US 1732791 A
Description (OCR text may contain errors)
Oct. 22, 1929, E. v. cRowELL WELL CEMENT ING Filed July 7, 1926 Mm u @K A TTORNEY.
M///////////,//////f/ A /l Patented Oct. 22, 1929 UNITED STATES' ERD V. CROWELL, 0F LOS ANGELES, CALIFORNIA WELL CEMENTING Application led July 7, 1926. Serial No. 121,040.
lllhis invention is an improvement. in well cementing as set forth in my prior Patent No. 1,502,179, granted July 22, 1924:; and it is the object of the present invention to discharge a cementing mixture downwardly through a well casing and outwardly through ports in the sides thereof so as to fill the surrounding bore,with the string ofcasing readily lowered to desired depth in the well bore by washing the casing free from cavings and ioating the casing to position and centering it on the bottom of the bore when landed.
It has been found by use of the construction set forth in my abo ve-mentioned patent, that in order to prevent freezing of the casing inthe bore and to properly center the casing and provide practical means for s lowering it into the bore, it is advantageous to position the normally closed valvular ports which control discharge of the cementing mixture, in a fixed section of the casing having a uniform bore, and provide for limited opening movement of the valves for the discharge ports so as to prevent the possibilityof their engagement with the wall of the well bore, and to also provide frangible valvular means in the bore of said section and arrange for attaching the conventional casing shoe guide to said section.
The present linvention provides means which have proved practical through use, for washing a string of casing free from being stuck or frozen in the well bore and centering the casing in the bore when seated on bottom, as has been found necessary to practical -and eicient operation when cementing the casing in the well. y
The invention will be readily understood from the following description of the accompanying drawings, in which:
Fig. 1- is a side elevation, partly in axial section, of the improved construction.
Fig. 2 is a detail vertical section through one of the valvular controls.
Fig. 3 is a transverse section on the line 3 3 of Fig. 2.
Figs 4 and 5 are views similar to Fig. 1, each showing a modified construction.
The cementing means is shown as a barrel l forming a fixed section of a string of casing 2 by usual threaded connections 3, the cementing barrel forming a continuation of the uniform bore of the string of casing which is adapted to be received in a well bore A.
The barrel 1 has outwardly opening valvular controls` which are shown as radial peripheral ports 8 normally closed by valves 9. he valves 9 preferably seat in countersunk outer ends 10 of the ports 8; and these counter-sunk seats 10 may open into grooves 12 in the outer surface of the barrel, which extend circumferentially in both directions from the valvular ports and gradually merge into the surface of t-he barrel for directing the material which is discharged outwardly through the valvular controls.
The valves 9 are normally yieldably closed, and for this purpose areshown mounted on spring arms 11, preferably medially thereof,
with the spring arms extending axially of barrel 1 and preferably received in grooves 13 which extend axially in both directions from counter-sunk seats 10, the spring arms being xed at one end in the grooves 13 as shown at 15, and the opposite free ends of the arms bearing in the grooves so as to provide supports for the valves which will exert the desired yielding pressure tending to close the valves.
Opening movement of the valves is limited so that the entire valvular controls are at all times within the outer periphery of barrel 1, and for this purpose abutments for the valves 9 are provided in the outerends of counter-sunk seats 10. Asan instance of this arrangement annular recesses 16 may be provided in the outer ends of seats 10, and segmental rings 17 are fixed in said recesses, as by welding or the like, with the separated segments of the rings providing space for the free passage of spring arms 11 between the same while positively engaging valves 9 so as to limit their opening movement. v
The cementing barrel may be positioned at the lower end of a string of casing as shown in Figs. 1 and 5, or the barrel may form an intermediate section of the string of casing as shown in Fig. 4, the particular arrangement which is employed depending upon the particular cementing operation.
The invention also provides for centering the string of casing as it is landed on bottom, and for this purpose a casing shoe guide maybe mounted on the lower end of the casing string. Such a construction is illustrated in Fig. 1, where the conventional casing shoe guide 20 is connected to the lower end of ceinenting barrel 1 by thel threaded connection 3.
When the cementing barrel forms an intermediate section of the string of casing as shown in Fig. 4, packing means may be employed on the casing below ports 8 for retaining the cementing mixture at the desired level in the well bore. The packing means is shown asspring fingers 5 fixed at their lower ends to a sleeve '6 which is adapted for limited sliding movement on the casing below the valvular discharge ports, the spring fingers by their yieldable engagement with the wall of the well bore being adapted to support packing material 7 which is radially expanded by the weight of the material discharged through ports 8 so as to close the space between the casing and the wall of the well bore.
- The cementing barrel may also be employed in connection with a string of casing having a usual casing shoe at its lower end, and for this purpose the lower end of barrel 1 may form casing shoe 30 as shown in Fig. 5.
With any ofthe constructions described the valves 9 are held in closed position by theiry springs 11 while the string of casing is being lowered to desired position in a well, and when cement is discharged downwardly through the casing the pressure thereof is adapted to open the valves so that the cement is discharged through ports 8 into the space 1petween the casingand the wall of the well ore.
In certain instances a back pressure valve 18 may be mounted in the bore of the string of casing below ports 8 to prevent cement owing downwardly through the casing below the discharge ports, and if desired a iioat valve 19 may be mounted in the bore of the string of casing above the ports 8 to permit the casing string being floated into the well ore.
The valves 18-19 may be mounted in place by providing shoulders 4 at the bases of the threaded ends 3 of the cementing barrel, with valves 18-19 seating against these shoulders and held in place by the ends of next adjacent sections of the string of casing which are engaged by the threaded connections 3. The valves 18-19 are of a frangible construction so'that after the casing is cemented in place the valves may be readily drilled through for resuming operations.
The specific arrangement of the cementing barrel, as shown in the various modifications,
will depend upon the particular cementing operation. If the bore of the well is of a caving formation there will be a tendency for cavings to fall in against the casing as it is being lowered and thereby cause it Lo wedge or stick so that it cannot be raised or lowered. Casing in this condition is commonly referred to as frozem and the invention provides for washing the casing free so that it may be raised or lowered and thereby positioned at the proper depth. As a consequence the casing may be lowered into a well and cemented in place with minimum expense, both through simplification of the operation and saving in casing by obviating the premature use of an extra string.
When washing down the casing preparatory to the cementing operation or when the casing freezes in the well bore, a circulating iiuid such as water may be discharged downwardly through the casing, and upwardly between the casing and thc wall of the .well for washing the casing free, various methods of circulating the washing medium being shown and described in my co-pending patent applications Ser. N o. 327 ,080, filed December 19, 1928, and Ser. No. 331,411, filed January 10, 1929. If the back pressure valve 18 is employed, flow of the circulating fluid downwardly through the casing below ports 8 is prevented by the back pressure valve, and the pressure of the flow thereby causes valves 9 -to open so that the water is discharged through ports 8 and upwardly at the .exterior of the casing for washing it free, so that'the casing may be readily raised and lowered.
During the washing operation opening of valves 9 is positively limited by the abutments 17 so `that the valves cannot swing outwardly beyond the outer periphery of the string of casing, and it is therefore impossible for the valves to impinge against the wall of the well bore and cause injury to the valves or sticking of the casing as it is raised and lowered during the washing operation. The practical advantages of the construction for overcoming the obstacles ordinarily encountered as a result ofthe casing freezing, have been recognized in practical operatlon by the adoption of the name set shoe or wash shoe for the device, the adaptability of the invention for washing down a string of casing being the result of limiting the outward swing of valves 9 and the tendency thereof to remain closed against discharge of the circulating fluid.
lVhen the wall of the well bore is of a formation which will stand up without caving so as to leave a clear open bore to bottom, the casing shoe guide 20 prevents shearing-off the walls of the bore as the casing is lowered, the shoe guide being of usual construction tapering to reduced diameter at its forw` rd end, so that it will freely enter the bore and properly center the casing when it is landed on bottom.
When the valves 18-19 are employed they may cooperate with valves 9 for controlling discharge of material from the bore of the casing and positioning a cementing mixture at the desired level, or either set of Valves may be dispensed with depending upon the particular cementing operation. The valve 18 will prevent passage of material downwardly through the casing below ports 8, and the valve 19 provides a normally closed means, adapted to open by pressure of material, for controlling discharge thereof through ports 8.
It will thus be seen that the modifications of the invention resulting in the various modes of operation, provide not only for cementing the casing in a well, but also make possible the proper conditioning of the Well bore for receiving the cement, as has been found through practical operation to be as essential to the success of a cementing operation as the actual application o f the cement.
The invention is adapted for use in either a caving or a non-caving formation, and provides for lowering the string of lcasing and centering it in an open bore, or lowering the casing as the hole is drilled, as for example in a caving formation where itis necessary to Idrill ahead of the casing in successive steps and lower the casing a joint at a time; and when used in a well bore which is liable to cavein and freeze the casing, the construction provides practical and efficient means for readily washing the casing free so that it may be lowered into place without prematurely employing an extra string.
1. Well cementing means comprising casing adapted for reception in a well with its exterior surface in close proximity to the wall of the well and its interior surface defining a uniform unobstructed bore through the casing, a port opening through the side wall of the casing, the exterior surface of the casing having a 'depression therein at the port, a radially outwardly opening valve.
mounted in the depression and normally closing the port, and an abutment seated in the depression so as not to extend outwardly be yond the exterior surface of the c asing, said abutment overlying the valve 1n normal spaced relation therefrom so as to permit limited opening movement of the valve, and the exterior surface of the casing having a laterally extending groove communicating with the depression. l"
2. Well cementing means comprising casing adapted for reception in a well with its exterior surface in close proximity to the wall o f the well and its interior surface defining a uniform unobstructed bore through the casing, a port opening through the side wall of the casing, the exterior surface of the casing having a depression therein at the port,
therefrom so as to permit limited opening movement of the valve. y 3. Well cementin'g means comprising casing adapted for reception in a well with its exterior surface in close proximity tothe wall of the well and its interior surface delining a uniform unobstructed bore through the casing, a port opening through the side wall of the'casing, the exterior surface of the casing having a depression therein at the port, a radially outwardly opening valve mounted in the depression and normally closing the port, and an abutment seated in the depression and overlying thevalve for preventing opening movement thereof beyond the exterior surface of the casing.
4.. W'ell cementing means comprising casing, a port opening through the side wall of the casing, the exterior surface of the casing having a depression therein at the port, a radially outwardly opening valve mounted in the depression and normally closing the port, and an abutment seated in the depression and overlying the valve for preventing opening movement thereof beyond the exterior surface of the casing, the exterior surface of the casing having a laterally extending groove communicating with the depression.
In testimony whereof I lhave aflixed my signature.
A ERD V. CROWELL.