US 2295803 A
Description (OCR text may contain errors)
Sept 15, 1942- c. M. oLEARY I l 2,295,803
CEMENT SHOE @zig/1.2.
lll/ll Chrles /17- Ozeary INVENTOR BY gb- ATTORNEYk sept'. 15, 1942. M, @LEARY 2,295,803
CEMENT SHOE Filed July 29, 1940 2 Smets-sheet 2 l' ,5 Z0 ya? l I K k 9/ 32 zg 55 34 Wy/( V `-f2 Z8 r;
\\ j @a/L96 /T 07).@ al' INVENTOR l 4f BY ATTORNEY Patented Sept. 15, u1942 AUNITED STATES PATENT OFFIC CEMENT SHOE Charles M. GLeary, Houston, Tex. Application July 29, 1940, Serial No. 348,198
The present invention relates generally to the setting and cementing of casing in the drilled bore of an oil well and has for its general purpose the provision of a cement or easing shoe of the guide shoe or float shoe type which will act to guide the casing into the well bore and also as a centralizer to hold the lower end of the casing spaced from the wall of the well bore when the position at which the lower end of the casing is to be set has been reached.
The invention has for a further object the provision of a cement shoe of the nature to impart a rotary motion to fluid emitted from the lower end of the casing as such fluid passes upwardly in the well bore around the casing, for the purpose of eiiiciently removing the mud sheath from the wall of the bore during circulation, as well as to evenly distribute cement around the casing during cementing operation.
A further object of the invention is the provision of a cement or casing shoe in the nature of a reamer adapted and arranged to reduce the normal clearance between the casing and the bore wall as the casing is run into the bore whereby the fluid in the Well bore, prevented f from passage upwardly in the casing, is forced to pass the restricted area between the reamer or shoe and the bore wall and, in so doing, is
directed powerfully in a swirling manner against the wall, serving as an efficient means to coact with the rearning shoe in the removal of mud coating from the wall as well as to continuously wash the helical vanes of the shoe and maintain the same in a clean eiiiciently cutting condition.
A still further object is the provision of a cement shoe having the above mentioned useful advantages during the run in of the casing and the setting and cementing thereof in the bore, and which has the further advantage of yieldable contraction in the event constricted portions or tight spots of the bore wall areencountered, so as to avoid the possibility of sticking in the presence of swelling rock or other'hard formation which circulation will not readily clear away.
With the above general objects in mind, other and further objects as well as the manner and means of carrying out the invention and its resulting advantages may be well understood and thoroughly appreciated in the course of the following detailed description thereof and by reference to the accompanying drawings, which form a part of the specification, and in which,
Figure l is a vertical longitudinal sectional View through a portion of a well bore showing 55 my improved shoe therein at the lower end of a casing string, partly in elevation and partly in section.
Figure 2 is a horizontal the shoe of this invention line 2-2 of Figure 1.
Figure 3 is a detail horizontal sectional View through the guide nose showing a modified construction presenting internal flutes as well as external vanes.
Figure 4 is a side view of a modified shoe, partly in elevation and partly in section, along the line of one of the vanes in a solid yieldable Figure 5 is a cross section taken substantially on line 5-5 of Figure 4.
Figure 6 is a side view of another modified construction in which provision is made for vanes yieldable against springs, and
Figure 7 is a partial cross section taken substantially on line 'I-'I of Figure 6.
Referring now to the drawings and particularly to Figure 1, the wall of the well bore is indicated at I0 and shown with a casing II suspended therein at the point selected for setting the lower end of the casing and also shown with the combination shoe of the present invention, generally indicated at I2, secured to the lower end of the casing, and comprising a collar portion I3 and a nose portion I4.
For the above purpose the nose of the shoe I2 has an upper threaded neck portion I 4a within collar I3, which may also serve as a support for a valve cage I5, having an opening in lilrlie with the axial fluid passage I6 through the s oe.
While a back pressure valve may be disposed at any point within the casing II, the lower end of cage I5 is shown as provided with a valve seat I'I around the lower end of its opening, against which a valve I8 seats to prevent upward or back flow from the well bore into the casing. This valve may be located at the lower end of a stem I9 which passes upwardly through a bridge 20 supported by cage I5. The stem I9 is also shown with an upper head 2I between which and the bridge 2U a spring 22 is compressed to normally hold valve I8 in upper seated position and at the same time permit the valve to yield downwardly for allowing outflow of circulating fluid as well as cement through the bore or flow passage of the shoe.
The nose portion I4 of the shoe as seen in Figures 1 and 2 is of downwardly tapering form below the collar I3 and has thereon external,
sectional view through taken substantially on spaced, helically inclined vanes 24, whose external surfaces form substantially a cylindrical guide, the diameter of which is substantially greater than the outside diameter of the collar I3 and the casing Il, to closely approach the inside diameter of the well bore and thus among other things hold the lower end of the casing l substantially centered in the well bore.
As seen in Figures l and 2, the axial flow passage IS of the shoe is plain, the external vanes 24 being solid ribs. However, as shown in Figure 3, the wall of the flow passage may be fluted by virtue of internal grooves 25 which preferably follow the external vanes 26 in this instance and act to impart a swirling motion to downwardly discharging fluid from within the casing.
In operation, the cement or casing shoe of the present invention, as thus far described, is screwed on the lower end of the casing and is run in` on a series of tubular joints of the casing to the desired point in the well at which the casing is to be Set. The nose portion of the shoe with its helical vanes acts to guide the casing around any bends or through rough places in the well bore during the run in and, when the casing isfflnely positioned, also acts to hold theV lower endof the casing away from the wall so as to substantially centralize it in the well bore. Mud is then pumped down the casing through the'valve cage on out at the bottom of the shoe through flow passage I6, which passage may be fluted, as above described in connectionV with Figure 3, with helically inclined groovesV to cause the fluid discharged therefrom to be emitted in a swirling turbulent mass to clean the well bore ahead of or below the shoeA If bridges; in the well are encountered this optional internally fluted structure enables them to be more readily washed away.
During the above circulating operationthefluid pumped down the casing returns up to the surface in the space between the casingand theV wall of the well bore and, as the fluid rounds the nose of the guide shoe in its upwardy travel, its course is changed by the helically inclined vaneson the outer surface o f the guide nose so that under the pressure andwvolume of the uid being discharged past the shoe, greatforce is imparted to the. fluid for scouring the wall of the well bore.
If there is any tendency for the shoe. and the casing to lay toward one side ofA the well bore more than the other, uid will be directed from the opposite side andv will washfav channel. and finally open up a space completely around the casing, allowing a, full and complete encirclement of cement, and cleaning the mud from the wall of the well bore so as to insure a perfect water. shut off'.
4With the backA pressure valve closed, wherever such valve isl located in the lower portion of` the casing string as the casing` is lowered into the well bore, the iiuid inthe well bore is prevented from upiiow inthe casing and isf thus displaced, upwardlybetween the shoe and the bore wall and is given a swirling movement by the helically in. clined vanes, Furthermore, since the vanes extendoutwardly beyondthe casing and closely approach the wall of the well bore, the fluid, in passing the same is, given a substantially increased velocity which, with the swirling movement thereof, causes substantially a jetting action of the fluid against the mudded wall so as to effectively accomplish removal of the mudsheath.
` t is obvious from the foregoingthat the guideY vanes also helpto remove the mud sheath by a Washing, scraping or reaming contact with the bore wall, and that the jetting fluid passing upwardly around the shoe keeps the guide vanes clean of mud and maintains them operative and effective as a wall scraper or reamer at all times.
While materials have not thus far been referred to, it will be understood that the nose of the shoe, and any parts thereof, are to be formed of any suitable drillable material so that such parts may be readily drilled out after the cementing operation incident to the setting of the casing, has been completed.
As before referred to in a general way, it may be desirable to have the helical ribs or vanes of the shoe nose capable of inward yielding movement so that contraction of the overall diameter ofthe shoe nose may be possible when encountering tight spots in the bore. To prevent sticking of the tool under such circumstances, the ribs or vanes may be formed entirely of rubber, or may as seen at 21 in Figures 4 and 5, be made of any suitable material partially embedded in rubber 28 molded around a tubular nose 2Q. If made of' a rigid material, itis preferable that the ribs or vanes 21 be provided with side flanges 313v along their inner longitudinal edges embedded in the rubber 2S, and with end flanges 3| to extend into cavities 32 in the shoe nose and a ring 33, the latter held by a threaded and pin-locked end piece 34.
It is, of course, possible to dispenseV with the use of molded rubber by utilizing small springs as shown at 35 in Figures 6 and 7, beneath the ribs or vanes 3` movably supported in this instance between radial walls 3lE of the shoe nose. Through such walls 3.1; cross pins. 38 may be fixed to extend through enlarged slotted openings.. 39 of the vanes 36, permitting thelatter toyield inwardly.v against the tension of springs 35.
With the above construction it is preferable to have openings i0 through the walls 3:1 and possibly also through the end piece 4il, to avoid any danger of entrapping well pressure or fluid behind the vanes which might otherwise prevent their freedom of movementtocontract whenever necessary during run in.
As there isa tendency for the helically vaned shoe to rotate, going into the well bore, as well as in circulation and pumping operations, it will be understood that the vanes shouldV incline in a direction calculated to tighten, rather thanloosen, thethreaded joints of the casing sections.
Having thus fully described the invention, what is clain'iedis:V
1.V A cement or casing shoe for the lowen end of well casing in thesettingthereofg, including a nose portion havingav downwardly tapering body below the casingprouidedwith flexible helically inclined external surface vanes, outstandingY sub.- stantially beyond the` diametrical limits of the Casing.
2, A` cement or casingY shoe for; the lower. end O f Well Casing inthe'setting thereof, including a noseporonbavine a downwardly tanerngbody below theV casing provided with flexible helically inclined surface vanes outstanding substantially beyond the diametricalj limits of the casing and whose outer edges presenti a Cylindrical casing guidingA and' bore wall scraping Surface of substantially the same diameter throughout the length ofthe nose.
3. A cement or casing shoe for the-lower end of well casing during run in and setting of the casing within a well bore, said shoe havinga body portion below, and' ofsubstantially greater overall diameter than-the casing,` said body being provided with an internal flow passage and external helically inclined vanes, the wall of said flow passage having helically arranged grooves.
4. A cement or casing shoe for the lower end of well casing in the setting thereof, having a flow passage lengthwise thereof and having a nose portion below the casing provided with external vanes for causing swirling of fluid or material forced upwardly between the shoe and the wall of a wel] bore and a molded rubber bed on the said nose portion in which said vanes are partially embedded and yieldingly supported.
5. A cement or casing shoe for the lower end of well casing in the setting thereof, having a flow passage lengthwise thereof and having a nose portion below the casing provided with external vanes for causing swirling of fluid or material forced upwardly between the shoe and the wall of a well bore and means yieldingly supporting said vanes on the shoe whereby the series of vanes may contract to pass a tight spot in a well bore.
6. A cement or casing shoe for the lower end of well casing in the setting thereof, having a flow passage lengthwise thereof and having a nose portion below the casing provided with external vanes for causing swirling of uid or material forced upwardly between the shoe and the wall of a well bore, means on .the shoe for supporting said vanes in radially shiftable relation with respect thereto, and means yieldingly bolding said vanes against inward movement.
'7. A cement or casing shoe for the lower end of well casing in the setting thereof, having a flow passage lengthwise thereof and having a nose portion below .the casing provided with external vanes for causing swirling of fluid or material forced upwardly between the shoe and the wall of a well bore, and means on the shoe for supporting said vanes in radially shiftable relation with respect thereto and limiting their movement in an outward direction, and springs between the shoe and the vanes for yieldingly resisting their inward movement.
8. A cement or casing shoe for the lower end of well casing in the setting thereof within a well bore, said shoe having a flow passage therethrough forming with the interior of .the casing an inner circulation channel including a back pressure valve, and said shoe having a lower nose portion provided with external helical vanes whose outer faces present substantially a cylindrical surface of considerably greater diameter than that of the casing and closely approaching the diameter of the well bore.
9. A cement or casing shoe for the lower end of well casing in the setting thereof within a well bore, said shoe having a flow passage therethrough forming with the interior of the casing an inner circulation channel, and said shoe having a lower nose portion provided with external helical vanes whose outer surfaces present substantially a cylindrical yielding surface of cony siderably greater diameter than that of the casing, said helical vanes being arranged relative to one another to form substantially narrow channels therebetween, for thus substantially increasing the velocity of upflowing well fluid past the shoe nose whereby to bring about a jetting action of such fluid against the mud sheath of the bore wall.
CHARLES M. OLEARY,