US2521976A - Hydraulic control for drilling apparatus - Google Patents

Description

Sept. 12, 1950 R. R. HAYS HYDRAULIC CONTROL FOR DRILLING APPARATUS Filed Efqb. 26, 1946 A i. 4 J

Patented Sept. 12, 1950 orsiiii'li liUUitl HYDRAULIC CONTROL FOR DRILLING APPARATUS Russell R. Hays, Lawrence, Kans.

Application February 26, 1946, Serial No. 650,276

6 Claims.

This invention relates to the drilling of lateral drainage channels transversely to a well bore, and more particularly to a method and apparatus for feeding a fluid supply hose that carries a hydraulically operated drill on its extending end into a hose turner such as that described in copending application Serial No. 687,028, now abandoned.

The apparatus used is broadly that described in Patent No. 2,345,816, in which a hose turning case containing a curved passageway for turning a high pressure hose through a 90 arc is run into a well bore on a string of tubing and positioned opposite a fluid bearing formation bymeans of an anchor carried on the bottom of the case. The well bore is filled with water and a high pressure hose carrying either a hydraulically operated water drill or a cutting nozzle at its end is run down the tubing, through the hose turner, and extended out against the formation for cutting lateral drainage channels therein, the cuttings being carried by the fluid exhausted from the drill, back into the well bore, and hence to the surface.

In horizontal drilling apparatus of this general type, various adaptations of the hydraulic control used to regulate drilling pressures with a conventional rotary drill have been proposed. These adaptations are of two types. In the first, a hydraulic cylinder on the drilling platform is used to relatively raise or lower a fluid supply conduit or other power transmission means operative to power a lateral drilling mechanism positioned at the bottom of a well bore. The up and down motion transmitted by the cylinder to the conduit is converted through suitable transmission means to backward and forward movement of a drill or high pressure cutting nozzle being projected transversely from the well bore. In the second type of adaptation, the equivalent of a hydraulic cylinder at the bottom of the hole is operated by fluid pressure to project a conduit transversely with a more or less uniform feeding pressure.

Either method is in itself inadequate primarily because the hydraulic chamber pressures do not accurately define the drilling pressure actually attained. The forces chiefly responsible for this inaccuracy are inertia and friction. Inertia forces become extreme in the case of movement of a conduit substantially the length of the well bore. In wells of any depth the weight of this conduit will be relatively great whereas any equipment capable of being turned in the bottom of a well bore through a 90 arc of small radius must of necessity be of relatively light and fragile construction. The process of turning the conduit involves considerable friction as does its projection in a lateral against a return flow necessary for flushing cuttings from the lateral bore. These friction forces may or may not vary, but the hardness of the formation is almost certain to vary through a considerable range. The direct consequence of this is that with slowing of the drill, the downward moving supply conduit may by its inertia transmit within a fraction of a second a load in excess of its weight to the drill and conduit turning mechanism.

Where the destructive nature of this type of lateral feed has been recognized, attention has centered on the prevention of overloads by hydraulically feeding the conduit from the bottom of the hole. In this method the equivalent of a piston carrying the lateral conduit on its lower end is hydraulically forced from a cylinder by fluid carried in a fixed string of tubing. Here the force applied to the piston is relatively constant whereas the required feeding pressure may vary widely in response to varying hardness of the formation, varying friction loads and varying inertia loads. In brief, although danger of overloads is circumvented by this method, the operator at the surface has no way of knowing whether a lateral is actually being out, much less' means of accurately controlling his feeding pressure.

When it is considered that any small bore drilling mechanism, particularly when it is of relatively light construction, is highly sensitive to feeding pressures, it becomes evident that the problem of correctly feeding a lateral drilling device is a highly specialized one. With an operator at the surface controlling the pressure applied to a drill head within an optimum range of a few pounds when the drill is operating horizontally at a distance of half a mile or more, certain basic requirements may be set up.

These are:

1. Accurate and instantaneous knowledge of the pressure being applied.

2. Finger-tip or even electronic control of this feeding pressure from the surface.

3. Prevention of inertia overloads to the horizontally operating equipment at the bottom of the hole.

4. Provision for simply and quickly removing the drilling parts from the hole for repairs and the changing of drills.

When a fluid motor is used as the drill activating means for a lateral drill, the operation of this motor propagates shock waves in the fiuid supply stream having a frequency substantially that of the motor. This is especially true of motors having a reciprocating action such as that described in co-pending application Serial No. 604,964. now Patent No. 2,441,881. This frequency may be picked up by a vibrating reed frequency meter mounted on the fluid supply line at a point adjacent its entry into the well bore. With a turbine type motor excessive feeding pressure acts to decrease the motors R. P. M. With the reciprocating type motor now used, excessive feeding pressure acts to progressively increase the frequency to slightly in excess of its minimum frequency for a given pressure before the motor kills. In either case, the frequency range for a given line pressure having been determined, the operator has at his disposal instantaneous and accurate means for observing the feeding pressure being applied.

. Finger-tip control of the drill head necessarily precludes the danger of inertia overloads by the nature of its attainment. To being with, the apparatus is broken down into two types of design. That run into the well bore and carrying a hose turner positioned opposite the formation to be drilled, follows conventional oil field practice in being of rugged construction and capable of being run with ordinary tools. This is referred to as the fixed line. None of its parts move during the cutting of a lateral and it serves as a housing for the running line. The running line is of fragile design in that low safety factors and materials chosen for lightness and strength are used. Thus in an installation suitable for drilling a 100 foot lateral of 1 4 inch bore from the bottom of a 1000 foot well, the fixed line will weigh in excess of 1 tons whereas the entire running line including drill, fluid motor, high pressure hose, hydraulic pistons and connecting cable weighs well under 200 pounds.

. This lightness of the running line is obtained through an arrangement of hydraulic cylinders, one of which is carried at the top of the fixed line and one at its bottom, by which feeding pressure is converted to a tensile load sustained by a light cable connecting the pistons of the two cylinders. This arrangement also makes possible a successive reduction in crosssection of the fixed line from the surface to the hose turner at the bottom of the well bore, thereby permitting easy running or withdrawal of the entire running line from the hole. Through such compactness and lightness of the running line, and the conversion of feeding pressures to tensile loads, the sensitivity of the surface hydraulic cylinder is increased to a point where theoperator can readily synchronize the cylinder control valves to maintain the desired frequency meter reading.

. With these considerations in mind the objects of this invention may be stated as being:

1. Provision of a method for surface control of the feeding pressure of a lateral drill operated by a fluid motor in which variations in the frequency of the drill in response to variations in feeding pressure are indicated at the surface through the medium of shock waves carried by the fluid supply line and are. utilized there as a guide in hydraulically varying the force acting to extend the drill horizontally from the well bore. I

2. Provision of apparatus for feeding a high pressure hose into a hose turning case for transverse projection therefrom in which the pistons of hydraulic cylinders of different cross-section integral with either end of a tubing string are connected by a cable as a result of which fluid entering the tubing under pressure between the cylinders acts to move the cable in the direction of the larger cylinder until manually controlled means for equalizing the pressure on the larger piston cause the cable to move in the opposite direction by reason of the fluid pressure exerted against the smaller piston.

3. The provision of apparatus of the nature described, suitable for running in a well bore and in which the valves for equalizing the fluid pressure effective against the larger piston are at the surface whereas the side opening of the hose turner case carried below the smaller cylinder lies opposite a fluid bearing formation.

4. The provision of apparatus of the nature described, in which a high pressure hose carried below the smaller piston communicates with the inside of the tubing so that a high pressure fluid stream is conducted to the hydraulically operated drill carried on its extending end.

5. The provision of apparatus of the nature described, in which the manually controlled fluid pressure maintained above the larger piston directly reflects the feeding pressure maintained on the hydraulic drill carried on the extending end of the hose being projected transversely from a well bore, and indicating means at the surface responsive to variations in the frequency of the drill to serve as a guide in correcting discrepancies between the pressure above the piston and that actually being maintained against the formation face being drilled.

6. The provision of apparatus of the nature described, in which beginning at the surface the cross-section of the elements comprising the fixed string decreases successively to the lower hydraulic cylinder to permit free running and withdrawal of the running line from the inside of the fixed line.

7. The provision of apparatus of the nature described, in which a measuring line carried in a well parallel to the fixed line and communicating directly with the upper hydraulic cylinder at the fixed string head, passes over a pulley to be afiixed to the top of the larger piston in order that the operator upon looking through a window in the top of the tubing head may know at all times the distance of the drill carried at the end of the running string has been projected from the main well bore.

Ancillary objectives such as the proper arrangement of valves, pressure guages, air bleeders, caps, cable swivels and the like, will become clearer from reading the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is a diagrammatic sketch showing the arrangement of the fixed string of elements in hose feeding apparatus, such as that embodied in this invention, disposed in a well bore, and in which a hydraulically operated drill carried on a high pressure hose is projected horizontally therefrom.

Fig. 2 is an enlarged cross-sectional view of the apparatus shown in Figure 1 in which parts have been fore-shortened and the essential elements have been enlarged in order to more clearly illustrate their operation, and

Fig. 8 is an enlarged sectional view of the hollow piston and hose connection taken from the lower cylinder of Figure 2.

Referring to Fig. '1 an anchor 8 seated at the SIzARCH @0593 bottom of a well bore 5 carries a hose turner case 4 containing a hose conducting passageway 6 opening against a fluid bearing formation 1 in which laterals 9 are to be cut by a fluid operated drill 22 carried on high pressure hose 20 which passes back through passageway 6 and into the hydraulic cylinder I2 carried above the turner case 4 by collar I0. The cylinder I2 is slightly longer than the hose 20 or the length of the lateral 9 which is to be drilled, and at its upper end is secured to a swedge coupling I4 to carry the tubing string I6 which is slightly larger in crosssection than the cross-section of the cylinder I2 the inside diameter of which is slightly greater than the diameter of the head of the drill 22 carried by hose 20 to permit passage of the latter therethrough.

The tubing string I6 continues upward in the wellbore 5 to a point below the surface slightly less than the length of the hydraulic cylinder I2 at which point it carries a swedged coupling I8 having side outlet I9 for the fluid supply line 30 which continues up to the surface beside the larger hydraulic cylinder 24 screwed in the top of coupling I8. The upper end of cylinder 24 carries a head 26, normally covered by an instrument protecting case 28 when the apparatus is not in operation.

The head 26, Fig. 2, of the fixed string is a casting usually positioned about two feet above the derrick floor of a conventional drilling rig used for running the apparatus into the hole 5. This casting 26 forms a fluid chamber having a top plug 82 larger than the cross-section of cylinder 24 and aligned therewith. A side chamber 13 in the head 26 has a hole 16 in its bottom into which is run tubing well 10 through aligned and canted plug hole I9. Well 10 which is of inch tubing and slightly longer than cylinder 24 carries cap II at its bottom and is solidly secured and sealed in head 26 at its upper end by collar 15 which rests on a resilient washer. Well 10 carries a steel measuring tape I13 having a weight 14 on its lower end and at its upper end passes over pulley 11 to be fixed to clamp 69 of the upper cylinder piston 60. In passing over pulley 11 the figures of tape I13 are maintained on the outside so that they are visible to the operator when looking through window in plug 18 which seals head opening 19.

At the opposite side of .head 26, the fluid line 8'! screws in hole 88 and carries needle valve 90 opening fluid escape line 34 and needle valve 92 communicating with fluid supply line 30 through tee 93 and line 32, an upward extension of which carries platform 95 on which vibrating reed frequency meter I00 is secured as well as fluid supply line guage 94. Fluid guage 84 which indicates the feeding pressure in the lateral being cut is mounted in the top of plug 82. Beneath plug 82 and inside of head 26 a stop bar 86 rests on top of cylinder 24 to arrest upward travel of piston 60 and thus prevent damage to measuring line I2 while at the same time positioning piston 60 so it may be caught by clamp screw I02 operative in cylinder Wall hole I03. Valve I beneath it is an air bleeder valve for the cylinder 24.

A high pressure hose 38 running from a high pressure fluid pump connects to the fluid supply line 30 carrying valve 36 at the derrick floor. This fluid supply line, the head 26 and parts secured thereto including the well 10, cylinders I2 and 24, tubing I6, hose turner 4 and anchor 8 constitute the fixed line of the apparatus.

The running line is composed of the water drill 22 mounted on high pressure hose 20 which is secured to hollow fitting 58, Fig. 3, having threaded end 5'! carried at the lower end of hollow piston body 40 threaded at its upper end to receive hollow cup spindle 48 which adjustably secures spacer 45 and hydraulic cups 42 and 43, to the top of piston 40. The hollow head of spindle 48 has holes 54 in its sidewalls to permit a free flow of fluid through piston 40 and into hose 20. and the top 49 of the head is tapered to receive and secure the babbitted lower end 52 of line cable 50. Cable 50 passes up through tubing I6 where it is secured to swivel 66 carried at the bottom of the solid piston barrel 64 operative in upper cylinder 24. Piston 60 is of ordinary construction, having downward facing cups SI and spacer 62 secured by piston head 68.

In operation, after running of the fixed string, valve 36 is opened until the well bore 5 fills with water. Plug 82 is removed from the head 26 and the running line fed inside the fixed line until piston 60 is caught by clamp I02. The lowering cable, not shown, is then removed from clamp 69 and the end of measuring tape I13 secured to the clamp in its stead. Stop 86 is inserted in the head and plug 82 replaced. Before tightening plug 82, drain valve 90 is closed and needle valve 92 opened and line valve 36 cracked to fill well 10 and the chamber of head 26 with fluid. Cylinder valve I05 is also opened to let any air trapped under piston 60 escape. When all air has been exhausted from inside the apparatus, plug 82 is tightened and valve I05 closed.

Needle valve 92 is then closed and line valve 36 opened; Guage 94 then indicates the line pressure and guage 84 a lesser pressure effective above the piston 60. The piston clamp I02 is now released and the piston 60 is forced up in cylinder 24 until head .guage 84 registers a head pressure which represents the cross-sectional area of cylinder 24 times the line pressure less the weight of the running line and a force equal to the cross-sectional area of the lower and small cylinder 12 times the line pressure. The ratio of the diameter of cylinder 24 to the diameter of cylinder I2 is considered satisfactory when the pressure shown on guage 84 times the cross-sectional area of piston 60, is substantially equal to the downward acting force effective upon piston 40.

Idling operation of drill 22 has already begun and frequency meter I00 is plugged in to record it. The operator standing in a position to observe the guages and the tape I13 seen through window cracks needle valve 92 thereby increasing the reading of guage 84 and directl reflecting the feeding pressure effective upon the drill 22 as 0 "hose 20 is pushed down cylinder I2 by piston 40. 6

The distance traveled can be observed on tape I13 and the rate controlled accordingly by variation of valve 92. As the drill passes through hose turner 4 its fluid engine, the operation of which is described in detail in co-pending application Serial No. 687,028, now abandoned, kills but takes off again as soon as the drill enters the horizontal positioning space in the hose turner 4. With continued travel the drill 22 contacts the formation face and begins to cut drainage lateral 9.

With cutting the frequency of the drill engine increases, and the shock waves propagated by its action record on the frequency meter. If the frequency increases too rapidly, the operator decreases the opening of valve 92, or if the frequency remains too low opens the valve slightly.

In the event the engine is fed too fast and kills, the operator closes feed valve 92 and opens drain valve 90, thus retracting the drill until the engine takes off again after which he begins feeding it again at a, slower rate. Feeding continues in this manner until tape I13 shows that the lateral has been completed?""valve f'is then closed, and drain valve 90 opened. The running line then reverses its direction until piston 60 contacts stop 86 at which time the screw I03 is used to lock piston 60 and line valve 36 is closed, head plug82 is removed, tape H3 is unclamped, and the running. line pulled from the hole. The drill engine 22 is removed and replaced with a new drill. The fixed string is raised ofl bottom, turned through the desired angle to position the turner case against a new formation face, and then reset. The process described is then repeated in drilling a new lateral.

I claim:

1. In well drilling apparatus, the combination of a rigid conduit positioned in a well bore and having a hydrauliceylinder integral with the upper end thereof, and a second hydraulic cylinder of different diameter integral with the lower end thereof, means for supplying fluid to said conduit intermediate said cylinders, a piston operative in each of said cylinders, connecting means. for the pistons of said cylinders, drilling means mounted below the lower of said pistons for travel therewith, pressure varying means mounted at the surface and above the upper piston, whereby fluid introduced under pressure into the conduit between said cylinders acts to extend or retract said drilling means in response to pressure variation above the upper piston.

2. In well drilling apparatus, hydraulic means for varying the feeding pressure of a drill, positioned in a well bore and operated by a fluid motor integral therewith, including a fluid conduit communicating with said motor, interconnected hydraulic cylinders integral with said conduit interconnected pistons operative in said cylinders, surface means controlling the extension and retraction of said drill by said cylinders, and surface means indicating the feeding pressure of said drill against the formation being drilled.

3. In surface apparatus controlling the feed- .ing rate of a mechanism for cutting lateral drainage channels from a well bore, the combination of a frequency meter indicating the frequency of said mechanism, a, cylinder varying a piston hydraulically extending said mechanism from said well bore, an associated surface controlled cylinder carrying a piston hydraulically retracting said mechanism from said well bore, a line for measuring the distance said mechanism has been projected, and pressure guages recording the fluid force available to produce lateral travel of said mechanism.

4. In surface apparatus controlling the feeding rate of a mechanism for cutting lateral drainage channels from a well bore, a head carried by a fluid conduit positioned in said well, a hydraulic cylinder below said head, a piston in said cylinder operative to extend or retract said mechanism from said well bore in response to operation of paired fluid valves mounted on said head, a fluid sealed measuring device fixed to said piston and passing through said head, a window in said head for observing said measuring device, a pressure guage in said head indicating the pressure available to extend or retract said mechanism, and a frequency meter mounted on said head for indicating the pressure exerted by said mechanism against the formation face.

5. In apparatus for drilling horizontal drainage channels from a well bore, a conduit turning case positioned opposite a fluid bearing formation, a hydraulic cylinder positioned above said case and communicating therewith, a hollow piston operative in said cylinder, a flexible conduit fixed below said piston and communicating with a fluid conduit extending from said cylinder to the surface, a fluid drill fixed to the extending end of said flexible conduit and responsive to fluid pressure above said piston for lateral extension from said case, and a hydraulically controlled cable extending from the top of said piston to the surface whereby the fluid force effective against said piston and said fluid drill to eject them from said cylinder is variably opposed by a tensile force acting to retract them from said cylinder.

6. In apparatus of the class described in claim 1, the combination with surface means indicating the frequency of the drill, whereby the optimum rate of extension of" said drill is indicated.

' RUSSELL R. HAYS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 21,102 Jakosky May 30, 1939 469,187 Tremain Feb. 16, 1892 1,082,901 Perkins Dec. 30, 1913 1,660,201 Lee Feb. 21, 1928 1,895,901 Smith Jan. 31, 1933 1,896,110 Simmons Feb. 7, 1933 1,954,176 Johnson Apr. 10, 1934 2,192,909 Hoffar Mar. 12, 1940 2,276,016 Brantly Mar. 10, 1942 2,345,816 Hays Apr. 4, 1944 2,347,302 Twyman et a1 Apr. 25, 1944 2,441,881 Hays May 18, 1948

Images