US2171049A

US2171049A - Shoe for oil well packers

Info

Publication number: US2171049A
Application number: US212881A
Authority: US
Inventors: John T Simmons
Original assignee: Halliburton Oil Well Cementing Co
Current assignee: Halliburton Oil Well Cementing Co
Priority date: 1938-06-10
Filing date: 1938-06-10
Publication date: 1939-08-29
Anticipated expiration: 1956-08-29

Description

. J. 1 SIMMONS snow FOR OIL WELL PACKERS Aug. 29,1939.

Filed June 10, 1938 I ":Q NVE TO Patented Aug. 29, 1939 PATENT OFFICE SHOEFOR OIL WELL PACKERS John T. Simmons; Casper, Wym, assignor to' Halliburton Oil Well cementing Company,

Duncan, Okla.

Application June 10, 1938, Serial No. 212,881

4 Claims. (01. 166-10) This invention relates to packers adapted for use in oil wells and more particularly to shoes adapted to be associated with a rubber packer.

Packers are used for various purposes in connection with oil wells and are usually referred to as wall packers, hook wall packers or rat hole packers. The term wall packer is usually applied to a cylindrical rubber sleeve mounted on a mandrel and adapted to engage the wall of the hole at an uncased portion thereof to effect a seal between the mandrel and the wall. A hook wall packer is somewhat similar to a wall packer but is provided with slips or similar devices for engaging casing and the packer is so designed as to effect a seal within the casing. By the term rat hole packer a cone shaped packing is usually meant and the construction is usually somewhat similar to that shown in the patent to Simmons, No. 1,930,987, granted October 17, 1933, for Method and apparatus for testing the productivity of formations encountered in wells.

The present invention is primarily concerned with wall packers, although it will be obvious to those skilled in the art that the principles of the invention may be applied to other types of packers as well.

It is common experience to find that after a packer has been set in a well and subsequently removed therefrom it has been torn or ruptured so that it cannot be used again. This is especially true with respect to wall packers because the wall of the hole with which they engage when set in the well is often rough and provided with sharp obstacles. This condition is further aggravated due to the fact that the rubber of the packer is often squeezed around the shoes-normally provided. at the top and bottom of the rubber. At the high temperatures prevailing in deep wells and with the rubber subjected to the terrifllc pressure which prevails in deep wells, it will exude through small crevices'or spaces and is commonly said to behave much like a liquid. The shoes which are ordinarily provided for use in expanding the packer, being of a diameter sufficiently small to prevent the possibility of their being stuck in the open hole, are of little effect in preventing the rubber from extending therebeyond as the packer is set.

It is an object of the present invention to provide a lower shoe for use in connection with a packer which will expand radially as the packer is set so as to prevent the rubber of,the packer from creeping beyond the shoe.

It is a further object of theinvention to provide a shoe for a packer which will effectively prevent the rubber from creeping downwardly and which will nevertheless be easily removed from the well when the packer is collapsed.

It is a further object of the invention to provide a shoe for a packer which will effectively protect the rubber of the packer and prevent it from tearing orrupturing as it is being set or removed from a well.

It is a further object to provide a lower shoe for a packer which will effectively center the packer with respect to the'bore of the well as the packer is being set therein.

Other objects and advantages reside in certain novel features of the arrangement and construction of parts, as will be apparent from the following description taken in connection with the accompanying drawing, in which:

Figure 1 is a view in side elevation of a formation testing assembly which includes a wall packer provided with a shoe constructed in accordance with the principles of the present invention;

Figure 2 is an enlarged fragmentary view of the lower portion of the packer shown in Figure 1 and of the shoe associated therewith, this view showing the parts in the position which they takewhile being lowered into the well;

Figure 3 is a view similar to Figure 2, but show ing the position which the parts occupy when the packer is set; and

Figure 4 is a fragmentary transverse 'crosssectional view of the apparatus in Figure 3, the view being taken on the line 4-4 thereof.

Referring to the drawing in detail, and first to the arrangement of Figure 1, it will be seen that the assembly there illustrated includes the lower portion of a section of drill pipe II to which a formation tester is connected. The present invention-is adapted for use wherever packers are. employed in a well, but for the purpose of illustration the invention is shown in connection with a formation tester because the difliculties mentioned above are perhaps encountered more often in connection with the tester than anywhere else. The formation tester may be of the general type disclosed in the patent to Simmons, No. 1,930,987 referred to above. However, the arrangement illustrated is more like that of Figure 5 of the Halliburton Reissue Patent No. 20,688, granted April 5, 1938, for Apparatus for testing oil wells", in that the Halliburton J-type tool is illustrated herein and a wall packer is illustrated.

In Figure 1 of'the present drawing the tester proper is illustrated at l2, the packer at Hand the perforated tool or strainer at [4.

As noted above, the present invention relates primarily to the construction of the shoes for the packer and these are shown in enlarged detail in Figures 2, 3 and 4. The packer I 3 consists of a cylindrical body of rubber mounted upon a central mandrel l5 which is connected to the perforated pipe lfl which rests upon the bottom of the well. When the assembly is lowered into the well, therefore, the mandrel l5 acts as a support for the lower shoe of the packer so that when the upper shoe is forced downwardly the packer is expanded into engagement with the wall of the hole and set. The lower shoe of the packer includes a tapered or conical collar l6 which is secured to the mandrel 55. A ring H is placed upon the mandrel just beneath the packer l3 and the collar Hi and ring I! are separated by means of two or more saucer-shaped members or discs I 8 and i9. These saucers are made of spring steel and are provided with a number of radially extending slots 20. The saucers are so assembled with respect to each other that the slots in one bear a staggered relation to those in the other as v illustrated in Figure 2.

- The parts occupy the position shown in Figure 2 when being lowered into the well. In this position it will be seen that the saucer members I 8 and I9 have suificient curvature that they do not contact the walls of the well and are within the confines of the collar It and ring I! in so far as the radial dimension is" concerned.

As further shown in Figure 2, it will be seen that the saucer members are so mounted that their rims are lower than their base portions, the base portion of the upper saucer member l8 abutting against the ring H while the rim of the lower saucer member is abuts against the collar Hi.

When the packer is expanded the parts take the position shown in Figure 3. It will be seen that in this figure the saucer members l8 and 19 are flattened out so as to be expanded radially well beyond the confines of the collar l6 and ring I'l. The saucers l8 and is may even bite into the formation slightly but whether this takes.

place or not they constitute a material aid in confining the rubber of the packer E3 to its proper location.

When it is desired to remove the packer from the well no difliculty is encountered. The saucers I 8 and I9, being made of spring steel, return to the position shown in Figure 2 as soon as the packer I3 is lifted.

If desired, a coil spring may be placed around the mandrel just beneath the lower saucer member Hi to aid in causing the saucer members l8 and I9 to assume the position shown in Figure 2 after the packer is lifted, but this coil spring will ordinarily not be necessary if the saucer members are constructed of a good grade of spring steel.

- It will be seen from the above description that well due to the fact that as they are compressed 5 longitudinally they engage the walls of the hole.

While only one embodiment of the invention has been shown and described herein, it is obvious that various changes may be made in the arrangement and construction of parts without departing from the spirit of the invention or the scope of the annexed claims.

I claim:

1. A shoe for rubber packers or the like adapted for use in oil wells, including a plurality of saucer-shaped members disposed one above another, said members being made of spring steel and having a number of radial slots therein, the slots in one member being staggered with respect to those in another member, the arrangement being such that upon pressure being exerted on said members, they expand radially and provide means for preventing the packer from flowing or creeping past the shoe thereof.

2. A shoe for oil wellpackers or the like, including a saucer-shaped member having a number of radial slots therein, said member beingmounted below the packer and with its rim normally lower than its base portion, and means for flattening out said saucer-shaped member to cause the same .to expand radially as the packer is set in the well.

3. In an oil well packer assembly the combination of a central mandrel, a rubber wall packer mounted thereon, and a shoe mounted on the mandrel beneath said wall packer, said shoe including a collar fixed to the mandreLa ring abutting against the wall packer and a radially expansible saucer-shaped member disposed between said collar and said ring with its rim normally lower than its base portion adapted to expand radially when force is applied to the packer to set the same, whereby said radially expansible member provides means for preventing the rubber of the packer from flowing or creeping downwardly beneath the shoe.

4. In an oil well packer assembly the combination of a central mandrel, a rubber wall packer mounted thereon, and a shoe mounted on the mandrel beneath said wall packer, said shoe inl extending slots so that they may expand radially when flattened out and provide means for pre venting the rubber of the packer from flowing or creeping downwardly beneath the shoe.

JOHN .T. SIMMONS. 1