US1860669A

US1860669A - Method and apparatus for cementing wells

Info

Publication number: US1860669A
Application number: US588110A
Authority: US
Inventors: Halliburton Erle Palmer
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-01-22
Filing date: 1932-01-22
Publication date: 1932-05-31
Anticipated expiration: 1949-05-31

Description

May 3l, 1932. E. P. HALLiBURToN I METHOD AND APPARATUS FOR CEMENTING WELLS Filed Jan. 22, 1952 5 Sheets-Shea?I l In ventor Attorneys'V E. P. HALLIBURTON METHOD AND APPARATUS FOR CEMENTING WELLS May 3l, 1932.

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E. P. HALLIBURTON METHOD AND APPARATUS FOR -CEMENTING WELLS 3 Sheets-Sheet 3 Filed Jan. 22, 1932 f Inventar i Patented May 31,' 1932 iJ-NITEDh sTArEs PATENT oFFlc-r';A

ERLE 'PALMER HALLIB'UBITON, 0F LQS ANGELES, -GAIIIFOIR'IIIA METHOD AND APPARATUS FOR CEMENTING WELLS Application'med January 22, 1932. serial No. 558,110.

. stantially ,uniform diameter is positioned in a well hole whereby the entire well hole exteriorly of the pipe or casing or any desired portion thereof, may be filled with a cementitious material in a rapid, economical'and positive i manner. The invention also relates to apparatus by means of which the method of this invention may be carried out.

The desirability of filling the space existing in a well hole exterior of a pipe or casing with a cementitious materialfor the purpose of preventing migration of fluids along the length of the pipe or casing and for sealing off strata bearing undesirable fluids such as, for example, salt water when the purpose of the well is to recover hydrocarbons, has been acknowledged by the prior art. As a matter of fact, the exclusion of water from oil bearing formations is amatter 'of very grave importance. v f

Heretofore, it has not been possible to cement a long string of pipe or casing within a well hole inone operation, this limitation being partially caused by thev relatively high temperatures encountered in deep wells, the presetting of the cementitious material when.

attempt ismade to pump the same downwardly through the pipe or casing and upwardly through the annular space between the casing and the surrounding wall, and the high pressures necessary to raise the cementitious slurry from the bottom of a deep well upwardly through such annular space. As a precaution against the aforementioned conditions, when long strings of casings are to be run in a well and when it is desired to exclude water or other fluid in the hole by the use of cementitious material, it has been necessary to resort yto very expensive and diiiicult practices.

For example, when it is desired to exclude water or other fluid from the well hole lil-:ISSUED by the use of cementitious material, it has been the practice to start drilling of the well by using a relatively large bit'and to set casing having a diameter of say 10 to 30 inches. After a few hundred; feet othis casing has been set, it is cemented in place in the well hole. -A smaller bit is then introduced through the center of this casing and several hundred feet or more of smaller casing then set and cemented within the larger casing. This procedure is employed until at a depth of say 8,000 feet, the casing is of a relatively` small diameter, as of the order of 3 to 7 inches.

y It is evident that this methodlof drilling and cementing wells is very costly, the cost being high not only because of the larger sizes of casing required, but also becausevof the larger Vamount of time required to drill the largeV diameter holes in 'theupper portion o the well. Furthermore, the drilling operation is periodically suspended during cementing and much time is lost in waiting for the cement to properly set before continuing the drilling operation to lower depths. i

The invention relates to a method whereby a long string of casing or pipe may be quickly cemented along its entire length in a well hole without the necessity of pumping the entire charge of cementing material downwardly throught-he entire length of the casing or pipe, thereby obviating the necessity of forcing the cementitious material upwardly along the 4 annular space surrounding the pipe or casmg from the lowermost portion of the casing to the top of the well'. By the method of .this invention, all or any portion of a wells exposed to high temperatures in the lower portions thereof.

An object of this invention is to disclose and provide a method of filling the annular space 1 said ports into the annular surrounding a lon string of casin or pipe in a well hole without passing al of the cementitious material around the bottom of the casin or through ports located near the bottom o the casing or pipe.

A further object of this invention is to disclose and rovide a method of cementing long strings oipcasing wherein ports are serially opened along the length of the casing and cementitious material serially ejected through space surrounding the casing. By the termserially ejected,

lit is meant that several batches of cementitiousmaterial, separated by batches of drilling fluid, are either simultaneously forced through a series of valve openings placed at different levels in the casing, or that such cementitious material may be serially ejected through said ports with suflicient time elapsing for each batch of cementitious material to set before the placing of the next batch in the series.

A still further object of this invention isV to disclose and provide a method of cementing long strings of casing in a well hole in which predetermined volumes of cementitious material and hydraulic fluid are alternately introduced into a casing and the cementitious 'material serially ejected from the casing into the annular space surrounding the same while i retaining the hydraulic fluid within the cas- Y Y string of casing, or any part thereof, may be cemented within time. 4

y Still another object of this invention is to disclose and provide means whereby a long a relatively short period of string of casing may be cemented in a deep well hole by progressively'opening ports in the walls of the casing in spaced relation along its length, whereby cementitious material may beserially'ejected from said casing-l through said ports.

In addition, it is an' object of this invention to disclose and provide a novel cement-ing 'valve for use in cementing casings and the like.

These and other objects, uses. and advantages of the invention will become apparent to those skilled in the art from a contem la- .tion of the invention 'as described hereina er.

In describing the invention, reference will l be had to the appended drawings, in which:

1 to4 7 inclusive diagrammatically represent a sequence of steps employed in cartying out a simple embodiment of this in vention.

Fig. 8 diagrammatically represents a section through a well hole in which a cementinnethod in accordance with this invention is ing performed.

, Fig. 9 is an enlarged longitudinal section through a casing provided with one form of cementing valve adapted to be used in carryinout the method of this invention.

ig. 10 is an enlarged longitudinal section through a casing and valve of the character shown in Fig. 9, the valve being in operated position.

Fig. 1'1 is an enlarged longitudinal section of a casing provided with a modified form of valve adapted to he used in carrying ont the method of this invention.

Figs. 12 and 13 are a side elevation, partly in section and a transverse section of one type of plug adapted for use with the valve assembl shown in Fig. 11.

A riely stated, he method of the invention fay be said to consist of the steps of alternately introducing predetermined volumes of a cementitious material' and a hydraulic fluid into a casing, ejecting the lowermost volume of cementitious material from the casing into a well hole while retaining the hydraulic fluid immediately thereabove,^and then ejecting the cementitious material next above said ejected volume into the well hole at a oint above said retained volume of hydrau ic fluid. In other words, the cementing of a long string may thus be accomplished as a step operation, the cementitious material being serially ejected into the annular space surrounding the casing at a plurality of vertically spaced points, such ejection occurring progressively. It is to be noted that hydraulic fluid is retained in the casing so that at the conclusion of the cementing operation, very little cementitious material remains in the casing, thereby permitting the casing to be readily cleaned.

The mode of operation of this invention may be best explained by reference to the appended drawings and particularly to Figs. 1 to 7 thereof. These figures diagrammatically represent a well hole, the numeral 1 indicating the outer walls of said well hole. Within said well hole is a long string of casing indicated at 2. The casing is preferably provided with a cementinvV valve 3 at a suitable point along its lengt For exam le, the well hole 1 maybe 6,000 feet long and) it may be assumed that the cementing sleeve or valve 3- is positioned at about the 3,000 foot level.

The method of this invention is carried out as follows:

Mud fluid is circulated downwardly through the casing 2 and upwardly through the annular space surrounding the casing, as indicated by the arrows in Fig. l. Such circulation is carried out until the interior of the well hole 1 is cleared of all dbris, lf.-

This predetermined quantity of cementitious material or slurry is indicated at 4. It may be preceded by a bottom plug also introduced into the casing. The volume of cementitious material or slurry 4 is suicient to lill the annular space surrounding the lower portion of the casing 2, that is to say, when the cementitious material 4 is eventually discharged from the bottom of the casing 2, it will rise within the annular space surrounding the lower portion of the casing 2 and fill such space from the bottom of the casing up to about the .level of a .cementing valve 3.

A top plug 6 is introduced into the top of the casing above this predetermined volume of cementitious material 4. This top plug 6, as well as the bottom plug 5, is so designed as to pass through a cementing valve or sleeve 3 without actuating such valve. A hydraulic fluid such as water, or a mud iuid, is then introduced into the casing 2 on top of the top plug 6 and in this manner the charge of cement 4, together with the bottom plug 5 and the top .plug 6, is forced downwardly through thecasing 2. y

As shown in Fig. 3, after the predetermined charge of hydraulic fluid' 7 is introduced into the casing 2, another bottom plug 8 is introduced into the top of the casing above such predetermined volume of hy draulic fluid 7. A second predetermined volume ofl cementitious material is then forced into the casing 2 on top of the bottom plug 8, this second charge of cementitious material being indicated at 9. Such second charge of cementitious material 9 is then capped or followed by a top plug l0 introduced into the casing 2 .immediately above the charge of cementitious material 9.

The volume of hydraulic Huid 7 introduced into the casing 2 on top of the irst charge of cementitious material 4 separates said `charge of cementitlous materlal' from the secondarycharge 9. In actual practice, the volume of said hydraulic fluid 7 is preferably slightly less than the volumetric ca- -pacity of the casing 2 below the cementing valve or sleeve`n3.- y s As shown in Fig. 5, the top plug 10 which was introduced .into the casing immediately above the secondary charge of cement 9, is followed by a hydraulic fluid 11 which is forced into the casing 2. By referring back to Figs. 2, 3 and 4, it will be noted that the first charge of cementitious material 44 has been forced downwardly through the casing until, as shown in Fig. 4, said charge of cementitious material is ejected from the lowerend of the casing 2 into lthe annular space surrounding said casing wherein it moves upwardly through said annular space. glich ejection of cementitious material is continued until, as shown in Fig. 5, the bottom plug 8 reaches the cementing sleeve or valve 3 and becomes seated therein, thus forming a barrier in the casing 2. By this time, the firstcharge of cementitious material, indicated by the numeral 4, has filled the annular space surrounding the lower portion of the casing 2 up to a point at or slightly above the cementing valve 3.

The bottom plug 8 not only becomes caught in the cementing sleeve 3, thus formingY a barrier in the casing 2, but in addition said Abottom plug opens ports in the cementing sleeve or valve 3, permitting the secondary charge of cementitious material 9 to Abe ejected through said ports into the annular space surrounding the casing 2.A The cementitious material 9 is ejected through the ports of the cementing sleeve 3 by reason of the pressure being exerted thereupon by the hydraulic fluid 11 being forced into the top of the casing 2.

, In this manner, the cementitious material 9 is ejected into the annular space surrounding the upper portion of the casing 2 and `rises in such annular space, encircling and cementing the upper portion of the casing 2 up to any desired level within the well hole, as indicated in Fig. 6. The introduction of the hydraulic uid l1 into the casing 2 is terminatedwhen the upper or top plug 10 approaches or reaches the level of the ccmenting sleeve 3. It is desirable, however, to discontinue the injection of hydraulic fluid 11 while a quantity of cementitious.

It is to be noted that the cementitiousma-` terial encircling and encasingthe upper por tion of the casing 2has not been forced to travel the entire length of the casing nor subjectedto the time necessary to travel such a distance and upward again. Also, as it was not ejected from the bottom-end of thecasing, it has not been subjected to the highv n temperatures existing in the bottom of the.

well. For thesexreasons, the pressures employed in forcing the cementitious material into .positionaround'the casing, have been` relatively low.

For example, the static head of 6,000 feet of cement slurry weighing 113 pounds per cubic foot, would be about 4700 pounds per square inch `at a depth of 6,000 feet. If .it had been necessary to pump the cement slrrry down through the center'of the casing and then upwardly around the casing from the 6,000 foot depth to the'surface, then Apressures in excess of 2,000-pounds per square inch would havebeen required in the illustrative example given hereinabove. 13?

Furthermore, although a 6,000 foot head of cement slurry exerts a pressure of about 4700 pounds per square inch, the pressure actually required to raise the cement to this height, will be muc-l1 greater. due to the resistance to flow of slurry caused by restrictions in the annular space surrounding the casing, relatively larve surface contact and friction. In the use o? cement slurry, there is also a decrease in fluidity and plasticity caused by hydration and partial setting of the slurry. This partialhydration or setting is particularly evident 1n deep wells and is partially caused bythe longer time necessary to place the slurry and thel high temperatures (150 F.250 F.) encountered in such wells. These high temperatures cause the cement slurry to stiifen or agglomerate so that not only is "a much higher pressure required to force the cement slurry up through the annular space surrounding the casing, but in addition the slurry loses its ability to set and form a coherent, strong body around the casing. Y

The method described hereinabove, however, permits the cement slurry to be placed in position within' a very relatively short time after it is mixed. In actual practice, it has been found that a cement slurry must be placed in final position within 40 minutes of the time that such batch of slurry was started to be mixed. Naturally, it would be almostimpossible to force a batch of slurry downwardly through the center of a casingfor a distance of '6,000 feet ormore and then upwardly for a similar distance, Within 40 minutes from the time it was started to be mixed. Under the method of operation described hereinabove, however, the various stages at which the cementing valves or sleeves 3 are set may be so chosen as to positively insure the placing of the cement slurry within the required 'time interval.

In the example illustrated in Figs. 1 to 7, a. two-stage method has been described employing but a single intermediate cementing sleeve or valvef3. It is to be understood that the method contemplates the utilization of a plurality of steps and valves when such procedure is deemed advisable as, for example` in wells of 6,000 feet or greater depth. For example, as shown in Fig. 8, the casing 2 may be provided with' cementing sleeves or

valves

13, 14, 15 and 16, at various levels. In cementing a deep well of this nature, a plurality of charges of cementitious material are introducedv into the casing, each of said charges being separated bv a redetermined volumeof hydraulic fluid. n Fig. 8, the casing 2 i's shown 'to contain a' lower charge of cementitious material 17, said charge of .cement being forced `downwardly by a'body 18-of hydraulicliuid, a superimposed body 19 of cementitious material, another body of hydraulic fluid 20, a still -furthercharge of cementitious material 21, another body 22 ot' hydraulic fluid, and a top charge 23 of cementitious material.y The various bodies of cementitious material are or may be provided with top and bottom plugs. The lowermost 4charge 17 may be ejected from the lower end of the casing 2. The charge next above and indicated by the numeral 19, will eventually be discharged from the casing by the cementing valve 13. The volume of cement, indicated by the numeral 21, will eventually be discharged by the cementing valve 14, etc.

It is to be understood that the various bottom plugs, such as for example, the bottom -plug 24 (Fig. 8) separating the hydraulic fluid 18 from the secondary charge of cementitious material 19, are so constructed as to operate but a specific cementing sleeve or4 valve. For example, the bottom plug 24 should not stop or operate the sleeves or

valve members

14, 15 and 16 but instead should pass therethrough. The bottom plug 24, however, should cooperate with the cement-- ingJsleeve or valve member 13.

Fig. 9 discloses one embodiment of means adapted to carry out the method described hereinabove. As shown in thisv figure, the bottom portion of the casing identified by the numeral 30, may be providedat its lower end with a guide shoe 31 provided with aback pressure valve 32. Such lower portion 30 of the casing may carry a suitable cementing sleeve or valve 33, said cementin sleeve or valve being positioned a suitable istance above the lower end of the casing 30. Other casing-sections 34 are connected to the upper end of the cementing valve or sleeve 33 and a secondary cementing valve 33 may be positioned a suitable distance above the lower cementing valve'33.

The cementing sleeve or valve 33 may consist of an outer tubular member 35 made of coupling stock and may-,be provided vwith a plurality of.valved ports-36. These ports may be closed exteriorly by means of valve members 37 provided with spring actuated means for maintaining the valve members 37 seated in the ports 36. Springs 38 may be provided for this purpose. Slidablygnounted wit-hin the tubular body portion may be a sleeve 40, the internal diameter of sa'id sleeve beingsubstantially identical with the internal vdiameter of the

casing sections

30 and 34.

Suitable means may be provided for maintaining' the sleeve 40in position within the body portion 35 so as to close the ports 36. Such means may comprise -shear pins 41 carried by the body portion 35 and connecting the sleeve with the -body portion. The sleeve 40 may also be provided with an inwardly v extending member or restriction 42.

' The cementin sleeve or valv.6 33 maybe identical with t e cementing device 33 although the vrestriction or inwardl ing4 member 42 of the cementing vice 33 extend- 6 cation in the apparatus described herein above, a bottom plug 44 may be introduced.

into the top ofl the casing and a predetermined volume of cementitious material introduced into the casing on top of the bottom 10 plug 44, the bottom plug 44 being preferably vvices 33 and 33 provided with a body portion of sufficiently small diameter to permit its passage through any of the restrictions in the cementing deositioned in the casing. Furthermore, the provided with two cups of flexible material such as leather, for example 'a lower flexible cup 45 and an upper flexible cup 46. The body portion of the plug 44. may also be provided with an axial bore 47 and branches 48.

The predetermined charge of cementitious material is introduced into the casing above the bottom plug 44 and a top plug 50 may be introduced into the casing on top of the charge of cementitious material, such charge being referred to by the numeral 4. A predetermined volume of hydraulic uidsuch as Nmud fluid, is then introduced into the casing above the top plug 50, thus causing the charge of cementitious material 4 to be forced downwardly through the center of the casing. The upper plug 50 may be provided with a body portion of sufliciently small diameter to pass through all of the cementing devices 33,33', etc., positioned in the casing. It may also be provided withtwo

flexible cup members

51 and 52 adapted to substantially seal olf the hydraulic fluid from the charge of cementitious material 4. After a suitable volume of hydraulic fluid is thus introduced on top of the top plug 50, the bottpm p1ug 8 is introduced into the top of the casing. This plug may be provided with a body portion adapted to pass' through those cementing devices such as the cementing device 33 but adapted to be stopped and retained the restriction 42 of the cementing device 33.

Y Such bottom plug may be provided with an upper cup member 53.

A suitable chargeof cementitious material 9 may be introduced into the top of the casing. above the bottom plug 8. A top plug 10 may then be introduced into the top of the caslng on top of the charge of cementitious material 9 and this may be followed by another charge of hydraulic fluid. The top plug 10 1s preferably of such diameter as to pass through the restriction 42 of the cementing device 33.

The mode of operation described hereinbefore with reference'to Figs. l to 7, is therefore taking place in the casing illustrated in Figs. 9 and 10. The bottom plug 44 eventually comes toA rest on the back pressure valve 32 carried by the guide shoe 31, the central bore 47 of said bottom plug-44. coming into ottom plug 44 may be ali ent with the outletof the backpressure valve 32. The-pressure of the cementi- I tious material 4 immediately above the b ottom plu 44 causes the upper cup member 46 to be de ected downwardly, additional pressure forcing the kcementitious slurry 4 to be ejected through the plug 44 and through the back pressure valve 32 into the annular space surrounding the bottom section 30 of the casing. This cementitious slurry is caused to rise u wardly in said annularl space. The top p ug 50 is being -constantly forced down# wardly by the res'sure applled to the slurry and hydraulic uid within the casing and the downward movement of the top plug 50 continues until the bottom plug 8 comes to rest on the restriction 42 of the cementing device f 33. By the time the bottom plug 8 comes to rest on the restriction of the sleeve 40, the cementitious material 4 has been forced upwardly through the annular space surrounding the lower-section 30 of the casing to a point contiguous to the cementing device 33 gg immediately above said cementingdevice The application of further pressure to the hydraullc fluidbeing introduced into the top of the casing causes the cementitious slur 9 to force the bottom plug 8 downwardly, Eis downward pressure causin the plug 8 to stride the restriction 42 an the sleeve 40 to such volume as'to completely fill the annular space surrounding the casing section 34 from the level of the cementing device 33 to the levelof the upper cementing device 33 or just above same. An action similar to that just described then takes lace in the cementing device 33', a tertiary ottom plug coming to rest upon the restriction 42 and eventually opening the cementingdevice 33 so as to permit the ejection of another batch of cementitious material through said cementing device.

It is to be noted that it is not absolutely necessary to use the top plugs (between batches of cementitious material and superimposed hydraulic fluid) -and in some instances, it is desirable to leave out the top plugs for'mechanical reasons.

A modified form of cementing means which does not employ restrictions of varying de' gree in the casing, is shown in Fig. 11. Two 4. cementing

valves

33 and 33 are shown in the casing 34. The cementing valve 33 comprises an outer tubular member 60 provided 'ately below the cementing valve 33 may be provided with a plurality of longitudinally extending grooves 64 adapted to slidably receive guiding fingers 65 carried by the sleeve 62. The fingers 65 are of less thickness than the sleeve 62, thereby leaving a shoulder 66 adapted to form a stop able to come into abutting relation with the upper edge 67 of the casing when the sleeve 62 is-moved downwardly within the member 60.

It is to be noted that when th-e sleeve 62 is retained 4within the tubular member 60 so as to cover the port 61, la certain predeterj mined space exists between the top 68 of the said plug sleeve and the edge 69 of the casing. -This space is adapted to readily receive expanding members or lugs carried by a plug whereby the plug introduced into the upper end of the casing'- and forced downwardly through the casing, may engage with the downwardly in the. member 60.

shoulc erV 68 yand cause the sleeve 62 to move A suitable plug is illustrated in Figs. 12

and 13'. -As there shown, the plug may consist of a body portion 70 provided at its upper end with a iiexible cup 7l. The upper part of the plug may contain two or more expandible members such as the lugs 72 slidably carried by the body portion. Springs 73 may normally force the lugs 72 radially` upwards. The lugs of a plug of this character will expand and enter the space between the upper edge 68 of the sleeve 62 and the edge 69 of the casing when the plug reaches the cementing valve, thereby permitting further application of pressure the top of the plug to release the hold' g means such as the bead 63 and cause the slee e to move downwardly uncovering the'po ts When a plurality of cementing valves re used in the same string ot casing, the valves are so arranged that the spaces as betwe 68 und 69 are smaller in the top cementing v ves and progressively larger in the lower valves. For example, as shown in Fig. 11, the space between 68 'and 69 is appreciably greater than the space between 68 and 69. By varying the width of the lugs 72 carried by the plugs, the plugs may be caused to selectively actuatc the cementing sleeves. For example, a plug ma be introduced into the casing of having lugs 72 of such width that they would not enter the space between 68 and 69 of valve 33 but would enter the space between 68 and`69 of valve 33. In this manner, the lower valve 33 may be actuated before the upper valve 33 is actuated by aseparate plug capable of cooperating with the particular space there used.

It is to be noted that the fingers carried by the sleeves 62 perform a number of separate functions, such fingers preventing lug 72 of plugs destined for lower valves from catchinnr u on the shoulders 6T. Furthermore, the ngers 65 prevent the sleeves 62 from rotating within the tubular members 60.

any desired upper portion of the same casing may be subsequently cemented by operating an upper cementing valve.

lThese and other modifications and changes coming within the scope of the appended 'claims are embraced thereby.

I claim: 1. In a method of cementing long strings of casing in a well hole, the steps of: alternately introducing predetermined volumes of a cementitious material and hydraulic fluid into a casing; ejecting the lowermost volume of cementitious material from said casing into a well hole while retaining the hydraulic iluid immediatelyr thereabove, and then ejecting the cementitious material next above said eJected volume into the well hole at a oint above said retained volume of hydrau ic luid.

2. In a method of cementing long strings of casing in a well hole, the steps of: alternately introducing predetermined volumes of a cementitiousV material and hydraulic lli fluid into a casing; ejecting the lowermost Y volume of cementitious material 'om said casing into a well holerwhile retaining the hydraulic fluid immediately thereabove, then ejecting the cementitious material next above said ejected volume into the Well hole at a point above said retained volume of hydraulic fluid, permitting said ejected'oementitious material to set in the well hole around said casing, and finally clearing the center of said casing.l

3. In a method of cementing long strings of casing in a' well hole, the steps of: alternately introducing predetermined 'volumes of a cementitious material and hydraulic uid into a casing; 'ejecting the lowermost volume of cementitious material from said vcasing into a well hole while retaining the i I hydraulic fluid immediately thereabove in the the cementitious material next ab ve said ejected volume from the casing into the well hole at a point above said barrier, and permitting said ejected cementitious material to p v set in the well hole around said casing.'

i 4. In a method of cementinglon'g strings i of'casing in a well hole, the steps of: alternately introducing predetermined volumes of a cementitious material and hydraulic fluid into a casing', ejecting the lowermost volume 'of cementitiousmaterial from said casing into a well-hole while retaining the hydraulic 4fluid immediately thereabove in the casing,

lforming a barrier in the casing above said retainedhydraulic iiuid, opening ports in said casing above said barrier, then ejecting the vcementitious material next abovey said ejected volume from the casing and through said ports into the well hole at a point above saidbarrier While retaining inthe casing the hydraulic fluid immediately'above said cementitious material, and permitting said ejected cementitious material to set in the well hole around said casing.

5. In a method of cementing long strings of casing in a well hole, the lsteps of: alternately introducing predetermined volumes of cementitious material and hydraulic Huid into acasing; serially opening ports along said casing,. and ejecting the cementitious material serially through said ports into the well hole while retaining the hydraulic Huid within said casing.

6. In a method 'of cementing long strings of casing in a well hole, the steps of: alternately introducingpredetermined volumes of cementitious material and hydraulic fluid into a casing; serially opening ports along said casing, ejectingxthe cementitious material serially through said ports into thev well hole while retaining the hydraulic Huid within said casing, permitting said ejected cementitious material to set in the well hole around 'said casing, and finally clearing the center of said casing. 1

7. In a method of cementing a long string of casing in a well hole, the steps of: circulating a fluid downwardly through the center of the casing and upwardly throughthe well hole and exteriorlyof the casing to remove dbris; introducing a predetermined volume of cementitious material into the top of the casing; introducing a top plug into the casing on top of'said cementitious material; introducing a predetermined volume of fluid on top of said top plug; introducing a bottom Y luo' into-said casino on to of said volume offiuid; then introducing a second volume of cementitious material into the top of the casing above said bottom plug; insertin a top plug into the casing on top of said v0 ume of fcementitious material; introducing a hydrauwardly around the. lower portion of the casing; forming a barrier in said casing at a point near the top of the section of casing cemented by said rst named volume of cementitious material; opening passageways in the walls of said casing above said barrier, forcing said second volume of cementitious material out of said casing through said passageways and upwardly around the upper portion of fsaidcasing; and permitting said cementitious material to set around said cas- 1n An apparatus of the character described comprising a 'string of casing provided with a plurality of cementing valves carried bv said string of casing in spaced relation, said cementing valves being selectively operable to open ports in said casing.

9. An apparatus of the character described comprising a string of casing provided with a plurality of cementing sections carried in longitudinally spaced relation by saidv @ring of casing.y each of said cementing sections including an outer ported member and an inner sleeve valve,V said sleeve valves being selectively operable to open said ports.

10. An apparatus of the character described comprising a string of casing provided with a plurality of cementing sections carried in longitudinally spaced relation bv said stringof casing, each of said cementing sections including an outer ported member and an inner sleeve-valve; said sleeve valves being selectively operable to open said ports. and a plurality of plugs adapted to selectively cooperate with said cementing sections to selectively actuate said sleeve valves to open ports controlled thereby.

11. An apparatus of the character described comprising a string of casing provided with a plurality of cementi'ng valves carried in longitudinally spaced relation by said casing, said cementing valves being selectively operable in upward series to open ports in said' casing. v

12. An appara us of the character described comprising a string of casing provided with a plurality of cementing valves carried vin longitudinally spaced relation by said string of casing, each of said cementing valves including port .means adapted to place the interior of the casing in communication scribed comprising an outer tubular'mernasv iso

ber adapted to connect aligned casing sections in spaced relation, ports in said tubular member, an inner sleeve valve in said tubular member, means for releasably holding said sleeve in position in said tubular member over said ports and in spaced relation to the cnds of said tubular member, and finger means carried by said sleeve and adapted to cooperate with a casing connected to said tubular member.

14. An apparatus of the character described comprising 'an outer tubular mem.

ber adapted to connect aligned casing sections in spaced relation, ports in said tubular member, an inner sleeve valve in said tubular member, means for releasably holding said sleeve in position in said tubular member over said ports and in spaced relation to the ends of said tubular members, and long extending fingers carried by said sleeve and adapted to cooperate with long grooves formed in a casing connected to said tubular member.

Signed at Los Angeles, Calif., this 9th day of January, 1932.

ERLE PALMER HALLIBURTON. Y