Downhole annular pump down assist tool

Abstract

A method and apparatus for assisting transportation of a tool down a wellbore wherein the apparatus comprises an elongate body having an exterior surface extending between top and bottom ends, a connector at the top end and end operable to be secured to a tool therebelow and a recess in the exterior surface thereof, the recess having at least one body therein adapted to restrict the flow of fluid past the recess. The method comprises suspending the elongate body within a wellbore from a connector at the top end and pumping a fluid around an annulus of the elongate body such that the recess receives the fluid to enhance the downward force on the elongate body from the fluid.

Description

[0001] DOWNHOLE ANNULAR PUMP DOWN ASSIST TOOL

[0002] BACKGROUND

[0003] 1. Technical Field

[0004] This disclosure relates generally to petroleum exploration and in particular to a method and apparatus for assisting with transporting a body into a wellbore.

[0005] 2. Description of Related Art

[0006] In the field of petroleum exploration one method of delivering tools and equipment to a location down a well-bore is to locate the tool within the wellbore and utilize a fluid pumped down the wellbore. In such a manner, the fluid will aid in carrying the tool or object into the well-bore.

[0007] One difficulty with current pump down methods is that the fluid will travel faster down the wellbore due to the fluid flowing therepast. Such fluid may adversely affect the movement of the tool down the wellbore by increasing the pressure below the tool.

[0008] SUMMARY OF THE DISCLOSURE

[0009] According to a first embodiment, there is disclosed an apparatus for assisting transportation of a tool down a wellbore comprising an elongate body having an exterior surface extending between top and bottom ends, a connector at the top end and end operable to be secured to a tool therebelow and a recess in the exterior surface thereof, the recess having at least one body therein adapted to restrict the flow of fluid past the recess.

[0010] The at least one body may comprise a fin. The fin may extend radially from the elongate body. The apparatus may further comprise a plurality of longitudinally spaced apart fins.

[0011] The fin may be substantially planar. The fin may be angularly oriented relative to orthogonal from the axis of the elongate body. The fin may include a different profile on a leading and trailing edge thereof. The leading edge may be substantially concave. The trailing edge may be inclined towards a leading edge of the elongate body.

[0012] The at least one body may comprises a toroidal body located within the recess forming a gap between the elongate body and the toroidal body having first and second entrances thereinto. The first and second entrances may be oriented towards a top end of the apparatus.

[0013] The apparatus may further comprise a central bore extending therethrough and a relief passage extending between an outer surface of the apparatus and the central bore. The relief passage may extend to a position within the recess. The relief passage may extend to an entrance of the recess. The relief passage may extend to a middle portion of the recess. The relief passage may extend to a position upstream of the recess. The relief passage may be substantially circular. The relief passage may be sized to permit a quantity of fluid therethrough from the exterior into the central passage to reduce pressure within the recess thereby reducing the downward force applied to the apparatus by the recess.

[0014] The apparatus may further comprise a mandrel located within central bore. The mandrel may be operably connected to a plug at the bottom end of the apparatus. The mandrel may include an expanded portion corresponding to the diameter of the central bore. The expanded portion may be positioned to cover the relief passage at an initial position thereof. The portion may be adapted to be displaced from the relief passage when the mandrel is disengaged from the plug.

[0015] According to a first embodiment, there is disclosed a method for assisting transportation of a tool down a wellbore comprising providing an elongate body having an exterior surface extending between top and bottom ends, the elongate body having a recess in the exterior surface thereof, the recess having at least one body therein adapted to restrict the flow of fluid past the recess, securing a tool to the bottom end, suspending the elongate body within a wellbore from a connector at the top end and pumping a fluid around an annulus of the elongate body such that the recess receives the fluid to enhance the downward force on the elongate body from the fluid.

[0016] The method may further comprise covering a relief passage extending between an outer surface in the elongate body and a central bore with an expanded portion of a mandrel and displacing the expanded portion to uncover the relief passage.

[0017] Other aspects and features of the present disclosure will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constitute part of the disclosure. Each drawing illustrates exemplary aspects wherein similar characters of reference denote corresponding parts in each view,

[0020] Figure 1 is a cross-sectional view of a wellbore having pump down assist apparatus according to a first embodiment located therein connected to a tool to be pumped down the wellbore.

[0021] Figure 2 is a perspective view of an apparatus for assisting the pump down of tools within a wellbore.

[0022] Figure 3 is a cross sectional view of the apparatus of Figure 2 as taken along the line 3-3 in an initial or run in configuration.

[0023] Figure 4 is a cross sectional view of the apparatus of Figure 2 as taken along the line 3-3 in a second or pull out configuration.

[0024] Figure 5a-b are cross sectional views of the apparatus of Figure 2 having no protrusions according to further embodiments of the present disclosures.

[0025] Figure 6a-d are cross sectional views of the apparatus of Figure 2 having split flow passages according to further embodiments of the present disclosures. Figure 7a-d are cross sectional views of the apparatus of Figure 2 having curved protrusions according to further embodiments of the present disclosures.

[0026] Figure 8a-c are cross sectional views of the apparatus of Figure 2 having flat protrusions according to further embodiments of the present disclosures.

[0027] Figure 9 is a cross sectional view of an apparatus or assisting the pump down of tools within a wellbore according a further embodiment of the present disclosure.

[0028] DETAILED DESCRIPTION

[0029] Aspects of the present disclosure are now described with reference to exemplary apparatuses, methods and systems. Referring to Figure 1 , a wellbore 10 is drilled into the ground to a production zone by known methods. The production zone may contain a horizontally extending hydrocarbon bearing rock formation or may span a plurality of hydrocarbon bearing rock formations such that the wellbore 10 has a path designed to cross or intersect each formation. As illustrated in Figure 1 , the wellbore may include a vertical section 12 and a bottom or production section 14 which may be horizontal or angularly oriented relative to the horizontal located within the production zone 6. Optionally, a casing 18 may be located within the wellbore as are commonly known. As utilized herein, all references to the wellbore in which the present apparatus and tool are pumped down shall be taken to mean both the wellbore formed in the surrounding rock as well as the passage formed by the casing as located within the rock wellbore. In order to locate tools and other bodies within the wellbore 10, they may be pumped down the wellbore. As illustrated in Figure 1 , an exemplary apparatus for assisting with the transportation of a tool down a wellbore according to a first embodiment is generally indicated at 20 connected to a tool 8. The tool 8 may be of any type as required to be pumped down the wellbore. In particular, the tool a bottom hole assembly may be located on the end of any suitable connection to the surface, including coiled tubing, wireline, slackline or independent pump- down. The present apparatus may also be useful for pumping down tools to be used in a plug and perforation operation.

[0030] With reference to Figure 2, the apparatus 20 comprises an elongate body extending between top and bottom ends, 22 and 24, respectively. The top end may include a top end connector, such as, by way of non-limiting example, internal threading 26 or a compression connector. The bottom end 24 includes a bottom end connector 28 such as a compression fitting or threaded fitting, by way of non-limiting example. The bottom end connector and the top end connector may optionally be selected to permit more than one apparatus to be connected end to end so as to increase the effectiveness of the overall apparatus. One or more of the present apparatus 20 may also be located at different locations along the bottom hole assembly or in the tool string.

[0031] Turning now to Figure 3, a cross sectional view of the apparatus 20 is illustrated. The apparatus includes an elongate tubular body 30 having an annular recess 32 located therearound and an optional central bore 31 therethrough. The annular recess 32 extends between a leading surface 34 and a trailing surface 36 inset into the outer surface 31 of the tubular body 30 with a bottom annular surface 38 therebetween. The leading surface 34 may be angularly oriented relative to an axis of the tubular body so as to form a frustoconical surface as illustrated in Figures 3 and 4. In such a configuration, the leading surface may have a constant angle relative to the axis of the tubular body. Alternatively, the leading surface 34 may have a variable angle relative to the axis such as, by way of non-limiting example, a gradual transition to the outer surface 31 and bottom surfaces 38. Similarly, the trailing surface 36 may also be angularly oriented relative to the axis or profiled relative thereto. The trailing surface 36 may also be substantially transverse to the axis so as to form a bottom end wall to the annular recess 30. The leading and trailing surface angles may be selected depending on the dimensions of the apparatus 20 and wellbore as well as the viscosity and other properties of the fluid utilized therein. In practice it has been found that leading angle of between 30 and 90 degrees from axial has been useful while a trailing angle of between 10 and 90 degrees has also been useful although it will be appreciated that other angles may also be useful.

[0032] As illustrated herein, the annular recess 32 includes at least one radially extending protrusion 40 therein. The protrusions 40 extend from the bottom surface 38 and are formed between a leading surface 42, a trailing surface 44 and an end surface 46. As illustrated in Figures 3 and 4, the leading surface is in a direction oriented towards the leading surface 34 of the recess 32. The leading surface 42 is profiled and configured to receive a flow of a fluid down the wellbore 10 around the outside of the apparatus 20 and enhance the force acted upon the apparatus 20 by such fluid flow. In particular, the leading surface 34 may be concave in a direction towards the leading surface 34 of the recess 32 so as to redirect flows down the surface of the tool back towards a flow passing down the outside of the wellbore. The curvature of the leading surface34 may be selected to enhance such flow and by way of nonlimiting example, it has been found a radius of between 0.06 and 2 inches has been useful although it will be appreciated that other dimensions may be useful as well.

[0033] The trailing surface 44 of the protrusion 40 may be profiled to assist with fluid flow moving in a direction up the wellbore 10 past the protrusions 40. As illustrated in Figures 3 and 4, the trailing surface 44 may be angled in a direction up the wellbore so as to redirect fluid flow to the wellbore wall away from the apparatus and other protrusions. It will be appreciated that angling the trailing surface 44 will also assist with directing flow in a downward direction down the wellbore past the apparatus into protrusions 40 below that trailing surface. In particular, the trailing surface may be angled at an angle of between 10 and 90 degrees. The end surface 46 may be configured to have any desired configuration to aid in fluid flow being retained above the protrusion 40 when flowing in a downward direction and past the protrusion in an upward direction. In particular, as illustrated in Figures 3 and 4, the end surface 46 may be substantially parallel to the axis of the apparatus. The protrusions 40 may have a thickness between the leading and trailing surfaces selected to both provide sufficient strength to resist bending from the flow of fluid therepast and thereon as well as to resist erosion from fluid flows therepast and resist damage during transportation while minimize resistance. As illustrated in Figures 3 and 4, the apparatus 20 may include a plurality of protrusions within the recess 30 with a spacing therebeween selected to adequately receive and contain downward fluid flow therebetween. In practice it has been found that a quantity of between 3 and 10 protrusions has been useful and that a spacing of between 1 and 3 inches has been useful although it will be appreciated that other quantities and spacings may also be useful. According to some embodiments, such as illustrated in Figures 5a and 5b, the recess 32 may not include any protrusions.

[0034] According to some embodiments, the apparatus 20 may include a pressure relieve passage 50 extending through the central bore 31 of the tubular body 30 adapted to be selectably opened during removal from the wellbore 10 or when fluid is desired to be moved past the apparatus. As illustrated, the pressure relief passage 50 may comprise one or more radial bores extending through the tubular body 30 and may be selectably closed by an inner movable mandrel 60 within the tubular body 30. It will also be appreciated that other passage shapes may be utilized as well including, without limitation, slots, ovals or irregular. As illustrated the inner mandrel 60 may include an expanded portion sized to engage on an inner surface 33 of the tubular body proximate to the relief passages 50. Alternatively, as illustrated in Figure 9, the central bore 31 may have a narrowed section containing the pressure relief passage 50 so as to bring the central bore 31 into sealing engagement with the mandrel 60 at that location. Furthermore, the mandrel 60 may seal below the pressure relief passage 50 as opposed to directly thereunder so as to prevent release of pressure in the recess until the mandrel 60 is shifted to permit flow therethrough. The inner mandrel 60 may selectably cover and seal the relief passage 50 or the inner passage through the cylindrical body 30 at a position below the relief passage as illustrated in Figure 3 until fluid flow therethrough is desired whereupon the inner mandrel may be retracted or otherwise axially displaced within the tubular body 30 so as to uncover the relief passage 50 as illustrated in Figure 4. In practice, the inner mandrel 60 may be connected to an end plug 70 or other device connected below the apparatus such that activation of the end device also uncovers the relief passages 50. The inner mandrel 52 may be shifted by any known means within the outer tubular body 30 such as a setting tool or the like. As illustrated in Figures 3 and 4, the relief passages 50 may extend through the outer tubular body 30 at a position above the annular recess. Optionally, the relief passages 50 may pass through the tubular body 30 within the annular recess as illustrated in Figures 6a, 7b and 7c, or below the annular recess as illustrated in Figure 6a.

[0035] As illustrated in Figures 5-8, the apparatus 20 may also include other combinations of the annular recess with protrusions and other flow enhancing structures therein. In particular, as illustrated in Figures 5a and 5b, the annular recess 32 may not include any protrusions. Furthermore, as illustrated in Figures 6a-6d, the annular recess may include a flow diverting ring as set out in US Patent no. 11 ,868,169, the entirety of which is incorporated herein by reference. As illustrated in Figures 7a-7d, the protrusions may include a curved leading surface and an angled trailing surface according to further embodiments and as illustrated in Figures 8a-8c, the protrusions may be substantially planar and radially extending from the recess 32.

[0036] Turning now to Figure 9, the recess 32 may include a flow diverting ring 80 having top and bottom fluid entrance passage 82 and 84. The pressure relief passages 50 may be positioned at any location within the recess 32, including without limitation within the top entrance portion 86, the middle portion 88, the bottom entrance portion 90 or upstream of the recess 92. While specific embodiments have been described and illustrated, such embodiments should be considered illustrative only and not as limiting the disclosure as construed in accordance with the accompanying claims.

Claims

What is claimed is:

1. An apparatus for assisting transportation of a tool down a wellbore comprising: an elongate body having an exterior surface extending between top and bottom ends; a connector at the top end and operable to be secured to a tool therebelow; and a recess in the exterior surface thereof, the recess having at least one body therein adapted to restrict the flow of fluid past the recess.

2. The apparatus of claim 1 wherein the at least one body comprises a fin.

3. The apparatus of claim 2 wherein the fin extends radially from the elongate body.

4. The apparatus of claim 2 wherein further comprising a plurality of longitudinally spaced apart fins.

5. The apparatus of claim 2 wherein the fin is substantially planar.

6. The apparatus of claim 2 wherein the fin is angularly oriented relative to orthogonal from the axis of the elongate body.

7. The apparatus of claim 2 wherein the fin includes a different profile on a leading and trailing edge thereof.

8. The apparatus of claim 7 wherein the leading edge is substantially concave.

9. The apparatus of claim 7 wherein the trailing edge is inclined towards a leading edge of the elongate body.

10. The apparatus of claim 1 wherein the at least one body comprises a toroidal body located within the recess forming a gap between the elongate body and the toroidal body having first and second entrances thereinto.

11. The apparatus of claim 10 wherein the first and second entrances are oriented towards a top end of the apparatus.

12. The apparatus of claim 1 further comprising a central bore extending therethrough and a relief passage extending between an outer surface of the apparatus and the central bore.

13. The apparatus of claim 12 wherein the relief passage extend to a position within the recess.

14. The apparatus of claim 13 wherein the relief passage extends to an entrance of the recess.

15. The apparatus of claim 13 wherein the relief passage extends to a middle portion of the recess.

16. The apparatus of claim 12 wherein the relief passage extends to a position upstream of the recess.

17. The apparatus of claim 12 wherein the relief passage is substantially circular.

18. The apparatus of claim 12 wherein the relief passage is sized to permit a quantity of fluid therethrough from the exterior into the central passage to reduce pressure within the recess thereby reducing the downward force applied to the apparatus by the recess.

19. The apparatus of claim 12 further comprising a mandrel located within central bore.

20. The apparatus of claim 19 wherein the mandrel is operably connected t a plug at the bottom end of the apparatus.

21. The apparatus of claim 20 wherein the mandrel includes an expanded portion corresponding to the diameter of the central bore.

22. The apparatus of claim 20 wherein the expanded portion is positioned to cover the relief passage at an initial position thereof.

23. The apparatus of claim 22 wherein the expanded portion is adapted to be displaced from the relief passage when the mandrel is disengaged from the plug.

24. A method for assisting transportation of a tool down a wellbore comprising providing an elongate body having an exterior surface extending between top and bottom ends, the elongate body having a recess in the exterior surface thereof, the recess having at least one body therein adapted to restrict the flow of fluid past the recess; securing a tool to the bottom end; suspending the elongate body within a wellbore from a connector at the top end; andpumping a fluid around an annulus of the elongate body such that the recess receives the fluid to enhance the downward force on the elongate body from the fluid.

25. The method of claim 24 further comprising covering a relief passage extending between an outer surface in the elongate body and a central bore with an expanded portion of a mandrel and displacing the expanded portion to uncover the relief passage.

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