US2009989A - Oil well casing head - Google Patents

Description

July 30, 1935. v ".i. Bl-:GG I 2,009,939

uon. WELL cAsINGv HEAD Filed March e, 1955 2 sheets-'sheet 1 z l l' l 3 3 3L '37 I 2 V4.23,51 lh l l I 3029.-. 27 Milt .I 40 3s 40 4L 36 'III l i l nl 25 n' I 3; I@ I A n 3 1 I 15 12 23- l 22 24 Il 26. 4] :I/ i9@ `l 2g h 25A Z316 I| ggg- Z2 I 'wr I f1* l un l .38- i 10 14? @1f 2 q Y zo l ,l es r C V l Juy 30, 1935. J. BEGG OIL WELL CASING HEAD Filed March 6, 1933 2 Sheets-Sheet 2 i: ,if/

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Patented July 30, 19.35

PATENT OFFICE OIL WELL CASING HEAD James Begg, San Pedro,

Calif., assignor to Regan Forge & Engineering Company, San Pedro, Calif., a corporation of California Application March 6,

9 claims.

This invention relates to `oil well equipment and more particularly to a casing support or control head.

In certain types of casing heads, the dead weight of the casing has been utilized to compress the packing therein employed to form a iluid tight seal between the several strings of casing or tubing.

While this is a very desirable feature for the l0 reason that it eliminates the use of bolts or the like to compress the packing, considerable trouble however has been experienced due to collapsing oi?` the casing caused by excessive compression of the packing, especially so in deep wells where long and heavy strings of casing are necessary.

It is therefore the principal object of the present invention to provide a casing or control head so constructed that the Weight of the casing or tubing itself may be utilized to compress the packing without danger of collapsing the casing or tubing.

Another object is to provide a casing head in which the'weight of one string is utilized to com-- press the packing around another of larger diwhereby the pressure exerted on the packing may be controlled.

Briey stated, the invention resides in a casing head construction comprising a base member adapted to be secured to an outer string of casing and having a plurality of slips for suspending a second string of casing.

An upper spool-like member is detachably secured to the base member and is provided with a plurality of slips adapted to suspend a string of tubing within the second string. Disposed in the base member is a packing ring that forms a fluid-tight seal between the second and outer strings of casing, which ring is compressed by 40 the weight of the tubing when suspended on the slips in the upper member, the degree of pressure exerted on the packing ring by the Weight of said tubing being controlled by adjustable means associated with said base and upper members.

yOther objects and advantages will be apparent from the following description, reference being had to the accompanying drawings, in which:

Fig. 1 is a side elevation of the improved casing head as it appears when applied to a casing 50 within a Well hole.

Fig. 2 is an enlarged vertical sectional view taken on line 2--2 of Fig. 7.

Fig. 3 is a side elevation partly in section, illustrating a slightly modiiied form of the casing head.

ameter and having means associated therewithl 1933, Serial No. 659,682

(Cl. 16B-14) Fig. 4- is a horizontal section taken on line 4-4 of Fig. 3.

Fig. 5 is a horizontal section taken substantially on line 5-5 of Fig. 3.

Referring to the drawings, more specifically to 5 Fig. 1, I0 designates an outer or iirst string of casing that has been landed in a well bore W and cemented therein as indicated at C.

The casing or control head of the present invention generally designated at I2 consists of l0 a hollow base member I3 that is adapted to be connected to the upper end of the casing I0 preferably by a pipe coupling I4 and an upper section or spool-like member I5.

Formed in the base member is a frusto-conica1 l5 seat. I6 for the reception of a plurality of slips I'I that serve to support the second string I8.

Mounted in a bore I9 formed in the upper end of member I3 and resting on a shoulder I9a is a metal ring that serves to support a pliable packing ring 2I (preferably formed of rubber or lead) which ring in turn is engaged by a gland 22 lformed on the lower end of member I5 and forms a fluid tight seal between the second and outer strings of casing when the same is compressed.

The metal packing supporting ring and end face of the gland 22 are preferably tapered or wedge shaped in cross section and engage correspondingly shaped grooves formed in the packing ring in order that the same will be equally expanded into engagement with the second casing and bore I9 of member I3.

The upper and lower members are connected by bolts 23 that are extended through slots or openings 24 in companion flanges 25 and 26 respectively formed on said members.

Mounted in a tapered bore or seat 26 formed in member I5 is a plurality of slips 21 the teeth of which engage and suspend the inner tubing or oil stringdesignated at 28, and disposed in a bore formed in the upper end of member I5 4above the slips is a metal ring 29 that supports a packing ring 30 which in turn is compressed by a gland 3I formed on a iitting 32, the supporting ring 29, packing ring 30 and gland 3| being of the same shape in cross section as those above described.

Fitting 32 is connected to member I5 by bolts 33 disposed in openings in companion anges 34 and 35 formed on said flange and member, respectively, and is provided with an externally threaded neck 36 for connection through Aa pipe 31 to the usual flow control pipe lines and u lill' nttlng coonly referred to as the Christmas tree (not shown).

The base and upper members of the casing head are provided with threaded openings 33 ior connection with the usual valve controlled gas vent pipes indicated at llt.

Screw threadedin flange 25 of member l5 is a plurality of set screws or the like il that engage the face of the ange 2S on the base member.

in actual practice the hole or bore for the second string is drilled (with the base member only applied to the outer casing lll) i. e. until conditions indicate that the second string l@ may be landed, whereupon the slips 2l are dropped into the seat so that they will. engage and support the same.

,The second casing i@ is then stretched (if cemented) and the end thereof projecting above flange 2li cut oi at the required length. The supporting ring 2@ and packing ring 2l are next placed in the bore lll, and the upper member l5 applied and connected to the base member by the bolts 23, which bolts then serve to compress the packing ring 2l until the hole for the tubin 2li has been drilled into the oil sands.

The string 253 is then lowered through member l5 to the required depth and slips 2l placedin bore 2@ to suspend the same.

From the above it will be apparent that when engaged by the slips the weight of the tubing 2S will be transmitted through member l5 and eiect compression of the packing ring 2l.

llt is desirable to utilize the weight of the tubing to eiect a compression of the packing, for the reason that it will relieve practically all strain on the bolts 23. The tubing, however, is

usually of such weight that if it were allowed to bear thereon, the packing ring would be cornpressed. to such an extent that it would result in collapsing the upper end of the second string oi casing. y

This inherent danger of collapsing the second string of casing is counteracted by the set screws ill. If required, set screws lll may be threaded in `tting i2 to regulate the pressure exerted and consequent compression of packing ring 3@ by the weight of the Christmas tree.

It will be noted that after the casing head has been assembled in the manner above described, practically all tension or strain on the connectlng bolts will be relieved and that by adjusting the set screws the compression of packing rings may be regulated from time to time as required.

Referring to the modication shown in Figs. 3, 4 and 5, 50 generally designates the casing head which is composed of a base member 5l provided with a flange 52 that is connected by bolts 53 to a flange 54 secured to the upper end of the outer casing 55, preferably by spot welding indicated at 56. Formed in the base member is a tapered bore 51 that forms a seat for a. plurality of slips 58 that serve to suspend the second string of casing indicated at 59.

Mounted on the slips 58 is a pliable packing ring 60 that is compressed by a gland 6l formed on the lower end of an upper member 62. The slips 5B are preferably provided with interlocking tongues and grooves indicated at 58a in Fig. 5 in order that their upper faces will present a. substantially at surface for engagement with the packing ring 60.

'I he base and upper members are connected by bolts 63 disposed in slots or openings 64 in com-y panion flanges 65 formed on said members.

Formed in member 62 'is a tapered seat 66 for aooaeee positioning a plurality of slips Gl that serve to support the inner or oil string of tubing designated at iid and mounted on the slips is a pliable packing ring @il which in turn is compressed to form a seal between the second string and tubing by a gland lil formed on a ow fitting l l.

The iicw fitting has an externally threaded neck 'l2 for connection with a Christmas tree and is removably secured to the upper member 52 by bolts i3 disposed in openings in flanges 'ill formed on said fitting and member.

Formed in members 5l and @E below the slips are threaded openings for connection with usual gas vent pipes designated at P.

Positioned between flanges E55 are a plurality of iiat spacer plates l5 that serve to control the pressure exerted on packing (it, i. e. when the inner tubing @d is suspended on slips iili.

A plurality of plates 'iii may be placed between .danges lil to adjust compression of packing t9 ii required.

The casing head above described is adapted to be assembled in the same manner as the preferred form, the spacer plates being employed in lieu of the set screw for the purpose set forth. Compression of the packing may be adjusted by substituting or interchanging spacer plates of varied thickness. This may be easily accomplished by loosening the bolts and driving wedges (not shown) between the anges.

I claim:

l. A casing head comprising a base member connected to an outer casing, gripping means carried by said base member for supporting a second concentric casing, packing disposed in said base member above said gripping means, an upper hollow body member mounted in slidable relation to said base member and engaging said packing, gripping means mounted in said upper member for supporting a string of tubing within said second casing whereby the weight of said tubing will be transmitted to and compress said packing to form a uid tight seal around the second casing with said base member.

2. A casing head comprising a base member connected to an outer casing, slips removably mounted in said base member for supporting a second concentric casing, packing disposed in said base member above said slips,l an upper body member mounted in slidable relation to said base member and', having a gland formed thereon engaging said packing, and slips mounted in said upper member forV supporting a string of tubing within said second casing.

3. A casing head comprising a base member connected to an outer casing, slips removably mounted in said base member for supporting al` second concentric casing, packing disposed in said base member above said slips, an upper body member mounted in slidable relation to said base member and having a gland formed thereon engaging said packing, slips mounted in said upper member for supporting a string of tubing within said second casing, and means associated with said base and upper member for controlling the pressure exerted on the packing when said tubing is suspended on the slips in said upper member.

4. A casing head comprising a base member having a tapered seat formed therein and adapted to be secured to an outer casing, slips mounted in the seat in said base member for supporting a second string of casing, a packing ring mounted in said base member above said slips, an upper spool-like member mounted in slidable relation to said base member having a gland formed thereon engaging said packing ring, means connecting said base and upper member arranged to temporarily compress the packing ring, slips mounted in said upper member for suspending a string of tubing extending through said second casing, whereby the weight of the tubing will compress said packing ring, and adjustable means carried by said upper member and engaging said base member for controlling pressure exerted on said packing ring when said tubing is engaged' by the slips in said upper member.

5. A casing head comprising a base member having a tapered seat formed therein and adapted to be secured to an outer casing, slips mountedin the seat in said base member for supporting a second string of casing, a metal supporting ring mounted in said base member above said slips, a pliable packing ring engaging said supporting ring, an upper spool-like member mounted in slidable relation to said base member having a gland formed thereon engaging said packing ring, means connecting said base and upper member arranged to temporarily compress the packing ring, slips mounted in said upper member for suspending a string of tubing extending through said second casing, whereby the weight of the tubing will compress said packing ring, and adjustable means carried by said upper member and engaging said base member for controlling pressure exerted on said packing ring when said tubing is engaged by the slips in said upper member.

6. A casing head comprising a base member connected to an outer casing, slips removably mounted in said base member for supporting a second concentric casing, packing disposed in said base member above said slips, an upper member detachably secured t said base member and having a gland formed thereon engaging said packing, slips mounted in said upper member for supporting a string of tubing Within said second casing, and a plurality of set screws threaded in said base member and engaging said upper member for controlling 4the pressure exerted on the packing when said tubing is suspended on the slips in said upper member.

7. A casing -head comprising a base member connected to an outer casing, slips removably mounted in said base member for supporting a second concentric casing, packing disposed in said base member above said slips, an upper member detachably secured to said base member and having a gland formed thereon engaging said packing, slips mounted in said upper member for supporting a 'string of tubing within said second casing, and a plurality of spacer plates resting on said base member and engaged by said upper member for controlling the pressure exerted on the packing when said tubing is suspended on the slips in said upper member.

8. A casing head comprisinga ybase member connected to an outer string of casing, slips mounted in said base member for supporting a second string of concentric casing, packing disposed in said base member above said slips, an upper body member mounted in slidable relation to saidl base member and having a gland formed thereon engaging said packing, slips mounted in said body member for supporting a second string of concentric casing Within said second casing, and means associated with said base and upper member for controlling the pressure exerted on the packing when said casing is suspended on the slips in said upper member.

9. A casing head comprising a base member connected to an outer casing, slips removably mounted in said base member for supporting a second string of concentric casing, packing disposed in said base member above said slip, an upper member mounted in slidable relation to .said base" member and having a gland formed thereon engaging said packing, slips mounted in said upper member for supporting a string of tubing Within said second casing, and means to prevent an upwardV movement of said body member and to temporarily compress the packing rings before suspending the casings therein.

JAMES BEGG.

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