Patent Abstract:
A wireline jar tool delivers instrument packages into wellbores and retrieves tools when they get stuck. The jar has several stored spring chambers connected to accelerate an upper spring chamber away from a stuck lower carrier chamber that supports instrument packages. Wireline tension actuates the jarring action and then lowers a sinker bar for reset as many times as required to incrementally jar the un-stick fish uphole. The wire line connects to a conductor that extends inside the tool through a main operating shaft, release coupling, hammer and anvil, lost motion coupling, into the lower chamber where the end connects to the instruments for communication to the surface. A small wireline tension provides unexpected large impact forces.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Provisional Patent Application:  
         [0000]     Ser. No. 60/349,955 Filed: Jan. 13, 2003 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable.  
       REFERENCE TO A MICROFICHE APPENDIX  
       [0003]     Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0004]     A novel resettable jar tool for use downhole in a borehole for enhancing the retrieval of stuck objects. The stuck object may be part of a tool string that includes the jar tool of this invention. The jar tool can withstand high temperature and other deleterious downhole conditions without significantly reducing the magnitude of the stored energy employed for actuating the jar tool.  
         [0005]     The jar tool is resettable as many times as required to dislodge a stuck object by manipulating the operating wireline that allows electronic communication between apparatus connected to the bottom of the tool and the surface by an electrical conductor that extends through the entire jar tool. The jar includes a hammer, anvil and releasable latch device cooperatively interconnected to increase the safety of the tool and to deliver a powerful uphole thrust responsive to wireline tension.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     In the art of producing fluid from a borehole, sometime a borehole is drilled fairly straight, sometime it is crooked, or is deliberately slanted. Most boreholes are crooked, thereby tremendously increasing the probability of a string of tools becoming stuck downhole in a borehole. This invention is directed to a wireline actuated jar tool for use in retrieving a stuck downhole tool from a borehole. Hence, it is apparent that the stuck tool string must somehow be unstuck without resorting to placing undue tension on the supporting wireline.  
         [0007]     A parted wireline is considered a catastrophe in the oil patch for a costly fishing job is then necessary, and such a delay will be disastrous for any delicate instrument package left downhole long enough to be fried by the bottom hole temperatures. The jar tool of this invention overcomes the necessity of ever applying excessive tension in the wireline that supports the tool string. This is achieved in accordance with the present invention by a resettable, stored energy jar tool system capable of multiplying the tension of the E-line as much as ten fold, as will be more fully appreciated as this disclosure is further digested.  
         [0008]     The preferred embodiment of the jar tool of this invention discloses a downhole tool string which includes the downhole jar tool. The jar tool includes an upper member opposed to a lower member with the two members being coupled together by means of a lost motion coupling in a manner to provide axial slidable movement therebetween, whereby the opposed members provide opposed masses that are selectively moved towards and away from one another a distance determined by the lost motion coupling which is attached therebetween.  
         [0009]     The lower member of the jar tool is attached to most any desired downhole tool, apparatus, or device, including an instrument package, for example, that might also be insulated from the high temperature formations, while the upper jar tool member is provided with a unique plurality of spaced stored energy chambers therein, whereby a plurality of forces are advantageously added together and made available for creating a powerful upthrust when one member is released from the other and is accelerated responsive the magnitude of the stored energy.  
         [0010]     Means are provided for releasing the energy of said stored energy chambers upon demand to effect rapidly accelerating movement of one member respective the other member and thereby propel one said member away from the other member. At a selected length of stroke, an internal part of the tool acts as a hammer with the hammer being positioned to strike another internal part of the tool which acts as an anvil, thereby providing sudden deceleration of a magnitude and direction to accelerate the entire tool string uphole with sufficient thrust to un-stick the tool string when it is stuck down-hole. This action incrementally drives the entire downhole tool string in an uphole direction with a thrust which un-sticks the stuck tool string.  
         [0011]     An outstanding feature of this invention is the provision of a longitudinally extending passageway disposed along the central axis of the jar tool and extends from the up-hole tool end, through each of the jar tool members, including the lost motion coupling, where the passageway terminates within the lowermost member of the jar tool and thereby allows for the employment of an insulated conductor within the passageway that continues through the remainder of the jar tool to an instrument package therebelow enabling transmission of important data along the conductor from and to the surface of the earth. Provision is made to eliminate problems associated with change in length of the insulated con-ductor as the jar tool components are extended in length and then retracted as the jar tool moves from the extended configuration following a jarring action into the retracted standby configuration.  
         [0012]     Furthermore, safe protection of the insulated conductor that extends through the jar tool is provided by a through tubing positioned within the recited axial passageway which encloses the insulated conductor so that the conductor is protected, whereby one terminal end of the insulated conductor ultimately is placed into electrical communication with the downhole instrument package, for example, or other tool package, with the opposed terminal end of the conductor being electrically connected to the wireline or other means for data transmission uphole to a surface receiver. Accordingly, the downhole instrument can conduct or electronically transfer various vital information between the instrument package, through the axial conductor within the jar tool, and finally to an above ground facility.  
         [0013]     Some instrument packages are extremely valuable, and contain confidential information and design secrets which must be protected from damage as well as from evil plagiarists. Therefore, it is essential that in such a situation, the electronic package must not remain downhole for extended lengths of time because the apparatus must be kept out of harms way. The present invention provides a unique safe guard for such valuable apparatus.  
         [0014]     This disclosure further provides means for resetting the jar tool a multiplicity of times to thereby again store energy within spaced energy storing chambers thereof so that the jar tool of this invention can provide a multiplicity of sequential jarring actions that sooner or later result of the jar tool being translocated axially away from the stuck location, dragging along any attached apparatus therewith.  
         [0015]     Another outstanding feature of this invention is the provision of a jar tool having multiple sources of energy available to strike the recited anvil with a powerful blow of the hammer, which jointly provide unexpected improvements in jar tools. These forces are realized by the joint action of the E-line tension, and the force derived from the multiplicity of energy storage devices. Further, adjustment means related to the magnitude and timing of the effect obtained from the use of the several stored energy devices is taught herein. Variation in the length of stroke of the two interconnected coacting jar tool parts, the cumulative force available from the stored energy chambers, and the tension required in the E-line to trigger the hammer blow is considered to be within the comprehension of this invention. Equally important is the novel concept and method of extending an electrical conductor through the axis of the jar tool, as well as the unique safety features presented and claimed herein. Other objects and advantages of this invention will be evident from the following description.  
         [0016]     Accordingly, a primary object of this invention is the provision of a down-hole jar tool for use in a bore-hole for enhancing the retrieval of stuck objects. The stuck object may be part of a tool string that includes the jar tool. The jar tool is made of suitable alloys which can withstand high temperature and other deleterious down-hole conditions without significantly or unduly reducing the operating efficiency of the jar tool.  
         [0017]     Another object of this invention is the provision of a preferred embodiment of the jar tool, having an upper member and a lower member coupled together by a lost motion coupling in the form of opposed members arranged for limited axially slidable movement thereof, whereby the opposed members provide opposed masses that are selectively moved towards and away from one another as determined by the characteristics of the a motion coupling located therebetween; thereby providing means by which a hammer and an anvil of the jar tool are manipulated to impact one said member against the other member with sufficient force which results in uphole thrust of the members. This action drives the entire downhole tool string in an uphole direction with a powerful upthrust which invariably un-sticks the stuck tool.  
         [0018]     A further object of this invention is provision of the above downhole jar tool wherein one said member thereof can be attached within most any desired downhole tool string, including an instrument package, for example, that often will be insulated from high temperature formations while the other said member of the jar tool is provided with a unique plurality of spaced stored energy chambers therein whereby a plurality of forces are advantageously added together and made available for creating upthrust when one impacts against the other, thereby unsticking a stuck downhole tool or tool string in a new and unobvious manner.  
         [0019]     A still further object of this invention is the above recited jar tool wherein means are provided for releasing the energy of said stored energy chambers upon demand to effect rapid accelerating movement of one jar tool member respective the other jar tool member and thereby propel one said member away from the other said member in a manner to move both members uphole. At a selected length of stroke, a part of the tool acts as a hammer positioned to strike a part of the tool which acts as an anvil, and thereby provides sudden deceleration having an impact of a magnitude to accelerate the entire tool string uphole with sufficient thrust to un-stick the tool when the tool is stuck down-hole.  
         [0020]     Another and still further object of the invention is a jar tool having the provision of a central passageway that lays along the longitudinal central axis of the tool extending from the up-hole tool end to the lowermost tool end and thereby allows for safe protection of an insulated conductor to be placed into communication with a downhole instrument or other package, whereby the downhole instrumentation can conduct and transfer electronically various vital information between the instrument package and an above ground facility.  
         [0021]     An additional object of the invention is the provision of means for resetting the tool set forth in the above objects, by manipulation of the wireline tension to thereby again store energy within the spaced energy storing chambers so that the jar tool of this invention can provide a multiplicity of sequential jarring actions.  
         [0022]     Still another and further object of this invention is the provision of adjustment means related to the magnitude and timing of the stored energy devices. In particular, the length of stroke of the two coacting tool parts, the force available from selected stored energy chambers, and the tension required in the E-line to trigger the hammer blow is considered to be within the comprehension of this invention.  
         [0023]     These and other objects and advantages of this invention will become readily apparent to those skilled in the art upon digesting the following detailed description and claims and by referring to the accompanying drawings.  
         [0024]     The above objects are attained in accordance with the present invention by provision of a combination of elements which are fabricated in a manner substantially as described herein.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0025]      FIG. 1  is a part schematical, part diagrammatical, part cross-sectional representation of a wellbore that produces fluid from a fluid producing strata and discloses the present invention associated therewith in the standby configuration ready to jar;  
         [0026]      FIG. 2  is an enlarged, broken or composite view of the tool disclosed in  FIGS. 1 and 4  illustrating the proper arrangement of the tool of  FIGS. 2A, 2B ,  2 C,  2 D,  2 E, and  2 F;  
         [0027]      FIGS. 2A, 2B ,  2 C,  2 D,  2 E and  2 F, when taken together, set forth an enlarged, detailed, part schematical, part diagrammatical, part cross sectional representation of the invention disclosed in  FIGS. 1, 2 , and  3 ;  
         [0028]      FIG. 3  is a part schematical, part diagrammatical, part cross-sectional, side view showing the assembled tool of this invention in the alternate extended configuration;  
         [0029]      FIG. 4  is a hypothetical plot illustrating the dissipation of the stored energy of the tool of the previous figures of the drawings during impact of a jar action.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]      FIGS. 1 and 2  of the drawings disclose an oil well or borehole  10  within which there is supported a tubing string  12  telescopingly received within a casing  14 . Casing  14  is located within the formed borehole  10  that extends from wellhead  18  at the surface  11  of the earth, through a formation or payzone F, and continues on downhole at  14 ′, or might instead curve into payzone F as noted at F 2 , such as is achieved with directional drilling. Casing  14  is perforated in the usual manner at P or P 1 .  
         [0031]     A wire line tool string  15  has been run into tubing string  12  contained within casing  14  of borehole  10  on an E-line  17 , a slick line or wire rope having an electrical conductor therein. Sometime the tool may be run into the borehole on the end of any suitable elongate member, such as a suitable conduit or elongate tendon such as a pipe, a sucker rod string, or most any logical support member suitable for the occasion.  
         [0032]     Usually, a wire rope  17  having a suitable insulated elec-trical conductor therewithin, is used for supporting a tool string  15 . A lifting rig  20  can take on any number of different forms and should include a weight indicator connected to determine tension of the wire rope or E-line  17  which is spooled onto a drum with the downhole end of E-line  17  terminating in a rope socket  19  at the up-hole end of a sinker bar  22  of tool string  15 . The insulated conductor is electrically connected to continue through a passageway formed in sinker bar  22 , through a jar tool  16 , made in accordance with the present invention, and to the lowermost apparatus  31  supported by the lower end of jar tool  16 , thereby providing transfer of electronic data signals downhole and uphole along E-line  17  that supports tool string  15 .  
         [0033]     Sometime borehole  10  is relatively straight, as seen in  FIG. 2 . Sometime a borehole is crooked, or is deliberately slanted as illustrated in  FIG. 1 . Most boreholes are crooked and this increases the probability of a string of tools becoming stuck downhole in the borehole, as seen illustrated in  FIG. 1  at  118 , for example.  
         [0034]     The uphole end of the jar tool  16  preferably terminates in a closure that takes on the form of a sub  30  presenting a box end  30 ′ opposed to the downhole end  31 , where various different apparatus, including instrument packages and the like, can be supported. The opposed ends  30 ,  31  are easily interfaced with other tools by standard subs in a manner that is known in this art.  
         [0035]      FIG. 3  discloses additional details of tool string  15  of  FIG. 1 , comprising, commencing at the upper end of  FIG. 2 , a wire line or E-line  17 , a rope socket  21 , a sinker bar  22 , the jar tool  16  of this invention, and an adaptor sub  31  which terminates in attached relation respective any desired tool or instrument package  24  that reasonably can be supported from the lower end  31  thereof.  
         [0036]     Still looking at  FIG. 3 , sinker bar  22  can be of any desired length, so long as its mass enables resetting jar tool  16  after a jarring action of the jar tool has taken place, thereby enabling multiple sequential jarring actions to be carried out, as will be more fully appreciated later on herein. At the top  30  of jar tool  16  and in underlying relationship respective sinker bar  22 , it will be seen that the diagrammatical representation of the jar tool  16  of  FIGS. 2 and 3  has been subdivided into the indicated  FIGS. 2A through 2F , thereby enabling the details of each of these assembled Figures to be more fully disclosed on six different sheets of drawing, submitted herewith and forming part of this non-provisional patent application. It should be appreciated that an E-line  17  or equivalent, is connected to a conductor extending axially through sinker bar  22  into communication respective the uppermost end  30  of jar tool  16 , and thereafter the electrical conductor extends axially through jar tool  16  into electrical contact respective the instrument package  24 .  
         [0037]      FIG. 2A  illustrates the preferred embodiment of the uphole marginal length of jar tool  16  in greater detail. An upwardly opening box end  30  forms the upper end of jar tool  16  and threadedly engages the lower end of the before mentioned sinker bar  22  by using a suitable interfacing sub as may be necessary. An axial passageway  32  extends longitudinally through the entire jar tool  16 , as well as through the sinker bar  22 . Hence numeral  32  indicates the initial part of the annular passageway formed between connector  35  and the connector  42 .  
         [0038]     The upper terminal end of a hollow protective tubing  33  is anchored or or removably received in close tolerance relationship within connector  142  in order to sealingly accommodate the electrically insulated conductor  34  suitably protected therewithin for providing a source of power to any desired instrument package  24  attached at the lowermost end  31  of jar tool  16  for data transmission from below jar tool  16  uphole to the surface  11 , as previously noted.  
         [0039]     Cylindrical insulator  35  provides for attachment of the conductor  34  at terminal end  36  of through conductor  34 . Connectors  37 ,  39  are male and female connectors that are telescopingly fitted together and mounted within the enlarged portion  38  of passageway  32  to facilitate assembly of the various threadedly connected tool components of this invention. Seal means (not shown) are suitably seated within the seal grooves  40  and preferably are high temperature o-rings. Chamber  141  formed within the bell shaped member  41  isolates connector  39  therewithin to enable access to connector  39  and to continue through chamber  241  into the next adjacent chamber  51  of  FIG. 2C .  
         [0040]     In  FIG. 2B , axial passageway  32  that accommodates tube  33  continues down through the central axis of jar tool  16  where it is concentrically arranged respective to a larger annular chamber formed between the outside diameter of protective tubing  33  and the inside diameter of the main housing  49 .  
         [0041]     Main housing  49  includes a marginal length of the hollow main shaft member  43  reciprocatingly received therein. Looking again now to  FIG. 2A  together with  FIG. 2B , the sealed connection device  142  in chamber  141  seals the working chamber or annulus  146  respective the hollow main shaft  43 . Any number of different seal devices can be used, this example being for teaching purposes in order to enable full comprehension of the disclosure.  
         [0042]     In  FIGS. 2B and 2C , conductor  34 , tube  33  and axial passageway  32  continue axially through jar tool  16  in order to protect insulated electrical conductor  34  which is coextensive therewith. The illustrated through conductor  34  is protected by suitable insulation which further is protected by the before mentioned through tubing  33 .  
         [0043]     The before mentioned hollow main shaft member  43  is threadedly engaged by adjustment nut  44  which is locked thereto by adjustable fastener means as indicated by numeral  45 . The lower end of adjustment nut  44  abuttingly engages the uphole end of the illustrated annular Bellville washer stack  46  having a strong spring or biasing action. Bellville washer stack  46  terminates with the downhole end thereof abuttingly engaging the uphole end of a powerful, fully compressible spring device  47 , with there being a spacer or separator  48 , such as a washer, placed therebetween and separating annulus  149  into stored energy chambers  146 ,  147 .  
         [0044]     Main housing  49  of  FIGS. 2A, 2B , and  2 C is seen to be sectioned into multiple lengths to facilitate assembly, and are connected together by means of a sub  50  ( FIG. 2C ) through which the before mentioned main shaft member  43  ( FIGS. 2B and 2C ) reciprocatingly extends. Main shaft  43  continues into threaded engagement with respect to an internal shaft connector  51 , which also serves as a guide that is slidably received within main housing  149 , which is considered a continuation of housing  49 .  
         [0045]     The tube  33 , positioned within axial passageway  32 , continues through hollow main shaft member  43  and includes insulated conductor  34  therein, all of which continues through main housing  49 ,  149  as shown in  FIGS. 2A, 2B ,  2 C and  2 D. Note that the upper housing  49 ,  149  are positioned above the lost motion coupling  68  of  FIG. 2D  while the lower housing  249  of  FIG. 2E  is therebelow, as will be more fully discussed later on herein. The housing  49  as seen in  FIG. 2C , is connected to housing  149  by means of a sub  50 , having opposed faces  150 , 250  through which internal threaded bores are formed for threadedly receiving the before mentioned hollow shaft member  43  into threaded engagement with respect to internal slidable connector  51 .  
         [0046]     As shown in  FIG. 2C , axial passageway  32  continues on through main housing  49 ,  149 , sub  50 , internal connector  51 , and axially through the lower spring chamber  154  where it is connected to the releasable latch apparatus  56 ,  57 ,  156  disclosed in  FIG. 2C .  
         [0047]     Adjustment nut  52 , as best seen in  FIG. 2C , threadedly engages the marginal threaded end  43 ′ of the lower end  43 ″ of hollow main shaft part  43 , while the lower end thereof also threadedly engages internal connector  51  as noted at  151  in  FIG. 2C . Internal main shaft connector  51  threadedly engages the uphole end  243 ′ of releasing member  53 ′ and is a continuation of the before mentioned main shaft part  43 . It can be seen that sub  51  is slidably received in a reciprocating manner within the interior of main housing  149 .  
         [0048]     In  FIGS. 2C and 2D , the upper end of power spring  54  abuttingly engages the lower end of sub  51  as noted by numeral  151  in  FIG. 2C , and is contained within the illustrated annular spring chamber  55 . As seen in  FIG. 2D , the lower end of spring  54  abuttingly engages the upper enlarged end of sleeve  156 , while the opposed circumferentially extending end  58  of sleeve  56  bears against internal shoulder  59  of the main housing. Sleeve  56 ,  156  can be moved axially within its chamber  154  between spring  54  and shoulder  156  responsive to movement of main shaft  43 . The sleeve has a counterbore forming an interior shoulder at  156  which abuttingly engages a complimentary shoulder  157  formed on enlargement  57  of latch member  60  that is formed at the lower end of main shaft  43 . Hence, lower terminal end  356  of sleeve  156  abuttingly engages shoulder  59  formed internally on main housing  149 . Enlargement  60 , which is part of latch apparatus  60 , 61  is a continuation of main shaft  43  and forms the male latch part  143 , 156 , 57 , the skirt  356 , and the enlargement  60  at the lower terminal end thereof. Male latch part  60 , when forced into the interior of female latch member  61  of the latch device  60 , 61 , occurs responsive to downhole movement of the main housing which concurrently compresses the before mentioned three spaced biasing or spring members seen in stored energy chambers  149 ,  147  and  55  when the tool is reset into the standby configuration, ready to deliver a jarring action. At terminal end  63  of enlargement  60  is a passageway  132  that is a continuation of passageway  32  that slidably receives through tube  32  therewithin, remembering that the tube is anchored to the before mentioned seal  142 , and thereby enables relative movement between main shaft  43  and the through tube  32  while the tube  32  forms a protective housing for conductor  34 . It should be noted at this time that the conductor  34  does not significiently telescope respective to the telecoping tube  32 .  
         [0049]     As further seen in  FIGS. 2D and 2E , releasable latch apparatus  60 , 61  includes female member  61  made of a multiplicity of radially arranged, circumferentially extending, longitudinally disposed resilient fingers  62  which enlarge at  64  to threadedly engage elongated lower main shaft member  65  while the lower end of main housing  149  threadedly engages a bottom closure member in the form of a sub  66  (see  FIG. 2D ). Sub  66  includes guide pin  168 ′ received within a keyway or spline  168  formed on lost motion coupling  68  to maintain closure member or sub  69  of lower housing  249  and sub  66  of upper housing  149  aligned respective to one another as the confronting faces  70 ,  71  of the spaced jar tool subs  66 ,  69  are moved towards and away from one another, but always remain spaced apart from one another a slight amount after the tool is scoped together for reset, and assumes the illustrated configuration of  FIGS. 2D,2E  following a jarring action and prior to reset. The spaced distance between subs  66 ,  69  is the measure of one stroke.  
         [0050]     In  FIGS. 2E and 2F , sub  69  is seen to include a radially formed longitudinal counterbore that forms blind passageway  73  within which a guide member  72  is reciprocatingly received such that upper terminal end  74  thereof is always spaced from the blind end of the counterbore that forms radial passageway  73 .  
         [0051]     As particularly illustrated in  FIG. 2E , one end of guide member  73  is affixed to a pressure differential traveling piston  74 . The piston has seals grooves  75  suitably formed thereon, thereby isolating chambers  76 ,  77  from one another as fluid enters and leaves through the ports  78 , thereby isolating chamber  77  from well fluids while subjecting chamber  76 , to the hydrostatic head of the well fluids.  
         [0052]     Chamber  77  is filled with a non-compressible, non-conducting mineral oil to reduce the likelihood of well fluids contaminating the electronic components of the jar tool.  
         [0053]     Accordingly, piston  74  moves in low friction relationship respective the interior of main housing  249  and the exterior surface of through tube  32  through which conductor  34  extends, thereby avoiding contamination of the interior of tube  32 .  
         [0054]     Conductor  34 , as shown in  FIG. 2E , is formed into a looped or serpentine configuration as indicated at numeral  80 , allowing the feed through wire tube  32  to move along the central axis of the jar tool while always having slack at  80  in order to accommodate undue wire tension during reciprocation of tube  32  within main shaft member  43 , noting that tube  32  reciprocates concurrently respective sub  49  seen at the anchor seal at the upper end of the jar tool. Enlargement  81  forms a stop member on the interior of main housing  249  for limiting travel of piston  74  in the unlikely event of leakage of well fluid thereinto.  
         [0055]     In  FIG. 2F , the lowermost end of conductor  34  is received by electrical connector  82  and continues through lowermost sub  83  that forms the lower terminal end of jar tool  16  and thereby enables jar tool  16  to be connected to any desired apparatus at threaded end  283 . As further seen in  FIG. 2F , a connector  84  is received within enlarged axial counterbore  85  for conducting current flow at  86  to and from the illustrated instrument package  24 . Seals  87  and  88  prevent entry of fluid into the lower end of jar tool  16 .  
         [0056]      FIG. 4  illustrates a hypothetical analyses of the action of jar tool  16  during one jar action. Curve  4  is a plot of the wire line tension commencing with the tool static, hanging free within the in borehole. Curves  1 - 3  illustrate the upthrust realized from each of the three spring or stored energy chambers. The remaining curve that reaches 1,000 pounds is the sum of curves  1 - 4 .  
         [0057]     Characteristics of curves  1 - 3  can be modified by various changes to the tool as set forth herein, and this, of course, results in a modification of the 1,000 pound curve. In actual practice, it is possible to develop approximately 3,000 pounds upthrust with this embodiment of the invention.  
       In Operation  
       [0058]     In operation, the assembled jar tool  16  is adjusted or set to be actuated at a predetermined fraction of the maximum tensile strength of the E-line. For example, if the E-line breaking strength is 1,000 pounds, the operator may elect to adjust the release tension of the tool latch  61  to be triggered by an uphole force of 200-300 pounds, as read on a weight indicator. This is the force required for the E-line to trigger or pull the male end  60  from the female end  62  of the releasable latch member  60 , 61 . Resetting the tool for subsequent jar actions requires a downhole force applied to the upper end of the jar tool, similar to the releasing force, depending on the design of releasable latch member  60 , 61 . Hence, sinker bar  22  must be of a weight greater than the releasing value of latch  61  in order to be on the safe side. Those skilled in the art know to consider the entire weight of the E-line and tool string when viewing the weight indicator at the surface.  
         [0059]     Adjusting nut  52  should be set by the shop technician who should make certain that latch means  61  is also adjusted into proper position respective sleeve  56 , and reduced diameter passageway at  349 , at this time by properly spacing out the component parts of the jar tool. Adjusting nut  44 , located immediately adjacent the upper stored energy or spring chamber  146 , is rotated or set for minor adjustments in the field. This action gains the desired releasing value of latch assembly  61  and is realized through trial and error while studying the situation using a suitable weight indicator for accuracy.  
         [0060]     The adjustments of nut  44  pre-loads the three spring chambers of the upper spaced spring chambers which in turn places a continuous uphole force on male member  60  of releasable latch assembly  60 , 61 . Accordingly, this action commences a releasing action which is somewhat analogous to the action of the E-line as the release tension force is applied.  
         [0061]     The complex action of the jar tool is easily comprehended when it is appreciated that the operating mandrel or main shaft  43  extends from enlargement  43 ′ located at the upper extremity thereof and extends through first spring chamber  146 , through second spring chamber  147 , through sub  50 , adjustment nut  52 , and operating chamber  152 , where it is joined to the threaded internal connector  51 , continues through the third and lowermost spring or energy storage chamber  55 , and terminates as the illustrated male part  60  of releasable latch device  61 . The main shaft  43  therefore can be forced to slide axially between the limits provided by opposed confronting faces  151 ,  252  and  250 ,  152  within chamber  350 .  
         [0062]     In  FIG. 2D , hammer  166  and anvil  165  are illustrated in the impact position.  
         [0063]     Male release member  60  together with female latch member  61  are unique in that it cooperates with the third spring chamber  55  in several different manners. Note sleeve  56  is slidably received within the third spring chamber  154  and has an enlargement  156  thereon that abuttingly engages power spring  54  as well as the enlarged diameter part  349  that forms shoulders  59 ,  59 ′ formed on an inner limited length of main upper housing  149 . Also note enlarged member  57  on latch member  60  that is also part of the main shaft  43  and engages member  156  at shoulder  157 . Further, sleeve  56  has a downhole end  58  that abuttingly engages shoulder  59  of outermost housing  249 . The third spring  54  biases sleeve  56  downhole while abutting internal slidable connector  51  to thereby provide part of the stored energy for contributing to the upthrust of main body  49  together with the other biasing means or stored energy devices of this disclosure. Hence, sleeve  56  is always biased or urged downhole against shoulder  59  by adjacent spring  54  as shown, except when main upper housing  149  moves downhole towards lower main housing  249  during reset. In order for connected or engaged latch assembly  61  to telescope into smaller diameter chamber  260 , the latch parts  60 ,  61  must be fully engaged while they are within the large diameter latch chamber  261 , because the latch assembly  61  cannot be reset nor released once it is positioned within small diameter chamber  169 , due to the relative diameters of the coacting members.  
         [0064]     The latch  60  telescopes into chamber large diameter bore that forms chamber  261  where latch parts  60 ,  61  have ample room to expand into latched engagement, while they are within the large part  349  of the latch chamber. Hence the latch cannot be set nor released once it is positioned within small diameter bore  359  of chamber  260 .  
         [0065]     Those skilled in the art having digested this disclosure will appreciate that the lower main housing of the jar tool, when stuck or otherwise held stationary, while the upper box end  30  is forced downward respective thereto, the lost motion coupling  68  telescopes into closure member or sub  66 , while the anvil  65  is reposition further towars the upper tool end as the main housing decends, thus moving the latch means and anvil uphole away from hammer  65  concurrently with the separation of faces  70 ,  71 , respectively, of the confronting subs  66 ,  69  while at the same time moving enlargement or anvil  65  along with the female latch part  162  into the latched position, which occures only in the large diameter latch chamber. Accordingly, confronting faces  70 ,  71  of the main chamber members are brought into proximity of one another, but preferably, they always remain slightly spaced apart.  
         [0066]     At this time, main housing  49  connector sub  50  contacts nut  52 , thereby forcing main shaft  43  downhole which compresses each spring associated with the three spring chambers  146 ,  147 ,  155  and latches members  60 ,  62  together.  
         [0067]     During this movement, the male latch part  60  is telescopingly received within the resilient fingers  62  of the female member of the latch device  61  as the female part  62  encapsulates the downwardly moving male part  60  of the latch device  61 , 61 . Simultaneously with this action, energy is stored within the three spring chambers.  
         [0068]     In addition to the ability to preload the various springs by addition of spacers and the like, the adjustment means  44  near the upper end of the main shaft as well as the other adjustment means  52  located within chamber  53  between sub  50  and internal slidable connector  51  are adjusted to control the required tension in the E-line for triggering the release of latch  60 , 61 . It should be noted that the uphole enlarged terminal end of main shaft  43  is always spaced from anchor and seal means  42  as shown to prevent impact therebetween. Further, nut  44 , when torqued against spring device  46 , preloads both the first and second spring devices with the equivalent of 50 pounds wireline tension, and consequently places an uphole force on male member  60  of the releasable latch device, thereby providing a means by which the tension in the E-line for releasing the latch device can be selected in the field.  
         [0069]     When adjusting nut  52  is moved along threaded surface  53 ′, the length of the jarring stroke is changed, while at the same time should the adjusting nut  52  be torqued against the downhole face of sub  50 , this action will force male part  60  further into female part  61  of the latch device while pre-compressing the springs in all three stored energy chambers. Further, it should be noted that latch device  60 ,  61  can always be set into the latched position so long as the parts are properly spaced out to provide for the before mentioned adjustment.  
         [0000]     springs in all three stored energy chambers. Further, it should be noted that latch device  60 ,  61  can always be set into the latched position so long as the parts are properly spaced out to provide for the before mentioned adjustment.

Technology Classification (CPC): 4