Multiple stage cementing

April 25, 1939. w. R. mcclendon et al 2,155,609

MULTIPLE STAGE CEMENTING

Filed Jan. 23, 1937

<img file="US2155609A_D0001.tif" />

Wallace £?. Fl-Ctendon.

INVENTORS.

<img file="US2155609A_D0002.tif" />

ATTORNEY

Patented Apr. 25, 1939

2,155,609

UNITED STATES PATENT OFFICE

2,155,609

MULTIPLE STAGE CEMENTING

Wallace R. McClendon, Houston, Tex., and William D. Owsley, Duncan, Okla., assignors to Halliburton Oil Well Cementing Company, Duncan, Okla.

Application January 23, 1937, Serial No. 122,012 (CI. 166—1) novel features of the arrangement and method, as will be more apparent from the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a vertical cross-sectional view of the 5 casing of an oil well with a multiple stage unit constructed in accordance with the present invention incorporated therein and showing the parts in their relative position as they are lowered into the well. . 10

Fig. 2 is a vertical cross-sectional view of the arrangement of Fig. 1, but illustrating the relative position of the parts during the time that cement is flowing outwardly through the multiple stage unit; and 15

Fig. 3 is a vertical cross-sectional view of the same apparatus as that shown in Fig. 1, but showing the parts in their final position after the cement has been placed around the casing through the multiple stage unit. 20

The various parts in the drawing are shown with certain elements exaggerated in size for the purpose of better illustrating the principles of the invention, but it will be understood by those skilled in the art that the various parts will be 25 . of the proper size to bear the strain for which they are designed and yet not occupy any more space than is necessary.

Referring to the drawing in detail, it will be seen that a multiple stage unit is there shown as 30 consisting essentially of a collar or casing member (I within which a sleeve 12 is positioned for longitudinal movement therethrough.

The upper end of the member ί ( is provided with screw threads 13 adapted to receive and be 35 secured to a stand or section of the casing 14 while the lower end of the member 11 is provided with similar threads 15 adapted to receive and support a lower section or stand of casing 16. Thus the member 11 may be made up with the 40 casing of the oil well.

The casing member 11 has a number of openings or ports 17 circumferentially spaced therearourid approximately midway between its ends. These ports are adapted to be opened and closed 45 by movement of the sleeve 12 into successive positions.

Normally the sleeve 12 occupies the position shown in Fig. 1. It is held in this position by means of shear pins 18 welded or swaged to the 50 casing member i I. In the arrangement illustrated in the drawing three pins 18 are used but it is obvious that their number and also their size may be varied to make them have the requisite strength. 55,,

Claims.

This Invention relates to the cementing of oil wells or the like, and more particularly to an arrangement for cementing long strings of casing or pipe in stages so that all the cement which 5 fills the annular space surrounding the casing may be supplied thereto without passing around the bottom of the casing.

The multiple stage cementing of wells is now well known to those skilled in the art. A method 10 and apparatus for accomplishing this is fully disclosed in the U. S. patent to Halliburton, No. 1,860,669, granted May 31, 1932, and in the reissue thereof, No. 19,570, reissued May 14, 1935.

In the multi-stage cementing of wells a valve 1* structure, usually called a multi-stage unit, is made up with the casing. The arrangement is such that at the proper time the valve in this unit is opened so that cement can flow outwardly therethrough to the annular space surrounding 20 the casing. The valve may be a sleeve valve, as taught in the patents mentioned above, and may be opened by one of the cementing plugs used in the multiple stage cementing operation.

As taught in the above mentioned patents, 25 a multiple stage cementing operation may employ several plugs. Thus, for example, in the illustration of Figs. 9 and 10 of the Reissued Patent No. 19,570, two plugs travel through the multi-stage unit without affecting it, a third 30 plug enters the multi-stage unit and opens the valve and a fourth plug follows the upper slug of cement, this being the cement which flows through the multi-stage unit.

After the cement has passed through the multi35 stage unit some means should be provided for preventing that cement from flowing back into the casing. The Reissued Patent 19,570 discloses spring-pressed valve 37 on the multi-stage unit for this purpose.

It is an object of the present invention to provide a sleeve valve arrangement for preventing cement from flowing back into the casing after it has passed outwardly through the multi-stage unit incorporated therein.

It is another object of the invention to provide a multi-stage cementing unit in which valve means will be opened and then closed by action of the cementing plugs used in the cementing operation.

It is a further object of the invention to provide a novel method of multi-stage cementing in which the plugs used in the operation actuate means which opens and then closes valves in the multi-stage unit.

Other objects and advantages reside in certain

3,166,609

Located beneath the shear p'ns It are a second set It which are preferably somewhat larger than the pins IS and also greater in number. In the arrangement of the drawing four shear pins 5 It are employed.

The casing member II also is provided with* latching means 26, these consisting merely of catch members mounted on leaf springs 21 secured on the inside of the casing member 11 in 10 recesses 22 as illustrated. The sleeve 12 is provided with circumferentially spaced ports 23 which serve the double purpose of allowing fluid to flow through the ports 17 in the member II when the ports 17 and 23 are in alignment and 15 also as means for cooperating with the latch members 20 to hold the sleeve 12 in one position as will be explained further hereinafter.

The lower end of the sleeve 12 is provided with a valve seat or doughnut ring” 24, as it is called ₂₀ in the trade, for cooperating with one of the cementing plugs to maintain a seal and cause the sleeve 12 to move downwardly in its Initial movement with respect to the casing member 11. The cementing plug which seats on the ring 25 24 is shown at 25 in the drawing. This plug may be of known construction and consist of a body of wood having an aluminum or other metallic valve member 26 mounted on its lower end and adapted to seat in the ring 24. The plug 30 may also be provided with one or more rubber cups 27 for maintaining a seal between the plug and the casing.

The drawing also shows another plug 26 which may be similar to the plug 25 except that it does 35 not have a valve member on its bottom.

In cementing an oil well by means of the multiple stage process and using the apparatus shown in the drawing, one slug of cement will be pumped to the bottom of the casing and there 40 distributed in accordance with known practices. If cementing plugs are used with this slug of cement they will pass right through the multiple stage unit without moving the sleeve 12 or otherwise altering the same. Since apparatus for 45 this purpose is well known it has not been shown herein.

The first slug of cement is followed by a body of mud or other fluid and then the plug 25 is placed in the well and the second slug of cement 50 is pumped in on top of this plug. The second slug of cement is followed by the plug 26. As the second slug of cement and the plugs 25 and 26 are pumped downwardly through the well the first slug of cement is forced outwardly 55 around the bottom of the casing. When the plug 25 reaches the ring 24 it seats therein and the pressure of the pump at the surface is raised sufficiently to cause the pins 18 to shear. This causes the sleeve 12 to move downwardly to the 60 position shown in Fig. 2, thus bringing the ports 17 and 23 into alignment and causing the second slug of cement to flow outwardly through the member 11. The second set of shear pins IS are designed to prevent the sleeve 12 moving down65 wardly further at this time and are preferably of larger diameter than the pins 18 and greater in number. However, there is but slight pressure exerted on the pins IS at this time due to the fact that as soon as the ports 17 are opened the 70 fluid pressure tending to move the sleeve 12 downwardly is released, the cement flowing outwardly through the ports. The ports are preferably opened before the sleeve 12 reaches the Irins IS.

After all of the second slug of cement has flowed outwardly through the casing 11 the plug 28 enters the sleeve 12 and rests upon the plug 25. The cups on the plug 28 maintain a seal with the sleeve 12. Upon raising the pressure at the pumps the second time the pins 19 will shear 5 and cause the sleeve 12 to move into the position shown in Fig. 3. This will close the ports 17 by bringing the upper portion of the sleeve 12 into alignment therewith. This will effectively seal the casing and prevent the flow of 10 any cement back through the ports 17 into the casing. Additional sealing means may, of course, be provided by poppet valve on the outside of the ports 17 in accordance with known practices.

The sleeve 12 is caught in its final position by the upper end of the stand of casing 16. To hold the sleeve 12 in this position the latch members 20 interlock with the ports 23 in the sleeve as shown in Fig. 3. It sometimes happens that ₂θ changes in pressure within the casing tend to cause the sleeve to move upwardly, and to avoid the danger of the ports 17 becoming accidentally opened agan the latch members 20 are provided.

The number of ports 17 and 23 may be varied 25 in number and spacing in accordance with the requirements but the arrangement is preferably such that some of the ports 23 will match up with some of the ports 17 when the members are in the proper alignment longitudinally, irrespective 30 of relative rotation. There should also be a sufficient number of latch members 20 to insure at least one catching in a port 23 at the proper time.

While only one embodiment of the invention 35 has been shown and described herein, it is obvious that the arrangement may be modified in a variety of ways and still accomplish the purposes set forth. Hie sleeve 12 may be made of two parts, one of which is actuated to open the ports 17 40 and the other of which is actuated to close the same, and the arrangement may cooperate with the plugs in various ways to bring about the desired action. To facilitate drilling out the plugs 25 and 28 after the cementing operation is com- 45 pleted, it is preferable to provide some means for preventing the sleeve 12 from rotating with respect to the casing member 11 but this has not been shown in the drawing because its use is obvious. One way of accomplishing this is to pro- 50 vide inter-engaging teeth on the bottom of sleeve 12 and the top of the section 16 of the casing. The latches 26 will ordinarily be sufficient to prevent rotation as well as longitudinal movement of the sleeve, however. Various other changes 55 may be made without departing from the spirit of the invention or the scope of the annexed claims.