme range anchor, having extending assemblies configured to engage a wellbore, for providing a self-centering, reusable anchor location within a wellbore. The extending assemblies include a first set of arms connected to a first brace, a second set of arms connected to a second brace, and a set of footplates. Each footplate in the set of footplates is connected to the first set of arms and the second set of arms. Each footplate includes a fixator coupled to a radially external face and configured to securely engage the wellbore. The system also includes a pull rod rigidly coupled to the first brace and slidably connected to the second brace. Forcing the pull rod in an axial direction shortens a distance between the first brace and the second brace and forces the set of footplates to move in a radial direction toward the wellbore.

Abstract: An embodiment of a system for performing a downhole operation includes a carrier having an isolation assembly including at least one packer having a deformable element configured to isolate a section of a borehole in the earth formation, and an injection assembly configured to inject a fluid into the isolated section and pressurize the isolated section. The system also includes a measurement assembly including an interrogation unit coupled to at least one optical fiber having a length disposed at the deformable element that includes a plurality of measurement locations, and a processor configured to receive signals reflected by the plurality of measurement locations in real time during the downhole operation, calculate an amount of deformation of the deformable packer element, and estimate at least one property of the formation based on the deformation, the at least one property including a strain of the formation in response to injection of fluid.

Abstract: A swellable packer which includes a generally tubular mandrel having a central axis and an exterior cylindrical surface. The swellable packer further includes a swellable elastomeric body fixed to the exterior cylindrical surface of the mandrel, wherein the swellable elastomeric body includes a plurality of grooves and wherein the generally tubular elastomeric sleeve has a circumference and a thickness.

Abstract: A downhole tool, e.g., a plunger, and a method for manufacturing a plunger. The downhole tool includes a mandrel including a flow-restriction recess, and a plurality of sealing pads configured to be disposed around the mandrel, biased radially-outward therefrom, and interlocked with one another. Each of the plurality of sealing pads includes a flow-restriction tab having an axial thickness that varies as proceeding circumferentially around the mandrel. The flow-restriction tab of each of the plurality of sealing pads is configured to be disposed in the flow-restriction recess when the plurality of sealing pads are disposed on the mandrel.

Abstract: A family of organic tracers is proposed for inter-well measurement of residual oil in petroleum reservoirs, as is their use as partitioning tracers in a petroleum reservoir. The tracers consist of at least one benzyl alcohol of formula i) wherein each of R1 to R5 is independently selected from H, F, CI, Br, I, CF3 CF2CI, CFCI2 and CCI3 and wherein at least one of R1 to R5 is not H.

Abstract: The present invention relates to a barrier testing method for testing a production casing in a borehole (4).

Abstract: Adaptive stimulation systems combine impulse-generated swept-frequency stimulation vibration with cyclically-varying hydraulic pressure to provide adaptive down-hole stimulation. Swept-frequency stimulation vibration arises from cyclical shifts of the power spectral density (PSD) of each stimulator's vibration (via closed-loop control of rebound cycle time). PSD's are adjusted for resonance excitation, fracturing and/or analysis of geologic materials at varying distances from a wellbore. And closed-loop control incorporates backscatter vibration from stimulated geologic material. Stimulators can be arranged singly or in spatial arrays of multiple stimulators, each stimulator generating vibration in bursts comprising a plurality of vibration frequencies. Timed signals from a programmable controller affect directional propagation of combined vibration wave fronts from a stimulator array. As fracturing proceeds to smaller (e.g.

Abstract: Optimized blending mode for mineralogy images. A luminosity value is determined for a pixel in a base layer or top layer mineralogy image. An image weighting value is determined from the luminosity value and an optional mixing parameter. A multiply value is determined by multiplying the base and top layer pixel values. An overlay value is determined from twice the multiply value if the value of one of the base layer or top layer pixel values is over a threshold, otherwise it is determined by inverting twice the product of the inverted top layer pixel value with the inverted base layer pixel value. A blended image pixel value is determined by adding the multiply value weighted with the image weighting value and the overlay value weighted with the inverted image weighting value.

Abstract: A formation tester tool can include a longitudinal probe drill collar having a surface, a formation probe assembly located within the probe drill collar, the formation probe assembly including a piston reciprocal between a retracted position and an extended position beyond the probe drill collar surface, the piston being slidingly retained within a chamber, a seal pad located at an end of the piston, the seal pad including an outer surface defining a partial cylindrical surface. The piston includes an outer surface having non-circular cross-sectional shape and the chamber includes an inner surface having a non-circular shape similar to the shape of the piston outer surface. The formation tester tool can include interchangeable draw down assemblies and a flow bore having a curving path.

Abstract: Systems and methods for restricting fluid flow in a casing conduit, including a wellbore that extends within a subterranean formation, a casing string that extends within the wellbore and defines a portion of the casing conduit, a plurality of motion-arresting structures that project from an inner surface of the casing string to define a plurality of reduced-area regions of the casing conduit, and an autonomous sealing device that defines a contracted configuration and an expanded configuration. The methods include conveying the autonomous sealing device through the casing conduit, determining that the autonomous sealing device is located within a target portion of the casing conduit, expanding the autonomous sealing device to the expanded configuration, retaining the autonomous sealing device on a selected motion-arresting structure, and restricting fluid flow within the casing conduit with the autonomous sealing device.

Abstract: Sealing devices for use in a wellbore to seal a leak path through an inner wall surface of the wellbore comprise a mandrel, an expandable element, and a shape deforming sealing element. Expansion or inflation of the expandable element moves the shape deforming sealing element from its run-in shape to its set shape. A stimulus, such as a change in temperature, acts upon the shape deforming sealing element facilitating the shape deforming sealing element changing shape. Removal of the stimulus causes the shape deforming sealing element to remain in the set shape. Thereafter, the mandrel and expandable element can be removed to leave only the shape deforming sealing element within the wellbore to seal the leak path.

Abstract: A packer system including a packer and a setting mechanism. The setting mechanism has a setting piston that is actuatable in response to a fluid pressure in order to set the packer with the setting piston. The setting mechanism prevents actuation of the setting piston until the pressure is decreased below a threshold pressure from a value greater than the threshold pressure. A method of setting a packer is also included.

Abstract: An annular fluid containment device includes a mandrel, and packing assembly disposed about the mandrel to form a seal between the mandrel and the well casing. A sleeve disposed within the mandrel defines a space between the mandrel and the sleeve. Seals are disposed between the mandrel and sleeve at upper and lower ends, wherein the upper seal is located above a location of the packing assembly, and the lower seal is located below the packing assembly. Upper and lower passages are defined in the wall of the mandrel, in communication with the annular space, wherein the upper fluid passage is located above the packing assembly and below the upper seal, while the lower fluid is located below the position of the packing assembly and above the lower seal. Hence, a fluid passage is formed bypassing the packing assembly within the mandrel.

Abstract: A system and a method are disclosed herein that relate to powering a pumping system within a downhole tool. The system may include a turbine having a shaft extending therefrom, in which the turbine is configured to convert energy from a fluid received therein into rotational energy for the shaft. The system may further include a pumping system coupled to the shaft of the turbine, in which the pumping system includes one or more driving devices coupled to one or more displacement units. The displacement units may have a cavity formed therein, in which the cavity is configured to receive a fluid therein. The driving devices may then be configured to drive the displacement units such that the fluid is received within the cavity of the displacement units.

Abstract: The techniques herein relate to a probe for forming a seal between a downhole tool and a wall of a wellbore. The probe includes a probe inlet extending from the downhole tool for fluid communication with a subterranean formation, a base positionable about the downhole tool about the probe inlet, a packer positionable on the base for forming a seal with the wellbore wall, and a raised packer support and/or packer stopper for supporting the packer as the packer is compressed against the wellbore wall. The packer may have an inlet channel extending therethrough for receiving the probe inlet. The raised packer support can extend from the base for supporting the packer, and the packer may have a support channel extending a distance therein for receiving the raised packer support. The packer stopper can extend from the base about a perimeter of the packer with an expansion gap defined therebetween.

Abstract: An expandable packer tool comprising a mandrel tool body; a sleeve-like packer element mounted on the tool body; and a setting mechanism that is operable to axially compress the packer element such that the diameter of the packer element in its compressed state is increased compared to it uncompressed state. An extrusion barrier can comprise a ring of seal elements disposed around the tool body on either side of the packer element, and arranged to engage the packer element so that expansion of the packer element causes the ring of seal elements to expand in a corresponding manner so as to form an extrusion barrier; wherein the ring of seal elements comprises wedge-shaped seal members comprising first seal members having a inner base wider than an outer surface, and second seal members having an inner base narrower than an outer surface, the ring comprising alternating first and second members, the inclined faces of each wedge-shaped member engaging the corresponding faces of adjacent members.

Abstract: A downhole seal element (10) comprises a cup portion (11) formed of or including a resiliently deformable material. The cup portion (11) extends between on the one hand a nose part (12) comprising an annulus intended for sealingly mounting the seal element on a mandrel (22) and on the other hand a skirt (13), the seal element flaring in shape between the nose part (12) and the skirt (13). The skirt includes extending therefrom away from the nose part (12) a plurality of elongate, flexible limbs (18) that are spaced at intervals about the skirt (13).

Abstract: Methods and mechanisms for fluid sealing are provided. The disclosed mechanisms include a tool having a cavity configured to form a toroidal vortex and a fluid sealing element to induce an azimuthal variation of the toroidal vortex (a “dynamic seal”). The fluid sealing element may include a sharp change in the axial symmetry of the cavity to induce the azimuthal variation. Some exemplary shapes of the fluid sealing element may include a notch in a cavity, a step shaped cavity, or an angular cavity in the tool. Methods for manufacturing such a dynamic seal is also provided as well as methods for producing hydrocarbons with a plunger having the dynamic seals. The tool may be a plunger, a pig, an in-flow control device, or other cylindrical device traveling through a conduit or tubular member.

Abstract: An in situ method deploy and/or plasticize a shape-memory material in order to change the material's physical dimensions and/or mechanical properties, including a method for deploying a shape-memory polymer having a deformed or compressed shape in an environment at a first temperature, the shape memory polymer having a first glass transition temperature which is greater than the first temperature. The method also includes decreasing the glass transition temperature of shape memory polymer from the first glass transition temperature to a second glass transition temperature which is less than or equal to the first temperature; and expanding the shape memory polymer to deploy the shape memory polymer in a deployed shape.

Abstract: Embodiments of the present invention generally relate to a method and/or apparatus for deploying wireline tools with a non-electric string. In one embodiment, a method of determining a free point of a tubular string stuck in a wellbore includes deploying a tool string in the stuck tubular with a non-electric string. The free point assembly includes a battery, a controller, and a free point tool. The method further includes activating the free point tool by the controller. The free point tool contacts an inner surface of the stuck tubular string. The method further includes applying a tensile force and/or torque to the stuck tubular string; and measuring a response of the tubular string with the free point tool.

Abstract: In one embodiment, an apparatus includes a base plate having a first aperture to receive an inlet in fluid communication with a downhole tool; a compliant outer cover having a first end terminating at the base plate and a second end terminating adjacent a forward opening of the inlet, the compliant outer cover having a first surface configured to engage a borehole wall and a second surface forming an inner cavity with the base plate; and a core disposed within the inner cavity and having a second aperture forming at least a portion of the inlet, wherein the outer cover comprises a first material and the core comprises a second material more compliant than the first material.

Abstract: A fracture plug seat assembly used in well stimulation for engaging and creating a seal when a plug, such as a ball, is dropped into a wellbore and landed on the fracture plug seat assembly for isolating fracture zones in a well. The fracture plug seat assembly has a fracture plug seat that includes elastomeric material and reinforcing material.

Abstract: A downhole element to isolate or complete a wellbore includes a shape memory material including polyphenylene sulfide. The polyphenylene sulfide is the cure product of being cured at a temperature of about 200° C. to about 400° C., for a total time of less than or equal to 200 hours. The shape memory material is thermally activated between an actuated and unactuated shape, and the polyphenylene sulfide in the shape memory material is a closed cell foam, open cell foam, or solid.

Abstract: The invention relates to a device (100) for moving in a tubular channel (199) comprising two gripping means (101) fluidly connected via a pump (400); wherein a first (G1) of the two gripping means comprises a fluid; wherein the pump is adapted to inflate a second (G2) of the gripping means by pumping the fluid from the first of the two gripping means to the second of the two gripping means; and wherein the gripping means comprises a flexible member (201) contained in a woven member (202), wherein the flexible member provides fluid-tightness and the woven member provides the shape of the gripping means.

Abstract: A pump apparatus for recovering hydrocarbons from downhole wells, having a seating surface adapted to sealingly engage an interior surface of a circumferential seal member situated within production tubing when said pump is in a downhole operative position. An isolation plug is provided, releasably coupled to a lower end of said pump, having sealing means thereon to sealingly engage said interior surface of said circumferential seal member when the isolation plug is linearly positioned within said circumferential seal member and decoupled from the pump assembly, thereby preventing gases and fluids from fluid communication to surface when the pump is raised and removed from the well. A method for sealing a well upon removal of a pump is further disclosed.

Abstract: A technique provides an electric submersible pumping system to facilitate a well treatment, such as a hydraulic fracturing well treatment. The electric submersible pumping system is positioned downhole and oriented to intake a fluid delivered downhole for use in the well treatment. Once the fluid is delivered downhole, the electric submersible pumping system pumps, pressurizes and discharges this fluid to perform the well treatment, e.g. the hydraulic fracturing treatment. The pumping system reduces the pressure at which the treatment fluid must be delivered downhole.

Abstract: According to the present invention, there is provided a well pumping system comprising a length of coiled tubing extending to the surface of the well, a first electric pump, a first electric motor, and a sealing means that seals against the side of the well. The sealing means include a first fluid path through which coiled tubing is in fluid communication with the well beneath the sealing means, and a second fluid path through which first electric pump is in fluid communication with the well beneath the sealing means.

Abstract: A hydraulic packer including a chamber and at least one piston that slides down inside said chamber. The entire hydraulic packer is made of a steel material and a glass-fiber composition including glass-fiber 30%, resin 60%, and epoxi with accelerator 10%.

Abstract: Embodiments of the present invention generally relate to a method and/or apparatus for deploying wireline tools with a non-electric string. In one embodiment, a method of determining a free point of a tubular string stuck in a wellbore includes deploying a tool string in the stuck tubular with a non-electric string. The free point assembly includes a battery, a controller, and a free point tool. The method further includes activating the free point tool by the controller. The free point tool contacts an inner surface of the stuck tubular string. The method further includes applying a tensile force and/or torque to the stuck tubular string; and measuring a response of the tubular string with the free point tool.

Abstract: The invention relates to an arrangement for positively pumping liquids to the surface of a hydrocarbon well where the hydrocarbon well has bee previously completed with a permanent packer and tailpipe. A rod pump having a plunger connected to a hollow rod string can positively pump the liquids collecting at the bottom of the well while the natural gas is produced up the annulus between the production tubing and the hollow rod string. In this invention, the tail pipe is perforated above the rod pump and below the packer to all the natural gas into the production tubing.

Abstract: The invention comprises a device for expanding tubular members to a controlled diameter and its method of fabrication. The device includes an expandable bladder held in a convoluted form. After the device is inserted into a cylindrical tube to be evenly expanded, the bladder is expanded by hydraulic pressure to a controlled maximum diameter. It is then deflated so the device can then be moved to another location and reused. The bladder is formed from a flexible impervious material having integral reinforcing fibers. It is initially formed in a fully expanded configuration over a convoluted mandrel and a removable cylindrical shell. When the shell is removed vacuum or external pressure draws the bladder against the mandrel. The bladder is overmolded with a resilient cover to hold it in reduced form until pressurized. The bladder cover prevents the bladder from kinking during the expansion.

Abstract: Well jet enables forming, via jet pump, range of different depressions in well tail area at specified differential pressure value. Logging instrument enables recording well and pumped out medium physical parameters. Well operating modes are adjusted by spring-loaded stepped piston positioned in seal unit body so as to open and close holes. Return valves in pumped out and active media supply channels, combined with stepped through channel, of diameter equal to or greater than diameter of the axial through hole of a packer and which is made in the pump body below a mounting seat, enable supplying chemical reagents along a pipe string to a production formation without additional units and prevent media pumped to the production formation, from annular above-packer space penetration. Said invention enables increasing reliability and performance by preventing active medium backflow and by maintaining the depression produced on the formation when the jet pump is stopped.

Abstract: A fitting arrangement and method of securing a fitting arrangement to a surface is provided. A plurality of adjacent fittings is coupled to and extends from a mounting surface of a structure in a well bore. Each fitting has an engagement surface that is configured to engage with an installation tool for coupling the fitting to the structure. The engagement surfaces of the adjacent fittings in the plurality are offset from each other to thereby define a clearance for the installation tool.

Abstract: A jet pump mounted on a pipe string and a packer, and a through channel with a sealing unit having a logging cable channel is in the pump body. A check valve is in a channel, for supplying a medium pumped out from a well, at the input thereof in the lower body. A guiding bush with a movable rod, arranged parallel to the logging cable, is fixed to the body under the valve. The top of the rod is positioned under the check valve closing element and a fork, over which the logging cable passes, fastens to the lower end of the rod. The closing element can be pressed out from a seat and brought into contact with the fork while a downhole instrument is lifted. The invention extends functionality by isolating pipe string spaces above and under the jet pump when the instrument is below the pump.

Abstract: A jet pump and packer. The pump body comprises nozzle and mixing chamber with diffuser, coaxially arranged therein, and a stepped through channel therein, tapers from the top downward and is provided with a seat between steps. The channel is made coaxially with a pipe string and coupled thereto. Channels for supplying pumped from the well and active media is provided with return valve and restrictor for limiting locking member displacement of the return valve upward respective to the seat thereof. A sealing unit being a hollow stepped body with sealing element can be arranged in the through channel. An axial channel for passing a rigid logging cable with well-logging instrument is made in the sealing element. A guiding separation bush cantilever fitted by the top end thereof to the top part of the body of the pump mounts above the channel axially thereto in the pump body. Longitudinal slotted orifices are made in the separation bush wall.

Abstract: The invention relates to device for controlling an inflatable tool used to treat a well or pipeline. The device, which is inserted between the outlet of a fluid supply pipe and the tool, comprises: a chamber communicating with the exterior through a tube and with the tool via a pipeline; and a piston mounted in said chamber, which, under the force of a spring, normally occupies a first position in which it seals the outlet of the pipe, the aforementioned tube then communicating with the pipeline. The pipeline is provided with at least one spring-loaded check valve which allows the passage of the pressurised fluid from the chamber to the tool when the pressure upstream of the valve exceeds a predetermined threshold value, which prevents the passage of the fluid in the opposite direction.

Abstract: Example methods and apparatus to perform stress testing of geological formations are disclosed. A disclosed example downhole stress test tool for pressure testing a geological formation comprises first and second packers selectively inflatable to form an annular region around the tool, a container configured to store a fracturing fluid, wherein the fracturing fluid is different than a formation fluid and a drilling fluid, a pump configured to pump the fracturing fluid into the first and second packers to inflate the first and second packers and to pump the fracturing fluid into the annular region to induce a fracture of the geological formation, and a sensor configured to detect a pressure of the fracturing fluid pumped into the annular region corresponding to the fracture of the geological formation.

Abstract: A flow control packer (FCP) includes a packer mandrel, and an inflatable element fixedly attached at each end to the mandrel. The inflatable element includes circumferential grooves and flow control grooves formed on an outside surface thereof configured to press against the inside diameter of a conduit to provide a flow resistant surface for controlling the flow rate of a fluid through the conduit. A system can include one or more flow control packers (FCP) configured to control fluid flow through different sections of the conduit.

Abstract: The invention concerns a system or a method for maintaining zonal isolation in a wellbore. According to the invention, the system comprises, at a specific location along said wellbore, a sealing element, said sealing element being able to deform both during and after placement and is maintained after placement under compression through a pressurizing fluid or by confinement in a volume.

Abstract: Redistribution of fluids present in well bore environments is disclosed. In some embodiments, the invention may be the redistribution of water produced in a coal bed methane well. The redistribution of water from one aquifer (27) to another aquifer in accordance with the present invention is also disclosed. Furthermore, the injection of a reservoir formation (39) with water, and in some embodiments as a flood of the reservoir formation, in accordance with the present invention is also disclosed. Each of the embodiments of the present invention is disclosed as methods and processes as well as one or more device or apparatus. Such processes and tools may avoid the requirement for surface discharge of water produced in a well bore and may minimize the regulatory costs associated with such water handling. Methods of compliance, water disposal, aquifer recharge, transfer of water from one aquifer to another, and obtaining a permit are also disclosed.

Abstract: A resettable antiextrusion system including a backup ring, a ramp in operable communication with the backup ring, and a gauge ring attached to the ramp. A method for sealing a tubular.

Abstract: A plug member can be mounted to the end of a pipe and removed therefrom by automated operation. A mounting and dismounting device 21 for mounting and dismounting a plug member 11 with respect to an oil country tubular good P. The plug member 11 comprises an outer tube 12 having seal portions 16a and 16b and a circumferential groove 12a, a shuttle 13, a cap 14, and a shuttle biasing spring 15 secured to the cap 14 and the shuttle 13. The mounting and dismounting device 21 comprises a tubular holding body 22, a rod 23 which has a conical end portion 23a and which is disposed so as to move inside the tubular holding body 22, and moving means 24 and 25 which allow the tubular holding body 22 and the rod 23 to independently move. The tubular holding body 22 has ball-receiving holes 22a into which fit balls 26 which engage with the circumferential groove 12a.

Abstract: A fitting arrangement and method of securing a fitting arrangement to a surface is provided. A plurality of adjacent fittings is coupled to and extends from a mounting surface of a structure in a well bore. Each fitting has an engagement surface that is configured to engage with an installation tool for coupling the fitting to the structure. The engagement surfaces of the adjacent fittings in the plurality are offset from each other to thereby define a clearance for the installation tool.

Abstract: The model consists of a hydraulic packer constructed in glass-fiber reinforced epoxy and stainless steel which has been developed and designed with wholly corrosion resistant material, being constructed with 70% glass-fiber reinforced epoxy and 30% stainless chromium steel. It has a larger area of packing and seal. It works with low driving pressure. Its hydraulic chamber achieves a greater packing force at normal pressure. It can be used in wells with tubing made of glass-fiber reinforced epoxy. It has a double anchorage system and a jack system.

Abstract: A flow control system includes a pump positioned in a wellbore to remove liquid from the wellbore. An isolation device is positioned downhole of the pump and is expandable within the wellbore between a sealed position and an unsealed position. The isolation device in the sealed position substantially reduces gas flow at the pump during removal of the liquid.

Abstract: An apparatus and method of forming a barrier to fluid flow behind a liner are provided. In one embodiment of the invention, a method includes the steps of conveying a tool to a position within a wellbore having a liner, the tool carrying a seal material, and injecting the seal material from the tool through the liner to form a barrier to fluid flow behind the liner. In another embodiment of the invention, the apparatus includes a housing having a chamber carrying a seal material, and a means for injecting the seal material through the wellbore liner.

Abstract: In pumping engineering, the inventive device comprises a ring provided with a sealing unit arranged on a casing string and smooth pipe column. The pump body has a channel supplying an active medium, a channel supplying an active medium pumped out of the well and a stepped through channel such that it is possible to mount therein a blocking insert which closes the active medium supply channel or a depression insert whose mounting cuts off the cross section of the pipe column. A logging device is arranged on the lower end of the pipe column, a sealing unit is put on said pipe column between said logging device and the jet pump such that it is axially offsetable with respect to the pipe column, the lower section of the pipe column above the logging device is embodied such that is perforated.