US2635697A - Apparatus for cementing wells - Google Patents

Description

April 21, 1953 G. E. CANNON 2,635,697

APPARATUS FOR CEMENTING WELLS Filed June 29, 1949 INVENTOR da... E'. )nf

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Patented Apr. 2l, i953 UNITED s'lfarlasv PATENT. OFFICE-fi wie? rife@ APPARATUS FOR CEMENTING WELLS George E. Cannon, Houston, Tex., assignor, by mesne assignments, to Standard Oil Development Company, Elizabeth, N. J., a corporation of Delaware A pplieatiqn June 29,1949, serial No. 102,045

' (cl. 16o-'1) plugs in 'cementing wells the plug placed ahead ofthe cement is usually provided with a apper type valve which is opened by pump pressure when it contacts the float collar. Thus, in the conventional operations it is necessary to cause actuation of the apper valve by controlling the pump pressure when the bottoml plug, whichis placed ahead of the cement,'reaches the float collar, on the end of the string of tubing. The conventional technique employing a dual plug with a conventional iioat collar is disadvantageous since the apparatus ordinarily employed may result in inefiicient cementing practices. For example, the conventional apparatus provided with a flapper valve when operated to allow the cement to be introduced into the well bore does not provide the top plug with a seat. Thus, when the top plug reaches the bottom plug which has been opened by pump pressure and when the mud column follows the top plug, the top plug may become distorted or deformed and thus fail to provide a seal and allow the mud to become admixed with the cement. In short, the conventional apparatus does not assure complete shut-off of circulation at all times.

It is, therefore, the main object of the present invention to provide an improved apparatus for introducing cementitious material in a well bore.

Another object of the present invention is to provide an improved float collar adapted to be attached to a string of pipe.

A still further object of the present invention is to provide an improved oat collar which allows the dispensing with the iiapper type valve in the bottom plug employed in dual plug cementing operation.

Still another object of the present invention is to provide apparatus for releasing cement from' a column of cement to be introduced in a well bore.

Other objects of the present invention will become apparent from the description of the drawing in which the sole ligure is a sectional elevation of a preferred embodiment of the apparatus of the present invention.

yReferring now to the drawing, numeralV I3. Float collar II includes a concrete plug'I4 defining a central passageway I5. Arranged in centralpassageway I5 is a plastic cage IB dening with its upper end rubber seat I6'. Seat I6' is adapted to form a close t with plastic ball valve Il when fluid pressure exerted upwardlytherein forces it against the seat I6. Rigidly afhxed to concrete plug I4 is a plate member I8 which is held rmly to concrete plug I4 by means of footings I9. Plate member I8 defines a rup..

ture cone 20 which is provided with perforations 2 disintegrated with a drill bit. Arranged in conduit I3 is a rubber bottom cement plug 22, above which is the column of cement which is introduced into the well and'which is followed by a second top plug not shown. The top plug is conventional and does not form a part of my invenion.

The cement plug 22 may be constructed so that its outer periphery will form a tight seal against the conduit I3. It should also be constructed of an easily rupturable material, such as rubber, which will allow the rupture cone 20 to perforate; besides rubber, the bottom of the cement plug 22 may be constructed of an easily rupturable metal such as sheet magnesium, sheet aluminum, sheet zinc, lead and the like.

It is understood, of course, that the conduit I3 and the oat collar II will form the bottom section of a string of pipe which is lowered into the well bore.

Assuming that the conduit I3 and the iloat collar I I have been suitably attached to a string of pipe and lowered into the well bore at a point slightly above the bottom thereof, the bottom plug 22 is introduced into the tubing and immedately followed by a column of cement. After the cement has been all introduced into the tubing, a top plug is placed thereon which may be similar to the conventional top plug employed in cementing practices. Drilling fluid is then introduced as a column on top of the top plug and the cement forced down into the tubing. As the bottom plug 22 comes into contact with rupture cone 20, the weight of the column of cement and the drilling fluid above it causes the bottom plug to come in contact with the pointed member of rupture cone 20 which perforates the bottom of the plug 22 and releases the column of cement for introduction into the well bore. The cement flows from the column through perforations 2l I I designates a float vcollar or float shoe which is Y attached by threaded connections l2 to a conduit Rupture cone 20 may be constructed of a metal such as cast iron which may be readily workman that the pointed member which piercesr the rupturable bottom of the cement plug 2'2 may be constructed in other shapes as desired; Fon;r

example, it may simply be a short plunger, such as a tubular member, providedwith an up thrust-- ing point which will pierce the bottom of the cement plug 22 and provide a passageway for. thecement to ow into central passageway I5. Nu-

merous modications of the up thrustingfmemA ber will be apparent to the skilled workman. Similar1y,1oat'collan H may be suitably modied in.accondaneewith-'the present. invention., There;

are manyfcement. oat acollarsf on `the market and` itA is within theipuryiewA of my invention that any floatgcollan may be modified.: byl providing anup thrustingvpointedfl member such` as; a-rupture. cone` rigidlyA attached to thet concrete.- plug to allow perforation; of the: bottom plug; in dualv plug: cementing operations;4

It isgalsoconsideredi within the purview of. my. inventionfto attach. the float collar, to; the conduit,

by.v` other.y means.; Thus the,y float. collanmayabe attached;.tol the. conduitby welding,l for 'example While zthesfloat; colla-r: ofthe present invention has :heenshownzas embodying aeconcrete` plug, it` is, also. considered .within the. scope ofthexinvenmA tion. to. construct: the plug` of other drillable ma terialsv such. as plastic or resins.. In this con nection it s-al'so consideredi that thedevice-ofl the presentY invention-may be employed-1 inf intro-- isL ducing other cementitious material besides cement into a well bore. For example, resin and plastic may be introduced into a well bore.

The nature and objects of the present invention having been fully described and illustrated, what I wish to claim as new and useful and to secure by Letters. Patent is :l

1. Apparatus forintroducing cementitious material in a well bore comprising, in combination, a conduit adapted to be attached to a string of pipe,v a collar rigidly attached to a free end of said conduit, a xed plug in said collar defining a central.z passageway and a valve seat, a valve member arranged in said central passageway and engageable with said seat adapted to close said central passageway, a xed upwardly extendinggmember defining a sharp point and at least one passageway uidly communicating said conduit with said central passageway and rigidly attached to said xed plug at the upper end thereof, anda; slidablee plug-inn said; conduitvv d'ening: a rupturahle.y bottom., member adapted: toV be:A perforated onf movingintovr Contactl with' said/j pointedmemben 2. Apparatus in accordance with clainr lV in which, the pointed: ,member :is: a; cone;

GEORGE;k E. CANNGNJ.;

References Cited in-v the' le of this patent.,

UNITED STATES PATENTS Number Name Date 884,675. Monroe etal. Y Apr. 14, 19084 1,569,293 Miller Jan.4 152,. 1926 1,906,312- Burt May 219335 2,109,058 Blee Feb,..,22.1938` 2,153,034 Baker Apr. 4,V 1939', 2,217,708. Scaramucci Oct. l5, 1940 2,253,536- |Scaramucci -Aug,.. 26; 1941`

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