Well Tubing Injector And Removal Apparatus

Abstract

Well tubing injector and removal apparatus having means for feeding the tubing from a reel into a well and vice versa while maintaining the tubing under tension between the reel and the tubing injector unit, whereby level winding and unwinding of the tubing relative to the reel is assured and dangerous movements of the portion of the tubing between the reel and the injector unit due to wind and other causes are avoided.

Description

BACKGROUND OF THE INVENTION

The field of this invention is apparatus for feeding tubing into and out of a well.

In the past, it has been found desirable to inject a continuous tubing from a reel into a well, using various types of tubing feeding apparatus such as disclosed in U.S. Pat. Nos. 3,182,877; 3,285,485; 3,313,346; and 3,330,531. None of such prior art discloses a satisfactory apparatus for feeding a well tubing between a reel and an injector unit. The arrangement suggested in U.S. Pat. No. 3,313,346 involves the use of a large loop formed by the tubing between the reel and the injector apparatus, which arrangement is especially undesirable because of the space required for the loop and the danger of excessive movements of the tubing in high winds.

SUMMARY OF THE INVENTION

The present invention relates to an apparatus for the feeding of tubing from a reel to a tubing injector unit, and vice versa, wherein the tubing is maintained under tension and in a substantially straight line in the span between the reel and the injector unit so that level winding and unwinding of the tubing relative to the reel is effected while dangerous movements of the tubing in high winds are avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation of the preferred form of the apparatus of this invention, shown in position for maintaining well tubing or pipe under tension and in a substantially straight line from a reel to the tubing handling apparatus; and

FIG. 2 is a plan view of a portion of the apparatus of FIG. 1 to further illustrate the reel which is preferably utilized in the apparatus of this invention; and

FIG. 3 is a schematic illustration of the hydraulic system of this invention which is used to control the operation of the reel and the injector or handling unit.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the drawings, the letter R designates generally the reel unit or assembly of the apparatus of this invention, and the letter I designates the injector or handling unit of this invention for the feeding in and the pulling out of well tubing T relative to a well or other bore in the ground, the upper surface of which is indicated at G (FIG. 1). As will be explained more in detail, by the utilization of the control means or system of FIG. 3, the reel unit R and the injector unit I are controlled so that the tubing T is fed off of the reel R and is wound on the reel R from the injector unit I under tension at all times so as to facilitate the level winding of the tubing T with respect to the reel unit R and to prevent excessive movement of the tubing T in high winds.

The details of the construction of the reel unit R are disclosed in copending United States patent applications Ser. Nos. 36,780 and 84,415. Briefly, for the purposes of this invention, the reel unit R includes a drum 10 having side flanges 10a between which the tubing T is wrapped. The drum 10 is driven by a hydraulic motor MR (FIG. 2) which has a pulley 12 or other suitable driven means therewith for connecting with a belt or chain 14 which is in driving engagement with another pulley or sprocket 15 secured to the drum 10.

A level wind mechanism M of any suitable construction is mounted with the reel drum 10 and is adjustable to different positions such as the solid line position of FIG. 1 and the dotted line position of FIG. 1 to assist in maintaining the tubing T in a straight line from the drum 10 to the injector unit I, as will be more evident hereinafter. Adjustable telescoping supports 20 of any suitable construction are provided on a skid or other base 21 for the entire unit R so as to position the level wind mechanism M at the desired elevation with respect to the drum 10. The skid 21 is preferably mounted upon a truck or other bed 22 having wheels 23 therewith so that the unit is portable, although it is not necessary for the skid 21 to be so mounted, since it may be positioned directly upon the ground or other base.

The injector unit I is preferably of the type shown in anyone of the foregoing patents listed above and therefore the details of such unit are not illustrated. The unit I is disposed above a typical well head assembly W which has a casing or other pipe C extending down into the well below the ground level G and into which the tubing T is inserted in the known manner. At the upper end of the injector unit I, a curved guide 30 is mounted over which the tubing T passes, with the curvature of the guide 30 being great enough to prevent any permanent distortion or bending of the tubing T as it is fed into or removed from the casing C.

The injector unit I includes drive rollers, which have therewith hydraulic motors MI--1 and MI--2 (FIGS. 1 and 3). As will be explained in detail hereinafter in connection with FIG. 3, such motors MI--1 and MI--2 serve to control the feeding of the tubing T from the reel unit R and also the withdrawal of the tubing T from the well when the tubing T is to be wound back upon the reel unit R.

Referring now to the control system of FIG. 3 in particular, two hydraulic pumps, preferably of the fixed displacement type which are driven by The pump with suitable throttle controls for ultimately regulating the speed of the lowering and raising of the tubing T within the casing C, are indicated at P--1 and P--2. The pump P--1 is a higher capacity pump than the pump P--2. Both of the pumps P--1 and P--2 are connected to a sump or reservoir 35 through a pipe 36 which preferably has a suction strainer 37 and a valve 38 therewith. A gauge 39 may also be incorporated to indicate the extent of the reduced pressure or vacuum being pulled by the pumps. The pump P--1 discharges through line 40 which connects through valves V--2 and V--1 to a flow line 41 which flows to the hydraulic motors MI--1 and MI--2. The return fluid from the motors MI--1 and MI--2 flows through line 42, and through the valve V--1 to a return line 42 which is connected to line 43 leading to a return filter 44 and ultimately to the sump 35 through a valve 45. It should be noted that in FIG. 3, the sump 35 is shown as being separated, but it is the same sump and they are interconnected or are integrally formed.

The pump P--2 discharges water or oil therefrom through a pipe or line 46 which passes through the valve V--2 when the valve V--2 is in the open position shown in FIG. 3. Fluid flows from the line 46 through the valve V--2 to the line 47 and then through a valve V--3 (FIG. 3) and line 48 to the hydraulic motor MR for operating same. The discharge or return from the motor MR is through line 49 and valve V--3 (FIG. 3) to the pipe or tubing 43 for ultimate return to the sump 35.

It should be noted that the valves V--1, V--2 and V--3 are shown schematically in FIG. 3 with arrows to indicate the positions of the valves, and with the three positions of each valve designated schematically. Thus, the first position on the right hand end of each of the valves is the normal flow position, the intermediate position of each of the valves is the cut off or closed position for each of such valves and the left hand position for each of the valves is the reverse flow position, as will be more evident hereinafter.

The extent of the pressure developed with the pump P--1 may be regulated through a bypass or relief valve 50, the opening of which may be adjusted in any known manner so as to regulate the amount of fluid from the line 40 which passes through a check valve 51, line 52 and the valve 50 to a discharge line 53 which connects with the sump 35. A gauge 54 is connected to he line 52 so that the pressure which is developed by the control of the discharge through the relief valve 50 from the pump P--1 may be indicated to the operator.

The pump P--2 is also preferably connected to the relief valve 50 through a check valve 55. It is to be noted that the check valves 51 and 55 are constructed so that the fluid flow from the pumps P--1 and P--2 cannot interconnect with each other.

A needle valve 57 is mounted in a bypass line 58, together with a check valve 59 so that during the normal direction of rotation of the motor MR which is used for driving the drum 10 of the reel unit R, the extent to which such motor MR can be driven by the withdrawal of tubing T therefrom by the injection unit I is regulated, as will be more fully explained. Another needle valve 57' disposed in a line 58' with a one-way check valve 59' is preferably included so that in certain circumstances where the motor MR is reversed in rotation when flow is through the line 49 and discharges through the line 48, the extent of the driven action on the motor MR is controlled in the same manner as previously explained in connection with the needle valve 57.

A relief valve 60 is preferably included in conjunction with the motor MR which is set to open at a pressure which is greater than the normal pressure developed at the motor MR, for example, 500 p.s.i., so that the higher pressure can be relieved and a portion of the fluid returned through line 42a which communicates back through the line 43 to the sump or reservoir 35. Suitable check valves 61 and 61' permit such return of flow to the relief valve 60, and a gauge 60a indicates the pressure at which such relief is occurring in the event this does happen in the operation. Return check valves 62 and 62' are also preferably provided in the circuit from the relief valve for safety purposes in the event there is a back pressure developed in the line 42a which prevents the relief flow therethrough.

In the operation or use of the control system of FIG. 3 in conjunction with the apparatus of this invention, the pumps P--1 and P--2 are operated by driving same with a gasoline engine, diesel engine or other suitable prime mover (not shown) in the conventional way, with the pump P--1 delivering a substantially greater volume of fluid than the pump P--2. Initially, when lowering the tubing T down into the well or casing C, the relief valve 50 is set to open at a very low pressure. At that time, the pump P--2 is supplying fluid under pressure to the reel motor MR so as to drive same in a direction tending to wind the tubing T upon the drum 10, which would be counterclockwise as viewed in FIG. 1. In view of such driving action by the motor MR tending to wind the tubing T upon the drum 10, it is necessary for the motors MI--1 and MI--2 to be driven with enough force to pull the tubing T in opposition to the motor MR.

To cause the motors MI--1 and MI--2 to exert a pulling force on the tubing T, the relief valve 50 is adjusted so as to increase the pressure at which relief occurs through the valve 50 until there is some pull developed on the tubing T by the motors MI--1 and MI--2. When such pull is indicated, the needle valve 57 is opened to some extent to short circuit a part of the fluid being discharged from the reel motor MR, which cuts down on the resistance of the motor MR to the unwinding of the tubing T from the drum 10. The motor MR is actually being driven as a pump by the pulling of the tubing T from the reel R with the motors M--1 and M--2, so that the fluid pressure relief provided by opening the needle valve 57 serves to reduce the effectiveness of the fluid drive to the motor MR through the line 48. Thus, during the lowering of the tubing T into the well, the tubing T is pulled by the motors M--I and M--2 away from the reel R, while the motor MR resists such pulling action without preventing it, so as to maintain the portion of the tubing T between the reel R and the unit I under tension as the tubing T is fed from the drum 10 and is lowered into the well.

When the tubing T is being removed or pulled out of the well casing C, the valve V--1 is shifted so as to be in the reverse position indicated by the position 70, which causes the motors MI--1 and MI--2 to operate in the reverse direction. The lifting force provided by the pump P--1 is regulated by adjusting the valve 50, as previously explained, so that sufficient force is developed to lift the weight or load of the tubing T. At the same time, the reel motor MR is operated in a direction tending to wind the tubing T upon the drum 10 so as to maintain the tubing T under tension while winding it upon the reel drum 10.

During both the operations, running in and raising the tubing T, the speed of the lowering or raising of the tubing T may be controlled within limits by the throttle on the engines operating the pumps P--1 and P--2.

In some situations, such as deep wells, the load of the tubing T in the well is so high that it is difficult to lift it using the pump P--1, in which case, the valve V--2 is switched to its reverse position 71, which causes the pump P--2 to be connected to the motors MI--1 and MI--2 which operate with a lower volume of fluid supplied at a higher pressure. The higher volume pump P--1 is then connected to the reel motor MR when the valve V--2 is in the reverse position 71, and the relief valve 50 is adjusted to bypass some of the fluid as desired to control the pulling force with the motor MR.

It is to be noted that although the motor MR may be reversed by pushing the valve V--3 to the reverse position 72, this would only be for certain operations unrelated to the normal operation of the apparatus of this invention. For example, it might be desirable to reverse the motor MR when tubing T is being fed therefrom without being introduced into a well and without the injector unit I working with it. However, normally, the motor MR is rotated in the same direction for both the feeding in of the tubing T into the well casing C and the pulling of the tubing T from the well or casing C so that, as previously explained, the tubing T is in a substantially straight line between the reel unit R and the injection unit I and is under tension at all times.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims

We claim:

1. Apparatus for feeding tubing into or out of a well or the like, comprising:

a reel having a fluid-actuated motor therewith for winding and unwinding tubing thereon;

an injector unit separate from and remotely spaced from said reel and having injector power means for injecting tubing substantially vertically into a well or the like and for withdrawing tubing substantially vertically from a well or the like;

a curved tubing guide disposed above said injector unit for directing tubing from said reel into said injector power means and having a substantially vertical portion above said injector unit which curves upwardly and with a lateral portion leading to said reel;

tubing disposed on said reel and spanning the space between said reel and said injector unit in a substantially straight line from said reel to said curved guide;

control means for said reel power means and said injector power means for maintaining the portion of said tubing spanning said space between said reel and said injector unit under tension and in said substantially straight line regardless of the direction of movement of said tubing with respect to said reel; and

said control means including means for driving said reel motor in a direction tending to wind the tubing on said reel and means for driving said injector power means in a direction for feeding the tubing off of said reel with a greater force than the force exerted by said reel motor.

2. The structure set forth in claim 1, wherein:

said control means further includes:

means for driving said injector power means in a direction for withdrawing the tubing from the well while said reel power means is driven in said direction for winding the tubing on said reel, said injector power means having means therewith for exerting a sufficient lifting force to overcome the weight of the tubing in the well, and said reel power means having means therewith for exerting a pulling force on the tubing to maintain same under tension when winding said tubing on said reel.

3. The structure set forth in claim 1, wherein:

said injector power means is a fluid-actuated injector motor; and

said control means further includes:

a first pump for supplying fluid under pressure to said reel motor;

a second pump for supplying fluid under pressure to said injector motor; and

said second pump supplying fluid to said injector motor at a greater rate than that supplied by said first pump to said reel motor.

4. The structure set forth in claim 3, wherein said control means further includes:

bypass means for bypassing fluid relative to said first pump for regulating the speed of said reel motor with respect to the speed of said injector motor.

5. The structure set forth in claim 3, wherein said control means further includes:

valve means for changing the flow of fluid from said first pump to said injector motor rather than to said reel motor, and for changing the flow of fluid from said second pump to said reel motor rather than to said injector motor, whereby heavier loads of tubing may be lifted with said injector motor than when said second pump is connected thereto.

6. The structure set forth in claim 3, wherein said control means further includes:

valve means for reversing the flow of fluid from said second pump to said injector motor for reversing the direction of rotation of said injector motor for selectively obtaining either a feeding of the tubing from said reel or a withdrawal of the tubing from the well.

7. The structure set forth in claim 1, wherein:

said reel is disposed below said curved tubing guide; and

said vertical and lateral portions of said curved tubing guide are formed with a bend which is at least about 90.degree. but is on a gradual radius so as to prevent permanent bending of said tubing.