Patent Publication Number: US-3880248-A

Title: Valve sleeve for use in association with oilfield hydraulic jar tool

Description:
United States Patent Mason Apr. 29, 1975 [5 VALVE SLEEVE FOR USE IN ASSOCIATION 3,088,533 5/1963 Sutliff 175/297 WITH OILFIELD HYDRAULIC JAR TOOL 3,405,773 10/1968 Sutliff et a1. 175/297 3,562,807 2/1971 Slator et a1. 175/297 [75} Inventor: Leonard Mason, Edmonton,  
 Alberta, Canada [73] Assignee: Lee-Mason Tools Ltd., Edmonton, Alberta, Canada [22] Filed: Apr. 16, 1974 [21] Appl. No.: 461,302  
 [52] US. Cl. 175/297 [51] Int. Cl. E211) 1/10 [58] Field of Search 175/296, 297  
 [56] References Cited UNITED STATES PATENTS 2,987,129 6/1961 Webb 1. 175/297 2,988,147 6/1961 Webb 175/297 3,004,616 10/1961 Nutter et a1.. 175/297 Primary Examiner-James A. Leppink Attorney, Agent, or Firm-Ernest Peter Johnson [57] ABSTRACT The valve sleeve is provided with one or more radial bores at the seat end of the sleeve. The bore connects the bypass passageway between the sleeve and mandrel with the annular metering passageway between the sleeve and the valve-fitting section of the barrel. In this manner, high pressure is transmitted from the bypass passageway to the annular passageway to reduce outward belling of the tail end of the valve sleeve. This results in reduced wear of the valve sleeve and improved performance of this portion of the tool.  
 2 Claims, 16 Drawing Figures PMENTEDAPRZSIHYS SHEET 2 OF 5 lyll rllll I! PATENIED PRZ B 3.880.248  
 sum 3 BF 5 PNENTEUA Z W 3,880,248  
 SHEET REF 5 VALVE SLEEVE FOR USE IN ASSOCIATION WITH OILFIELD HYDRAULIC JAR TOOL BACKGROUND OF THE INVENTION This invention relates to an improved valve sleeve for use in a hydraulic jarring tool of the type used in oilfield drill strings.  
  In the oilfield drilling art, a hydraulic jarring tool or combination jarring and bumping tool is used in the drill string as a device to enable upward blows to be delivered via the free upper end of the drill string to the stuck, lower portion thereof. In this manner. the stuck drill string is frequently loosened from the grip of the surrounding rock formation and may be withdrawn from the well bore.  
  Although many different hydraulic jarring tools have been developed, they all operate on the same principle. More particularly, the tools each have a telescopically related inner mandrel and outer barrel. The tool is positioned intermediate the ends of the drill string; its barrel is usually connected to the lower portion of the string and the mandrel is connected to the upper portion. The tool incorporates a means for delaying for a period of time the rapid telescoping of the mandrel and barrel when the drilling rig pulls on the free, upper portion of the drill string. This delay permits the rig to stretch the free, upper portion of the drill string, whereby considerable elastic energy is stored therein. After a suitable interval, the delaying means release and the tool is allowed to rapidly telescope. The stored, elastic energy accelerates the section of the tool which is attached to the upper portion of the drill string when the end of the tool&#39;s telescoping stroke is reached, the accelerated mandrel strikes the barrel of the tool, which is attached to the stuck portion of the drill string, and delivers an upward jar or blow.  
  The jarring tool with which this invention is concerned comprises. as stated, an inner mandrel and an outer barrel. These two tubular parts are connected together in a manner which permits of relative longitudinal sliding movement, but they are locked together for rotational movement; preferably this is accomplished by means of a spline assembly. The barrel is formed to provide a lower valve-fitting section and an upper, contiguous jar free-stroke section. The valve-fitting section is of reduced inside diameter relative to the jar freestroke section. The mandrel and barrel sections combine to define between them an axial, annular hydraulic chamber which is filled with operating liquid, such as a light oil. Packing is provided between the barrel and mandrel to seal the hydraulic chamber at its ends. The mandrel carries an annular radial shoulder and an annular valve stop spaced axially above the shoulder. The shoulder is ground to provide a valve seat. A tubular valve sleeve is slidably mounted on the mandrel between the shoulder and stop. In this interval, the rounded face of the tubular mandrel is flattened to provide a plurality of axial flats; an axial passageway is therefore formed between the mandrel flats and the inside surface of the sleeve. At its lower end, the sleeve has a ground face which, when pressed against the shoulder seat effects a liquid-tight seal therewith; thus operating liquid cannot, at that end of the sleeve, pass from the axial passageway to the hydraulic chamber when the sleeve is seated. At its upper end, the sleeve is notched to provide a transverse opening connecting the hydraulic chamber with the axial passageway.  
  In operation, with the tool in a collapsed position, the sleeve is positioned in the valve-fitting section. A narrow annular passageway is formed between the sleeve and the valve-fitting section. By way of example, the clearance between the sleeve and the valve-fitting section may be one half thousandths of an inch, whereas the clearance between the sleeve and the free stroke section may be sixty-five thousandths of an inch. As the rig pulls upwardly on the drill string, the sleeve is drawn upwardly through the valve-fitting section toward the jar free-stroke section. During this operation, the hydraulic fluid in the free stroke portion of the hydraulic chamber is compressed. The compressed hydraulic fluid can bleed only slowly through the annular passageway from the high pressure zone above the sleeve to the low pressure zone below it. The telescoping or expansion of the tool is thus retarded, providing an opportunity for the rig to stretch the upper portion of the drill string. After a length of time, enough fluid will have escaped from the high pressure end of the chamber and the sleeve will clear the valve-fitting section and pass into the jar free-stroke section. At this point, the pressurized fluid can quickly bypass the sleeve; the drill string contracts freely and the mandrel is rapidly accelerated upwardly until a hammer which it carries strikes an anvil carried by the barrel, with a jarring impact. To re-set the tool, the mandrel is lowered. As the sleeve enters the valve-fitting section, the fluid contained therein is compressed, thereby shifting the sleeve upwardly until it contacts the valve stop. Hydraulic fluid can then bypass freely through the notch and the axial passageway behind the sleeve, allowing the sleeve to drop quickly through the value-fitting section to the collapsed position.  
  The condition of the sleeve is important to the proper operation of the tool. For example, if the outside surface of the sleeve becomes worn, the clearance between the sleeve and the valve-fitting section is increased and the rate of bleeding of pressurized fluid is drastically increased. Wearing is increased if the valve swells from internal pressure and presses at localized points against the barrel.  
 SUMMARY OF THE INVENTION The present invention is concerned with the combination of a novel valve sleeve and a hydraulic jarring tool. The valve sleeve is provided with one or more bores extending through the sleeve wall and connecting the high pressure zone of the hydraulic chamber with the outer surface of the sleeve adjacent to but spaced above its seat end. Preferably the bore extends transversely through the sleeve wall and provides communication between the axial bypass passageway, between the sleeve and mandrel, and the annular passageway between the sleeve and valve-fitting section of the barrel. As a result of this arrangement, the high pressure behind the valve sleeve is transmitted to the lower portion of the annular passageway, thereby reducing the outward deformation or belling of the tail or lower end of the sleeve. In this way, constriction of the annular passageway, arising from deformation of the sleeve, is reduced. Wear of the tail end of the sleeve is effectively eliminated. The cumulative result is a more consistent and break-down free tool.  
 DESCRIPTION OF THE DRAWING In the drawing:  
  FIG. la is a sectional side view showing the upper section of a combination jarring and bumping tool;  
  FlG. lb is a sectional side view showing the intermediate section of the tool, including the novel valve sleeve positioned within the valve-fitting section;  
  FlG. it&#34; is a sectional side view showing the lower section of the tool;  
  FIG. 2 is a sectional side view of the entire tool, with the valve sleeve positioned in the bumping chamber;  
  FIG. 3 is a perspective view, partly broken away. showing the valve sleeve in place on the mandrel;  
  FIG. 4 is a top plan view of the sleeve and mandrel along the line A-A of FIG. 3;  
  FIG. 5a is a side view in section showing the valve sleeve of the prior art, in broken lines, in the valvefitting section the arrows provide an indication of what l believe is the pressure distribution along the inner face of the barrel;  
  FIG. 5b is a side view in section showing the valve sleeve of FIG. 5a the arrows provide an indication of what I believe is the pressure distribution along the inner and outer faces of the prior art sleeve;  
  FlG. Se is a composite side sectional view of the valve-fitting section and prior art valve sleeve, showing the distortions which l believe take place when the valve sleeeve is passing through the valvc-fitting section toward the jar free-stroke section;  
  FIG. 6a is a side view in section showing my novel valve sleeve, in broken lines, within the valve-fitting section the arrows provide an indication of what I believe is the pressure distribution along the inner face of the barrel.  
  FIG. 6b is a side view in section showing the valve sleeve of FIG. 6a the arrows provide an indication of what I believe is the pressure distribution along the inner and outer faces of the sleeve;  
  FIG. 61&#39; is a composite side sectional view of the valve-fitting section and sleeve, showing the distortions which l believe take place when my novel valve sleeve is passing through the valve fitting section toward the jar free-stroke section.  
  FIG. 7 is a perspective view, partly broken away, showing an alternative version of the sleeve valve on the mandrel;  
  FIG. 8 is a top plan view of the sleeve and mandrel taken along the line A-A of FIG. 7.  
  FIG. 9 is a view similar to that of FIG. 7 showing still another embodiment of the valve sleeve; and  
  FIG. 10 is a top plan view of the sleeve and mandrel taken along the line A-A of FIG. 8.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is concerned with the combination of a transversely bored valve sleeve and a hydraulic jarring tool. For purposes of illustration, the sleeve is described herein in conjunction with the combination jarring and bumping tool disclosed in my Canadian Pat. No. 93l,l36, issued July 31, 1973, which is incorporated herewith.  
  With reference to the drawing, the tool 1 comprises a male spline sub 2 having a threaded box 3 at its upper end for connection with the upper portion of the drill string (not shown). At its lower end, the spline sub 2 has a second threaded box 4 for connection to the mandrel 5. The male spline sub 2 extends downwardly into a female spline sub 6. The female spline sub 6 is internally threaded at its lower end and is connected with the barrel 7. The splines 2a, 6b of the two spline subs 2, 6 intermesh to permit of longitudinal movement of the parts 5, 7 relative to each other, but lock them together with regard to rotational movement.  
  The barrel 7 carries packing 8, e.g. O-rings, on the inner surface of its upper pin end 9. The mandrel 5 extends downwardly into the barrel 7 through the relatively tight-fitting axial bore 10 of the pin end 9. The packing 8 effects a liquidtight, pressure-resistent seal between the barrel 7 and mandrel 5.  
  The barrel 7 is formed to provide a jar free-stroke section ll of relatively large inside diameter and short length. a valve-fitting section [2 of reduced inside diameter. and a bumper free-stroke section 13 of relatively large diameter and extended length. The sections ll, 12 and 13 combine with the mandrel to form a hydraulic chamber 32. The lower shoulder 30 of the barrels upper pin end 9 provides an anvil.  
  A &#34;floating&#34; packing element 14 is mounted on the lower end of the mandrel 5. This element 14 comprises a cylindrical brass body having O-rings 14b fitted in its internal and external surfaces. The body substantially fills the annular space between the mandrel 5 and the barrel 7, so that the O-rings 1417 provide a liquidtight seal. A shoulder or pin 15 limits the travel of the packing element 14; the shoulder 16 of a mandrel tail pipe sub 17, attached to the lower end of the barrel 7, limits the downward travel of the element 14.  
  While the present invention is illustrated as comprising a combination jarring and bumping tool, it will be understood by those skilled in the art that the bumping section could easily be deleted from the tool in the event that only a jarring capability is desired.  
  The mandrel 5 carries an annular radial shoulder member 18 threaded thereon. This member [8 has a ground end face 19, providing a valve seat. The mandrel 5 also carries an annular valve stop 20 spaced axially above the shoulder member 18. This valve stop 20 also functions as a hammer when it comes in contact with the anvil at the end of the jarring stroke. lntermedime the member 18 and the stop 20, the face of the mandrel 5 is formed so as to provide axial flats 21.  
  A brass valve sleeve 22 is slidably mounted on the maandrel 5 between the valve stop 20 and shoulder member 18. The lower end face 23 of the sleeve 22 is ground so that, when the sleeve 22 presses against the shoulder member 18, a liquid-tight seal is effected between them. An axial passageway 24 is formed between the mandrel flats 21 and the internal surface 25 of the sleeve 22. One or more transverse openings 26, such as the notches shown, are provided through the sleeve wall at its upper end. When the sleeve 22 is located in the valve-fitting section 12, a narrow annular passageway 27 is formed between its outer surface and the internal surface of the section. Adjacent the lower end of the sleeve 22, one or more transverse, radial bores 28 are provided through the sleeve wall; these bores 28 provide communication between the axial and annular passageways 24, 27.  
  While not wanting to be bound by this explanation, I now propose to explain what I believe occurs in the tool 1 when the sleeve 22 is being drawn through the valve-fitting section 12 toward the jar free-stroke section 13 on the jarring stroke, as a result of including the radial bores 28 in the tail end of the sleeve 22. With reference to FlGS. 5a, 5b and 50, showing the prior art sleeve arrangement, a high pressure zone is created in the jar free-stroke section 11. This pressure diminishes in the annular passageway 27 from the high pressure zone to the low pressure zone located beneath the sleeve 22a. However. the high pressure is present along the full length of the axial passageway 24. As a result of these distributions of pressure. the barrel 7 is distorted outwardly adjacent the upper end of the axial passageway 24. The sleeve 22a is also distorted outwardly, but only at the lower end thrrcof. These assumptions are supported by examination of the prior art sleeve after use. It is worn only at its lower end.  
  Turning now to FIGS. 6a, 6b and 60, l have illustrated my understanding of the pressure distribution which occurs with my novel sleeve. High pressure is transmitted through the radial bores 28 from the axial passageway 24 to the lower portion of the annular passageway 27, thereby distorting the barrel 7 at that point and equalizing the pressure across the sleeve wall adjacent the bore 28, so that the belling out of the lower end of the sleeve 22 is reduced.  
  In practise, it is found that wear on the novel sleeve 22 is negligible and the time taken for the sleeve 22 to travel through the valve-fitting section 12 on the jarring stroke remains constant through a prolonged period of use.  
  In the alternative embodiment of the invention, shown in FIGS. 7 and 8, bores 28a extend from the upper end face of the sleeve 22 to adjacent the lower end of its outer surface 31. These bores 28 provide communication between the jar free-stroke section 11 of the hydraulic chamber 32 and the lower portion of the annular passageway 27.  
  In still another embodiment, shown in FlGS. 9 and 10, longitudinal grooves 28b are formed in the outer surface of the sleeve 22, extending from adjacent the upper end face 30 thereof to adjacent the lower end of its outer surface 31.  
  Obvious variations in the specific constructional details described may be made without departing from the spirit of this invention, and such embodiments of the invention that come within the scope and purview of the appended claims are to be considered as part of this invention.  
 What is claimed is:  
 1. In a hydraulic jarring tool comprising a telescopically related outer barrel and inner mandrel,  
 said barrel and mandrel forming between them a hydraulic chamber containing operating liquid,  
 packing elements at each end of the chamber effecting a liquid-tight seal between the barrel and mandrel,  
 said barrel having a valve-fitting section and a jar free-stroke section,  
 said mandrel carrying an annular radial shoulder member and a valve stop spaced axially from the member,  
 said shoulder member having an end face to provide a valve seat,  
 the improvement comprising:  
 a tubular sleeve slidably mounted on the mandrel between the stop and shoulder member,  
 said sleeve having first and second ends, said first end being closest to the shoulder member,  
 said sleeve combining with the valve-fitting section,  
 when the sleeve is being drawn therethrough toward the jar free-stroke section on the jarring stroke, to form a narrow annular passageway between them,  
 said sleeve having a face at its first end whereby,  
 when the sleeve presses against the valve seat during the jarring stroke, a liquid-tight seal is effected,  
 said sleeve combining with the mandrel to form therebetween an axial passageway,  
 said sleeve having a transverse opening at its second end to permit operating liquid to enter the axial passageway,  
 said sleeve having a bore for providing communication during the jarring stroke between the jar freestroke section of the hydraulic chamber and the lower portion of the annular passageway, whereby high pressure may be transmitted to said lower portion to reduce outward belling of the adjacent portion of the sleeve.  
 2. The tool as set forth in claim 1 wherein:  
 the bore extends transversely through the sleeve wall to provide communication between the axial and annular passageways, said bore terminating at a point adjacent to but spaced above the seat end of the sleeve.