US3419088A - Apparatus for perforating wells - Google Patents

Description

Dec. 31, 1968 Filed July 7, 1967 R. H. GRAY 3,419,088

APPARATUS FOR PERFORATING WELLS i QQ.

JZeHZO/i' if W Dec. 31, 1968 R. H. GRAY 3,419,088

APPARATUS FOR PERFORATING WELLS Filed July 7, 1967 Sheet 2 of 2 nited States atent O 3,419,088 APPARATUS FOR PERFORATING WELLS Richard H. Gray, Houston, Tex., assignor to Gramar Company, Houston, Tex., a corporation of Texas Filed July 7, 1967, Ser. No. 651,887 7 Claims. (Cl. 1754.51)

ABSTRACT OF THE DISCLOSURE Apparatus for orienting a through-tubing perforating gun in a multiple completion well for perforation of the well casing without damage to the tubing strings, comprising a pair of vertically spaced side kickers on the gun having releasable arms for outward extension within the casing and switch means actuated only upon a predetermined outward extension of the arms correlated to the diameter of the casing so that the switch means cannot be actuated if the gun is either within or interfers with a tubing string, the switch means and release means for the arms being connected in series with one another and the gun so that the second side kicker cannot be released until the arm on the first side kicker is fully extended and the gun cannot be fired until the arms of both side kickers are fully extended.

The drawings FIGURE 1 is a schematic diagram of a multiple completion well showing the apparatus of the invention in the process of being lowered through one tubing string which terminates at a level above the lower end of another tubing string.

FIGURE 2 is a vertical section of the upper side kicker showing the same in latched position.

FIGURE 3 is a view smiliar to FIGURE 2 showing the upper side kicker in unlatched, extended position.

FIGURE 4 is a view like FIGURE 2 showing the lower side kicker.

FIGURES 5, 6 and 7 are schematic diagrams of the electrical circuitry of the tool.

The drawings and the following description are given for purposes of exemplification to those skilled in the art of the best mode contemplated by me of carrying out my invention.

Description Referring to FIGURE 1, a conventional multiple completion oil well is illustrated as comprising an outer well casing 10, a first string of tubing 12 extending through the casing to a lower producing zone, a second string of tubing 14 terminating above the lower extremities of the first string for production at a second and higher zone, and packing means 16 sealing off the respective zones.

To accommodate oil production at the upper zone, a perforating gun is lowered through the tube 14 until the gun is disposed in the casing below the lower end of the tube, whereupon the explosive charges carried by the gun may be detonated or fired to shoot several holes in the wall of the casing between the packing glands, thereby to accommodate entry of oil into the casing and the tube 14.

In the drawing, the tubing strings have been illustrated as being straight and perfectly parallel. In actual practice, however, the strings may be skewed or canted so that from the surface of the earth it is impossible (without appropriate tools and instruments) to determine precisely where the first string 12 will be located relative to the second string 14. Consequently, unless the perforating gun can be precisely located relative to the two strings, there is a strong likelihood of perforating the tube 12 rather than the casing 10.

According to the present invention, means are provided for the multiple purposes of (1) preventing firing of the gun should it fail to clear the tube 14, (2) orienting the gun in the casing so that there is no likelihood of perforating the tube 12, and (3) positioning the gun with the charges thereof against the casing wall for optimum perforating performance. A preferred embodiment of the composite tool is indicated generally at 20 in FIGURE 1, the tool being adapted to be lowered through the tube 14 by means of the electrically conductive wire line 18 conventionally employed in the well service art.

The tool is comprised of an upper side kicker 22 suspended on the line 18, a conventional perforating gun 24 which may have either fixed or swing charges of either the jet or projectile type, and a lower side kicker 26.

The upper side kicker is comprised of a generally tubular housing 30 having a vertical slot or opening 32 in the side wall thereof at a location diametrically opposite the direction in which the charges of the gun are faced. Pivotally mounted in the housing is an arm or lever 34 aligned with and adapted to extend through the slot. A tension spring 36 connected between the housing and the lever acts to urge the lever outwardly toward a radially extended position. As the tool is lowered into the well, the lever is latched within the interior of the housing parallel to the gun by a suitable releasable retainer, which I refer to provide in the form of a small explosive squib 38.

The side kicker also includes a double pole double throw switch 40 having a reciprocable actuating plunger 42 conneted by a link 44 to the lever or arm 34 for actuation thereby. One of the input terminals of the switch is connected to an electric power supply line 46 connected to or forming part of the wire line 18; one output terminal is connected to the squib 38 and another output terminal is connected to a connecting line 48 extending from the upper side kicker to the lower side kicker. In the latched position of the lever 34 as shown in FIGURE 2, the power supply line 46 is conected through the switch 40 to the squib 38, and the adjacent end of the connecting line 48 is grounded as shown schematically in FIGURE 5. In this position, the squib 38 may be fired by supplying current thereto via the line 46 from the surface of the earth.

When fired, the squib 38 disintegrates thereupon releasing the lever 34 for outward swinging movement under the bias of spring 36. The lever thus swings outward toward the wall of the casing 10 and forces the gun into engagement with an opposite portion of the casing wall. The connection between the switch plunger 42 and the lever 34 is such that the switch can be thrown into its second switching position only upon a predetermined amount of movement of the lever. The lever in turn is constructed in correlation with the diameter of the casing 10 so that said predetermined amount of movement occurs only when both the gun and the lever are a'butted against opposite surfaces of the casing wall. Consequently, if the squib 38 is fired while the upper side kicker is still within the interior of the tube 14, the switch cannot close in its second switching position. Likewise, if the tool was below the tube 14 but abutted against the tube 12, the lever could not move sufiiciently to close the switch in its second switching position. If desired, the tool could be equipped with rotating means (not shown) to rotate it out of the latter position and into a position accommodating full extension of the lever arm 34.

In any event, when the lever arm is fully extended, the plunger 42 is moved sufficiently to close the switch 40 in its second position, wherein it connects the supply line 46 to the connecting line 48, as shown in FIGURES 3 and 6.

The lower side kicker 26 is substantially identical to the upper side kicker 22 and corresponding parts are therefore indicated by the same reference numerals with the suflix a. In the latched position of the lever 34a, the lower switch 40a connects the connecting line 481 to the latching squib 38a as shown in FIGURES 4, and 6. Until the upper side kicker arm is fully extended, the line 48 is grounded, as is the squib 38a, so that said squib cannot be fired inadvertently or at an improper time. Once the upper arm has been fully extended, the supply line 46 is coupled to the lower squib 38;: via switch 40, line 48 and switch 40a. A short supply of current will then serve to detonate squib 38a to release the lower lever arm 34a. Again, if this arm cannot reach a fully extended position, the switch 40a cannot be closed in its second switching position and no further functions can be performed.

If the tool throughout its entire length can be abutted against the casing wall, both arms will be fully extended and the switches 40 and 40a will be closed in their second switching positions. In this condition of the circuit, as shown in FIGURE 7, the supply line 46 is connected via switch 40, line 48 and switch 40a to a detonating line 50 leading to the detonating means, such as a blasting cap 52, for the explosive charges of the gun. Preferably, a resistor 54 is connected in series with the detonating means thereby to afford the safety factor of a higher voltage requirement for detonation of the guns than for releasing the side kickers, thereby to mitigate against inadvertent firing of the gun.

Should the tool, in the process of actuating the lower side kicker, become disoriented at the upper side kicker, or be raised partly back up into the tube 14, the upper lever arm 34 will be partly retracted, thereby opening switch 40 to prevent improper firing of the perforating charges.

Should the gun fail to fire, or should it be decided at the last moment not to perform the perforating function, withdrawal of the tool into the tube 14 will depress the lever arms 34 and 34a and operate first to open switch 40 and subsequently to open switch 40a thereby further insuring against inadvertent or improper firing of the perforating charges.

It is apparent therefore that the present invention provides an economical, convenient and practical means for (1) preventing improper and/ or untimely shooting of perforating charges, (2) insuring proper orientation of the perforating tool throughout its full length to eliminate the possibility of perforating either the tube 12 or the tube 14, and (3) positioning the gun with its charges against the casing wall for optimum perforating performance.

While I have shovm and described what I regard to be the preferred embodiment of my invention, it is to be appreciated that various changes, rearrangements and modifications may be made therein without departing from the scope of the invention, as defined by the appended claims.

I claim: I

1. Orienting means for well perforating guns comprising a pair of side kicker assemblies mounted in vertically spaced relation to one another on the gun; each of said side kicker assemblies comprising an arm movable from a position parallel to the gun to a position radially extended from the gun, means biasing said arm to its radially extended position, means normally retaining said arm in its said parallel position against said bias and including means for remote operation to release said arm, and switch means actuated by said arm upon predetermined radial extension thereof; the switch means and the release means of the two assemblies being connected in series with one another and the gun so that one of said arms must be released and extended said predetermined amount before the second arm can be released and both arms must be released and extended said predetermined amount before the gun can be fired.

2. Orienting means as set forth in claim 1, one of said assemblies being mounted at the upper end of the gun and the other being mounted at the lower end of the gun.

3. Orienting means as set forth in claim 1, each of said assemblies comprising a generally tubular housing of approximately the same diameter as the gun and having an opening in the side wall thereof, said arm comprising a lever pivotally mounted in said housing in alignment with said opening, said biasing means comprising a spring connected to said arm and housing and normally biasing said lever to the position radially extended from the housing, said switch means including a reciprocable plunger pivotally connected to said lever for actuation thereby, and said retaining means comprising an explosive squib mounted on said housing adjacent the lever for normally retaining the lever within the interior of said housing.

4. Orienting means as set forth in claim 1, said switch means each comprising a double pole double throw switch, a power supply line running from the surface to one of said switches, a connecting line running from said one switch to the other switch and a detonating line running from said other switch to the gun, said one switch in the parallel position of its said arm connecting said supply line to its release means and grounding said connecting line, said one switch when its said arm is extended said predetermined amount connecting said supply line to said connecting line, said other switch in the parallel position of its said arm connecting said connecting line to its release means and grounding said detonating line, said other switch when its said arm is extended said predetermined amount connecting said connecting line to said detonating line.

5. Orienting means as set forth in claim 4, said retaining means each comprising an explosive squib.

6. Orienting means as set forth in claim 4 including a safety resistor in series with said detonating line.

7. Orienting means for well perforating guns comprising a pair of side kicker assemblies mounted at the opposite ends of the gun; each assembly including a generally tubular housing connected to the respective end of the gun and having an opening in the side wall thereof, a lever pivotally mounted in the housing in alignment with the opening, an explosive squib mounted in the housing adjacent the lever for normally retaining the lever within the interior of said housing, a spring biasing said lever toward a position radially extended from said housing, and a switch having a plunger connected to said lever for actuation thereby; a power supply line running from the earths surface to the switch of the upper assembly; a connecting line extended between the two switches; and a detonating line running from the switch of the lower assembly to the gun; the switch of the upper assembly when the lever thereof is within the interior of the upper housing connecting said supply line to the squib of the upper assembly and grounding said connecting line, and when the lever thereof is pivotally extended a predetermined amount connecting said supply line to said connecting line; the switch of the lower assembly when the lever thereof is within the interior of the lower housing connecting said connecting line to the squib of the lower assembly and grounding said detonating line, and when the lever thereof is pivotally extended a predetermined amount connecting said connecting line to said detonating line; so that the squib of the lower assembly cannot be fired until the lever of the upper assembly is extended said predeter- 5 6 mined amount and the gun cannot be fired until the levers 3,064,571 11/1962 True 175-451 of both assemblies are extended said predetermined 3,168,141 2/1965 Lebourg 1754.51 amount. 3,338,317 8/1967 Shore 1754.51

References Cited UNITED STATES PATENTS 5 DAVID H. BROWN, Primary Examiner. 3,058,522 10/ 1962 McElheny 1754.54 US. Cl. X.R

3,063,372 11/1962 Diebold 175-4.51 166-63

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