US3117627A

US3117627A - Cementing tool

Info

Publication number: US3117627A
Application number: US26392A
Authority: US
Inventors: Jr Ralph R Jarboe; Don C Henningan
Original assignee: Cities Service Research and Development Co
Current assignee: Cities Service Research and Development Co
Priority date: 1960-03-14
Filing date: 1960-03-14
Publication date: 1964-01-14
Anticipated expiration: 1981-01-14

Description

Jan. 14, 1964 R. R. JARBOE, JR.. ETAL CEMENTING TOOL 2 Sheets-Sheet l 7 IN V EN TOR.

Filed March 14, 1960 RALPH R. JARBOEJR DON C. HENNIGAN ATTORNEY Jan. 14, 1964 R. R. JARBOE, JR.. ETAL 3,117,627

CEMENTING TOOL 2 SheetsSheet 2 Filed March 14, 1960 INVENTORS RALPH R. JARBOE JR. DON C..HENNIGAN WMM??? 9m .w i

ATTORNEY ite This invention relates to cementing tools and more particularly to a down hole cementing tool for use in forming cement casing or conduit within bore holes.

Conventional well completion practices involve placing pie-formed metal conduit or casing within the bore hole and then cementing this string of casing in place by forcing cement into the annular space between the wall of the bore hole and the outer wall of the casing. Such methods of cementing casing create numerous problems such as mud channeling, cement stratification, loss of fluid to the formation which the bore hole penetrates and flash set. Also, considerable difficulty is frequently experienced in centralizing the casing within the bore hole. Due to these dificulties the casing is rarely cemented throughout its entire length except in very shallow wells. As a result, corrosion of the metal casing and casing joint leaks are very common and locating and patching such leaks is frequently extremely difficult.

The above mentioned diliiculties may be substantially eliminated by form ng a cement well casing in place without the use of conventional metal casing. It is, therefore, an object or" the present invention to provide an improved cementing tool for forming cement casing within a bore hole.

For a better understanding of the invention reference should be had to the accompanying drawings in which:

FEGURE 1 is a side elevation view partially in vertical section taken as indicated by the line AA of FIG. 2 and showing a down hole cementing tool constructed in accordance with the invention;

FZGURE 2 is a sectional view taken as indicated by line 2-2 of FIGURE 1;

FTGURE 3 is a plan view of a cement wipe plug suitable for use with the cementing tool shown in FIGURE 1;

FIGURE 4 is a sectional elevation view taken as indicated by line 4-4 FTGURE 3;

FIGURE 5 is an elevation view sirnil-ar to FIGURE 1, partly in vertical section taken as indicated by line A-A of FIG. '2 and showing a later stage in the formation or" a cement casing using 16 apparatus shown in FIGURE 1; and

FIGURE 6 is an elevation view similar to FIGURE partly in vertical section taken as indicated by line A-A of FIG. 2 and showing a still later stage in the formation of the cement casing.

Referring to the drawings, FEGURES l and 2 show a down hole cementing tool 11 adapted for use in forming a cement casing in a bore hole 12. The cementing tool it includes a generally cylindrical mandrel 13 having an axial fluid passageway 14 extending from the top of the mandrel and terminating in the lower portion thereof. The upper end of the mandrel 13 is preferably adapted to receive a suitable conduit or string of tubing such as a drill stem or tubing 16 through which fluid or cement may be passed to the axial passageway 14 of the mandrel. Alternatively, the portion of tubing 16 shown in FIGURE 1 may form an integral part of the mandrel 13. in any case the portion of the tubing 16 shown in FIGURE 1 may be considered a portion of the cementing tool 1 1. A plurality of generally radial fluid passageways 17 extend from the lower portion of the axial passageway 14 to the exterior of the mandrel. The mandrel i3 is also States Patent 0 "Ice provided with longitudinally extending peripheral passageways 18. As best shown in FIGURE 1, the peripheral passageways 18 provide fluid cormnunication between the exterior of the upper portion of the mandrel and the bottom of the mandrel. A conventional one way check valve 19 is provided in the bottom of the mandrel l3 and is arranged so as to allow passage of fluid through the peripheral passageways 18 to the space below the mandrel without allowing passage of any fluid in the reverse direction.

The upper portion of the cementing tool 11 is preferably provided with a radially extending formation scratcher such as 41 of conventional design and adapted to dislodge filter cake from the bore hole 12 as described below. The upper portion of the mandrel may be provided with a collecting collar 42 secured around the mandrel immediately below the openings of the passageways 18 and extending outwardly and upwardly from the point of contact with the mandrel to provide a suitable collecting funnel for collecting solids dislodged by the formation scratcher 41. Collecting collar 42 may be of suitable material such as rubber and is preferably mounted on the mandrel by frictional engagement therewith.

Centralizers

31 and 32 are preferably provided for centering the cementing tool 11 in the bore hole 12. The centralizer 31 is a pull elf centralizer adapted to remain embedded in the first batch of cement injected into the bore hole while the centralizer 32 is a fixed centralizer adapted to remain fixed to the cementing tool. As shown in FIG. 1, the centralizer 32 may comprise outwardly bowed metal straps 33 secured to the cementing tool by collars 34. Similarly, the pull off centralizer 3-1 may comprise outwardly bowed tmetal straps 36 which pass around the end of the mandrel and are secured thereto by a collar 37. The collar 37 may be separate from or integral with the straps 36 and holds the centralizer 31 on the mandrel with a friction fit sufiiciently loose so that the centralizer 31 may remain embedded in a batch of cement when the mandrel 13 is rotated and withdrawn therefrom as described below. The straps 36 are shaped so as to allow passage of fluid through the passageway 18 and valve 19 as described above.

FIGURES 3 and 4 show a cement wipe plug 51 adapted to be forced down the axial passageway 14 of the mandrel 13 for clearing cement therefrom as described below. As shown in FIGURES 3 and 4 the Wipe plug 51 has a body which includes an outer jacket 52 having a plurality of longitudinally spaced circumferential flanges 53 of resilient material such as rubber extending outwardly therefrom and preferably integral therewith. An interior liner 54 of non-resilient material such as cast aluminum forms at least a portion of a generally cylindrical valve chamber 55 within the wipe plug 5 The lower end of the wipe plug 51 takes the form of a valve seat 56 adapted to receive valve means such as a ball valve 57. Spring means such as a spring is provided for urging the valve means into engagement with the valve seat. This may be accomplished in any suitable manner such as by forming the valve 57 on the end of a rod 59 which may be provided with an eye 61 at its upper end for receiving retrieving means such as a wire line 63. The rod 59 may also be provided at an intermediate point with an outwardly extending shoulder 62 for engaging the spring 58. Suitable means such as a perforated plate 64 may be provided for engaging the spring 58 at the upper end of the valve chamber 55. From FIGURE 4 it can be seen that while the perforated plate 64 provides free passage for fluids and allows vertical movement of the rod 59, the spring 58 is confined between the plate 64- and the shoulder 62 so that the spring 58 constantly urges the valve 57 into engagement with the valve seat 56.

In operation, the cementing tool 11 is lowered down 3 the bore hole 12 to the lowest point to be cemented as shown for instance in FIGURE 1. The mandrel 13 is centered in the bore hole by the pull off centralizer 31 and fixed centralizer 32. Cement is then injected through the drill stem to, axial passageway 14 and radial passagei'ays 17. The quantity of cement injected at this time is preferably sufiiciently small so that the level of cement in the bore hole does not extend above the top of the mandrel. This quantity of cement may be estimated but is preferably determined by gauging the diameter of the bore hole with a conventional gauging tool prior to introducing the mandrel into the hole. After injection of this first stage of cement the wipe plug 51 is injected down the drill stem and axial passageway with suitable fluid such as drilling mud to wipe cement therefrom. During injection of the wipe plug the valve 57 remains seated on the valve seat 56 thereby preventing passage of cement upwardly through the plug and insuring that all cement in the drill stem 16 and axial passageway 14 is forced out through the radial passageways 17 into the bore hole surrounding the mandrel. When the wipe plug 51 reaches the bottom of the axial passageway 14 (FIGURE 5) the wipe plug is left in position in order to prevent back flow of cement through the passageways 17. While the first stage of cement is setting the mandrel is slowly rotated either intermittently or continuously. When the cement is sufficiently set the cement wipe plug 51 is retrieved by the wire line 63. During withdrawal of the wipe plug the upward force of the wire line 63 acting on the rod 59 compresses the spring 58 and withdraws the valve 57 from its engagement with the valve seat 56 thereby allowing fluid to pass freely through the plug. Injection fluid thus remains in the drill stem during withdrawal of the plug. Following withdrawal of the cement wipe plug the mandrel is raised slowly by raising the drill stem 16. Rotation of the mandrel is preferably maintained while the mandrel is thus withdrawn. As soon as withdrawal of the mandrel brings the exterior openings of the radial passageways 17 above the level of cement in the bore hole circulation of the fluid through the drill stem and bore hole returns thus indicating that the mandrel is in position for injecting another batch of cement. At this point withdrawal of the mandrel is terminated and a second batch of cement may be injected. During injection of the second batch of cement the lower portion of the mandrel below the radial passageways 17 is centered in the bore hole by the previously injected and set cement. By thus utilizing previously injected cement to centralize the lower end of the mandrel it is unnecessary to replace the pull olf centralizer which was used to centralize the mandrel raised for injection of the next batch of cement. In this manner the time required for the initial cure of the cement may be as little as about 1 hour.

Since the exterior of the mandrel serves to finish the interior of the cement casing as the mandrel is rotated and raised it is preferred that the mandrel be constructed with an external surface of low roughness. This may be achieved by any suitable means such as the use of an aluminum or stainless steel mandrel or any other suitable low roughness alloy or material. The use of a high lubricity mandrel coating such as polyethylene or Teflon is also suitable to achieve the desired low roughness on the exterior surface of the mandrel.

By recording the volume of cement injected in each batch and the distance the mandrel is raised in order to bring the radial passageways of the mandrel above the injected cement it is possible to plot a hole diameter log giving the relative bore hole diameter through each cement injection stage. Such information is useful in many well operation problems, particularly in perforating where it is useful to know how much of the actual earthen formation was penetrated by the perforating bullets, jets, etc.

As mentioned above, the one way check valve H1 the bottom of the mandrel permits fluid to pass freely through the passageways 18 to the space below the mandrel. Thus, as the mandrel is raised, wash fluid is free to pass through the mandrel via the passageways 1S and valve 19. This serves to balance forces on the newly injected cement and aids in preventing slumping of the cement until further curing of the cement occurs and the casing attains a greater measure of its ultimate strength. 7

The removal of filter cake deposited by drilling fluids is a problem which is encountered in preparing most bore holes for cementing. This problem is solved with the cementing tool of the present invention by the use of a formation scratcher such as the formation scratcher 41 described above. As the mandrel is rotated and raised preparatory to injecting batches of cement as described above, the formation scratcher scrapes away from the hole walls any filter cake not previously purged by other means such as mud acid or hole clean up solutions. Solid filter cake thus dislodged from the bore hole walls is collected by the collecting collar 42 and washed through the peripheral passageways 18 with wash fluid as the mandrel is raised. v

By utilizing the cementing tool of the present inveri= tion as described above, the mandrel of the cementing tool acts as a slip form for the placement of cement in the hole in successive stages. Continuous or intermittent rotation of the mandrel during setting of each cement stage insures freedom to raise the mandrel to the proper position for injecting the next stage of cement while also providing a smooth finished surface on the cement casing which is more impervious to acid and bacterial attack than is an unfinished cement surface. It has been found in practice that a comparatively small amount of torque is required to rotate the mandrel. For instance less than 2 foot pounds per linear foot of cement fillup on the mandrel is needed to rotate a mandrel having an outside diameter of 5 inches during the setting of neat cement. Mandrel lengths of up to 100 or even 200 feet are thus practicable.

The radial pasageways 17 of the mandrel are prefera= bly slanted in a slightly downward direction as shown in FIGURE 1 in order to assist in filling the portion of the bore hole below the passageways 1 .7 in the initial stage and also to aid in cleaning the top of the previous Ce ment column prior to injection of the next subsequent cement stage. The passageways 17 are also preferably polished and tapered or flared outwardly in order to prevent plugging of these passageways with cement.

The batchwise placement of cement by the use of the cementing tool constructed in accordance with the present invention enables various types of cement to be placed in the same hole relative to their respective areas of use or need. For instance, permeable cement may be placed opposite zones of possible hydrocarbon production while placement of possolanic mixes or other cements of simi larly impermeable nature through gas cap areas helps contain the gas as an energy sourse for producing oil zones below the gas. Likewise, other special cements such as latex cements or high temperature or sulfate resisting types may be used in particular areas as needed or desired.

While the invention has been described with respect to a preferred embodiment thereof, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended to cover all such changes and modifications in the appended claims.

We claim:

1. Apparatus of the character described comprising a generally cylindrical mandrel having a first longitudinal fluid passageway extending from the upper end thereof and terminating within the lower portion thereof, a fluid passageway extending from the lower portion of said first lon itudinal passageway to the exterior of said mandrel, and a second longitudinal passageway for carrying fluid rom an exterior space adjacent the upper portion of said mandrel to a space below said mandrel; a one way check valve in fluid communication with said second longitudinal passageway and adapted to allow fluid to pass from said second longitudinal passageway to the space below said mandrel; a wipe plug of a suitable size and shape to be forced down said first longitudinal passageway and retrieved therefrom; means carried by said wipe plug for retrieving the wipe plug; said wipe plug having valve means therein for permitting passage of fluid through said wipe plug only while said wipe plug is being retrieved.

2. Apparatus of the character described comprising a generally cylindrical mandrel having an axial fluid passage-way extending from the upper end thereof and terminating within the lower portion thereof, a plurality of generally radial fluid passageways extending rom the lower portion of said axial passageway to the exterior of said mandrel, and a plurality of longitudinally extending peripheral passageways for carrying fluid from an exterior space adjacent the upper portion of said mandrel to the bottom thereof; a one way check valve in fluid communication with said peripheral passageways and adapted to allow fluid to pass from said peripheral passageways to the space below said mandrel; a wipe plug of a suitable size and shape to be forced down said axial passage- Way and retrieved therefrom; means carried by said wipe plug for retrieving the wipe plug; said wipe plug compris ing a body portion having a plurality of longitudinally spaced circumferential flanges of resilient material extend ing outwardly therefrom, and said wipe plug having valve means therein for permitting passage of fluid through said wipe plug only while said wipe plug is being retrieved.

3. A down hole cementing tool comprising in combination; a generally cylindrical mandrel having an axial passageway ex nding from the upper end thereof and terminating within the lower portion thereof and a plurality of generally radial fluid passageways extending from the lower portion or" said axial passageway to the exterior of said mandrel; a formation scratcher extending radially outward from the upper portion of said cementing tool and adapted to dislodge filter cake from the walls of a hole as the cementing tool is rotated and raised therein; a collect. g collar extending outwardly and upwardly from said mandrel and encircling said mandrel immediately below said formation scratcher, said collecting collar being ada ted to catch particles of filter cake dislodged by said formation scratcher; said mandrel also being provided with a plurality of longitudinally extendperipheral passageways for carrying fluid from the space within said collecting collar and exterior of said mandrel to the bottom of said mandrel; a one way check valve in fluid communication with said per pheral passageways and adapted to allow fluid to pass from said eripheral passageways to the space below said mandrel; a cement wipe plug adapted to be forced down said an outer longitudinally extending circumferential jacket having a plurality of longitudinally spaced circumferential flanges of resilient material extending outwardly therefrom, a liner of non-resilient material within said jacket, said liner forming at least a portion of a generally cylindrical valve chamber, the lower end of said valve chamber having a valve seat, means for admitting fluid to said valve chamber, valve means adapted to engage said valve seat to prevent flow of fluid through said valve chamber, spring means urging said valve means into engagement with said valve seat, the upper end of said wipe plug being provided with means for the p ssage of fluid; and retrieving means for retrieving said wipe plug and removing said valve means from said valve seat.

4. A down hole cementing tool comprising a generally cylindrical mandrel having an axial passageway extending from the upper end thereof and terminating within the lower portion thereof and a plurality of generally radial fluid passageways extending from the lower portion of said axial passageway to the exterior of said mandrel; a formation scratcher extending radially outward from the upper portion of said cementing tool and adapted to dislodge filter cake from the walls of a hole as the cementing tool is rotated and raised therein; a collecting collar extending outwardly and upwardly from said mandrel and encircling said mandrel immediately below said formation scratcher, said collecting collar being adapted to catch particles of filter cake dislodged by said forma tion scratcher; said mandrel also having a plurality of longitudinally extending peripheral passageways for carryfluid from the space within said collecting collar and exterior of said mandrel to the bottom of said mandrel; and a one way check valve in fluid communication with said peripheral passageways and adapted to allow fluid to pass from said peripheral passageways to the space below said mandrel.

5. A down hole cementing tool comprising a generally cylindrical mandrel having a first longitudinal passageway extending from the upper end thereof and terminating within the lower portion thereof and a fluid passageway extending from the lower portion of said first longitudinal passag way to the exterior of said mandrel; a formation scratcher extending radially outward from the upper portion of said cementing tool and adapted to dislodge solids from the walls of a hole as the cementing tool is rotated and raised therein; a collecting collar extending outwardly and upwardly from said mandrel and encircling said mandrel immediately below said formation scratcl er, said collecting collar bein adapted to catch solid material dislodged by said formation scratcher; said mandrel also having a second longitudinal passageway for carrying fluid from the space within said collecting collar and exterior of said mandrel to the space below said mandrel; and a one way checl; in fluid communication with said second longitudinal passageway and adapted to allow fluid to pass from said second longitudinal passageways to the space below said mandrel.

6. A down hole cementing tool comprising a generally cylindrical mandrel having an axial passageway extending from the upper end thereof and terminating within the lower portion thereof, a plurality of generally radial fluid passageways extending from the lower portion of said axial passageway to the exterior of said mandrel and a plurality of longitudinally extending peripheral passageways for carrying fluid from an exterior space adjacent the upper portion of said mandrel to the bottom of said mandrel; a one way check valve in fluid communication witn said peripheral passageways and adapted to allow fluid to pass from said peripheral passageways to the space below said mandrel; a fixed centralizer connected to the upper portion of said cementing tool; and a detachable centralizer attached to the lower portion of said mandrel so as to be readily removable therefrom by raising said mandrel while said detachable centralizer is embedded in at least partially cured cement surrounding the lower portion of said mandrel.

7. Apparatus of the character described comprising in combination; a generally cylindrical mandrel having an axial passageway extending from the upper end thereof and terminating within the lower portion thereof, a plurality of generally radial fluid passageway extending from the lower portion of said axial passageway to the exterior of said mandrel, and a plurality of longitudinally extending peripheral passageways for carrying fluid from a space adjacent the upper portion of said mandrel to the bottom thereof; a one-way check valve in fluid communication with said peripheral passageways and adapted to allow fluid to pass from said peripheral passageways of the mandrel to the space below the mandrel; a retrievable wipe plug of suitable size and shape to be 7 forced down said axial passageway and retrieved therefrom; and means for retrieving said wipe plug; said wipe plug having valve means associated therewith operable by said retrieving means for permitting passage of fluid through said wipe plug only while said wipe plug is being re ieved.

8. Apparatus of the character described comprising tubing adapted to be lowered down a bore hole for injection of fluid therethrough; a generally oylindrioal mandrel operatively connected with the lower portion of said tubing; said mandrel having an axial fluid passageway extending from the upper end thereof and terminating Within the lower portion thereof, a plurality of generally radial fluid passageways extending from the lower portion of said axial passageway to the exterior of said mandrel, and a plurality of longitudinally extending peripheral passageways for carrying fluid from a space adjacent the upper portion of said mandrel to the bottom thereof, said axial passageway of the mandrel having substantially the same internal diameter as the tubing and being in fluid communication and coaxial with said tubing; a oneway check valve in fluid communication with said peripheral passageways and adapted to allow fluid to pass from said peripheral passageways to the space below said mandrel; a wipe plug or" a suitable size and shape to be forced down said tubing and axial passageway and retrieved therefrom; and a line attached to said wipe plug for retrieving the same; said wipe plug having valve means associated therewith operable by said line for permitting passage of fluid through said wipe plug only while said wipe plug is being retrieved.

References Cited in the file of this patent UNITED STATES PATENTS 158,865 Pontez Jan. 19, 1875 1,466,986 Burgher Sept. 4, 1923 1,656,526 Lincoln Jan. 17, 1928 1,669,130 Jensen May 8, 1928 2,141,370 Armentrout et al Dec. 27, 1938 2,253,537 Scaramucci Aug. 26, 1941 2701,019 Steed Feb. 1, 1955 2,740,480 Cox Apr. 3, 1956 2,897,524 Varner et al. Aug. 4, 1959 2,941,594 Ladd et al. June 21, 1960 2,999,545 Bigelow Sept. 12, 1961

Claims

1. APPARATUS OF THE CHARACTER DESCRIBED COMPRISING A GENERALLY CYLINDRICAL MANDREL HAVING A FIRST LONGITUDINAL FLUID PASSAGEWAY EXTENDING FROM THE UPPER END THEREOF AND TERMINATING WITHIN THE LOWER PORTION THEREOF, A FLUID PASSAGEWAY EXTENDING FROM THE LOWER PORTION OF SAID FIRST LONGITUDINAL PASSAGEWAY TO THE EXTERIOR OF SAID MANDREL, AND A SECOND LONGITUDINAL PASSAGEWAY FOR CARRYING FLUID FROM AN EXTERIOR SPACE ADJACENT THE UPPER PORTION OF SAID MANDREL TO A SPACE BELOW SAID MANDREL; A ONE WAY CHECK VALVE IN FLUID COMMUNICATION WITH SAID SECOND LONGITUDINAL PASSAGEWAY AND ADAPTED TO ALLOW FLUID TO PASS FROM SAID SECOND LONGITUDINAL PASSAGEWAY TO THE SPACE BELOW SAID MANDREL; A WIPE PLUG OF A SUITABLE SIZE AND SHAPE TO BE FORCED DOWN SAID FIRST LONGITUDINAL PASSAGEWAY AND RETRIEVED THEREFROM; MEANS CARRIED BY SAID WIPE PLUG FOR RETRIEVING THE WIPE PLUG; SAID WIPE PLUG HAVING VALVE MEANS THEREIN FOR PERMITTING PASSAGE OF FLUID THROUGH SAID WIPE PLUG ONLY WHILE SAID WIPE PLUG IS BEING RETRIEVED.