UNITED STATES PATENT OFFICE
ROTARY WELL DRILLING APPARATUS
Guy K. Claire, Rolling Hills, Calif., assignor of
one-third to Arthur L. Armentrout, one-third to
Elwin B. Hall, and one-third to Virgil P. Baker,
all of Los Angeles, Calif.
Application March 10,1939, Serial No. 260,971
18 Claims. (Cl. 255—23)
This invention relates to well drilling equipment and relates more particularly to a rotary table or rotary for use in the rotary method of well drilling. A general object of this invention is to provide a practical effective and improved rotary table for rotating the well strings and for performing the other functions of typical rotary tables and for making up and breaking down the drilling strings and other sectional well strings.
In the rotary method of well drilling a power driven rotary table is provided in the derrick to carry the bushings, slips and other devices for supporting and engaging the tool-carrying drilling strings, the casing strings, etc. A well string such as a rotary drilling string is made up of a plurality of stands of pipe connected by threaded couplings and during the drilling operation a polygonal or fluted kelly is connected in the upper portion of the string to operate through the rotary table. The kelly is engaged by a correspondingly shaped bushing in the rotary table to provide a rotary transmitting drive between the table and the drilling string. In making up and breaking down a rotary drilling string it is the general practice to support the string in the table by means of slips and to turn the uppermost stand of pipe while securing the lower portion of the string against rotation. One set of tongs is usually engaged about a section of the tool joint at the table and another set of tongs is engaged about the other section of the tool joint. The last named set of tongs is usually operated by a line handled by a cathead of the draw works. T^e operation of the tongs and the lines is a time consuming operation and is accompanied by considerable danger to the workmen and equipment. Furthermore, in making up the threaded connections by tongs and a Jerk line it is difficult, if not impossible, to gauge the torsion applied to ;the connections and in many cases the threads of the pipe connections are galled or strained endangering the entire well string and shortening the life of the joints.
Rotary tables known as make and break totaries have been proposed to facilitate the makV ing up and breaking down of the well strings. These make and break rotary tables usually embody inner and outer independently rotatable table parts with means on the inner table part to hold the oipe against turning and means on the outer table part to turn the upper stand of pipe. In these so-called make and break rotary tables the drive for the main inner table part, used during drilling operations, is utilized to rotate the outer part in making up and breaking
down the well strings. This use of the main power means of the rotary table to drive the outer table part is very unsatisfactory in many respects. For example, it necessitates a special 5 complicate! means for connecting and disengaging the inner and outer parts of the table and requires the continuous operation of the rotary engine throughout the making and breaking operations. Furthermore, the make and break ro
10 tary tables that have been proposed do not em
. body practical or effective mearis for gauging the
torque applied to the threaded connections of the
well strings. It has been proposed that friction
brake means be utilized to hold one section of
15 the table against turning during the making up of the threaded joints, which brake means will release when a given torque is applied to the threaded connections Such brake means are impractical, are not dependable, and do not as
20 sure the uniform application of torque to the many joints of the drilling string.
Another object of this invention is to provide a rotary or a rotary table operable to make up or thread together the Joints of a rotary well
25 drilling string under a given uniform torque or rotational force to assure the dependable connection of the string sections and to prevent galling and straining of the threads. Another object of this invention is to provide
30 a rotary table operable to make up and break down sectional well strings that embodies an automatic torque governed drive or power means for rotating one part of the table, which power means may be set or conditioned to make up the
35 Joints under a given or selected uniform rotational force.
, Another object of this invention is to provide a rotary table of the character mentioned embodying a ring or outer part rotatable relative
40 to the inner table part to make up and break down the threaded connections of the well strings and a separate drive and power means for rotating the said outer part. The improved rotary table of the present invention embodies a
45 drive of suitable or customary form for rotating the main inner table part and a separate drive and power means for operating the outer table part to break and make the threaded joints of the well strings.
50 Another oblect of this invention Is to provide a rotary table of' the character mentioned in which the drive for the outer table part may be utilized Bs an emergency drive or special drive for jotating the entire table and this drive is
55 torque controlled thereby adapting the rotary ta