US1884297A - Hydraulic drilling method and automatic control therefor - Google Patents

Description

Oct. 25, 1932. c, $LATER ET AL 1,884,297

HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROL THEREFOR Filed April 23. 1928 4 Sheets-Sheet l Edwin Ken/z e170 CSdater BY JWZZW Oct. 25, 1932. c, 5 1,884,297

HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROL THEREFOR I Filed April 23, 1928 4 Sheets-Sheet 2 IN V EN TORS Edwin OBezuwtt Ken/will 0501a ter 4 Sheets-Sheet 3 WINVENTIORS Edwia 0.5mm 1 BY Kzluwtlz 6501012," I

F 'My -l K. ,c. SCLATER ETAL Filed April 25, 192s mum; I!

Oct-25,1932.

'HYDRAULIC DRILLING ls'raon AND- AUTOMATIC CONTROL THEREFOR /a a m Oct. 25, 1932. K; c. SCLATER ETAL 1,334,297

HYDRAULIC DRILLING IETHOD AND AUTOIATIC CONTROL THEREFOR Filed April 25. 1928 4 Sheets-Sheet 4 BY KeIuwt/z 6'. S'clater Patented Oct. 25, 1932 UNITED STATES PATEN OFFICE KENNETH C. SCLATER AND EDWIN BENNETT, OF PONCA CITY, OKLAHOMA 'HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROL THEREFOR Application filed April 23, 1928. Serial No. 272,236.

This invention relates to improvements in hydraulic drilling methods and automatic control therefor, and refers more particularly to a rotary drilling method in which the bit rotating system and the hoisting system of. a

for cores; a drilling method and system of control which will regulate the torqueor turning effort on the'drill stem at all times and. will prevent the serious and detrimental effects resulting where permissible limits are exceeded; and finally, will provide a mechanismand method which has the benefits of an unlimited number of speeds without jar or shock to the mechanism,-and other advanwith present drilling methods.

Fig. 1 is a side elevational view of the mechanism, with partsbroken away.

Fig. 2 is a plan view of the mechanism shown in Fig. 1.

Fig. 3 is a sectional side elevational view -of a hydraulic pump and motor adapted to be Used in connection with the present invention.

Fig. 4is a sectional view of the automatic control mechanism.

Fig. 5 is a sectional view of the manually operated control mechanism.

Referring to the drawings, at 1 is shown a Deisel engine which is the prime mover most conveniently shown, but may be replaced by a steam engine, motor, or other type of power source. This type of engine is particularly adapted to drilling where operations are being carried on at a considerable distance from an electrical power source, and

where wildcatting operations necessitate the use of a relatively small, convenient and R0 efficient prime mover. This engine is direct-connected to two hytages which will be obvious to one familiarwith wedging slips.

draulic, variable speed, reversible gears or pumps 2 and 3. These pumps are positioned at the ends of the engine and give a balancing effect when the engine is in operation. These pumps or hydraulic gears are preferably of the type manufactured by either the Waterbury Tool Company of Waterbury, Connecticut, or the Oil Gear Company of Milwaukee, Wisconsin, although the invention contemplates the use of any type of reversible, variable speed, hydraulic pump.

The pump 2 is connected by fluid lines 4 and 5 to secondary connections 6 and 7 leading to the fluid motor 8 and through lines 9 and 10 to the fluid motor 11. Valves 12 and 13 are positioned at the junction of the pipes to regulate the direction 'of'flow of the liquid. These valves may be connectedto act jointly or separately as desired. Normally the will be connected so as to be manipulated ointly. 'The fluid motors 8 and 11 are direct-connected to the axle or shaft 14 of the hoisting drum 15.

The hydraulic pump 3 is connected by pipes 16 and 17 to the fluid motor 18, the 7 shaft 19 of this fluid motor having at its outer extremity a beveled gear 20. The shaft is supported by a bearing diagrammatically shown at 21. The beveled gear 20 meshes with a larger beveled gear affixed to .the'ro- 30 tary table which is mounted on the floor -of the drilling derrick. The rotary table 22 is centrally apertured by a square hole 23 into which-fits what is termed in drilling practice the Kelley or grief stem 24 along To the bottom of the v grief stem is attached the drill pipe 25 at the lower end of which is a bit 26.

The drill pipe and drill bit are supported by the hoisting system which consists of a hook 27 engaging a swivel head bail or loop a on the top of the grief stem by sheave blocks 28 and lines 29 rove over the crown block 30 of the derrick 31, a portion of which is shown in Fig. 1, the rest of the derrick having been broken away in the interest of simplicity. The live end 29 of the supporting lines 29 is reeled upon the drum 15 which may be rotated in either direction by the motors 8 and 11, or separately by either motor to I00 raise the bit from the bottom of the hole or lower the bit to an operating position when drilling operations are being carried on.

The control system consists of a hydraulic cylinder 32 positioned above the controlling is attached tothe top of t is rod also a' wire 35 running over the pulley 36 and attached to a sheave 37 rotatably pivoted on any convenient standard, such as a leg of the derrick 31 or other suitable upright. A second wire or line 38 runs over a pulley 39 on the control mechanism of the pump 3 and also over a pulley 37. This type of control is but one form of possible controls for this type of mechanism, and while this type is shown in the drawings for the purpose of disclosing an operable control, other types are contemplate A manually oper- 1 ated handle 40 furnishes a means for manipulating and controlling the pumps when the automatic control is to be eliminated when pulling or running the pipe in the well, under which conditions the drilling mechanism is not usually operated. This disengaging device eliminates the automatic control which functions as follows: A pressure control line 41 is connected to the discharge of the pump 3 and to the cylinder 32. When the pressure in the pump 3 tends to exceed a predetermined value depending on the torque exerted on the drill bit 26, which is fixed to prevent damage due to excess strain, the piston within the cylinder 32 will be lifted and will cause the shaft or rod 33 to travel upwards. This upward motion of the control shaft serves to actuate the pump 2 so that the motor 8 or 11, whichever is connected, or both, will rotate and lift the drill pipe up, relieving the load or torque on the drill stem. When the load has been relieved the pressure in the line 41 will drop and the control cylinder 32 will be lowered and will cause the control shaft 33 to travel downward' to a neutral position and the hoisting drum 15 will come to rest. If the torque' on the drill bit 26 is below the amount it is desired to maintain when the control shaft reaches the neutral position the pressure in the line 41 will be low enough to cause the piston within the control cylinder 32 to lower the control shaft 33 beyond the neutral position and the hoisting drum will start rotating in the opposite direction to lower the bit to a point where the desired torqueis maintained.

The amount of dead weight imposed upon the piston controlling the pump 2 is asoertained to impose the pro er torque or pressure upon the discharge 0 the pump 3, the

control being regulated by maintaining a relatively constant pressure in the control line 41. When the equipment is in operation for drilling, the bit is rotated by means of the rotary table. Mud-laden fluid is circulated down inside the drill pipe 25 and out through the water courses in the bit This mud-laden fluid is used to carry awa cuttings from the bit face, up and out o the hole. The mud fluid pipes are connected to the drill pipe at its upper end by means of a flexible hose and acked swivel head 48.

As the ri lling proceeds and the hole is deepened, more joints of drill pipe are added below the grief stem 24. During the process of drilling, the driller usually stands by the hoisting drum and feeds the bit. Heretofore this has been accomplished by paying out line from the hoisting drum at a desired rate, thus lowering the drill pipe and permitting the bit to penetrate deeper into the rock structure. If too much line is paid out, excess weight will be placed upon the bit and the bit will wear rapidly, break,

or sometimes stick. If it sticks and there is suflicient ower on the rotary table, the drill pipe may e completely twisted ofi', resulting in a shut-down of operations and the necessity of fishing out the part remaining in the hole.

bit the drill pipe will kink or become bent, thereby causing the hole to be drilled ofi' plumb. In some instances in deep wells this deviation from the vertical may amount to as much as several hundred feet.

The results of a crooked well or one that has been drilled ofi lumb are detrimental and cause reat difiicu ties in production after a well has een completed. If a crooked hole is swabbed for production, the casing in the well is often worn throughby the wire line pulling the swab. When a crooked well has to be pumped for production there is great danger of the pump rods cutting through the side of the tubing. Also on account of additional load, there is much greater wear and rod breakage in crooked wells, which cause shut-downs and resultant loss of production. There is also great danger of twisting off the drill pipe where acrooked hole is being drilled, and additional power is necessary for drilling as compared with the power necessary for a straight hole. The cores and cuttings from a crooked hole give erroneous geological information regarding contour of subsurface structure.

A system of control that will regulate the torque or turning efiorton the drill stem at all times will govern the pressure on the bit and will prevent the very serious detrimental effects resulting where permissible loads are exceeded. The general practice in drilling is for a driller to determine these conditions by feel or experience. When holes are drilled as deep as 8,000 feet, it can-readily be i If too much pressure is applied on the seen that it is practically a physical impossibility for the driller to control by feel and experiencealone, these conditions, with any degree of accuracy. Recently there has been developed a tension indicator which is placed on the dead line. This indicator helps the driller to control more closely his equipment, but at best there is an intermittent action and a proper control relies wholly upon human vagaries.

Prior art There have been two automatic methods of controlling the torque on the drill stem developed which are an improvement over the hand-controlled methods. One of these methods is operated electrically and the other mechanicall Both are operated on a differential drive. The total power'is divided between torque on the draw works or hoisting drum and torque on the rotary table. \Vhen the torque on the rotary table exceeds a predetermined value, the differential gearing acts and causes the hoisting drum to wind or unwind until desired conditions are established. Thus the bit is retrieved or allowed to travel ahead in accordance with the torque imposed upon it. The obj ectionable features of these methods, however, are that they require considerably greater equipment, the permissible range of speeds is' limited, clutches are necessary for starting of the hoisting drum or rotary table, and sudden acceleration from rest to full speed is detrimental and imposes extremely high stresses in the shafting and various parts of the equipment;

Furthermore the electrical method de pends uopn the availability of electricalpower and requires operators skilled in the use of electrical equipment. Also these methods permit runnng the pipe into the hole on the brake and over speeds are often encountered which cause failures of equipment and possible loss of life.

The present method is a new and unique type of drive and control as applied to oil Well drilling and earth boring operations by rotary means. It employs a rotary table and hoisting drum similar to equipment in common practice. The principal difference from the methods discussed or methods in use is the manner in which the drilling and hoisting units are driven and the direct automatic method of control byhydraulic means.

The motors 8, 11 and 18 are connected to their pumps by pipes, one a feed line and the other a return-line. designed that the stroke of the fluid cylinders' contained-therein are variable and the direction of flow is reversible. A better understanding of how this variable stroke hydraulic mechanism functions and how the direction of fluid flow is reversed will be had by reference to Figures 3, 4 and 5. Pumps 2 and 3 operate at constant speed and in one The pump units are so direction of rotation. They are driven by a suitable prime mover such as the engine shown at 1. When the control shaft 33 of the pump 2 is in a neutral position the tilting box 49 which contains the socket ring 50 and in which the connecting rods 51 to the piston 52 are'socketed, is perpendicular to the control shaft 33. In this position there will be noreciprocation or movement of the pistons 52 in the cylinders and no fluid will be dis- I placed when the pump shaft 53 rotates. If the control shaft 33 of the pump 2 is moved upward from a neutral position, the tilting box 49 will assume an angular position (other than with respect to the pump shaft 53, and as the pump shaft 53 rotates, the pistons 52 Will'be given a reciprocating motion, causing the fluid to be pumped. The amount of lateral motion or reciprocation given to the pistons for each revolution of the pump shaft 53 depends upon the position of the control shaft 33 and the angle which the tilting box 49 makes with the shaft 53. It will beseen ward half of its rotary cycle each piston will draw in fluid and during the downward half of, its rotary cycle will expel fluid. The fluid is discharged through the valve plate 54,

thence through piping to the cylinders of the motor. This motor is also equipped with a valve plate 54 similar in construction to that of the pump. It will readily be seen from this brief description that the direction of flow in the pipe 4 and 5 is governed by the position of the control shaft 33 and depends upon the direction of theangle that the tilting box 49 makes with the horizontal shaft 53. The construction and operation of the pump 3 are essentially the same as pump 2 except that the control shaft of the pump 3 is manually operated instead of being automatically operated. The construction of motors 8, 11 and 18 is essentially the same as motors 8, 11 and 18 is fixed, it will be realized that the speed of rotation ofthe motors will vary in accordance with the displacement of the pumps 2 and 3 and will depend upon the movement and position of the control shafts of the pumps. It will also be seenthat the stem 25.

direction of rotation of the motors 8, 11 and 18 will be governed by the position of the control shafts 33 and 42 of the pumps 2 and 3 respectively, and whether the motors are operated ahead or in reverse will be regulated by the position of the control shafts with respect to the neutral position of the pumps. From this it is evident that the control shaft of the pumps can be set to cause'a large difference in speed between the pump driving shaft and the motor shaft controlled thereby, the speed ratio being dependent upon the relative angles of the socket rin of the pump and motor. Reversing of t e motor is accomplished by shifting the pump control shaft across neutral from the opposite direction. The pressure of the fluid circulated to the motors is governed by the resistance offered to turning the motor shaft and not upon the speed of the motor. The pressure in the fluid circuit will rise immediately to meet the torque demands on the motor shaft up to the pressure limits of the machine. Therefore, this type of transm ssion has a'wide range of speeds and can develop high torque at low speeds which is very advantageous or starting conditions in drilling practice.

Referring now to the details of the two control mechanisms shown in Figures 4 and 5, and describing the association and control with the pumps 2 and 3, pipe 41 connects the high pressure fluid circuit of the valve plate 54 of pump 3 with the cylinder 32 on the control shaft of motor 2. This pipe transmits iressure throu h the fluid contained in it etween the'hig pressure circuit in the amp 3 and the control cylinder 32 in Fig. 4. When the pressure in the pump becomes too great on account of the work done by the motor 18 exerting too much torque, the pressure above the limited valve which is determined by weights 34 on the piston of the control cylinder 32, causes the control shaft 33 to move upward.

The motion of control shaft 33' causes fluid to be circulated between the pump 2 and motors 8 and 11. These motors 8 and 11 then turn in a direction to wind up the cable on the drum 15. The winding up of this cable lifts the bit 26 free from the formation which is being drilled and the torque in the shaft and motor 18 is decreased. The fluid pressure in the pump3, line 41 and cylinder 32 will then decrease and weights 34 will cause the shaft 33 of the cylinder 32 to travel downward. This will cause the fluid in the pump 2 to be circulated so that the motors 8 and 11 will rotate to allow the line on the drum to feed out, thus allowing the bit to press into the formation with'greater'force until the desired torque is maintained on the drill either direction to raise or lower the drill n order to maintain the desired torque there- Thus the drum T5 is rotated .in

on, and this torque is controlled by the pressure in the line 41. The rotation of the shaft 42 by means of the lever controls manually the angle of the tiltin box 49 in the pump 3 and thereby the spec and direction of flow and amount of fluid being pumped.

The hydraulic pumping and motor mechanism are the universal hydraulic, variable speed ears manufactured by the W'aterbury Tool ompany, of Waterbury, Connecticut, and no claim is made in the present invention to this equipment, as hydraulic mechanism 0 any type may be used in place of this equipment. The amount of fluid pumped may therefore be made to vary from zero 7 to a maximum, in either direction, the direction and volume of fluid handled by the pumps depending upon the position of the stroke-controlling shafts designated as 33 on motor 2 and as 42 on motor 3. These shafts project from the casingof the pump units and are made in two types, one which operates the travel of the shaft by rotation and the other by vertical translation and are shown in Figs. 4 and 5. In this method of hydraulic transmission we prefer to use the vertical translation method of control on the pum 2 and the rotativecontrol on the control 5 aft 42 of the pump 3. It is understood, however, that either method of control may be used.

The rotation of the motors depending for their power upon these hydraulic pumps or gears is governed by the volume and pressure of oil pumped, and the direction of rotation of the motors 8, 11 and 18 respectively, is controlled by the direction of flow through the pumps 2 and 3 and their connecting lines to these motors.

The torque or turning efl'ort produced on the shafts of the motors is governed by the pressure of the fluid discharged from the pumps. This type of hydraulic pump orgear is primarily a constant torque unit, but will develop torque in proportion to the pressure developed up to the limits of the strength of the units. The allowable pressure on the unit is. governed by the setting of a pressure valve which permits the by'passin of the fluid from the pump discharge bac to the suction. The speed of the unit may be varied from zero to maximum while the torque remains (practically constant.

The a vantage of using a separate hydraulic motor for the draw works hoist and the rotary table is: that each can be operated independently of the other. There is ab solutely no jar or shock in startin a load with this equipment, and it also a ords an infinite number of speeds attain-able at the willof the o rator'. The benefits of an unlimited num er of stepsin speed control without jar or shock will be ap reciated by one familiar with drilling met ods.

Since the torque delivered to the drill pipe is governed by the pressure in the pump under conditions: where greater torque is required. The weight may be replaced by a spring which can be set at a variable tension or compression. Capstans or catheads may be operated by separate hydraulic motor units connected to the pumps 2 and 3 but not shown, such units eliminating the sprocket chain drive, overhead shaft in use at present.

While two motors have been shown connected .to the draw works drum to equalize the torque, one motor may be satisfactorily employed. Pipes 43 and 44 communicate between the lines 4 and 16, and '5 and 17 re'' spectively. Valves 45 and 46 are mterposed in the junctions of the lines 43 and 16,- and 44 and 17. These valves arefor thepurpose of cutting ofi the motor driving the rotary table and throwing the pump in parallel with the pump 2 connected to the draw works hoisting system. The valves 12 and 13, as

suggested, will normally work in conjunction and will operate simultaneously by a control from the derrick floor. They are so arranged that either one or I the draw works drum can be'cut oil of the circuit. When drilling is progressing it is only necessary to use one motor on the draw works drum, and at such times the other ma be cut off. This makes the one motor which is used for retrieving or feeding out the line supporting the drill pipe more sensitive to its action.

When it is necessary. to do heavy pulling, both motors are thrown on the system and a greater torque can be exerted. At' this time the control of the rotary table motor is changed so that both of the pumps-2 and 3 can be operated on the circuit of the. mo-

tors 8 and -11, the motor .18 being cut out by the valves 45 and 46.

It will also be appreciated that with the arrangement shown, both pumps can be applied to the rotary table should increased both motors on works system the'indicating gauge would be a fixed and sensitive mechanism, registering at all times the weight on the bit. Such an indicator is diagrammatically shown at 47 We claim as our invention: 1. A rotary drill mechanism comprising in combination a prime mover, a first hydraulic pressure generator, a second hydraulic pressure generator, a hydraulic motor actuated by said first hydraulic pressure generator, a I

second hydraulic motor operated by said second pressure generator, and means responsive to variations of pressure in the first hydraulic system for controlling the pressure in said second pressure system.

2. A rotary drill mechanism comprising in combination a prime mover, a first hydraulic pressure generator, a second hydraulic pressure generator, a hydraulic motor actuated by said first hydraulic'pressure generator, a second'hydraul'rc motor operated by said second pressure generator, and automatic means responsive to variations of pressure in the hydraulic system for controlling the pressure in said second pressure system.

:33. A rotary drlll mechanlsm comprls ng in "combination a prime mover, a first hydraulic pressure generator, a second hydraulic pressure enerator, a hydraulic motor actuated by said first hydraulic pressure generator, a

second hydraulic motor operated by said second pressure generator, automatic means responsive to variations of pressure in the first hydraulic system for controlling the pressure insaid second pressure system, and means for manually operating said automatic means.

. KENNETH C. SCLATER.

EDWIN O. BENNETT.

speed-be necessary. A pressure gauge may be I inserted in the circuit of the draw works system and this will be indicative at all times of the weight at the bottom of the bit. The-registration of pressure on this gauge would correspond to the registration of weight indicators now in use on the dead lines in present day practice. The indicator on the dead the indicatormust be removed. By use of the pressure "gauge in the hydraulic draw

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