US3572435A - Load support for use in well casing or bore hole - Google Patents

Abstract

TO SUPPORT IN A TUBULAR WELL CASING OR BORE HOLE A PIPE CONSISTING OF A SERIES OF LENGTHS JOINED BY THREADED NIPPLES, AND A LOAD ATTACHED TO THE LOWER END OF THE PIPE, STIFFLY RESILIENT ELEMENTS TO THE LOWER END OF THE PIPE, STIFFLY NIPPLES PROJECTING RADIALLY OUTWARD FROM THE NIPPLE OR NIPPLES, WHEN UNSTRESSED, TO A DISTANCE GREATER THAN THE INTERIOR RADIUS OF A TUBULAR WELL CASING OR BORE HOLE SO THAT WHEN THE PIPE AND NIPPLES ARE INSERTED IN THE CASING THE ELEMENTS ARE FLEXED TO AN INCLINED POSITION, THE TIPS OF THE ELEMENTS ENGAGING THE WALL OF THE CASING TO RESIST A CHANGE OF DIRECTION OF MOVEMENT OF THE PIPE. WHEN THE ELEMENTS SLOPE DOWNWARD, THEY TEND TO SUPPORT THE WEIGHT OF THE PIPE. TO REVERSE THE SLOPE OF THE ELEMENTS THE PIPE IS ROTATED A FEW DEGREES TO FLEX THE ELEMENTS HORIZONTALLY PERMITTING THEM TO SPRING INTO HORIZONTAL PLANES. UP OR DOWN MOVEMENT OF THE PIPE THEN MOVES THE ELEMENTS INTO INCLINED POSITIONS.

Description

R. E. PRESCOTT. JR 3,572,435

March 23, 1971 LOAD SUPPORT FOR usm IN WELL CASING on BORE HOLE Filed Feb. 10, 1969 L4 4 4441 VY/F r/VV/VY/VV 3 ll U si l FIG.

FIG. 7

INVENTOR. ROBERT E. PRESCOTIJR. BY

FIG. 3

AT TORN EYS United States Patent 3,572,435 LOAD SUPPORT FOR USE IN WELL CASING OR BORE HOLE Robert E. Prescott, Jr., 10 Railroad Ave., Exeter, N.H. 03833 Filed Feb. 10, 1969, Ser. No. 797,797 Int. Cl. E21b 23/00 US. Cl. 166-214 4 Claims ABSTRACT OF THE DISCLOSURE To support in a tubular well casing or bore hole a pipe consisting of a series of lengths joined by threaded nipples, and a load attached to the lower end of the pipe, stiflly resilient elements are mounted on one or more of the nipples projecting radially outward from the nipple or nipples, when unstressed, to a distance greater than the interior radius of a tubular well casing or bore hole so that when the pipe and nipples are inserted in the casing the elements are flexed to an inclined position, the tips of the elements engaging the wall of the casing to resist a change of direction of movement of the pipe. When the elements slope downward, they tend to support the weight of the pipe. To reverse the slope of the elements the pipe is rotated a few degrees to flex the elements horizontally permitting them to spring into horizontal planes. Up or down movement of the pipe then moves the elements into inclined positions.

This invention relates to relatively simple but effective means for supporting in a tubular well casing a pipe and Whatever objects may be attached to the lower end of the pipe. It is customary, when a well has been drilled with, e.g., a six-inch tubular casing, to lower into the water at the bottom of the casing a motor and pump or jet assembly attached to a delivery pipe which extends down from the top of the casing and is supported by a cap over the top of the casing. The pipe is assembled by connecting convenient lengths with screw-threaded nipples. By mounting on one or more of the nipples large members of stiflly resilient elements such as bristles, normally straight spring wires, or the like, extending horizontally a greater radial distance than the interior radius of the well casing, these elements will flex from the horizontal when the nipple is introduced into the well casing, the tips of the elements engaging the rough interior wall surface of the well casing or bore hole, thus opposing any reversal of direction of up or down movement of the nipple and the pipe assembly of which it is a part. If, for example, the elements slope downward, they will oppose downward movement of the pipe assembly and will thus tend to support the weight of the assembly.

For a more complete understanding of the invention, reference may be had to the following description thereof, and to the drawing, of which:

FIG. 1 is an elevational view of part of a well casing containing an embodiment of the invention with the resilient elements sloping upward;

FIG. 2 is a similar view, showing the resilient elements sloping downward;

FIG. 3 is an elevational view of a nipple with resilient elements in the open, unstressed position;

FIG. 4 is a plan view of the same;

FIG. 5 is a plan view of a nipple in a well casing, showing the flexing of the resilient elements when the nipple is rotated;-

FIG. 6 is a plan view of a modified form of the invention; and

FIG. 7 is a sectional view of the device shown in FIG. 6.

3,572,435 Patented Mar. 23, 1971 The illustrative embodiment shown in FIGS. 1 to 5 of the drawing consists of a pipe nipple 10 from the outer surface of which radiate a large number of stiffly resilient elements 12 such as spring wires, bristles or the like. These elements when unstressed are in planes perpendicular to the axis of the nipple, the assembly resembling a cylindrical wire brush. As the device is designed for use in a tube or bore hole of a specified interior diameter, e.g., a fourinch, six-inch or eight-inch well casing 14, the length of the elements 12 is such that they extend out, when unstressed, a radial distance from the axis of the nipple 10 somewhat greater than the radius of the interior of the casing 14, the length of the elements being such that when the device is pushed into the casing 14 'as indicated in FIG. 1, the elements 12 will be flexed to slopeupward at an angle of 30 or so from the horizontal. When in that position the elements 12 strongly resist any effort to raise the nipple 10 and the pipe lengths 16 which are attached to it. To reverse the slope of the elements 12 so that they will incline downward as indicated in FIG. 2 the nipple is rotated a few degrees so as to flex the elements laterally as indicated in FIG. 5. When this is being done, the resilience of the elements springs them into planes which are perpendicular to the axis of the nipple. If the nipple is then drawn upward the elements straighten into radial planes and incline downward as indicated in FIG. 2. When in this position they resist downward movement of the nipple and the pipe attached to it and thus tend to support the weight of those parts. By using elements in sufficient number and of suflicient stiffness, the entire weight of the pipe assembly can be supported. This not only relieves the cap of the load but also is of help when a heavy pipe assembly is being removed from the well casing. When the pipe is being hauled up, the operation is usually interrupted frequently to shift the device that grips the pipe to a lower hold. The elements support the pipe during such interruptions.

The stiffness of the support elements will depend on their length as well as on other factors, the shorter elements being stiffer. The elfective length of the elements 12 can be materially reduced by the use of radial fins 18 projecting outward from a hub 20 on which groups of elements may be mounted. The fins 18 are preferably of rigid material such as polyvinyl chloride, cast bronze, cast iron or the like. These fins support the elements 12 in such a way as to resist rotary movement of the load and to limit flexing of the full length of the elements to vertical planes. This is found to increase the supporting power and the stability of the device as a whole. Yet when rotation is strongly impressed on the device, the end portions of the elements projecting beyond the fins 18 will flex, permitting movement of the load in the direction opposite to its previous movement.

I claim:

1. A device for supporting a load in a well casing comprising a pipe nipple having numerous stiflly resilient elements projecting radially out therefrom to a distance from the axis of said nipple greater than the radius of said well casing, said elements being of suflicierit stiffness to support said load in said well casing, the free ends of said elements operate to engage the interior wall of said well casing, said nipple being slidable within said well casing in a first direction and being fixed within said Well casing against movement in a second direction when said elements are in an operative condition, said first and sec- 0nd directions being along the longitudinal axis of said well casing, said first direction being opposite to said second direction.

2. A device as claimed in claim 1, said elements consisting of normally straight spring wires.

3. A device as claimed in claim 1, said device including radial fins in vertical planes projecting for a portion of the length of adjacent elements.

4. The device as claimed in claim 1 wherein said elements slope upward at an angle of about 30 to the horizontal when said device is inserted in said well casing, and said elements slope downward at an angle of about 30 to the horizontal when said device is extracted from said well casing, said first direction being from the top of said well casing to the bottom of said well casing, the tips of said elements being in fixed engagement against movement of said nipple with respect to said well in said second direction when said elements slope upward, the tips of said elements being in fixed engagement against movement of said nipple with respect to said well casingin said first direction when said elements slope downward, said elements being flexed into a plane perpendicular to the longitudinal axis of said nipple when said nipple is rotated.

References Cited UNITED STATES PATENTS 2,102,178 12/1937 Gerhardt 166170X 2,447,966 8/1948 Stephens 166-170X 2,654,433 10/1953 Piety 166202X 2,683,491 7/1954 Gassaway 166173 2,713,912 7/1955 Baker 166--173 2,846,016 8/1958 Hanes 166173X DAVID H. BROWN, Primary Examiner

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