Method and apparatus for removing sand from wells

Claim 2

A pump for removing sand from a well of the class having a casing subject to intrusion by sand and like detritus, from within which casing liquid is conventionally pumped through a passage in a tubing which passes axially through the casing, said pumping comprising: a plunger attachable to said tubing and movable axially therewith, said plunger having a passage extending axially therethrough and making a fluid connection with the passage through the tubing; an outer wall on said plunger; a reference tube having a passage therethrough and extending in axial alignment with the plunger; an inner wall on said passage in the reference tube, the plunger and reference tube being so disposed and arranged that the walls are telescopic; a sliding fluid seal extending between said walls and attached to one of them, there being formed by the inner wall of the reference tube and the seal a pumping chamber of volume which is varied by moving the tubing and thereby the plunger axially relative to the reference tube; a first check vAlve in the passage in the plunger; a second check valve in the passage in the reference tube, the check valves being unidirectional and permitting flow only toward the tubing; the mass of the reference tubing biasing itself against motion toward the tubing when the pump is suspended by the tubing, whereby with an opening of the passage in the reference tube located in the sand to be pumped, the plunger may be reciprocated by the tubing to provide a pumping action in the chamber that unidirectionally pumps a suspension of sand in liquid into the tubing; an axially extending extension of the tubing disposed outside the reference tube which is rigidly connected relative to the plunger, and adjacent to the outside of the reference tube; and interfering shoulder means on said extension and on said reference tube which abut one another in one relative axial position thereof so as to prevent further separating sliding movement of the reference tube and the plunger before the sliding seal leaves sealing contact between the inner wall of the reference tube and the outer wall of the plunger, whereby upon lifting of the reference tube by the tubing, the lifting force is exerted on the reference tube through the said interfering shoulder means in abutment without axial contact against the sliding seal.

Claim 3

A sand pump according to claim 1 in which a bit is attached to the end of the reference tube away from the plunger in order to facilitate the penetration of the reference tube into the material to be pumped.

Claim 4

A sand pump according to claim 1 in which the shoulder means on the reference tube is an annular ring, and in which the extension of the tubing is a cylindrical member, the inwardly overhanging shoulder being a ring attached thereto.

Claim 5

A sand pump according to claim 3 in which a bit is attached to the end of the reference tube removed from the plunger in order to facilitate the penetration of the reference tube into the material to be pumped.

Claim 6

A pump system for removing sand from a well of the class having a casing subject to intrusion by sand and like detritus, comprising: a hollow tubing used in the well for extraction of fluid in normal operation extending from the surface to a region near the sand, there being a passage through the tubing; means axially to reciprocate the tubing; a plunger attached to said tubing and movable axially therewith, said plunger having a passage axially therethrough and making a fluid connection with the passage through the tubing; an outer wall on said plunger; a reference tube having a passage therethrough and extending in axial alignment with the plunger; an inner wall on said passage in the reference tube, the plunger and reference tube being so disposed and arranged that the walls are telescopic and freely slidable relative to one another; a sliding fluid seal extending between said walls and attached to one of them, there being formed by the inner wall of the reference tube and the seal a pumping chamber of volume which is varied by moving the tubing and thereby the plunger axially relative to the reference tube; a first check valve in the passage in the plunger; a second check valve in the passage in the reference tube, the check valves being unidirectional and permitting flow only toward the tubing; the mass of the reference tube biasing itself against motion toward the tubing when the plunger is suspended by the tubing, whereby with an opening of the passage in the reference tube located in the sand to be pumped, the tubing may be reciprocated to move the plunger and provide a pumping action in the chamber that unidirectionally pumps a suspension of sand in liquid into the tubing and to the surface; an axially extending extension of the tubing disposed outside the reference tube which is rigidly connected relative to the plunger, and adjacent to the outside of the reference tube; and interfering shoulder means on said extension and on said reference tube which abut one another in one relative axial position thereof so as to preveNt further separating sliding movement of the reference tube and the plunger before the sliding seal leaves sealing contact between the inner wall of the reference tube and the outer wall of the plunger, whereby upon lifting the reference tube by the tubing, the lifting force is exerted on the reference tube through the said interfering shoulder means in abutment without axial contact against the sliding seal.

Claim 7

A pump system for removing sand from a well of the class having a casing subject to intrusion by sand and like detritus, comprising: a hollow tubing used in the well for extraction of fluid in normal operation extending from the surface to a region near the sand, there being a passage through the tubing; means axially to reciprocate the tubing; a plunger attached to said tubing and movable axially therewith, said plunger having a passage axially therethrough and making a fluid connection with the passage through the tubing; an outer wall on said plunger; a reference tube having a passage therethrough and extending in axial alignment with the plunger; an inner wall on said passage in the reference tube, the plunger and reference tube being so disposed and arranged that the walls are telescopic and freely slidable relative to one another; a sliding fluid seal extending between said walls and attached to one of them, there being formed by the inner wall of the reference tube and the seal a pumping chamber of volume which is varied by moving the tubing and thereby the plunger axially relative to the reference tube; a first check valve in the passage in the plunger; a second check valve in the passage in the reference tube, the check valves being unidirectional and permitting flow only toward the tubing; the mass of the reference tube biasing itself against motion toward the tubing when the plunger is suspended by the tubing, whereby with an opening of the passage in the reference tube located in the sand to be pumped, the tubing may be reciprocated to move the plunger and provide a pumping action in the chamber that unidirectionally pumps a suspension of sand in liquid into the tubing and to the surface; an axially extending extension of the tubing disposed outside the reference tube which is rigidly connected relative to the plunger, and adjacent to the outside of the reference tube; and interfering shoulder means on said extension and on said reference tube which abut one another in one relative axial position thereof so as to preveNt further separating sliding movement of the reference tube and the plunger before the sliding seal leaves sealing contact between the inner wall of the reference tube and the outer wall of the plunger, whereby upon lifting the reference tube by the tubing, the lifting force is exerted on the reference tube through the said interfering shoulder means in abutment without axial contact against the sliding seal.

Claim 8

A sand pump system according to claim 5 in which a bit is attached to the end of the reference tube away from the plunger in order to facilitate the penetration of the reference tube into the material to be pumped.

Claim 9

A sand pump system according to claim 5 in which the shoulder means on the reference tube is an annular ring, and in which the extension of the tubing is a cylindrical member, the inwardly overhanging shoulder being a ring attached thereto.

Claim 10

A sand pump system according to claim 7 in which a bit is attached to the end of the reference tube removed from the plunger in order to facilitate the penetration of the reference tube into the material to be pumped.