US 3444928 A
Description (OCR text may contain errors)
May 20, 1969 c. A. PITTS 3,444,928
PLUG INJECTOR APPARATUS Filed Nov. 3, 1967 INVENTOR. Char/e5 6'. P/f/s United States Patent US. Cl. 166-70 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to cement plug injector apparatus which is adapted to be rotated if desired. The plugs are enclosed in sleeves in the device which drop into place and seat in alignment with the well casing as the retainer elements are moved to the plug injection position.
This invention relates to plug injector apparatus and particularly to apparatus used for injecting so-called cementing type plugs into the casing of earth wells during a well treating operation.
In conventional cementing plug injector apparatus the plug or plugs are usually held in position in the injector apparatus by means of a pin which extends across the apparatus either through or below the plug. Extraction of the pins is often difficult to accomplish in a timely manner because the pressures encountered during the cementing or other treating operation cause the pin to bind as it is being retracted.
Accordingly, a principal object of this invention is to provide an improved plug injector apparatus for use in treating earth wells.
Another object of this invention is to provide an improved, easy to actuate plug injector apparatus for use in treating earth Wells.
In accordance with this invention there is provided plug injector apparatus comprising a hollow cylindrical body section adapted to receive a plug of the so-called cementing plug type. Cement enters the body section from the top thereof.
The plug or plugs are disposed within a sleeve which is of smaller diameter than the inner diameter of the body section. The plug is axially aligned with the longitudinal axis of the body section and is held in position prior to its release by an arcuate (generally circularly shaped) element which extends across the diameter of the body section with its convex part facing upwardly and supporting the lower part of the plug.
Means are provided for rotating the arcuate element from a position Where the elements convex part faces upwardly generally along the longitudinal axis of the body section to where the arcuate element lies perpendicular to the longitudinal axis of the body section along the wall of the body section. The sleeve then seats against the arcuate element and the plug is then forced, by pressure exerted from above, down the body section, past the arcuate element and into the well casing (not shown).
The invention, as well as additional objects and advantages thereof, Will best be understood when the following detailed description is read in connection with the accompanying drawing, in which:
FIG. 1 is a side elevational view, in section, of injector apparatus made in accordance with this invention, and
FIG. 2 is a sectional View taken along the line 22 of FIG. 1.
Referring to the drawing, there is shown plug injector apparatus, generally indicated by the numeral 10. The apparatus comprises an elongated generally tubular body section, indicated generally by the numeral 12, which has side walls 14 and threaded upper and lower ends 16, 18, respectively.
The upper end 16 is adapted to receive fluid or pumpable cement slurry from a pipe or rotatable swivel head assembly (not shown). The lower end 18 is adapted to be coupled to a casing string, for example, which is to be cemented in place in a well bore (not shown).
The upper end 10 of the body 16 may have a bushing 18 which adapts the body section to be coupled to a swivel head, as mentioned above, which is usually coupled to drill pipe rather than casing.
Arcuate, generally circularly shaped plug retaining and seal elements 20, 22 are disposed in the body section 12 intermediate the ends thereof.
The height of the circular part of the elements 20, 22 is a minor part of their inner diameter. The elements 20, 22 have diametrically oppositely disposed pins 24, 26 and 28, 30, respectively. The pins 24, 28 are each journalled in bores 32, 34, respectively, in the side walls of the body section. The pins 26, 30 are each mechanically coupled to rotatable shafts 36, 38, respectively which extend through bores 40, 42, respectively, in the side walls.
The means for rotating the shafts 36, 38 may be the lever arms 44, 46, respectively, or remotely controlled means (not shown) coupled to the outer ends of the shafts 36 or 38, for example.
The shafts 36, 38 each have an O-ring type seal 48, 50 respectively and are held in place by suitable retainer and rotation limiting elements 52, 54, respectively.
Each of the plug retaining and seal elements 20, 22 are disposed with the periphery of the circular parts of the elements disposed on an up and down position across the inner diameter of the body section rather than aligned parallel with the side walls of the body section 12 when the elements 20, 22 are in the retaining position.
A cementing plug 56, 58 is disposed in a slidable but close fitting manner within a sleeve element 60, 62, respectively, which is of smaller diameter than the inner diameter of the body section 12. Each of the plug-sleeve assemblies are retained on an element 20 or 22 within the body section 12 until they are to be forced from the apparatus and down the well casing, for example.
The diameter and wall thickness of the sleeves 60, 62 are the same (at least usually). The sleeves fit loosely in the body section to permit cement to flow around the sleeves and into the well casing until such time as each plug is to be introduced into the casing.
In operation, with a cement line (not shown) coupled to the upper end of the body section and the lower end of the body section coupled to well casing (not shown), fluid or cement is pumped through the apparatus between the sleeves '60, 6'2 and the inner wall of the body section.
When it is desired to introduce the first plug 58 into the casing, the retainer-seal element 22 is rotated until the edges of the circular part of the element 22 are aligned with the seat 64 of a reduced inner diameter part of the lower end of the body section. The inner diameter of the lower end part 66 of the body section is at least approximately the same as the diameter of the well casing and equal to the inner diameter of the sleeve 62.
When the element 22 is turned, the sleeve 62 seats against the upper part of the circular part of the element 22. Then, because the seating of the circular part of element 22 on seat 64 and the seating of the sleeve 62 against element '22 shuts off substantially all fluid flow through the apparatus, pressure on the fluid (or cement slurry) forces the plug 58 down through the sleeve and into the well casing.
When suflicient material has been introduced after the plug 58 is in the casing, the retainer element 20 may be rotated to be disposed in alignment with the upper end Further, apparatus may be provided which has a single I plug-retainer assembly and which has more than two plug-retainer assemblies.
The end-feeding feature of this invention permits the use of a swivel head in conjunction with the apparatus and thus permits the casing to be rotated or oscillated as the cementing operation is underway. Such movement of the casing is advantageous in many cementing operations.
Because the elements 20, 22 always remain within the body part, the apparatus is safer to use than devices wherein pins are pulled to release the cementing plugs.
What is claimed is:
1. Plug injector apparatus for use in earth well cementing or treating operations, comprising an elongated, generally tubular body section having an upper end, a lower end, and side walls extending between said ends, upper and lower annular shaped elements rotatably disposed in said body section with the axis of rotation of said elements being perpendicular to the longitudinal axis of said body section, means external of said body section for rotating said annular shaped elements, said annular shaped elements being of equal inner and outer diameters and of substantially smaller outer diameter than the inner diameter of said body section above said lower annular element, said inner diameter of said body section lying between said lower end and the lower annular shaped element being of substantially the same diameter as the inner diameter of said annular shaped element and having a tapered seat-like end part adjacent to said lower annular shaped element, a pair of open ended sleeve elements, said sleeve elements having the same outer and inner diameters as said annular shaped elements and each having a length dimension permitting said sleeve element to fit in said body section, one sleeve element being disposed between said annular shaped members and the other sleeve element being disposed between said upper end and said upper annular shaped member, said sleeve element each being supported on a side of one of said annular shaped elements, a pair of plug elements, one of said plug elements being disposed in each of said sleeve elements in frictional engagement with the side walls thereof, means for coupling said lower end to well casing, and means for introducing pumpable material into said upper end.
2. Apparatus in accordance with claim 1, wherein the inner diameter of said sleeve element is the same as the inner diameter of the casing of the well with which said apparatus is used.
3. Apparatus in accordance with claim 1, wherein said means for rotating said annular shaped elements each comprises a lever actuated shaft extending through the side wall of said body member and mechanically coupled to an annular shaped element.
References Cited UNITED STATES PATENTS 2,620,037 12/1952 McClendon 166-70 2,630,179 3/1953 Brown 166-70 X 2,713,909 7/1955 Baker 16670 3,216,500 11/1965 Diehl 166-70 CHARLES E. OCONNELL, Primary Examiner.
J. A. CALVERT, Assistant Examiner.
U.S. Cl. X.R. l5104.06