Pressure drilling head

Application filed June 1, 1927.

My invention is a pressure drilling head for drilling wells, such as oil wells, by rotary drilling.

An object of my invention is the construc₅ tion of a drilling head which will allow a drill pipe to rotate and to pass downwardly therethrough, whereby a drill bit at the lower end may be rotated and a circulation fluid may be forced downwardly through the drill io pipe.

An object of my invention is the construction of a pressure head which has an inner part or sleeve rotating with the drill pipe, and with packing rings therein to form a 15 tight seal with the drill pipe or with the couplings of such pipe.

In constructing my invention I mount a valve on the top of a well casing, this valve perferably being of the gate type, and above 20 this valve there is a false or upper casing which extends to a sufficient height to form a support for the inner rotary sleeve of the drilling head. This sleeve is mounted on a cap with, preferably, antifriction bearings 25 and is suspended inside of the upper or false casing, passes downwardly through the valve and extends into the upper part of the casing. This sleeve is provided with packing rings secured thereto, these rings being of 30 such character as to form a fluid tight and gas tight seal with the couplings of the stands of drill pipe. The sleeve with the packing rings is of such length that in the downward or upward movement of the drill 35 pipe one or more of the couplings engages the packing rings.

My invention is illustrated in the accompanying drawing, this being a vertical sectional view partly in elevation.

The well is indicated by the numeral 11, having a well casing 12 extending downwardly from the surface of the ground. At the top of the casing a collar 13 is attached thereto and above , the collar is secured a 45 valve, designated generally by the numeral

Serial No. 195,696.

14. This valve is indicated as being of the gate type and has a slidable valve gate 15 which may be moved from open position, in which it is shown in full lines to closed position, as shown in dotted lines and indicated 50 by the numeral 16, thereby forming a closure for the well when the remaining parts hereunder set forth are removed or before their attachment.

An upper collar 17 is secured to the upper 55 face of the valve 14 and to this collar there is attached and upper or false casing 18. This casing has a closure head 19, screw threaded thereon or otherwise attached, such head having a flange 20. A cap 21 is secured 60 to the flange 20 of the head 19, this cap having a cylindrical wall 22 with openings 23 therein for a purpose hereunder set forth. A shoulder 24 forms part of the cap, with a clamping ring 25 secured to the cap. A pack- 65 ing gland 26 fits in the upper portion of the head 19, which head has a cylindrical opening 27, and such gland compresses the packing 28, there being bolts 29 which may be . reached through the openings 23 in the 70 wall 22.

A cylindrical sleeve 30 extends downwardly from the cap through the false casing 18 through the main part of the valve 14 and into the upper part of the casing 12. This 75 tube has a bearing ring 31 on the upper end fitting against a shoulder 32 and retained in place by a lock nut 34. On the shoulder 24 there is a lower ring raceway 35 of the antifriction bearing, and the balls 36 of such 80 bearing engage between this lower ring raceway 35 and the bearing ring 31 and the clamping ring 25. The gland 26 with the packing 28 forms a liquid and gas tight seal on the outside of the sleeve 30 but allows ro- ⁸⁵tation of such sleeve.

Internally of the sleeve there are a series of packing rings 37 formed of rubber or the like which are spaced apart by spacing rings 38, the bottom ring being held by an internal ®°

1,813,402 nut 39 at the lower end of the sleeve 30. This sleeve may have a joint such as 40 if desired, this being illustrated as a screw threaded joint.

' The drill bit 41 is illustrated as being connected to a drill tube 42 which has the different stands joined together by couplings 44. These couplings are of such diameter that . they form a tight seal with the resilient 10 packing rings 37 on the sleeve and when such rings are formed of rubber the rubber is tightly compressed during the downward and upward movement of the couplings through the sleeve 30. The drill pipe is ro¹⁵ tated by a rotary rig designated generally by the numeral 45, this rig being illustrated as being supported in any suitable manner above the top of the false casing 18 and above the cap 31 thereon. This rotary rig is of stand²⁰ ard construction and does not form an immediate part of my invention.

I do not show the mechanism for feeding a circulation fluid to the top drill pipe as this does not form an immediate part of my in²⁸ vention, but the circulation outlet is indicated by the numeral 46, this being connected, preferably, to the false casing above the valve 14. ;

The manner of functioning and operation of my pressure drilling head is substantially as follows:./

As it is desired to maintain a pressure on the well, therefore, before the false casing is connected in place, the valve 14, which is on the top of the casing 12, will be closed. The false casing, its head 19, and the cap 21 are then assembled above the valve 14. The rotary sleeve 30 is then fitted in the assembly, the antifriction bearing being assembled in the procedure, and the packing in the head 19 being clamped to a sufficient extent to prevent escape of gas but to,allow rotation of the sleeve 30»

When the drill pipe is being lowered into the well, as each coupling 44 passes downwardly through the sleeve 30, it-engages the resilient packing rings 37, thereby forming a tight seal,, ana, as above mentioned, this sleeve is of sufficient length so that there will always be at least one coupling engaging * i · · _____ Ί--__ΊΊΥϊ-1-ιητι nnll85 the antifriction bearings on the cap may be disassembled, the rotary sleeve may then be withdrawn and such sleeve raised above the valve 14 and the bit drawn above such valve. The valve may then be closed and after this assembly, including the false casing 18, removed.

From the above description, together With the drawings, it will be seen that I have de- . veloped a simple type of. pressure drilling head suitable for rotary drilling or other . operations, and maintaining a tight seal on the well whereby the well may be maintained under pressure. It is manifest that the same type of head may be utilized for lowering well casings or the like of a smaller diameter than the main casing, and for other operations in which it is desired to maintain a pressure in the well.

It is to be understood that instead of having separate resilient packing rings 37 in the · cylindrical sleeve 30,1 may (have a _a continuous ring fitting inside this sleeve so that the collars 44 oh the drill pipe or other assembly passing therethrough will form a tight seal.

Various changes may be made in the principles of my invention without departing from the spirit thereof, as set forth in the description, drawing and claims.