US2091680A - Jar - Google Patents

Description

Aug. 3l, 1937. J. R. GREENLEE JAR Filed Feb. 1s, 1935 INVENTOR.

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BY 'R D ATTORNEY.

w B l i @lh I l I .I .I a l Patented Aug. 3l, 1937 UNITED STATES PATENT OFFICE 6Claiml.

This invention is a jar adapted to release a well string when stuck in a well bore, or to impart a jarring blow to a drill bit when drilling in hard formation; and has for its object to actuate the jar by electromagnetic means.

More particularly it is the object of the invention to provide a jar comprising a body adapted for incorporation in a well string and forming an anvil, and a cooperating harrmier adapted for reciprocation in the body to strike the anvil, the hammer being reciprocated by electromagnetic means.

It is a further object of the invention to incorporate the jar in a drill string so that when the jar is not in use drilling may progress in usual manner, with the drill string and the jar adapted for unobstructed circulation of drilling fluid both when the jar is inoperative and when it is in use.

It is a still further object of .the invention to provide simple means for transmitting electrical energy to the jar, the transmission means being readily run into the well string and connected to the jar when the latter is to be operated, and being as readily disconnected and removed when the jar is not in use.

It is a still further object of the invention to provide electromagnetic means for actuating the hammer, preferably adapted to alternately positively elevate and lower the hammer for alternately striking upward and downward jarring blows, with a control for the electromagnetic means arranged whereby at the will of the operator the hammer may be only positively elevated (being, lowered simply by gravity) so as to strike only upward jarring blows.

It is a still further object oi' the invention to provide a construction whereby tension may be maintained on the well string while striking the jarring blows, an arrangement which is particularly advantageous when releasing a stuck well string, in that an upward strain may be exerted on the string while it is being jarred loose.

Further objects of the invention will be readily understood from the following description of the accompanying drawing, in which:

Fig. 1 is an axial section through the ,lar incorporated in a drill string.

Fig. 2 is a diagram of the electromagnetic means.

Fig. 3 is a transverse section on the line 3 3 of Fig. l.

Fig. 4 is an enlarged axial section through the contact plug for the power cable.

'I'he jar comprises a tubular body adapted for (Cl. Z55-27) 5 The body preferably comprises a plurality of tubular sections having threaded connections for conveniently assembling the jar; and in the illustrated embodiment wherein an electromagnet elevates the hammer and an electromagnet is 1 also provided for positively lowering the hammer, tubular sections I 2 for the electromagnets are connected by a tubular section 3 which forms vertically spaced upper and lower anvil surfaces 4 5. A sub 6 extends upwardly from sec- 1 tion I and carries contact means whereby an electric cable may be connected to the jar; and a sub 1 depends from the section 2 and supports a wash pipe 8 which extends through the jar. The threaded connections for these various sections of the body are shown at 9.

The sub 6 at the top of the body is suspended from the upper portion A of a well string, for examplea string of drill pipe, by means of a usual threaded coupling I0, and the sub 1 at the lower end of the body is connected by threaded coupling Ila to the lower portion B of the well string.

An electromagnet I 6 is mounted in section I, being preferably wound on a spool I1 which is held in place between abutment surfaces formed by the proximate ends of sections 3 6; and in similar manner an electromagnet I8 is mounted in section'2, being wound on a spool I9 which is supported between abutment surfaces formed by the proximate ends of sections 3 1. The wash pipe 8 extends through the bores of spools I1 I9 and throughy the sections 3 1 with its upper end threaded into the bore of section 6 as shown at Il and its lower end depending from section 1 and adapted toreceive a nut Il for holding the wash pipe in place.

The hammer comprises a head 2l slidable on pipe l in an enlarged bore 22 of section 3, and having upper and lower striking surfaces 2& 24 which respectively cooperate with anvil surfaces 4 5. Sleeves 25-26 respectively project upwardly and downwardly from head 2| and are slidable on the pipe 8 in the bores of spools I1 I9; and the sleeves 25-26 are cores which are respectively attracted by the electromagnets II I8 when the latter are energized. The core 25 together with its electromagnet I6, and the core 28 together with its electromagnet I8, thus constitute solenoids for actuating the hammer.

leads from the socket through a transverse bore 32 which is formed in the sub. The cable exltends downwardly through a vertical bore 33 in the sub, and thence through the electromagnet I6 and through a bore 34 in the section 3. As shown at Fig. 2. thewires 35-36 of the cable are connected to the respective electromagnets I6-I3, with the opposite ends of the electromagnets grounded on the body of the jar as shown at 31-38.

In the illustrated embodiment ofthe invention the socket is of insulating material as shown at Fig. 4 and supports contact sleeves 40-4I, insulated from one another at 42 and connected to the respective wires 35-36. A plug 43 is adapted for reception in the socket 30. and comprises contacts 44-45 insulated from one another as shown at 46, and respectively making electrical connection with the contacts -4I when the plug is inserted in the socket. are connected to the contacts 44-45, and extend upwardly through a cable 49 from which the plug 43 is suspended. The plug 43 is run into the drill string on the cable 49; and the cable is prefb erably weighted as shown at 50 and the mouth of socket 30 may be ared as shown at 5I, to insure the plug seating in the socket.

Circulation is provided around the socket 30, and for this purpose the bore of sub 6 may form an enlarged chamber 55 surrounding the mouth of socket 30 and communicating with the circuflation bore of drill string A, and bores 56 may extend downwardly through sub YIl from the chamber 55, with the bores 56 communicating via a chamber 51 with the lower end of the bore of sub 6 which in turn communicates with the wash pipe vIi. The wires of cable 49 are connected to a suitable source of electrical energy; and the circuits through the wires 41-48 for the respective electromagnets are adapted to be alternately made and broken. For this purpose suitable switch mechanism may be provided at the earths surface, and the cable 49 is wound on a suitable reel (not shown) whereby the cable may be run into the drill pipe for making electrical connections at the plug and socket 43-30, and at the top of the well bore the wires 41-48 lead from the cable to the switch mechanism via any usual connections (not shown). I

The switch mechanism may be of the type shown at Fig. 2, comprising a pivoted arm v6I) having contacts ISI-62 at its ends cooperating respectively with contacts 63-64. Electromagnets 65-66 cooperate with the respective ends of the pivoted arm, so that when alternately energized the arm is rocked to alternately make and break the contacts ISI-63 and at the same time alternately break and make the contacts 62-64. The electromagnets 65-66 may be respectively energized by local circuits 61-68 and 61-69, the local circuits having brushes 10-1I which cooperate with a commutator 12. The commutator may be rotated by a motor 'I3 through gear reduction 14, and has circumferentially spaced contacts whereby rotation of the commutator alternately energizes the local circuits. The wires 41-48 are connected to the contacts' 63-64, and one side of a power circuit leads to the arm 60 as shown at 16 and thence through the arm to its Wires 41--46 contacts 6I-62, with the other side of the power circuit grounded as shown at 11.

The arm 60 being oscillated by the rotation of commutator 12, a power circuit is closed through electromagnet I6 via 16, 60, 6I, 63, 41, and 35 and at the same time the power circuit for electromagnet I8 is broken at 62--64 (see Fig. 2); and

then the circuit for electromagnet I6 is broken at 6I-63 and the circuit for electromagnet I8 is closed via 16, 60, 62, 64, 48, and 36. The electromagnetsv I6I8 are thus alternately energized, and the frequency of alternation is preferably adjustable at the will of the operator. This is accomplished by varying the speed of rotation of commutator 12, which may be done by employing a manually controlled variable speed gear reduction 14.

The electromagnets I6-I8 being alternately energized, the electromagnet I6 will rst attract its armature 25 so as to elevate hammer 2| and cause it to strike an upward jarring blow against anvil 4; and when electromagnet I6 is 'subsequently deenergized and electromagnet I8 is energized, the latter will attract its armature 26 and positively lower the hammer so that it strikes a downward jarring blow against the anvil 5. The operation is then repeated, due-to the continuing oscillation of arm 60.

If it is desired to strike only upward jarring blows the circuit for electromagnet I8 is left open, as for example by opening a switch 8D in the wire 48. When energized, the electromagnet I6 will thus elevate the hammer to cause an upward jarring blow, but when the electromagnet is then deenergized the hammer will drop simply by gravity without striking any appreciable downward blow, ready to be again elevated when the electromagnet I6 is againv energized.

It will also be apparent that if only upward jarring blows are desired, the electromagnet I8 and its power circuit may be completely eliminated when constructing the jar.

In operation the jar is incorporated in a well l string and the cable 49 may be withdrawn while the jar is not in use, with unobstructed circulation via the bores 56 and the wash pipe 8. When it is desired to jar the well string, the cable 49 is run in until plug 43 seats in socket 30, vand the leads 16-11 are connected to a suitable source of electrical energy. The motor 13 is started, and the -gear reduction 14 is adjusted to provide the desired frequency of jarring blows, the switch 80 being closed if both upward and downward jarring blows are desired, or the switch 80 being opened if only upward jarring blows are desired. During the jarring action circulation may be continued via the bores 56 and the wash pipe 8, and tension may be maintained on the well string throughout the jarring action if so desired.

The invention thus provides for electromagnetically operating a jar so as to strike positive upward and downward jarring blows or only positive upward blows, with the frequency of the jarring blows readily controlled, and with the electromagnetic means readily connected to a suitable source of electrical energy whenever the jar is to be used. '4

The invention also provides a jar which may be employed for releasing a well string which has become stuck in a well bore, or for imparting a jarring action to a drill bit during the drilling operation.

It will also be apparent that the electromagnets Iii- I8 may be of a type adapted for operation by direct current, or may be of a type designed for operation by alternating current, the proper type of electromagnets being selected in accordance with the available electrical energy.

I claim:

1. In a jar, spaced anvils, a hammer, and a pair of electromagnets each adapted to be energized and deenergized, one of said electromagnets when energized being adapted to move the hammer in one direction to strike one of the anvils, and the other electromagnet when energized being adapted to move the hammer in the opposite direction to strike the other anvil.

2. In combination, a body, an anvil associated with the body, a hammer, electrical means associated with the body for operating the hammer to strike the anvil, and an electrical contact for said means mounted in the body and adapted for releasable engagement by a cooperating contact of an electrical power transmitting cable.

3. In combination, a body adapted for incorporation in a Well string, an anvil associated with the body, a hammer, electrical means associated with the body for operating the hammer to strike the anvil, and an electrical contact for said means mounted in the body in alinement with the bore of the well string, the body having a bore extending around the contact and communicating with the bore of the well string, and the contact being adapted" for releasable engagement by a cooperating contact of an electri cal power transmitting cable which extends through the bore o1 the well string.

4. In a jar, spaced anvils, a hammer, operating means supported by the Jar and adapted to move the hammer in one direction to strike one of the anvils, and operating means supported by the :lar and adapted to move the hammer in the opposite direction to strike the other anvil.

5. In combination, a well string, a body, means for suspending the body from the well string so that upward strain exerted on the well string is imparted to the body, means for connecting the body to a depending element so that upward strain exerted on the body is imparted to said element, an anvil rigid with relation to the body, a hammer movable longitudinally with relation to the body and the well string, and electromagnetic means supported by the body for elevating the hammer to strike an upward jarring blow against the anvil.

6. In combination, a well string, a body, means for suspending the body from the well stringso that upward strain exerted on the well string is imparted to the body, means for connecting the body to a depending element so that upward strain exerted on the body is imparted to said element, an anvil rigid with relation to the body, a wash pipe extending longitudinally through the body, a member in the body slidable on the wash pipe relative to the body and the well string and including a hammer and a core, and electromagnetic means supported by the body and co-` operating with the core for elevating the hammer to strike an upward jarring blow against the anvil.

JOSEPH R. GREENIEE.

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