US2829190A - Subsurface electric cable protector and guide - Google Patents

Description

SUBSURFACE ELECTRIC CABLE PROTECTOR AND GUIDE Harold Comlossy, Jr., Whittier, (Ialifi, assignor to Baker Oil Tools, Inc., Los Angeles, Calif, a carporation of California Application September 8, 1953, Serial No. 378,948

5 Claims. (Cl. 174-47) The present invention relates to well apparatus, and more particularly to apparatus adapted to be run and usedwithin a well bore.

In the removal of fluid, such as oil, from a well bore, an electric motor and pump combination may be run in the well bore on a tubing string to the desired depth. Current for the motor is carried from the top of the well bore through a suitable cable connected to the motor. The motor drives the pump which forces the fluid up through the tubing string to the top of the hole.

The tubing string is made up of sections connected to each other as the tubing string is lowered in the well bore. At the same time the conductive cable, which is connected to the electric motor, is also fed into the well bore alongside the tubing string sections. During the running of the tubing string and cable in the well bore,

the cable oftentimes twists and wraps itself around the tubing, or it may become pinched or jammed between the tubing and the surrounding well bore or casing, causing failure of the cable. Such occurrences may also create difliculty in later removing the tubing string and cable from the well bore. The electric cables are expensive and their twisting and wrapping around the tubing string, or pinching, may result in their severance, or in otherwise being rendered unfit for further use.

Accordingly, it is an object of the present invention to provide apparatus for preventing the electric cable from twisting itself around the tubing string, or from becoming jammed between the tubing string and the wall of the surrounding well bore or casing containing the tubing string.

Another object of the invention is to provide apparatus releasably secured to a tubing string disposed in a well bore, which protects an electric cable disposed alongside the tubing string.

A further object of the invention is to provide an electric cable protecting apparatus that is easy to mount upon and remove from a tubing string adapted to be disposed in a well bore.

This invention possesses many other advantages, and

has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification.

It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Eigure l is a side elevational view of apparatus embodying. the invention disposed in a Well bore;

Fig- 2. is a greatlyenlarged cross-section taken along the Intel-.2 on Fig. 1; 1

Fig.3 is an isometric. projection disclosing one of .the cable prot ective devices, adapted for mounting .on. the

ta n w s.

atent As disclosed in the drawings, a tubing string A is disposed in a well casing B located in a well bore C, from which fluid, such as oil, is to be pumped. The tubing string includes the usual tubing sections 10 connected together by coupling collars 11, the lower portion of the tubing string being connected to an electric motor 12 which is to drive a pump 13. As is well known, the pump forces the well production up through the tubing string A to the top of the well bore.

Current is fed to the electric motor 12 from the top of the hole by means of a suitable electric conductor or cable 14, usually disposed alongside the tubing string and between the tubing string and the surrounding casing B. The lower portion of the electric cable 14 is connected to the electric motor 12, whereas its portion above ground passes over a suitable winding drum (not shown), for lowering and elevating the cable in the well casing.

Since well bores are practically never truly vertical throughout their length, the well casing B and the tubing A will assume a somewhat sinuous form when disposed in the well bore C. Thus, the string of tubing A may very well lean over against the casing B at certain points, where jamming or pinching of the cable therebetween can occur. This jamming or pinching action is enhanced considerably, with corresponding deleterious effects on the electric cable, while the tubing string A and cable 14 are being run simultaneously in the well casing, since the cable will be rubbed with substantially great force along the inner surface of the well casing B.

In the running of the apparatus in the well casing, the tubing sections 10 are coupled to each other at the top of the hole, the tubing string A, with the electric motor 12 and pump 13 at its lower portion, then being lowered in the well casing B, the cable 14 also being fed into the well casing at the same time. When it is considered that the tubing string A may be many thousands of feet in length when the electric motor 12 and pump 13 are disposed at their desired location in the well casing, it is quite evident that great harm can be done to the electric cable during its running in the well casing. In addition, the cable 14, while being fed into the well casing, may move around the tubing string A and wrap itself around the latter, to cause additional jamming or pinching between the tubing string A and the well casing B.

The present invention overcomes the aforenoted difiiculties. At regular intervals along the length of the tubing string A, for example, about every sixty to eighty feet, a protective collar or ring 15 is secured to the tubing string A. Each protective collar or ring may consist of a sleeve or ring portion 16 adapted to snugly embrace the exterior of the tubing string A. This ring or sleeve portion has a pair of longitudinally extending and spaced guide ribs or runners 17 secured to it and extending laterally outward from the ring. The runners 17 are separated arcuately from one another a sufficient distance to acommodate the electric cable 14. They also extend laterally outward from the periphery of the ring 16 a sufficient distance to engage the casing B and force the tubing string A in the opposite direction to a position adjacent the diametrically opposite portion of the casing. Thus, with one side of the tubing string A being forced adjacent the wall of the casing B (Fig. 2), the outer edges 13 of the runners or guide ribs 17 extend adjacent the diametrically opposite portion of the casing wall. Actually, there is ample space and running clearance between the tubing string A and runners 17, on the one hand, and the wall of the casing B, on the other hand. However, the runners 17 are not disposed sufficiently away-from the wall of the casing to allow the electric cable 14 to pass or be jammed between the outer edges -18 of the runners and the wall of the casing B.

The runners 17 are secured to the ring 16 in any suitable manner, as by welding. The inner portions 19 of the runners are notched, the base 2t of the notch engaging the periphery of the ring 16 and the upper and lower sides 21, 22 of the notch engaging the upper and lower ends, respectively, of the ring. The runners i7 are mounted on the ring 1-6 the appropriate arcuate distance apart to accommodate the electric cable 14, with the ring disposed in the notches 19, the runners then being welded to the ring by applying suitable welding material along the upper and lower sides of the ring, its outer periphery and the adjacent portions of each runner. in this manner, the runners are strongly integrated to the ring 16.

The runners 17 have their outer intermediate portions 24 extending parallel to each other and to the axis of the ring 16, these outer intermediate portions or surfaces being adapted to slide along the wall of the casing B. The upper and lower ends 25 of the runners are tapered to guide the runners properly along the casing and past any spaces in the casing that might exist between casing sections, which are usually secured together by easing collars (not shown). As a matter of fact, the runners 17 are substantially longer than the usual coupling spaces between adjacent casing sections, so that the device cannot hang up on the casing sections during their lowering with the tubing string A in the well casing B.

For the purpose of facilitating mounting of each protective device 15 on the tubing string, the ring 16 is preferably made in sections 16a, or in split fashion, each section being substantially semi-cylindrical. The sections 16a are secured together by diametrically opposed hinges 26. Thus, hinge plates 27 of a hinge may be secured to the exterior of the ring sections 16a, as by spot welds 28, the hinge knuckles Z interleaving and being secured to one another by a suitable hinge pin 30 extending therethrough. When one of the hinge pins 39 is removed, as shown at the right portion of Fig. 3, then the split ring 16 may be opened, its two halves 16a swinging about the axis of the other hinge pin 30, allowing the ring to be mounted transversely over a tubing section 19, whereupon the split ring is closed and the other hinge pin 3t! inserted through the hinge knuckles 29, thereby completing the circumferentially extending ring 16.

The inside diameter of the split ring 16 is slightly greater than the outside diameter of the tubing section 10, which enables the ring to be secured firmly to the tubing section 1% through use of a plurality of set screws 31 threaded through the split ring, with their inner ends adapted to bear and bite into the tubing section. After the ring has been disposed around the tubing section, as

described above, the set screws 31, which are preferably only disposed on one segment 16a of the ring, are tightened against the tubing section 10, the inner ends of the set screws engaging the periphery of the tubing section, which forces the opposite side of the split ring 16 into close bearing engagement with the opposite side of the exterior of the tubing string (see Fig. 2). In the manner just described, the protective device 15 is firmly mounted on the tubing section it).

In the use of the apparatus, the electric motor and pump 13 are suitably secured to the lower end of the tubing string A, the lower end of the electric cable l4 being connected to the motor. A tubing section Til is then lowered into the well casing B at the top of the hole. A comparatively short distance above the electric motor 12, one of the protective devices 35 can be mounted on a tubing section, the set screws being suitably tightened against the tub .g string. The cable lid is then placed between the runners 17 of the protective device, and the tubing string A and cable 34 are then lowered into the well casing B, additional tubing sections 19 and collars 11 being added as the descent of the tubing string and cable into the casing proceeds. The desired distance above the previously installed protective device, say, sixty to eighty feet, another protective device 15 is likewise mounted on a tubing section 10, the mounting occurring, of course, while that portion of the tubing section is disposed above ground. The runners or guide ribs 17 of the second device face in the same direction as the runners 17 of the device already disposed in the well casing, the set screws 31 being tightened against the tubing string A, to firmly secure the second protector to the tubing string. The electric cable 14 is then placed between the runners 17 of the second protective device and the tubing string A and. electric cable l4 run to a greater extent in the ll casing.

The foregoing procedure is repeated during the connecting of the tubing string sections ll) to one another, and the lowering of the tubing string A and cable 14 in the well casing. At desired intervals, a protective device is is mounted on the portion of the tubing string disposed above ground, with the runners 17 facing in substantially the same direction as the runners of the previously installed protective devices, the cable 14 being disposed between the runners l7, and the tubing string A and the cable 14 then lowered in the well casing B until the tubing string and cable have been lowered to the desired depth in the casing.

During the lowering of the tubing string A and electric cable 14, with the protectors l5 in place, the fact that the runners 1'7 extend laterally outward a greater distance from the rings 16 than the diameter of the cable prevents the tubing string A from jamming or pinching the cable between it and the well casing B. in addition, the runners l7 prevent the cable from wrapping itself around the tubing string. The spaced runners 17 of each device act to force the tubing string out of a coaxial position with the well casing, affording ample room for the disposition of the conductive cable 14 between the tubing string and the well casing. As was stated above, the runners 15 may force the portion of the tubing string A diametrically opposite the runners to a position adjacent the casing wall. With this position of adjacency, the edges 18 of the runners are still adjacent the casing wall,

which will prevent the cable 14 from being removed inadvertently from its required location between the spaced runners T7 of each protective device 15.

If it is desired to remove the tubing string A and electric cable 14 from the well casing 13, the elevation of the tubing string and electric cable can occur without damage to the latter, since the runners 17 will still offer protection to the electric cable in the same fashion as when the tubing string and electric cable were being lowered in the well casing. When a tubing section 10 to which a protective device has been afiixed is elevated above ground, the protective device 15 may, if desired, be removed from that section. All that need be done is to loosen the set screws 31 from the tubing string, remove one of the hinge pins 3d, and swing the ring about the other hinge pin to an open position, allowing the device 15 to be removed laterally from the tubing string.

The inventor claims:

1. In combination: well casing disposed in a well bore; a tubing string in the well casing; an electrically operated apparatus secured to the tubing string; an electric line connected to said apparatus and disposed between the tubing string and easing; protective devices secured to the tubing string at spaced intervals along its length against substantial arcuate movement on the tubing string; each device including an annular member encompassing the tubing string, a pair of guide members secured to and extending laterally outward from said annular member and disposed on opposite sides of the electric line, said guide members being engageable with the well casing at one side of the well casing to displace and hold the tubing string eccentrically of the casing and closely adjacent to the opposite side of the well casing, whereby said guide members are retained closely adjacent said one side of the well casing to prevent the electric line from passing between the outer ends of the guide members and the 5 well casing; said electric line being free from attachment to the tubing string substantially from said apparatus to the top of the well casing.

2. In combination: well casing disposed in a well bore; a tubing string in the well casing; an electrically operated apparatus secured to the tubing string; an electric line connected to said apparatus and disposed between the tubing string and easing; a protective device secured to the tubing string against substantial arcuate movement on the tubing string, said device including an annular member encompassing the tubing string, a pair of guide members secured to and extending laterally outward from said annular member and disposed on opposite sides of the electric line, said guide members being engageable with the well casing at one side of the well casing to displace and hold the tubing string eccentrically of the casing and closely adjacent to the opposite side of the well casing, whereby said guide members are retained closely adjacent said one side of the well casing to prevent the electric line from passing between the outer ends of the guide members and the well casing; said electric line being free from attachment to the tubing string substantially from said apparatus to the top of the well casing.

3. The combination defined in claim 2, wherein said annular member is split longitudinally to permit said annular member to be disposed laterally over the tubing string.

4. In combination: well casing disposed in a well bore; a tubing string in the well casing; an electrically operated apparatus secured to the tubing string; an electric line connected to said apparatus and disposed between the tubing string and easing; protective devices secured to the 6 tubing string at spaced intervals along its length against substantial arcuate movement on the tubing string, each device including an annular member encompassing the tubing string, a pair of guide members secured to and extending laterally outward from said annular member and disposed on opposite sides of said wire line closely adjacent said wire line, said guide members extending laterally outward from said annular member a greater distance than the diameter of said wire line; said guide members being engageable with the well casing at one side of the well casing to displace and hold the tubing string eccentrically of the casing and closely adjacent to the opposite side of the well casing, whereby said guide members are retained closely adjacent said one side of the well casing to prevent the electric line from passing between the outer ends of the guide members and the well casing; said electric line being free from attachment to the tubing string substantially from said apparatus to the top of the well casing.

5. The combination defined in claim 4, wherein said guide members extend lengthwise of said amiular memher with their outer ends in generally parallel relation to each other and said guide members projecting longitudinally beyond the upper and lower end of said annular member.

References Cited in the file of this patent UNITED STATES PATENTS 1,383,777 Stephens July 5, 1921 2,561,249 Tomlinson July 17, 1951 2,632,836 Ackley Mar. 24, 1953

Images