US1998833A - Cementing guide - Google Patents

Description

Aprii 23, 1935. A. B. @HOWELL 1,993,833

CEMENTING GUIDE Filed March 17, 1950 1Patented Apr. 23, 1935 PATENT OFFICE CEMENTING GUIDE Alvin B. Crowell, Houston, Tex., assignor to Baker Oil Tools, Inc., Huntington Park, Calif., a corporation Application March 17, 1930, Serial No. 436,531

6 Claims.

My invention relates to equipment for cementing wells and pertains more particularly to the means for equipping the lower end of the casing which is to be cemented in the well.

In the usual installation for cementing wells the lower end of the casing has thereon a shoe which protects the said lower end in going into the Well. The cement is introduced into the Well by placing a plug on top of the cement after itl 10 has been forced into the casing and then pumping mud down behind the plug, the plug acting as a piston to force the cement downwardly through the casing and out around the lower end thereof. When the .plug reaches the bottom of the well it contacts therewith and the fact that the plug has stopped is indicated by the pumps. One or two plugs may be' used, one in advance and one behind the cement. I have illustrated the use of but one plug between the cement and the mud above.

The diiculty with the usual method of cementing wells is that the casing is not evenly .centered in the well and may project against one side thereof and when the cement is discharged i from the lower end of the casing it is liable to issue in a stream at one side only of the casing and to be distributed above the lower end of the casing in the Well at one side only-leaving channels or openings through the cement where the cement does not travel, thus providing openings that are not lled so that leakage may occur to the bottom of the well.

It is an object of my invention to provide a device for evenly centering the casing in the well and to thereafter discharging the cement in such manner that it will be evenly distributed around the'c'asing and assure a tight cementing'job between the casing and Walls of the well.

It is a further object to -distribute the cement in a direction upwardly and spirally about the casing so that it may more freely circulate into proper position. l

It is another object of the invention to provide an effective valve or closure for the discharge openings which will allowthe casing to be -floated into `the well and will, however, not interfere with the discharge of cement when the cementing operation is performed. u p

I also aim to provide a guide shoe for rthe casing, so constructed that the cement may be disi charged evenly about the casing butwhichwill Aalloiv the circulation of iluid through the 'casing vwhile the casing is being introduced into thewell.

The further objects and advantages of the device will be obvious to those skilled in the art (Cl. 16S- 1) when considered in connection with the accompanying drawing wherein Fig. 1 shows a side View of the casing in the well, the same being partly in elevation and partly in section.

Fig. 2 is a side view, the upper portion of which is in elevation and the lower in central vertical section showing the particular construction of my guide shoe.

Fig. 3 is a top plan view of the structure shown 10 in Fig. 2.

Fig. 4 is a broken detail illustrating the manner in which the. discharge openings may be temporarily closed while the casing is being lowered into the well.

In the drawing I have shown a casing I, of the usual construction, the lower end being connected to a casing shoe 2. This shoe is in turn connected at its lower end to' a cementing guide shoe 3. The casing shoe 2 is threaded internally at its upper end for connection to the casing I and internally at its lower end for connection with the guide shoe 3.

'Ihe guide shoe is preferably tapered toward its lower end so as to more effectively pass any obstructions encountered in going into the well. The lower end of the shoe may be provided with an opening 4 threaded for engagement with a plug. Said plug may be removed if desired in case the passage of uid therethrough is neces- Above the opening at the lower end I may provide a seat 5, which may receive a ball 6, the use of which will be later described.

To center the device in the Well I provide spring arms 1, a plurality of Vwhich may be mounted on the upper end of the shoe 3. As will be seen from Fig. 2 recesses 8 are counter-sunk in the upper end of the shoe to receive the lower ends of the spring arms 1. Rivets or set screws may be used' extending through the springs and into openings lll in the body of the shoe whereby the spring arms may be secured rmly in position projecting upwardly along the face ofthe casing shoe 2. As will be seen from Fig. 1, said casing shoe may be grooved at II to provide a channel kin which the said guide arms may be housed in going past projections in the well.

The cement is preferably distributed in adirec- .tion upwardly fromthe shoe 3'andl in a laterally inclined direction to'give. a' `whirling motion to the iiuid cement as it is discharged. Referring A particularly. to Figs. 2 and 3 I have shown one means by which this may he accomplished. I have thickened the wall of the shoe at I2 to form an annular ring or `shoulder and have extended channels upwardlyvand laterally through the thickened wall of said shoe. These channels I3 are provided on the lower end with an inlet port I4.` The uid. will pass upwardly through the channels which are shown as being inclined both axially and circumfelfentially with respect to the guide shoe I3 and issue from the outlet ports I5 at the side of the shoe.

The upper portions of the channels I3 are enlarged, as shown at I6, and thus provide chambers in which removable members l1 may be placed. These members may be seen best in Fig. 4. They comprise cylindrical discs fitting the opening I6 and adapted to rest upon shoulders I8 on the inner ends of said chambers. A cork or other like material I9 may be placed on the outer sides of said discs I1 and assist in holding the said discs temporarily in position. From Figs. 2 and 3 it will be seen that the fluid discharged through the channels I3 will issue with an upwardly whirling motion about the casing so as to evenly distribute the cement in the well bore. While I have shown these discharge channels as being formed in a thickened portion of the shoe 3, it will be obvious that any tubular discharge connection with the outlet port I5, to obtain this whirling motion of cement, may be substituted within the scope of my invention.'

In the use of my device the outlet ports I will ordinarily be closed by the discs I1 and in case the lower opening 4 is closed, one or more of the discharge ports I5 may be left open to allow some of the liquid in the hole to pass therethrough so as to gradually fill the casing as it is lowered into the well. The inlet openings for the mud will be regulated so that the casing will be filled slowly, allowing a floating action on the casing tending to take oi the load from the derrick during the lowering of said casing. It will be seen that there will be a pressure from the outside of the mud tending to enter the interior of the casing while the said casing is lowered into the well and there will be no tendency to displace the member I1. When the bottom of the well has been reached, however, these openings will allow the mud within the casing to be forced outwardly therethrough and to then allow the discharge of the cement.

As the device is moved downwardly in the well the centering arms 1 will hold the casing evenly positioned axially of the well bore. When the bottom is reached, therefore, the device will be in a position as is shown in Fig. 1. All of the outlet ports I5 will tnerefore be spaced from the wall of the well so that cement may issue therefrom. The cement will be pumped downwardly in front of the plug 20 through the mud 2| forced into the well by the mud pumps. As the cement is thus forced downwardly it will issue through the outlet ports I5 in a direction such as shown by the arrows in Fig. l. It will take a spiral path about the casing and will fill all thespace around the easing and between the same and the wall of the well as is necessary to secure a good cementing job. The members I1 which close the outlet ports will be easily removed by the pressure of the fluid when the pumps are started.

If it is desired to allow free entrance of liquid to the casing while it is being introduced into the well the plug at the lower end of the shoe 3 may be removed thus allowing the liquid to enter upwardly without restriction. When the bottom is reached with this arrangement the shoe may be set on the bottom of the hole to close the open- Lacasse ing 4, if desired, or, if the casing is held off the bottom of the well, the opening 4 may be closed by dropping the ball 6 from the surface downwardly through the casing before the cement is poured into the upper end of said casing and, in such case, the cement will issue through the ports l5, as previously described.

The advantages of this invention have already been noted. The casing will be centered in the well so that all of the ports I5 will be open and the cement may be freely discharged through said openings in streams whirling about the lower end of the casing and forced uniformly upwardly about the casing in the well and assure an even discharge of cement. Difiiculties due to uneven centering of the casing and the discharge about one side only will be eliminated.

The shoe 3, as shown in section in Fig. 2, is illustrated being made of metal. It is to be understood, however, that the shoe may be made of any desiredy material which will be of sufficient strength to withstand the stresses encountered. It is particularly contemplated that the shoe may be made of concrete so that it may be readily disintegrated when the hole is to be drilled out. Another material which is desirable for making the shoe is baked sulphur and in some instances it might be made of tar, asphalt, or some similar material which would be decomposed by the gases and oil present in the well.

What I claim as new is:

1. A cement guide for attachment to the lower end of well casings including a body rounded at its forward end, said body having upwardly and laterally inclined openings therein to give the cement a whirling action when discharged therefrom, and means to close said openings but adapted to be removed in response to pump pressure in the casing.

2. A cementing shoe to close the forward end of a well casing including a body having lateral outlets directed upwardly and laterally to impart an upward whirling motion to the cement and spring arms to center said shoe in the well bore, the outer ends of said outlets being enlarged, and valve discs adapted to seat in said enlarged ends.

3. A cementingshoe to close the forward end of a well casing including a body having lateral outlets directed upwardly and laterally to impart an upward whirling motion to the cement, spring arms to center said shoe in the well bore, and valve discs in the outer ends of said outlets, adapted to be removed by fluid pressure from within said shoe.

4. A guide and discharge shoe for use in cementing wells including a body, an internally projecting annular shoulder inside of said body, and a plurality of axially and circumferentially inclined ports leading from said shoulder to disycharge cement upwardly with a whirling motion about the casing.

5. A combined cementing and oat shoe for well casing including a body having lateral outlets directed upwardly and laterally to impart an upward whirling motion to the cement discharged outwardly therethrough, plug means frictionally tted within the outer ends of said outlets and held from Lmoving inwardly therein but capableof being discharged from the outer ends of said outlets by pump pressure created within said body.

6. A cement guide for attachment to the `lower end of well casings including a body roundedat its forward end, said body having upwardly andv laterally inclined openings therein to give the cement a whirling action when discharged therefrom. means to close said openings but adapted to be removed in response to pump pressure in the casing, saidbody having a co-axial opening of reduced diameter formed through its lower end, and a ball valve adapted to be passed downwardly through the casing after the same has been positioned in a well into said body and. seat on the upper end of said co-axial opening below said upwardly and laterally inclined openings to prevent the further passage of uid downwardly through said co-axial opening.

vALVIN B. CROWELL.

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