Oil Well Drilling Rig Mover

In our copending patent application Ser. No. 88,555, filed Oct. 26, 1979 and issued Apr. 13, 1982 as U.S. Pat. No. 4,324,077, a vehicle or mover for transporting an erected oil well drilling rig over land is disclosed. During drilling, the body of the mover is supported by mats resting on the ground, but when it is desired to move the rig, its body is raised relative to its wheels so that the mover then can travel along the ground. However, the rig mover can only travel in a longitudinal direction and if it comes to a narrow bridge, it cannot travel across it.

It is among the objects of this invention to provide a rig mover of the general type shown in our copending application, but which can be moved laterally as well as lengthwise and which can readily be separated into two narrow dollies that can cross a narrow bridge and then be reconnected.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which

FIG. 1 is a schematic side view of the rig mover in well-drilling position;

FIG. 2 is a side view showing the rig mover ready for travel along the ground;

FIG. 3 is a plan view of the mover in its over-the-well position but with its wheels down;

FIG. 4 is similar to FIG. 3 but with the wheels moved inwardly for travel;

FIG. 5 shows the rig mover with the wheels turned 90 degrees for lateral travel;

FIG. 6 is a plan view of one of the dollies in traveling position;

FIG. 7 is a fragmentary enlarged plan view of one end of the rig mover with the wheels in over-the-road position;

FIG. 8 is a vertical section taken on the line VIII--VIII of FIG. 7;

FIG. 9 is a vertical section taken on the line IX--IX of FIG. 7; and

FIG. 10 is an enlarged fragmentary end view showing a pair of wheels partly broken away.

Referring to the drawings, a supporting structure 1, indicated in dotted lines in FIGS. 1 and 2, for an erect oil well drilling rig (not shown) rests on a skid base formed as shown in FIGS. 3, 4 and 5 from two laterally spaced beams 2 that are rigidly but detachably connected by means of braces 3 and 4 between them. Preferably, each beam is formed from a pair of laterally spaced girders 5 that likewise are rigidly connected by cross braces 6. During drilling of a well, this skid base rests either directly on the ground, or on one or more skid mats 7 shown in FIG. 1 that can be attached to the bottom of the base.

In order to permit the skid base to travel over the ground from one well drilling site to another, there is a pair of laterally spaced wheels 8 at each end of each beam. Each pair of wheels is mounted on the opposite ends of an axle 9 that normally extends transversely of the beams as shown in FIGS. 8 and 10. The lower end of a shaft 10 is pivotally connected to the central portion of each axle on a transverse axis and the shaft extends upwardly through the outer end of a braced arm 11, in which the shaft is rotatably mounted so that it can be turned. The inner end of the arm is rigidly, but detachably, connected to the outer end of a support member 12 that has a pair of downwardly extending portions pivotally connected to brackets 13 (FIG. 8) on the underlying beam on a horizontal axis extending transversely of the beam. Each beam and its wheels form a dolly.

While the skid base is resting on the ground or mats, the outer ends of arms 11 and support members 12 are tilted up. At such times it is best to support the wheels by wire lines 14 (FIG. 1) that connect the arms to structure 1 to relieve the wheels and their bearings of deadweight loads.

While the rig mover is immobile as a well is being drilled between the dollies, the wheels at each end are spaced their maximum distance apart as shown in FIG. 3 so that there will be room for a truck to be driven in between the dollies to take equipment in. A hydraulic cylinder 16, pivotally connected at its lower end to a bracket 17 in the beam beneath the inner end of each support member 12, has a piston rod 18 projecting from its upper end. When it is desired to move the skid base, the outer end of the piston rod projecting from each cylinder is connected to the inner end of the adjacent support member 12 as shown in FIG. 1. Fluid under pressure then is delivered to the lower ends of the four cylinders, which causes them to tilt the support members of each dolly away from each other. This causes the outer ends of the arms to press down on the wheel axles, which act as fulcrums, while the inner ends of the support members rise away from the skid base. Consequently, support members 12, through their connections to the underlying beams, lift the skid base from the ground until arms 11 are substantially horizontal and shafts 10 are vertical as shown in FIGS. 2 and 8. Then the support members are locked in that position, preferably by means of links 19 that are pinned to the bottoms of the support members and to brackets 20 on beams 2. The piston rods then can be disconnected from the support members until it is time to lower the skid base.

The rig mover then can be pulled away from the well by a suitable vehicle connected to tongues 22 that are fastened to the axles and extend away from the skid base. The tongues at the leading end of the rig mover are held parallel to each other by a cross bar 23 that is pivotally connected to the tongues by removable pins 24. Before the skid base can be moved, braces 3 and 4 at its trailing end must be removed. After the rig mover has been pulled away from the well and the rear braces 3 and 4 replaced, the wheels at each end of the skid base are moved closer together so that they will not be spread too far apart for road travel, as shown in FIGS. 4 and 7. This can be done by disconnecting arms 11 from supporting members 12 and reconnecting them to brackets 25 projecting from the support members at the inner sides of the dollies. Cross bar 23 is an adjustable telescoping bar than can be shortened to compensate for the reduced distance between the tongues at its ends. When a new drilling location is reached, the piston rods are connected to the support members again, links 19 are disconnected and the hydraulic cylinders allow the skid base to slowly descend between the wheels at its ends until mat 7 rests on the ground.

If it is desired to move the skid base laterally, cross bar 23 can be disconnected from tongues 22 and all four tongues can be swung 90 degrees to turn the wheels at right angles to the skid base as shown in FIG. 5.

Means are provided at the upper ends of shafts 10 to lock them in either of their two positions. For over the road travel, the trailing shafts are locked but the leading shafts are left free so that the rig mover can be steered. The locking means for each shaft 10 preferably consists of a short lever 26 rigidly mounted on the upper end of the shaft and provided in its outer end with a hole for receiving a locking pin 27 that can extend into a hole in either end of a bar 28 extending across the top of arm 11 and secured thereto. When the locking pin extends through the hole in one end of the bar the wheels are positioned for longitudinal travel of the dolly. When the pin is in the other end of the bar the wheels have been turned 90 degrees for lateral movement of the dolly.

Sometimes the road over which the rig mover must travel includes a bridge that is too narrow for the rig mover to traverse. In such a case, the two dollies are separated by removing all of the braces 3 and 4 and, of course, cross bar 23. At this time the wheels must be in their outer position as shown in FIG. 3, so that arms 11 will be located along the central longitudinal axis of each beam 2. At this time each dolly appears as indicated in FIG. 6. The two narrow dollies then can be moved in succession across the bridge and then be reconnected by braces 3 and 4. Part of the mast-supporting structure 1 on each dolly may be carried across the bridge with the dolly but the rest of the components will have to be broken down to truck load size and trucked across the bridge and then reassembled on the skid base for further drilling.

While the two dollies are connected, it is desirable that axles 9 be able to tilt as the wheels travel over uneven ground. This is permitted by the pivotal connection of shafts 10 to the axles. However, when the dollies are separated for individual travel, such tilting must be prevented. Otherwise, shafts 10 would fall sideways onto one of the wheels at each end of the dolly, and beam 2 would be tilted sideways. Locking of the axles at right angles to shafts 10 can be accomplished, as shown in FIG. 10, by mounting a pair of locking members 30 for sliding vertical movement on a pair of brackets 31 projecting from opposite sides of each shaft 10. The locking members normally are held in an upper inoperative position by pins 32 extending through them and the bracekts. When it is desired to lock the axle, the pins are removed and the locking members allowed to slide down until their lower ends project into slots 33 in sleeves 34 on the axle. Then pins 32 are inserted in the bottom holes in the brackets to hold the locking members in their lower position, in which they prevent relative movement between the shaft and axle. The forked inner end of a tongue 22 also is secured to sleeves 34.

Although the term "wheels" has been used herein, it is to be construed broadly as also covering any means that permit the skid base to travel over the ground, such as the well-known Athey tracks.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.