Apparatus and methods for pumping solids and undesirable liquids from a well bore

Claim 1

An apparatus for removing debris from a well comprising: an elongate string connectable to a source of reciprocating and rotating motion located at the surface, the string including: a vertically extending debris-receiving tubing portion having an outlet at the upper end thereof, and an inlet at the lower end thereof; a debris retaining check valve sub positioned in said elongated string below said vertically extending debris-receiving tubing portion, and including a debris retaining check valve positioned to close said inlet to said debris-receiving tubing portion; a lower downhole pump in fluid communication with the outlet of said debris-receiving tubing portion and connected to the upper end of said debris-receiving tubing portion, and including a lower pump cylinder, an apertured lower pump piston and a hollow lower pump piston rod, said lower pump piston connected by said hollow lower pump piston rod to the outlet of said debris-receiving tubing, and said lower pump cylinder retained in the string for reciprocation upwardly and downwardly around said apertured lower pump piston, and forming the upper end of said lower downhole pump; an intermediate check valve sub connected to the upper end of said lower pump cylinder, and vertically reciprocable with said cylinder, said intermediate check valve sub including a check valve preventing retrograde flow of fluid downwardly into said lower pump cylinder; an upper downhole pump connected to said intermediate check valve sub above said intermediate check valve sub in said string, and on the opposite side of said intermediate check valve sub from said lower downhole pump, said upper downhole pump including an upper pump cylinder and an apertured upper pump piston and a hollow upper pump piston rod, said apertured upper pump piston being connected by said upper pump hollow piston rod to the upper end of said intermediate check valve sub, and said upper pump cylinder being retained in the string for reciprocation upwardly and downwardly around said apertured upper pump piston, and forming the upper end of said upper downhole pump; an upper portion of said string communicating with said upper downhole pump and connectable to said surface-located source of reciprocating and rotating motion on one end, and to said upper downhole pump cylinder on the other end, said upper pump cylinder being keyed to said hollow upper pump piston rod to communicate the rotation motion of said upper portion of said string via said hollow upper pump piston rod, and via said lower pump cylinder and via said lower pump piston rod keyed to said lower pump cylinder to said debris-receiving tubing located below said upper downhole pump and below said lower downhole pump; said lower pump piston rod and lower pump piston including an internal passageway open and unobstructed from one end to the other thereof and establishing fluid communication between said lower pump cylinder and said debris retaining portion; said hollow upper pump piston rod and apertured upper pump piston including an internal passageway open and unobstructed from one end to the other and establishing fluid communication between said upper pump cylinder and, through said intermediate check valve sub, with said lower pump cylinder of said lower downhole pump; and an upper check valve sub located above said upper downhole pump and connected to said upper pump cylinder and to said upper portion of said string for permitting flow of fluid through said last-mentioned internal passageway and through said upper pump cylinder into said upper portion of said string at a location above said upper check valve sub, and to prevent fluid flow in the reverse direction.

Claim 2

An apparatus for removing debris from a well comprising: an elongate string connectable to a source of reciprocating and rotating motion located at the surface, the string including: a vertically extending debris-receiving tubing portion having an outlet at the upper end thereof, and an inlet at the lower end thereof; a debris retaining check valve sub positioned in said elongated string below said vertically extending debris-receiving tubing portion, and including a debris retaining check valve positioned to close said inlet to said debris-receiving tubing portion; a lower downhole pump in fluid communication with the outlet of said debris-receiving tubing portion and connected to the upper end of said debris-receiving tubing portion, and including a lower pump cylinder, an apertured lower pump piston and a hollow lower pump piston rod, said lower pump piston connected by said hollow lower pump piston rod to the outlet of said debris-receiving tubing, and said lower pump cylinder retained in the string for reciprocation upwardly and downwardly around said apertured lower pump piston, and forming the upper end of said lower downhole pump; an intermediate check valve sub connected to the upper end of said lower pump cylinder, and vertically reciprocable with said cylinder, said intermediate check valve sub including a check valve preventing retrograde flow of fluid downwardly into said lower pump cylinder; an upper downhole pump connected to said intermediate check valve sub above said intermediate check valve sub in said string, and on the opposite side of said intermediate check valve sub from said lower downhole pump, said upper downhole pump including an upper pump cylinder and an apertured upper pump piston and a hollow upper pump piston rod, said apertured upper pump piston being connected by said upper pump hollow piston rod to the upper end of said intermediate check valve sub, and said upper pump cylinder being retained in the string for reciprocation upwardly and downwardly around said apertured upper pump piston, and forming the upper end of said upper downhole pump; an upper portion of said string communicating with said upper downhole pump and connectable to said surface-located source of reciprocating and rotating motion on one end, and to said upper downhole pump cylinder on the other end, said upper pump cylinder being keyed to said hollow upper pump piston rod to communicate the rotation motion of said upper portion of said string via said hollow upper pump piston rod, and via said lower pump cylinder and via said lower pump piston rod keyed to said lower pump cylinder to said debris-receiving tubing located below said upper downhole pump and below said lower downhole pump; said lower pump piston rod and lower pump piston including an internal passageway open and unobstructed from one end to the other thereof and establishing fluid communication between said lower pump cylinder and said debris retaining portion; said hollow upper pump piston rod and apertured upper pump piston including an internal passageway open and unobstructed from one end to the other and establishing fluid communication between said upper pump cylinder and, through said intermediate check valve sub, with said lower pump cylinder of said lower downhole pump; and an upper check valve sub located above said upper downhole pump and connected to said upper pump cylinder and to said upper portion of said string for permitting flow of fluid through said last-mentioned internal passageway and through said upper pump cylinder into said upper portion of said string at a location above said upper check valve sub, and to prevent fluid flow in the reverse direction.