Fluid Pulse Apparatus

Abstract

A fluid pulse apparatus for down hole drilling having a turbine assembly actuated by a flow of drilling fluid. The apparatus has a narrowed fluid flow section that cooperates with a piston that moves between an open a fluid flow restricting position. The apparatus has a turbine assembly that rotates in response to a flow of drilling fluid. The turbine apparatus has upper and lower cam followers that cooperate with fixed cam surface such that rotation of the turbine assembly and cam action between the cam followers and the fixed cam surface causes the turbine assembly to reciprocate axially. The piston is fixed to either of the upper or the lower turbine surface such that as the turbine assembly reciprocates axially, the piston moves between the open and the flow restricting positions to create a pulsed fluid flow.

Claims

1. A fluid pulse apparatus for down hole drilling, comprising; a housing defining a fluid flow passage for a flow of drilling fluid from an upstream end towards a downstream end; a turbine assembly within the fluid flow passage, the turbine assembly having an upstream annular cam follower and a downstream annular cam follower, at least one turbine sleeve that is operatively connected to the upstream annular cam follower and the downstream annular cam follower and is actuated by the flow of drilling fluid so as to cause rotation of the turbine assembly and a piston fixed to the upstream turbine surface; the fluid flow passage has a narrowed fluid flow passage upstream of the turbine assembly such that the piston is receivable within the narrowed fluid flow passage; at least one upstream cam surface fixed to the housing for cooperation with the upstream annular cam follower and at least one downstream cam surface fixed to the housing for cooperation with the downstream annular cam follower; such that when the turbine assembly is caused to rotate, there is a cam action between the upstream cam follower(s) and the upstream annular cam surface and between the downstream cam follower(s) and the downstream annular cam surface that causes the turbine assembly to reciprocate axially within the fluid flow passage such that the piston moves axially between a flow restricting position within the narrowed fluid flow passage and an open position to effect periodic restriction of the flow of drilling fluid through the fluid flow passage.

2. The apparatus of claim 1, wherein there is a single turbine member that is an Archimedes screw.

3. The apparatus of claim 1, wherein the upstream and downstream cam surface can be changed with another cam surface profile.

4. The apparatus of claims 1, wherein the turbine assembly includes a turbine sleeve and outer edges of the at least one turbine blade member(s) are fixed to the turbine sleeve.

5. The apparatus of claim 1, to wherein, a symmetrical cam force is applied to the upstream annular cam surface by the at least one upstream follower and a symmetrical cam force is applied to the downstream annular cam surface by at least one downstream follower.

6. The apparatus of claim 1, wherein the narrowed fluid flow passage includes a plate with an orifice.

7. The apparatus of claim 1, wherein the narrowed fluid flow passage includes a plate with an orifice that has an extended opening over a portion of the fluid flow passage wall.

8. The apparatus of claims 6, wherein the plate is adapted so that it can be removed and replaced with a plate with an orifice of a different size.

9. The apparatus of claim 1, wherein the piston is adapted for replacement with a piston of different dimensions.

10. The apparatus of claim 1, wherein the piston has a tapered head.

11. The apparatus of claim 1, wherein the piston has a tapered head across itself so that fluid is directed to exit to the side of the piston.

12. A fluid pulse drilling tool for downhole drilling comprising the fluid pulse apparatus of claim 1.

13. An assembly for delivering a percussive effect in a down hole drill string; the assembly including the fluid pulse apparatus of claim 1 and a fluid actuated pressure pulse response device that is actuated in response to the fluid pulse generated by the fluid pulse apparatus.

14. The assembly of claim 13, wherein the fluid actuated pressure pulse responsive device is located upstream of the fluid pulse apparatus.

15. The assembly of claim 13, wherein the fluid actuated pressure pulse responsive device is located downstream of the fluid pulse apparatus.

16. A method of drilling comprising operatively connecting the fluid pulse apparatus of claims 1 to a drill string and operating said drill string in a down hole mode.

17. A method of drilling comprising operatively connecting the assembly of claim 13 to a drill string and operating said drill string in a down hole mode.

18. A fluid pulse apparatus adapted to be connected to a pipe line, the apparatus comprising; a housing defining a fluid flow passage for a flow of fluid from an upstream end towards a downstream end; a turbine assembly within the fluid flow passage, the turbine assembly having an upstream annular cam follower and a downstream annular cam follower; at least one turbine member that is operatively connected to the upstream annular cam follower and the downstream annular cam follower and that is actuated by a flow of drilling fluid in the fluid flow passage so as to cause rotation turbine assembly; a piston fixed to the upstream turbine surface or the downstream turbine surface; the fluid flow passage has a narrowed fluid flow passage section located upstream of the turbine assembly when the piston is fixed to the upstream turbine surface such that the piston is receivable within the narrowed fluid flow passage or the narrowed fluid flow passage is located downstream of the turbine assembly when the piston is fixed to the downstream turbine surface such that the piston is receivable within the narrowed fluid flow passage; at least one upstream cam surface fixed to the housing for cooperation with the upstream annular cam follower and at least one downstream cam surface fixed to the housing for cooperation with the downstream annular cam follower; such that when the turbine assembly is caused to rotate, there is a cam action between the upstream follower(s) and the upstream annular cam surface and between the downstream cam follower(s) and the downstream annular cam surface that causes the turbine assembly to reciprocate axially within the fluid flow passage such that the piston moves between a flow restricting position within the narrowed fluid flow passage and an open position to effect periodic flow restriction of the flow of fluid through the fluid flow.

19. The assembly of claim 13, wherein a piston is tapered across itself so as to provide a restrictive fluid flow passage on one side of the piston and an unrestricted flow passage on the opposite side of the piston; the fluid flow passage has an extension of the opening of the fluid flow passage within its wall; the piston fluid flow passage and the fluid extension opening of the fluid flow passage are aligned so that a closed position is achieved when the cam follower is in the high point position of the cam; wherein as the cam follower rotates around to the low point position of the cam, the piston fluid flow passage will rotate 180 and axially be lifted so that the piston fluid passage and the fluid flow passage opening are completely mis-aligned; and the piston rotates around an additional 180 enabling the piston to return to the aligned open position.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0091] FIG. 1 is a schematic view of the lower end of a drill string;

[0092] FIG. 2 is a schematic cross sectional view of an apparatus of one aspect;

[0093] FIG. 3 is a schematic cross section of the upper section of the aspect shown in FIG. 2;

[0094] FIG. 4 is a schematic cross section of the lower section of the aspect shown in FIG. 2

[0095] FIG. 5a is a schematic of the piston in the closed position;

[0096] FIG. 5b is a schematic view of the piston in the open position;

[0097] FIG. 6 is a schematic cross sectional view of an apparatus of a further aspect; shown in FIG. 2;

[0098] FIG. 7 is a graph showing pulse pressure as a function of time as generated by an apparatus of the present disclosure and

[0099] FIG. 8 is a further graph showing pulse pressure as a function of time generated by an alternate configuration of an apparatus of the present disclosure.

[0100] FIG. 9a is a schematic of the piston fluid flow passage in the open position;

[0101] FIG. 9b is a schematic of the piston fluid flow passage in the closed position.

[0102] FIG. 10 is a schematic of the cam profile high position and low position.

DETAILED DESCRIPTION OF THE FIGURES

[0103] FIG. 1 is a schematic view of the lower end of a drill string 8 that includes a fluid pulse apparatus 7 of the present invention. The drill string 8 includes a conventional drill string component 2 that may be a drill collar, a drill pipe, a down hole mud motor or a measurement while drilling tool or a shock tool.

[0104] FIG. 1 shows the Fluid pulse apparatus connected to the drilling tubular via 1 and 6. 1 is the top of the tool where the fluid enters into the fluid pulse apparatus (upstream end). 6 is where the fluid exits the fluid pulse apparatus (downstream end).

[0105] The fluid pulse apparatus 7 comprises a housing with an upper sub 3 connected to a lower main body sub 4. The housing defines a fluid flow passage for a flow of drilling fluid from an upstream end towards a downstream end 5.

[0106] The main body sub 4 is connected to a lower drill string component 6 that can also be any conventional down hole drilling component such as that may be a drill collar, a drill pipe, a down hole mud motor, shock tool or a measurement while drilling tool but not limited to.

[0107] FIG. 2 shows a schematic cross section of the fluid pulse apparatus 7, with FIGS. 3 and 4 showing details of the upper and lower sections respectively.

[0108] The upper sub 3 is connected to the lower main sub 4 through threaded connection 10. The upper sub 3 has a bore 9 defining a fluid flow passage. A bore restriction or narrowed fluid flow section 11 is located at the downstream end of the bore 9.

[0109] An orifice plate 21 inserted into the downstream end of the connection 10 downstream of the bore restriction 11.

[0110] FIG. 2 illustrates a cut away of the tool.

[0111] FIGS. 2 and 3 show that the flow from the bore restriction 11 through the orifice 21a of the orifice plate 21 is restricted by the head 12 of a piston 13. The piston 13 is moveable between an open position (shown in detail in FIG. 5b) in which there is no fluid flow restriction through the bore restriction 11 and a fluid restricting position (shown in detail in FIG. 5a). As can be seen in FIG. 5a, the fluid flow is not restricted completely as this will cause the turbine to stall, as will be discussed further below.

[0112] FIGS. 5a and FIG. 5b show a close up view of FIG. 3. The piston (13) travels up and down into the orifice (11) and then back out which causes a tight restriction of the fluid passage in the up position and then a loose open restriction when the piston goes back down. In turn, the fluid will have high pressure in the up position and low pressure in the down position. By adjusting the internal diameter of the orifice 11 and the outside diameter of the piston 13, the fluid pressure (pressure pulse) can be manipulated to be higher or lower. This is shown in FIGS. 7 and 8 wherein pressure is measured in PSI.

[0113] The orifice plate 21 can be readily replaced with a plate having a different sized orifice. In this way, the apparatus can be adapted for different flow rates, fluid types and mud types.

[0114] The head 12 of the piston 13 piston is designed to have a taper so as to reduce the downward hydraulic force exerted on the piston 12 so as to reduce the torque required for rotation of the turbine.

[0115] The main body sub 4 has a radial bushing 20 pressed into the inner diameter. A shaft less helical screw or Archimedes screw 16 is mounted within the main body sub 4 for rotation.

[0116] The outer edges of the screw 16 are fixed to a turbine sleeve 17. The turbine sleeve 17 is fitted into the bushing 20 with a clearance.

[0117] The upstream and downstream ends of the turbine sleeve 17 are defined by respective cam followers 14, 18.

[0118] Opposed cam profiles 15, 19; are attached to main body 4 with threaded pins 22, 23, 24, 25 through the outer walls of the main body and project inwardly into the main body 4 to lock the opposed cam profiles 15, 19.

[0119] The upper and lower cam surfaces 15, 19 are in contact with the cam followers 14, 18; and the sleeve 17 is thereby supported by the lower cam follower 18.

[0120] In use the fluid flows into the main sub body 4 and causes the screw 16 to rotate as per conventional pulse tools. However, contrary to conventional tools, the present apparatus includes upper and lower cam followers that rotate with the turbine.

[0121] The cam action of the rotating cam followers 17,18 on the fixed cam surfaces 15,19 causes the screw 16, piston 13 and turbine sleeve 17 to reciprocate axially and the whole turbine assembly 26 is alternatively positively pushed upwards by the lower cam action and positively pushed downwards by the upper cam action.

[0122] Such positive action in both directions imparts a high degree of axial stability to the reciprocating movement. The result is an increase in reliability and tolerance to working angles, varying fluid flows and the like.

[0123] The cam profiles can be adjusted so as to adjust the overall axial movement of the piston. This could be from 1 mm movement through to 20 mm movement but not limited to. This adjustment can then be used to tune the apparatus so as to achieve a fluid pulse under different conditions.

[0124] FIG. 6 shows an aspect of a main sub body 4. The body 4 is similar to that describe above with respect to FIGS. 1 to 5 in having an Archimedes screw 16 attached to a turbine sleeve 17. Upstream and downstream cam followers 14, 18 are attached to the turbine sleeve 17. In this case, the screw 16 has a shaft 27. FIG. 6 shows the piston 13 attached to the turbine 17. The turbine is mounted and fixed into a sleeve 17 which is also rotating due to the turbine 17.

[0125] FIG. 7 is a graph showing pulses per second at 700 psi that are created over one second by a fluid pulsing apparatus of the invention pumping 120 gallons per minute. There are 5 revolutions of the turbine apparatus per second and 5 pulses, representing one pulse per revolution.

[0126] FIG. 7 and FIG. 8 also show how many times the piston 13 moves in and out of the orifice 11 over a time frame of 1 second. The amount of pressure pulses per second can be increased or decreased by adjusting the pitch of the turbine. (This method is very similar to adjustment of a boat propeller). The piston goes up and down for every one completed revolution of the turbine because it is fixed to the turbine. Therefore, the piston also rotates through its up and down movement.

[0127] FIG. 8 is a graph of showing pulses per second at 850 psi that are created over one second by the same fluid pulsing apparatus as that used to generate the graph of FIG. 7, also pumping 120 gallons per minute. There are 5 revolutions of the turbine apparatus per second and 10 pulses, representing one pulse per revolution.

[0128] The fluid pulses may be seen to be very consistent in frequency and pulse height. This makes the pulses that this tool creates very easy to filter out so that the pulses do not interfere with other tools such as directional tools and (measurement while drilling) MWD tools.

[0129] As disused above, the maximum fluid pressure is achieved when the piston is in the fluid restricting position. The narrower the restriction, the greater the increase in pressure. The graph of FIG. 7 was achieved with a piston of smaller diameter than that used to generate the graph in FIG. 8. It will be appreciated that by simply changing the piston and/or orifice diameter, the fluid pulse apparatus of the present invention can be easily tuned.

[0130] Alternatively, a piston 29 may be tapered across itself so as to provide a restrictive fluid flow passage 31 on one side of the piston and an unrestricted flow passage on the opposite side of the piston. Further, the fluid flow passage 28 can have an extension of the opening of the fluid flow passage 28 within its wall. The piston fluid flow passage 31 and the fluid extension opening 30 of the fluid flow passage 28 so that a very effective closed position is achieved when the cam follower 18 is in the high point position 32 of the cam surface 19. Once the cam follower 18 rotates around to the low point position 33 of the cam surface 19, the piston fluid flow passage 31 will rotate 180 and axially be lifted so that the piston fluid passage 31 and the fluid flow passage opening 30 are completely miss aligned. Rotating the piston around an additional 180 will return the piston 29 to the aligned open position. The benefits of timing the movement of the piston 31 and the fluid flow passage opening 30 with the cam profiles 15 and 19, allows for a cleaner, more defined and hydraulically adjustable pulse which allows for less turbulent flow so as to achieve a clean pulse.

[0131] Further adjustments may be made by adjusting the pitch of the turbine and size of the piston while using different fluid property and pumping different gallons per minute, it is possible to adjust the frequency of pulse over a second and to adjust the pulse height to create many different configurations tailored to match different conditions.

[0132] FIGS. 9a and 9b show another piston 29 moving up and down and rotating one revolution during its up and down movement and another orifice 28. This works in the same way as orifice 11 and piston 13 however the big difference between the two is that a slot cuts into the side of the orifice 28 and the piston is not pointed but instead it is scalloped from one side to the other.

[0133] FIG. 10 shows the cam surface that is mounted above and below the turbine sleeve 17 and does not rotate. The cam followers 14 and 18 are apart of the sleeve 17. The cam followers will rotate because the sleeve and turbine are attached to each other. The cam followers, sleeve, turbine and piston are all kept in place via the fixed cam surface and can only rotate.

[0134] Due to the interaction of the rotating cam followers following the path of the fixed cam surface, when the turbine 16 is rotating, the cam followers, sleeve, turbine and piston have to move up and down when they rotate over the fixed cam surface located above and below. FIG. 2 shows how all the parts are located within the tool.

[0135] The advantage of this embodiment of the invention is that it can achieve a very sharp pressure pulse by increasing the loose fluid restriction (marked up in FIG. 9a and a very tight high fluid flow restriction as noted in FIG. 9b.

[0136] This is achieved by ensuring that each of the components is timed and lined up during the rotation and up, down movement of the piston 29.

[0137] The fluid pulse apparatus does not have elastomers, such as those found in positive displacement motors that are used to drive valves to produce a pressure pulse as per known devices. The lack of elastomers can extend the life of the apparatus while being used in hot hole conditions and when there is abrasive matter being pumped through the apparatus.

[0138] Still further without elastomers, non-aqueous chemical fluids can be pumped through the apparatus.

[0139] Further, without elastomers or seals, the apparatus can tolerate higher pressures.

[0140] As a result of the upstream and downstream cam action, the fluid pulses are very consistent in frequency and pulse height. This makes the pulses that this tool creates very easy to filter out so that the pulses do not interfere with other tools such as directional tools and (measurement while drilling) MWD tools.

[0141] Unlike other fluid pulse apparatus on the market, the flow control components of the present apparatus only move axially. This in turn means that there is no harmful and unwanted lateral vibration created. Those apparatus on the market that use mud motor technology do create lateral vibration that in turn causes damage to other components that make up and are included within the drill string.

[0142] The present fluid pulse apparatus can be used with or without a shock tool. An advantage of the present apparatus is that the apparatus without a shock tool can induce a hammer effect on coil tubing which in turn creates axial movement of a coil tubing string.

[0143] When the fluid pulse apparatus is used with a shock tool the pulse will react on the pump open area of the shock tool. This will cause the shock tool to axially extend and retract with each pulse. The shock tool can be placed below the fluid pulse apparatus or above the fluid pulse apparatus. If the pump open area of the shock tool is increased, the pulse will have a larger area for the hydraulic force to act upon which in turn will increase the axial extend and retract the shock tool. If the pump open area of the shock tool is reduced, the pulse will have less area for the hydraulic force to act upon which in turn will reduce the axial extend and retract the shock tool. This is known as a hammer effect as described in U.S. Pat. No. 4,830,122.

[0144] It will be appreciated that various changes and modifications may be made to the apparatus as described and claimed herein without departing form the spirit or scope thereof.