Method of Temporarily Plugging Openings In Well Casing and Apparatus Therefor (Patent No: 651333)

Inventor: Caldwell, Lyle

Location: Los Angeles, CA

Comments: N/A

Description:
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:

1. The method of temporarily plugging openings in a casing set in a well that comprises:

Lowering within the casing a plurality of discrete plugging elements, while externally confining the elements in a compact group, to a position in the vicinity of the openings in the casing;

Introducing fluid under pressure into said casing to cause the fluid to flow outwardly through said openings while the elements in said group are isolated from the flow of fluid under pressure;

Transmitting a control impulse through the well to the magazine;

Separating at least one of the plugging elements from the group and in response to said control impulse releasing the separated element into the fluid stream at a position in the vicinity of but above the elevation of an opening to be plugged to be carried by the stream to the opening to be plugged and seated in said opening.

2. The method of temporarily plugging openings in a casing set in a well that comprises:

Lowering within the casing a plurality of discrete plugging elements, while externally confining the elements in a compact group, to a position in a vicinity of the openings in the casing;

Introducing fluid under pressure into said casing to cause the fluid to flow outwardly through said openings while the elements in said group are isolated from flow of fluid under pressure;

Transmitting a control impulse through the well to the magazine;

Separating plugging elements individually from the group and in response to said control impulse releasing the individual elements in succession into the fluid stream at a position in the vicinity of openings to be plugged, to be carried individually by the fluid stream to the openings to be plugged and seated in said openings.

3. The method of manipulating plugging elements within a well down which fluid is being pumped that includes the steps of lowering in the well a plurality of elements as a group within a container to a position in the vicinity of holes to be plugged by the elements; generating a control impulse at the ground surface; transmitting the control impulse through fluid in the well to releasing mechanism carried by the container for the group of elements; and releasing a predetermined number of elements from the group in response to a control impulse received at the releasing mechanism.

4. The method as claimed in claim 3 in which the control impulse is a transient change in fluid pressure within the well.

5. The method of manipulating plugging elements within a well down which fluid is being pumped that includes the steps of lowering in the well a plurality of elements as a group within a container to a position in the vicinity of holes to be plugged by the elements; controlling fluid flow down the well; and effecting release of the elements from the group in a predetermined number in response to a change in a characteristic of said controlled fluid flow past the group of elements.

6. In apparatus for releasing plugging members into a body of fluid in a well, the combination with a tubing string extending down into the well, comprising: a magazine mounted on the lower end of the tubing string and holding a plurality of plugging elements, the magazine having an outlet for said elements opening into the well space containing the body of fluid; gate means at the outlet from the magazine controlling passage of elements from the magazine into the well space; means defining a fluid passage separated from the magazine and communicating at the inlet end with the tubing and at the outlet end with the well space; and fluid actuated gate operating means in said passage responsive to fluid flowing through the passage to release elements from the magazine to pass into the well space below the tubing string.

7. The combination as claimed in claim 6 in which the gate operating means includes: an operating member connected to the gate; a fluid pressure responsive means also connected to the operating member to move said member in response to a pressure differential between fluid in the tubing and in the well space.



8. Apparatus for temporarily plugging openings in casing set in a well having a tubing string within the casing comprising: a magazine attached to the lower end of the tubing string and containing a plurality of plugging elements, said magazine being located in the vicinity of the openings in the casing to be plugged and adapted at its lower end to discharge plugging elements into the casing; gate means at the lower end of the magazine adapted to control the passage of elements out of the magazine; and gate operating means operable in response to the flow of fluid from the tubing into the casing and toward the openings to be plugged.

9. Apparatus according to claim 8 in which the gate is a pivotally mounted member having limited vertical travel to discharge the plugging elements one at a time, and the gate operating means includes a gate operating rod connected to the gate and movable in response to a change in pressure differential between the fluid within the tubing and within the casing.

10. Apparatus for temporarily plugging openings in casing set in a well having a tubing string within the casing, comprising: a magazine attached to the lower end of the tubing string and containing a plurality of plugging elements, said magazine being located in the vicinity of the openings in the casing to be plugged and open at its lower end to discharge plugging elements into the casing; gate means at the open end of the magazine adapted to control the passage of elements out of the magazine; a first fluid passage means between the interior and exterior of the tubing; a spring biased check valve in said passage opening in response to a predetermined excess fluid pressure in the tubing; and operating rod interconnecting the gate means and said check valve to shift the gate in one direction to pass an element out of the magazine in response to motion of the valve means to return the gate to a position holding the elements in the magazine; a second fluid passage between the interior and the exterior of the tubing; and a second check valve located in the second passage opening in response to a higher fluid pressure in the casing than the first mentioned predetermined fluid pressure at which the first mentioned valve opens.

11. Apparatus for temporarily plugging openings in casing set in a well having a tubing string within the casing, comprising: a magazine attached to the lower end of the tubing string and containing a plurality of plugging elements, said magazine being located in the vicinity of the openings in the casing to be plugged and open at its lower end to discharge plugging elements into the casing; gate means at the open end of the magazine adapted to control the passage of elements out of the magazine; a spring biased piston exposed to fluid pressure in the tubing and movable in response to a predetermined excess of fluid pressure in the tubing over the fluid pressure in the casing, said piston being connected to the gate means to shift the gate in response to said motion of the piston to a position passing an element out of the magazine; a fluid passage between the interior and the exterior of the tubing; and a check valve located in the fluid passage opening in response to a higher fluid pressure in the casing than the first mentioned fluid pressure to which the piston responds.

12. In apparatus for releasing plugging members into a body of fluid in a well, the combination comprising:
a magazine holding a plurality of plugging elements, said magazine having an outlet opening to the well space containing the fluid body; means supporting the magazine a substantial distance down the well below the top of the
well; gate means at the outlet from the magazine adapted to control the passage of elements from the magazine into the well space; gate operating means responsive to an impulse generated at the top of the well; and means transmitting said impulse from the top of the well down the wall to said operating means.

13. Apparatus as claimed in claim 12 in which the means transmitting the impulse includes a column of liquid in the well extending between the top of the well and said gate operating means.

14. Apparatus for temporarily plugging openings in casing set in a well having a tubing string within the casing, comprising: a magazine attached to the lower end of the tubing string and containing a plurality of plugging elements, said magazine being adapted at its lower end to discharge plugging elements; gate means at the lower end of the magazine adapted to control the passage of elements out of the magazine; and gate operating means.