Method of pulling a drill string

Feb. 19, 1957

D. W. HARRIGAN

2,782,004

METHOD OF PULLING A DRILL STRING

Filed April 23. 1952

Sheets-Sheet 1

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Feb. 19, 1957 d. w. harrigan 2,782,004

METHOD OF PULLING A DRILL STRING Filed April 23, 1952 2 Sheets-Sheet 2

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INVENTOR

Ραν/el Ward Harrigan by iL· I

ORNEY

United States Patent Office _{Palenled Fe}^*²^

2,782,004

METHOD OF PULLING A DRILL STRING Daniel Ward Harrigan, Brooklyn, N. Y.

Application April 23,1952, Serial No. 283,900

Claims. (CI. 255—1.8)

My invention relates to drilling apparatus and more particularly to an apparatus for drilling oil wells, core drilling for subsurface tectonic formations and the like.

Modern drilling operations are conducted by means of drill pipe the lowermost section of which carries a drill bit. The drill pipe is rotated by a rotary device which is well known to the art. As the drilling proceeds, additional sections of pipe are attached to the drill pipe which has penetrated the earth following the drill bit. Several sections of drill pipe may be assembled in stands. The entire assembly is called a “string.” Frequently drilling mud is circulated downwardly through the drill pipe and upwardly out of the hole to carry the cuttings to lubricate the drill bit and to provide a hydraulic seal in event oil or gas is encountered during the drilling. In core drilling a special bit is used which will take samples of the strata as desired. In the drilling of oil wells, great depths are involved, frequently in excess of fifteen thousand feet. It frequently becomes necessary to pull the string to replace the drill bit. After completion of such replacement the drill string must be lowered back into the hole to drilling depth. As now practiced, an oil well derrick hoists the string to the top of the derrick exposing a joint between two drill pipe stands. The stand of pipe may involve two or more sections, depending on the height of the derrick. One reason for building derricks to a great height is to reduce the labor of breaking the joints when removing the drill pipe from the hole. When a stand of drill pipe has been pulled out of the hole the balance of the string is supported by slips for holding the string from the rotary. The string is then broken at the tool joint and the stand stacked to one side. The elevators which are attached to the hoisting equipment now at the top of the derrick are lowered and are secured to the remainder of the drill string. The drill string is again hoisted until the exposed joint is in position for uncoupling and the operation repeated. Fully thirty percent of the time consumed in the operation of pulling a string out of a well is owing to the necessity of intermittent operation. In other words, the string remains stationary while the tool joint is being broken, the uncoupled stand of pipe is being hoisted clear and racked, and the elevators are being lowered and resecured to the string for the next step. It will be seen that in the prior art we have a step-by-step or ratcheting method for pulling a drilling string. In lowering the drill string into the hole, the procedure is reversed, but again we have an intermittent operation which is time-consuming and costly.

One object of my invention is to provide drilling apparatus in which a string of drill pipe may be continuously removed from or continuously lowered into a drill hole.

Another object of my invention is to provide drilling apparatus which will permit a substantial reduction in the time required to service an oil well.

Another object of my invention is to provide drilling apparatus to reduce the expense of drilling oil wells by

IS eliminating unproductive intervals during which all movement of the string is stopped.

Other and further objects of my invention will appear from the following description.

In general my invention contemplates the provision of a derrick provided with a suitably controlled reciprocating beam which carries the rotary and on which the string of drill pipe may be supported for movement out of or into the well while the tool joint of a section of drill pipe is broken or made.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Figure 1 is a diagrammatic view showing oil well drilling apparatus containing one embodiment of my invention.

Figure 2 is a diagrammatic view drawn on a smaller scale showing the position of parts at the beginning of the operation of pulling the drill string out of the hole.

Figure 3 is a view similar to Figure 2 showing the position of parts at another stage of the operation.

Figure 4 is a diagrammatic view similar to Figure 2 showing the drill string being hoisted by the reciprocating beam and the uncoupled stand of pipe being hoisted clear by the elevators at a further stage in the operation of my drilling apparatus.

Figure 5 is a view similar to Figure 2 showing the drill string being hoisted by the reciprocating beam while a stand of pipe just uncoupled from the drill string is being racked.

Figure 6 is a view similar to Figure 2 showing the position of parts at a later stage in the operation in which the elevators have again been attached to the drill string and are in the process of relieving the reciprocating beam of the hoisting load.

Figure 7 is a view similar to Figure 2 showing the position of parts following the completion of the cycle in the operation of pulling a drill string.

Figure 8 is a diagrammatic view showing oil well drilling apparatus containing one embodiment of my invention and the associated drive means.

More particularly referring now to Figure 1, the oil well derrick indicated generally by the reference numeral 10 may be of any suitable construction having inclined upright legs 12 suitable placed and supported by any suitable derrick foundation 14. The construction of the derrick is well known to the art and need not be described in detail. The derrick is provided with the customary crown block 16 over which the hoisting cable 18 is adapted to pass. The end of the hoisting cable carries the customary links 20 to which the elevator 22 known to the art is attached. It is understood, of course, that the links 20 are swivelly carried from the member 24 suitably secured to the end of the cable 18. In this manner the links 20 and the elevator 22, which is secured to the upper section of the drill pipe 26, may rotate with respect to the cable 18 along with the drill pipe during the operation of drilling. A shaft 30 is supported a suitable distance above the derrick floor in any suitable manner, being journaled in bearings for ready rotation. A cable drum 32 is secured to the shaft 30 for rotation therewith. A pair of hoisting drums 34 and 36 are likewise secured to the shaft 30. A reciprocating beam 40 supports the rotary 42. Since the instant invention relates to the apparatus for pulling and lowering the drill string, power means (not shown) for driving the rotary may be carried by the derrick foundation 14 and connected when the beam is in the position shown in . Figure 1. Alternately, the means for driving the rotary could be carried by the beam 40 and could be engaged with

9,782, 3 or disengaged from the rotary in any manner known to the art. When it is desired to pull the drill string or lower it, this power means may be disconnected and the drill string supported by means of slips 44. Extending through the beam 40 I provide a shaft 46. The ends of the shaft 5 46 carry for rotation with respect thereto a pair of drums 48 and 50. The ends of a cable 38 are secured to the drum 36 and loops of the cable pass around the rotatable drum 48. Similarly, the ends of a cable 52 are secured to the drum 34 and loops of the cable pass around the 10 drum 50. A cable 54. is wound around the drum 3?.. It will be clear that as cable 54 is pulled, the cables 38 and 52 will wind about the drums 34 and 36, pulling the beam 40 upwardly. When cable 54 is slacked, the weight of the beam 40 and the associated parts will permit it 15 to move downwardly, unwinding the cables 38 and 52 from the drums 36 and 34.

It is to be remembered that the figures are diagrammatic. Any suitable means for hoisting and lowering the beam 40 may be provided, as will be well under- 20 stood by those skilled in the art. Any suitable means (not shown) for pulling or slackening cable 54 may be provided. Similarly, while I have shown a two-point suspension for the beam 40 for purposes of simplicity, a four-point suspension employing two shafts 30 and 25 two shafts 46 may be employed. The reciprocating beam 40 is guided to move in a horizontal position primarily by four guide members 60 extending vertically through each of the four corners of the beam 40 throughout the amplitude of its motion. The purpose of this reciprocal- 30 ing beam is to provide continuous upward motion of the drill string during the uncoupling and racking of the exposed stand of drill pipe and throughout the remainder of the period until the elevators return to a position wherefrom they can again be synchronized with the drill 35 string attached thereto at a suitable point and resume hoisting. A stationary stacking platform 62 is carried by the derrick above the upper limit of motion of the reciprocating beam upon which stands of drill pipe may be placed. If desired, uncoupled stands of pipe could be 40 racked on the derrick foundation 14 or at any other convenient location. Referring now to. Figure 8, the end 64 of the hoisting cable 18 goes to a cable drum 70 carried by a shaft 72 for rotation with it. A continuously driven shaft 74 carries a pinion 76 for rotation with it. 45 Pinion 76 drives a gear 78 carried by a shaft 80 for rotation with it. Shaft 80 drives bevel gears 82 and 84 fixed on the respective ends of shaft 80. Bevel gear 82 engages and drives a pair of bevel gears 86 and 88 loosely carried in spaced axial relationship on a shaft 90. It 50 will be appreciated that as pinion 76 drives shaft 80, bevel gear 82 drives the gears 86 and 88 in opposite directions. I slidably mount a driven clutch member 94 on shaft 90 between gears 86 and 88 by means of a spline 92 or the like. Clutch member 94 is adapted 55 to be engaged with one of a pair of respective driving clutch member 96 and 98 integrally formed with the respective gears 86 and 88. An actuating lever 100 provides a means for shifting member 94 into engagement with either member 96 or member 98. It will be under- 60 stood that the direction of rotation of shaft 90 may be reversed by shifting member 94 out of engagement with a member 96 or 98 and into engagement with the other member 98 or 96.

Shaft 90 also loosely carries in spaced axial relation- 65 ship a pair of gears 102 and 104 formed with respective clutch members 106 and 108. I mount a clutch member 112 between members 106 and 108 by means: of a spline 110 or the like. An actuating lever 114 provides a means for engaging member 112 with either of the members 70 136 or 108. The respective gears 102 and 104 engage respective gears 116 and 118 carried by shaft 72 for rotation with it. The relative, diameters of gears 104 and 118 are such that with member 112 in engagement with member 108, shaft 72 is driven at the same speed 75

004 as shaft 90. With member 112 in engagement with member 106, shaft 72 is driven at a faster speed than shaft 90, since the diameter of gear 102 is greater than the diameter of gear 116.

Bevel gear 84 engages and drives respective bevel gears 120 and 122 loosely carried on a shaft 124 in spaced axial relationship. Respective clutch members 126 and 128 formed integrally with gears 120 and 122 are adapted to be selectively engaged by a clutch member 130 slidably mounted on a spline 132 on the shaft 124 intermediate members 126 and 128. A lever 134 provides means for shifting member 130 axially of shaft 124. This shaft 124 drives cable drum 32.

The foregoing systems described for driving cable 64 and beam 40 are conventional and well known in the art. The clutch including member 94 provides a means for reversing the direction of drive of cable 64. The pair of gears 104 and 118 provide .a means for driving the elevator 22 at the same speed as beam 40. The pair of gears 102 and 116 provide a means for driving elevator 22 at a more rapid speed than beam 40. The clutch including member 130 provides a means for reversing the direction of movement of beam 40. It will be understood further that with a clutch in its intermediate position the corresponding drive will be disengaged. Actuating levers 100, 114, and 134 permit an operator to control the relative speed and direction of movement of elevator 22 and beam 40.

In operation, referring now to Figure 2, the reciprocating beam 40 is at the bottom of its travel resting upon the derrick foundation 14, Let us assume that we desire to pull the drill string. The elevator 22 is lowered by cable 18 and secured to the projecting section 26 of the drill string. The rotary 42 has been disconnected from its power drive and the cable 64 is set taut and the drill string pulled out of the well. Let us assume, further, that a stand of pipe with which we are dealing is two sections high. As soon as the second tool joint 66 is pulled out of the hole sufficiently past the rotary 42 so that men can break the tool joint, the cable 54 which has been set taut is pulled so that the shuttle platform 40 will move upwardly at the same rate as the drill string. Thereupon the power slips 44 are set to grip the drill string at a suitable point, the strain on cable 64 Is lessened after the support and upward motion of the drill string are absorbed by cables 54 through the reciprocating beam, and the tool joint 66 is broken. As soon as the tool joint is broken the speed of hoisting through the cable 64 is accelerated and the stand of drill pipe is pulled upwardly clear of the broken tool joint 66. The reciprocating beam 40 continues to move upwardly under the. influence of the hoisting cable 54. During this movement the drill string is supported by the reciprocating beam 40 from the slips 44. The position of parts is shown in Figure 4 at this stage of the operation of my drilling apparatus. The stand of pipe removed is stacked upon the platform 62. The elevator 22 is uncoupled from the top bf the stand and lowered to take hold of the projecting end of the drill string being carried upwardly by the beam 40. The position of parts after this operation is completed is shown in Figure 6, in which the reciprocating beam is still moving upwardly and the elevator has just been secured to the end of the drill string. The cable 64 is then again set taut and pulled upon at the predetermined rate of operation so that the cable. 18 will be moving upwardly at the same rate as the reciprocating beam 40. When this occurs, the power slips 44 open and the upward motion of the reciprocating beam 40 is slowed and stopped so that cable 18 again is supporting the drill string. After this occurs, the cable 54 is slacked off and the beam 40 is allowed to move downwardly to the position shown in Figure 7, during which step the cable 18 is moving upwardly pulling the drill string with it. When the second tool joint again gets in the position of Figure 3 the cable 54 is

2,782,004 again employed to lift the reciprocating beam 40 and the operation is repeated.

It will be seen that by means of my apparatus which produces continuous motion of the drill string by co-ordination of the separate ratcheting effects of two different applications of hoisting effort, a drill string may be continuously removed from a well instead of by the step-by-step, intermittent, single ratcheting method used by the prior art.

When it is desired to lower the string into the well the same apparatus is used but the order of procedure is reversed. With the reciprocating beam 40 in the position shown in Figure 6, a section of drill pipe is secured to the drill string, it being understood that the elevator 22 is adjacent the top of the derrick. While the joint is being made, the reciprocating beam 40 is moving downwardly, the movement of cable 64 being synchronized in this downward motion. After the joint is made the drill string weight is carried by the cable 18, the power slips are opened and the reciprocating beam 40 is moved upwardly again until the end of the section being lowered occupies the correct position for the making of a joint. Then the reciprocating beam 40 is permitted to move downwardly in synchronization with the movement of the drill string and at a suitable point the power slips grip the drill pipe. After this, the cable 18 is slacked, the elevator 22 detached, hoisted to the top of the derrick, secured to another stand of pipe, and the operation repeated. It will be apparent, therefore, that the hoisting means function equally as well as lowering means.

It will be seen that I have accomplished the objects of my invention. I have provided drilling apparatus in which the drill pipe may be continuously removed from or continuously lowered into a hole, for example, when it becomes necessary to service the drill bit.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is therefore to be understood that my invention is not to be limited to the specific details shown and described.