two parts are interconnected by a vertically extending be rotated about its axis for the purpose of threadedly
stem- coupling the casing section to an aligned section of
The Bolpin patent includes a good description of the casing which is suspended in the rotary table of the rig.
difficulty posed to the drilling crew in quickly and accu- Each of the piston and cylinder subassemblies in
rately swinging the new section of casing or drill pipe 5 cludes a spring element positioned to accommodate
the°welT bore ... ... ... ... ... TM lateral movement of that portion of the casing section
T r> i '■ * Li.' -j L i i i engaged by the stabbing system in those instances
In the Bolpin stabbing guide, the element which actu- ,„t,„„ „ „ e • r u.i u . j j
„ ., K r j ii • • i where a section of casing is slightly bent and departs
ally guides the upper section of drill pipe is merely a r . ■ , ,. ,
finger against which this section of drill pipe is abutted 10 fr°Am true aXlal lln"anty ,ts ,enSth-.
or rested as it descends to the point where the male An TMportant object of the invention is to provide a
threads at the lower end thereof make contact with and system for mechanically aligning casing sections to be
engage the female threads in the box section carried on J01ned ln a casl"g stnn8 be,ng made UP ln an ol1 or
the upper end of the pipe section therebelow. No posi- we" bore n0'e
tive retentive engagement of the finger with the upper 15 Another object of the invention is to provide a casing
section of pipe is provided. stabbing system which can be operated with a minimum
Other types of stabbing devices and guides are shown of manual force applied to the various elements of the
in Graham et al. U.S. Pat. No. 2,206,184, Calhoun U.S. system in moving the system between an operative and
Pat. No. 2,450,934, True U.S. Pat. No. 2,828,024, an inoperative position.
Scaggs U.S. Pat. No. 4,274,777, Guier U.S. Pat. No. 20 A further object and marked advantage of the present
3,533,516 and Moise U.S. Pat. No. 2,184,051. invention is the ability of the casing stabbing system of
The Moise patent employs a pair of hydraulic piston the invention to yield to, or accommodate wobbling of,
and cylinder assemblies extended from two adjacent a casing section which is to be stabbed into an aligned
corners of the derrick so as to be generally at right casing section located therebelow as such upper casing
angles to each other with the free ends of the piston 25 section may undergo wobbling or movement at the
rods carrying elements which can push against a well point of engagement by the stabbing system due to
casmg section to cooperatively (as between the two warping or misalignment of the casing section over its
pushing elements) bring the casing into a vertical posi- length
tion in which it is aligned for stabbing into the casing A furthef object of ^ inventio„ is to ide a cas.
section therebelow. The casing is not, however, reten- 30 • . ... . ,. , , ., ,
, , , , ,. ° ,' , x, ... mg stabbing system which can be more easily utilized
tively clamped or physically surrounded by the guiding . , • ■ * j- . , • , •• ,-,
,r . -T for making minute adjustments m the position of the
structure during its use. , , , ,6 , ^ , , ■ • ,
threaded lower end of a suspended casing section dur
BRIEF DESCRIPTION OF THE PRESENT ing a casing stabbing operation than previously used
INVENTION 35 devices of this general type.
The present invention provides a system for mechani- Additional objects and advantages of the invention cally handling vertically suspended casing sections so as wil1 become apparent as the following detailed descripto alleviate the necessity for drilling rig personnel to *»on of the invention is read in conjunction with the man-handle such casing sections, thereby imperiling life accompanying drawings which illustrate a preferred and limb, and causing extreme bodily fatigue and con- 40 embodiment of the invention, commitant loss of efficiency.
Broadly described, the present invention comprises a pair of cooperating piston and cylinder subassemblies FIG. 1 is a schematic view illustrating the general which extend at substantially right angles to each other, location and relative arrangement of the casing stabbing and which are disposed at locations on the drilling rig 45 system of the invention, an oil well derrick upon which between the rig floor rotary table and the crown block the casing stabbing system is mounted, a suspended by which a casing section is suspended in a vertical upper section of casing and a rotary table located at the orientation during the making up of a string of casing ^g floor and suspending a second section of casing for positioning in a well bore. The piston and cylinder below that upon wnicn the casjng stabbing system of subassemblies each have one end pivotally connected to 50 the present invention is utilized.
structural elements of the derrick so that they can be FIG 2 js a p]an view of the casing stabbing system of
pivoted about horizontal axes. Each piston and cylinder the invention> showing certain parts broken away for
subassembly is counterbalanced to reduce the force ^ of illustration> further showingj in section> casing
required to move each of the subassemblies between an the M and showj jn AM
inoperative, vertically extending position, and a posi- 55 .. ,,, . r , . ?, ,
,. . , . , J, ,, ^ , , , ,, lines, one of the jaws of a clamp subassembly opened
tion in which the subassembly extends substantially .. . . r . . . . r
horizontally in an operative position for purposes of ^ *°its lnoPerat«ve; caslnS rfcelv'ng P08*10"
„ „„:„„ „ ♦„ „t„Ku=,i „, „„„„\,„*„j FIG. 3 is a sectional view taken along line 3—3 of
engaging a casing section to be stabbed or connected to"
an aligned casing section therebelow.
The piston and cylinder subassemblies carry cooper- 60 FIG- 4 ls a vlew ln elevation of a part of one of the
ating clamping elements at the free ends of the piston Plston and cylinder subassemblies, and of a part of the
rods of each, and these cooperating clamping elements clamP subassembly included in the casing stabbing sys
function to closely surround a casing section to enable tem °ftne present invention.
the casing section to be precisely positioned by manipu- FIG. 5 is a detailed view, in plan, of the connection
lation of the piston and cylinder subassemblies. The 65 between a part of the clamp subassembly and the piston
clamping elements are dimensioned to closely surround rod of one of the piston and cylinder subassemblies,
the casing section to be engaged, yet do not fit so tightly FIG. 6 is a sectional view taken along line 6—6 of
about the casing section that the casing section cannot FIG. 5.