HYDRODYNAMIC PULSE TOOL

Abstract

A hydrodynamic pulse tool and method for cleaning, stimulation and production enhancement of oil, gas and injection wells by propagating successive pressure waves through the wellbore and/or the producing/injecting formation in a directional or vectored manner. The tool comprises a resonance chamber defined by a generally cylindrical hollow tubular member adapted for connection to conventional coiled or jointed tubing, and at least one hydraulically driven pulse generator rotatably disposed within the resonance chamber. The hydraulic force of pressurized fluid pumped through the tool drives the rotation of the at least one pulse generator, which generates successive sequential hydraulic pressure pulses in a sequential, sequential offsetting and/or sequential reinforcing manner.

Description

TECHNICAL FIELD

The presently described subject matter relates to apparatus and methods for the cleaning, stimulation, and production enhancement of oil, gas and injection wells.

BACKGROUND

Sonic pulse tools that emit pressure waves to vibrate/pulse fluids and solids within the production formation of a petroleum or gas production well are commonly used in the oilfield industry to stimulate production or injection enhancement. Without restriction to a theory, it is believed that the propagation of pressure waves through the production or injection formation may cause the vibration at the molecular level of fluids and solids within the producing/injection zone, and that this in turn assists in the mobilization and production of fluids. Molecular vibration may also result in one or more of the following beneficial effects: repair and removal of naturally occurring or man-made formation damage; suspension of wellbore damage in suspension fluid; removal of scale, filter cake, wax, asphaltenes, bitumen or other materials; increasing reservoir connectivity, injectivity and production; selective enhancement of stimulation fluid; and decreasing viscosity of heavy oil to facilitate mobilization. Sonic pulse tools may also be used to facilitate the cleaning of the wellbore itself, or of individual production, injection or casing string components thereof.

By way of example, U.S. Pat. No. 8,069,914 describes a hydraulic actuated pump system that may include a sonic pulse tool comprising a hydraulic coupling or resonance assembly that generates pulsed pressure waves, which are emitted into a formation production zone through a plurality of jet members. The pressure waves propagate radially outward from the pulse tool through the formation, in some embodiments up to about 12 feet, and together with the venturi effect created by the action of the jet members generate a radial “push/pull” type of positive/negative pressure face at the formation to mobilize production fluids into the wellbore. The wave frequency is determined by the number of pulses per second, which can be used to calculate the wavelength being exerted on the production formation. The pressure or flowrate at which hydraulic fluid is injected through the sonic pulse tool determines the amplitude or power of the pressure waves.

U.S. patent publication no. US 2010/0290313 describes downhole pulse stimulation tools comprising a resonance chamber defining at least one pulse emitting opening, and a pulse generator that is either rotatably disposed within the resonance chamber and directly or indirectly rotated by the wellbore rod string, or that is slidingly disposed within the resonance chamber and directly or indirectly reciprocated by the rod string. The pulse generator defines at least one pulse generating opening that periodically aligns with the at least one pulse emitting opening as the pulse generator cycles within the resonance chamber housing. The fluid pressure within the pulse generator is at a higher pressure than the outside pressure due to pump action, so a pulse of fluid pressure is emitted outward from the resonance chamber with each cycle of the pulse stimulation tool.

As with the sonic pulse tools described in U.S. Pat. No. 8,069,914 and other prior-known pulse stimulation tools, each pressure pulse generated by the pulse stimulation tools of U.S. 2010/0290313 is emitted generally simultaneously through each of the plurality of pulse emitting openings (or jets) that are provided. In some embodiments of U.S. 2010/0290313, paired upper and lower pulse emitting openings generate two sequential pulses for each rotation of the single pulse generator. Nevertheless, in such embodiments, each sequential pulse continues to comprise a simultaneous pulse from each of the upper and lower pluralities of pulse emitting openings.

The pressure waves that are generated within a producing formation by prior-known pulse stimulation tools accordingly propagate outward from the tool in a generally radial “push/pull” positive/negative, but non-directional manner.

SUMMARY

Improvements in the cleaning, stimulation and/or production enhancement of a hydrocarbon production or injection well may be achieved by propagating successive pressure waves through the wellbore and/or the producing/injecting formation in a directional or vectored manner. The presently described subject matter is accordingly directed to hydrodynamic pulse tools and methods that generate sequential hydraulic pressure pulses that propagate pressure waves radially outward along successively different directional vectors. In some embodiments, sequential offsetting and/or reinforcing pressure pulses may also be generated.

In preferred embodiments, a hydrodynamic pulse tool comprises a resonance chamber defined by a generally cylindrical hollow tubular member adapted for connection to conventional coiled or jointed tubing, and at least one hydraulically driven pulse generator rotatably disposed within the resonance chamber. The hydraulic force of pressurized fluid pumped through the tool is employed to drive the rotation of the at least one pulse generator substantially about the longitudinal axis of the tubular resonance chamber.

The inner profile of the generally tubular resonance chamber may in some embodiments define one or more internal flanges or seats for retaining or limiting the longitudinal travel of the at least one pulse generator within the resonance chamber, and in some embodiments these flanges or seats may further include a taper that corresponds with an outside taper of the pulse generator. In some applications, annular bushings or bearings may also be used to facilitate the rotation and/or the longitudinal location of the at least one pulse generator within the resonance chamber.

In preferred embodiments, each of the at least one pulse generators of the tool comprises a generally cylindrical member with a central longitudinal bore. The outside diameter of at least a portion of each pulse generator comprises a zone that is dimensioned for rotational sliding fit within the resonance chamber, and a plurality of tangential jets extend through the annular body of the pulse generator tangentially from the central longitudinal bore surface to the outside radial surface of the pulse generator within the zone. In preferred embodiments, the tangential jets extend in an orientation that is substantially perpendicular to the longitudinal axis of the pulse generator and the tool.

The resonance chamber further comprises a plurality of spaced-apart pulse emitting outlets positioned to correspond with the tangential jets of the pulse generator, and through which pressurized fluid may exit the tool to create a hydraulic pressure pulse. At least one of the tangential jets is in fluid communication with a corresponding one of the plurality of pulse emitting outlets provided in the resonance chamber at any one time. As pressurized fluid passes through a tangential jet that is in fluid communication with a corresponding pulse emitting outlet, fluid pressure acts on a wall surface of the pulse emitting outlet and the reactionary force thereby created causes rotation of the pulse generator. The release of the pressurized fluid through the pulse emitting outlet also creates a pressure pulse that propagates a pressure wave through the wellbore and/or the producing/injection formation.

To sustain the rotational drive of the at least one pulse generator during use, the tangential jets of the pulse generator and the pulse emitting outlets of the resonance chamber are suitably oriented and dimensioned to provide a selected limited degree of overlap, such that fluid communication between a subsequent tangential jet/emitting outlet pairing is initiated just before the rotation of the pulse generator closes off the fluid communication between a current tangential jet/emitting outlet paring. Accordingly, apart from this required but limited overlap, only one tangential jet of each pulse generator (or, in the case of a “multi-level” hydrodynamic pulse tool, one tangential jet of each level—see, below) is substantially in fluid communication with a pulse emitting outlet at any one time. The degree of overlap that may be necessary to sustain rotational drive of the at least one pulse generator is dependent in part upon the pressure and viscosity of the fluid being pumped through the tool. In most embodiments, the cross-sectional dimensions of the pulse emitting outlets are larger than those of the tangential jets.

In order to generate sequential hydraulic pressure pulses that cause the propagation of pressure waves along successively different directional vectors (as opposed to the generally radial “push/pull” positive/negative, but non-directional propagation of pressure waves of prior-known devices) while sustaining rotational drive, in embodiments of the tool that employ a single one-level pulse generator, the resonance chamber comprises at least three pulse emitting outlets and the pulse generator comprises at least four corresponding tangential jets. In such a configuration, which may be designated a “3:4 tool” configuration, each of the three pulse emitting outlets are oriented about the radial periphery of the resonance chamber and spaced apart at roughly 120° intervals relative to the longitudinal axis of the resonance chamber, and each of the four tangential jets are spaced apart at roughly 90° intervals relative to the longitudinal axis of the pulse generator. As the pulse generator is rotated by the hydraulic force of the pressurized fluid, the pressurized fluid is sequentially released through each of the three pulse emitting outlets, thereby generating sequential hydraulic pressure pulses that propagate pressure waves radially outward at 0°, 120° and 240° vectors relative to the longitudinal axis of the tool.

Similar preferred single pulse generator embodiments include “4:5 tool” and “5:6 tool” configurations, in which sequential hydraulic pressure pulses propagate sequential pressure waves radially outward at 0°, 90°, 180° and 270° vectors (in the case of a “4:5 tool”), and at 0°, 72°, 144°, 216° and 288° vectors (in the case of a “5:6 tool”) respectively relative to the longitudinal axis of the tool. Single generator pulse stimulation tools in accordance with embodiments of the present subject matter may theoretically be provided in any ratio of “n” pulse emitting outlets to “n+1” tangential jets, but for tools that are adapted for connection to conventional coiled or jointed tubing, size and manufacturing constraints typically limit the upper ratio to tools with a configuration of about “7:8”.

In other preferred embodiments comprising a single pulse generator, the tangential jets and the corresponding pulse emitting outlets are arranged in two or more discrete levels along the longitudinal axis of the tool to provide a “multi-level” single pulse generator hydrodynamic pulse tool. In one such multi-level tool embodiment, which may be designated a “double 3:4 tool”, the upper level of pulse emitting outlets comprises three outlets that are spaced apart by 120° relative to one another about the longitudinal axis of the resonance chamber and the lower level of pulse emitting outlets similarly comprises three pulse emitting outlets that are also spaced apart by 120° relative to one another about the longitudinal axis of the resonance chamber, but that are out of phase with the outlets of the upper level by about 60°. In combination, this “double-deck” multi-level single pulse generator embodiment accordingly comprises a single pulse emitting outlet at roughly every 60° about the longitudinal axis of the tool. The single pulse generator of this embodiment comprises two sets of four tangential jets, each set of four being spaced apart at 90° intervals relative to the longitudinal axis of the pulse generator (for a total of eight tangential jets, four corresponding to the upper level of pulse emitting outlets and the other four corresponding to the lower level of pulse emitting outlets). The two sets of four tangential jets may be in phase or “aligned”, such that each of the four tangential jets of the upper level is located directly in line longitudinally above a corresponding one of the four tangential jets of the lower level, or the two sets of four tangential jets may alternatively be out of phase by a selected angle such as 60°.

If the two sets of tangential jets of this “double 3:4 tool” embodiment are aligned, then as the pulse generator is driven by the pressurized fluid, the tool will sequentially propagate offsetting pressure waves radially outward along simultaneous 0° and 180°; 120° and 300°; and 60° and 240° vectors relative to the longitudinal axis of the tool. Conversely, if the two sets of tangential jets of this embodiment are out of phase by 60°, then as the pulse generator is driven by the pressurized fluid, the tool will sequentially propagate reinforcing pressure waves along simultaneous 0°, 60°, 180° and 240°; followed by 0°, 120°, 180° and 300°; and then 60°, 120°, 240° and 300° vectors relative to the longitudinal axis of the tool.

As will be readily apparent to those of skill in the art from an appreciation of the present disclosure, numerous other degrees of phase shift or “offset” between the upper and lower levels of pulse emitting outlets and/or between the tangential jets, as well as other tool configurations (such as “double 4:5 tools”, “double 5:6 tools”, etc.) may also be selected to provide further alternate embodiments that generate pressure pulses to propagate pressure waves radially outward along, for example, sequential 0°, 60°, 120°, 180°, 240° and 300° vectors, or along offsetting 0° and 180° vectors alternating with 90° and 270° vectors.

By way of example, in one family of “double-deck” single pulse generator embodiments that may be designated “double 4:5 tools”, the upper level of pulse emitting outlets comprises four outlets that are spaced apart by 90° relative to one another about the longitudinal axis of the tool and the lower level of pulse emitting outlets similarly comprises four pulse emitting outlets that are also spaced apart by 90° relative to one another about the longitudinal axis of the tool. In one such embodiment, the upper and lower sets of pulse emitting outlets are longitudinally aligned so that twin pulse emitting outlets (one upper outlet and one lower outlet) are positioned at every 90° about the longitudinal axis of the tool. The single multi-level pulse generator of this embodiment comprises two sets of five tangential jets, each set of five being spaced apart at 72° intervals relative to the longitudinal axis of the pulse generator (for a total of ten tangential jets, five corresponding to the upper level of pulse emitting outlets and the other five corresponding to the lower level of pulse emitting outlets), and in which the upper and lower sets of tangential jets are either aligned or out of phase by a selected angle such as 45°. It will also be readily apparent to those of skill in the art from an appreciation of the present disclosure that numerous other single multi-level pulse generator embodiments comprising, for example, three or more levels of jets and corresponding outlets (such as “triple 3:4 tools”, “triple 4:5 tools”, “quadruple 4:5 tools”, etc.) may also be provided.

Further alternate embodiments that are within the scope of the presently disclosed subject matter include multiple independent pulse generator embodiments, in which two or more individual pulse generators (as opposed to a single pulse generator) are driven independently or in unison within a single resonance chamber to propagate sequential, offsetting and/or reinforcing pressure waves along successively different directional vectors. Yet further alternate embodiments within the scope of the presently disclosed subject matter comprise multiple independent pulse generators in which two or more individual pulse generators are driven independently or in unison within two or more individual resonance chambers to generate sequential, offsetting and/or reinforcing hydraulic pressure pulses that propagate pressure waves radially outward along successively different directional vectors.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and advantages of the disclosed subject matter, as well as the preferred mode of use thereof, reference should be made to the following detailed description read in conjunction with the accompanying simplified drawings. The drawings are not necessarily to scale, with the emphasis instead being placed upon the principles of the disclosed subject matter. The drawings are intended to be illustrative, and therefore should not be used to limit the scope of the disclosed subject matter. In the following drawings, like reference numerals designate like or similar parts or steps.

FIG. 1 is a schematic perspective view of a hydrodynamic pulse tool in accordance with an embodiment of the presently disclosed subject matter.

FIG. 2 is a front elevational view of the hydrodynamic pulse tool of FIG. 1.

FIG. 3 is a front elevational cage line view of the hydrodynamic pulse tool of FIG. 1.

FIG. 4 is a front elevational cage line view of the pulse generator of the hydrodynamic pulse tool of FIG. 1.

FIG. 5 is schematic perspective view of a hydrodynamic pulse tool in accordance with another embodiment of the presently disclosed subject matter.

FIG. 6 is a front elevational view of the hydrodynamic pulse tool of FIG. 5.

FIG. 7 is a top plan cage line view of a “3:4 tool” hydrodynamic pulse tool in accordance with an embodiment of the presently disclosed subject matter.

FIG. 8 is a top plan cage line view of a “4:5 tool” hydrodynamic pulse tool in accordance with an embodiment of the presently disclosed subject matter.

FIG. 9 is a schematic perspective view of a representative downhole assembly comprising a hydrodynamic pulse tool in accordance with an embodiment of the presently disclosed subject matter.

DETAILED DESCRIPTION

With reference to FIGS. 1 to 4, there is illustrated a hydrodynamic pulse tool 10 in accordance with an embodiment of the presently disclosed subject matter. Pulse tool 10 generally comprises cylindrical hollow resonance chamber 12 having upper 14 and lower 16 ends adapted respectively for connection to conventional coiled or jointed tubing, or other conventional downhole well elements (not shown), such as by conventional threaded connection recognized and accepted in the oilfield industry. Rotatably disposed within resonance chamber 12 is single one-level pulse generator 18. Both the resonance chamber 12 and the pulse generator 18 may be constructed of 4140 steel or other materials suitable for downhole applications, the selection of which is within the ordinary knowledge of those of skill in the art.

Resonance chamber 12 further comprises a plurality of spaced-apart pulse emitting outlets 20 and, in the illustrated embodiment, a lower flange 22 for limiting downward longitudinal travel of pulse generator 18 within the resonance chamber 12. Pulse generator 18 further comprises outside taper 24 for rotational sliding contact with flange 22. In other embodiments, annular bushings or bearings (not shown) may be disposed between flange 22 and outside taper 24.

Pulse generator 18 further comprises zone 26 having an outside diameter dimensioned for rotational sliding fit within the resonance chamber 12, and a central longitudinal bore 28 extending therethrough. A plurality of tangential jets 30, two of which are illustrated in FIG. 1 as tangential gets 30a and 30b respectively, extend through the annular body of the pulse generator 18 tangentially from the surface of central longitudinal bore 28 to the outside radial surface of the pulse generator within the zone 26. As best seen in FIGS. 2 and 3, pulse emitting outlets 20 of resonance chamber 12 have a cross-sectional dimension that is larger than that of tangential jets 30, and are positioned to sequentially correspond with tangential jets 30 as pulse generator 18 rotates within resonance chamber 12.

Pressurized fluid (indicated by arrow A in FIG. 1) is pumped through the hydrodynamic pulse tool 10 to drive the rotation of pulse generator 18 substantially about the longitudinal axis of the resonance chamber 12. As pressurized fluid passes through a given tangential jet 30 that is in fluid communication with a corresponding pulse emitting outlet 20 (as best seen in FIG. 2), fluid pressure acts on a wall surface 32 of the pulse emitting outlet 20 and the reactionary force thereby created causes rotation of the pulse generator 18. The release of the pressurized fluid through the tangential jet 30 and thence through pulse emitting outlet 20 also creates a pressure pulse that propagates a pressure wave through the wellbore and/or the producing/injection formation in the vicinity of hydrodynamic pulse tool 10. The rotational sliding fit between zone 26 of the pulse generator 18 and the resonance chamber 12 substantially prevents bypass of pressurized fluid directly between the cylindrical hollow resonance chamber 12 and the pulse emitting outlets 20.

As best understood with reference to FIGS. 1, 7 and 8, to sustain the rotational drive of the pulse generator 18 during use, tangential jets 30 and pulse emitting outlets 20 are oriented and dimensioned to provide a selected limited degree of overlap, such that fluid communication between a subsequent tangential jet/emitting outlet pairing (30a and 20 respectively in FIG. 1) is initiated just before the rotation of the pulse generator 18 closes off the fluid communication between a current tangential jet/emitting outlet paring (30b and 20 respectively in FIG. 1). Accordingly, apart from this required but limited overlap, only one tangential jet 30 of each pulse generator 18 is substantially in fluid communication with a pulse emitting outlet 20 at any one time. The degree of overlap that may be necessary to sustain rotational drive of pulse generator 18 is dependent in part upon the pressure and viscosity of the fluid being pumped through the tool, and the calculation thereof is within the ordinary skill of those in the art.

FIGS. 1 through 4 illustrate a single one-level pulse generator 18, and FIGS. 5 and 6 illustrate an alternate embodiment comprising a single multi-level pulse generator 40 (discussed in further detail below). In order to generate sequential hydraulic pressure pulses that cause the propagation of pressure waves along successively different directional vectors (as opposed to the generally radial “push/pull” positive/negative, but non-directional propagation of pressure waves of prior-known devices) while sustaining rotational drive of a single one-level pulse generator 18 during use, the resonance chamber 12 comprises at least three pulse emitting outlets 20 and the pulse generator 18 comprises at least four corresponding tangential jets 30. In such a configuration, which may be designated a “3:4 tool” configuration, each of the three pulse emitting outlets 20 are oriented about the radial periphery of the resonance chamber 12 and spaced apart at roughly 120° intervals relative to the longitudinal axis of the resonance chamber 12, and each of the four tangential jets 30 are spaced apart at roughly 90° intervals relative to the longitudinal axis of the pulse generator 18 (see FIG. 7). As the pulse generator 18 is rotated by the hydraulic force of the pressurized fluid, the pressurized fluid is sequentially released through each of the three pulse emitting outlets 20, thereby generating sequential hydraulic pressure pulses that propagate pressure waves radially outward at 0°, 120° and 240° vectors relative to the longitudinal axis of the tool 10.

Referring now to FIG. 8, there are illustrated in top plan cage line view a “4:5 tool” embodiment of a hydrodynamic pulse tool 50 from which sequential hydraulic pressure pulses propagate sequential pressure waves radially outward at 0°, 90°, 180° and 270° vectors. Apart from the number and size of the pulse emitting outlets and tangential jets, the structure of tool 50 is essentially parallel to that of tool 10 described above with reference to FIGS. 1-4 and 7. As seen in FIG. 8, tool 50 comprises resonance chamber 52 having four pulse emitting outlets 54 oriented about the radial periphery of the resonance chamber 52 and spaced apart at roughly 90° intervals relative to the longitudinal axis of the resonance chamber 52. As pulse generator 56 is rotated by the hydraulic force of the pressurized fluid, the pressurized fluid is sequentially released through each of the five tangential jets 58 and the four pulse emitting outlets 54, thereby generating sequential hydraulic pressure pulses that propagate pressure waves radially outward at 0°, 90°, 180° and 270° vectors relative to the longitudinal axis of the tool 50.

Returning again to FIGS. 5 and 6, a multi-level single pulse generator hydrodynamic pulse tool 40 is illustrated. As shown, multi-level single pulse generator tool 40 comprises a resonance chamber 41 with two opposing upper pulse emitting outlets 42 (one shown in FIG. 6), and two opposing lower pulse emitting outlets 43 (both shown in FIG. 5). Opposing pairs of pulse emitting outlets 42 and 43 are out of phase by 90°, so in combination, the illustrated “double-deck” multi-level single pulse generator tool 40 comprises a single pulse emitting outlet at roughly every 90° about the longitudinal axis of the tool 40. As best seen in FIG. 5, tool 40 further comprises pulse generator 44 with three upper tangential jets 45 and three lower tangential jets 46. Each of the three upper tangential jets 45 and each of the three lower tangential jets 46 are spaced apart at roughly 120° intervals relative to the longitudinal axis of the pulse generator 40, and the upper and lower sets of tangential jets 45, 46 are out of phase by roughly 60° such that, in combination, the pulse generator 44 comprises a tangential jet at roughly every 60° about the longitudinal axis of the pulse generator 44. Accordingly, as the pulse generator 44 is driven by the pressurized fluid in use, the tool 40 will sequentially propagate pressure waves radially outward along 0°, 90°; 180° and 270° vectors relative to the longitudinal axis of the tool 40.

FIG. 9 illustrates a schematic perspective view of a representative downhole assembly comprising a hydrodynamic pulse tool in accordance with embodiments of the presently disclosed subject matter. Downhole assembly 60 comprises a hydrodynamic pulse tool 62 that may be constructed in accordance with any of the pulse tool embodiments described above with reference to any of the preceding Figures. However, for ease of reference, pulse tool 62 is described in the following discussion in relation to the embodiment of FIGS. 1-4. Pulse tool 62 is connected such as by conventional thread means at its lower end 16 to a section of cylindrical tube 64, and at the opposite end of tube 64 is similarly connected a tip portion 66 of a conventional well entry guide system that has a bevelled development to allow ease of access into well bores that may have inset or upset applications within the primary well bore itself (such as packer restrictions, profile nipples, etc. . . . ). Cylindrical tube 64 may or may not comprise “reflective focusing chambers” of conventional form and construction to provide an entry/exit point for fluid or fluid/gas, and/or to allow a pulse to enter and respectively exit the reflective focusing chambers.

Pulse tool 62 may similarly be connected such as by conventional thread means at its upper end 14 to a further cylindrical tube 68 that may again comprise reflective focusing chambers of conventional form and construction. If present, these upper reflective focusing chambers are typically oriented in the opposite manner relative to the lower reflective focusing chambers. A conventional jetted top 70 having an angle of declination away from the main central axis of downhole assembly 60 may optionally also be connected to the opposite end of tube 68 and used to facilitate downward thrust while providing for the appropriate removal of solids from around the assembly 60 to be evacuated from the well bore. The entire downhole assembly 60 may be connected such as by thread means to coiled or jointed tubing in a conventional manner.

The present description includes the best presently contemplated mode of carrying out the subject matter disclosed and claimed herein. While specific terminology may have been used herein, other equivalent features and functions are intended to be included. The description is made for the purpose of illustrating the general principles of the subject matter and not be taken in a limiting sense; the claimed subject matter can find utility in a variety of implementations without departing from the scope of the invention made, as will be apparent to those of skill in the art from an understanding of the principles that underlie the invention.

Claims

1. A hydrodynamic pulse tool for generating sequential hydraulic pressure pulses within a production or injection well, the tool comprising:

a generally cylindrical tubular resonance chamber defining at least three annular pulse emitting outlets spaced apart at a regular interval with respect to the longitudinal axis of the resonance chamber; and

at least one pulse generator comprising a cylindrical member with a longitudinal bore, the pulse generator being rotatably disposed within the resonance chamber and further comprising a zone dimensioned for rotational sliding fit within the resonance chamber, the zone extending along at least a portion of the outer diameter of the pulse generator, and at least four tangential jets extending between the longitudinal bore and the outer diameter of the pulse generator within the zone,

wherein the pulse emitting outlets of the resonance chamber and the tangential jets of the pulse generator are suitably dimensioned such one of the tangential jets of the pulse generator is in substantial fluid communication with one of the pulse emitting outlets at any angle of rotation of the pulse generator within the resonance chamber,

and wherein when pressurized fluid is pumped through the longitudinal bore of the pulse generator, said pressurized fluid exiting the pulse generator through the tangential jet that is in fluid communication with one of the pulse emitting outlets and acts on a wall surface of said pulse emitting outlet to cause the rotation of the pulse generator, thereby causing the sequential generation of pressure pulses within the production or injection well.