Apparatus for removal of milling debris

• US 6,276,452 B1
• Filed: 11/05/1999
• Issued: 08/21/2001
• Est. Priority Date: 03/11/1998
• Status: Expired due to Term

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Cassel, Terry Edgar, Davis, John Phillip
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US09/434,665
• Time in Patent Office: 655 Days
• Field of Search: 166/55.1, 166/55.6, 166/99, 166/105.1, 166/105.4, 166/107, 166/158, 166/169, 166/222, 166/298, 166/311, 166/312, 166/376, 175/308, 175/312, 175/314
• US Class Current: 166/298
• CPC Class Codes: E21B 21/002 Down-hole drilling fluid separation systems containers comprising collecting means with a strainer E21B27/005; subsoil filtering E21B43/02; down-hole production separators E21B43/38
• CPC Class Codes: E21B 27/005 Collecting means with a strainer
• CPC Class Codes: E21B 29/00 Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
• CPC Class Codes: E21B 37/00 Methods or apparatus for cleaning boreholes or wells E21B21/00 takes precedence

Abstract

An apparatus and method for drawing small milling debris into a combination milling and debris retrieval tool, during the performance of the milling operation. A milling tool has a fluid intake port near its lower end, where debris-laden fluid is drawn into the milling tool and subsequently into a separator section. The separator section has a debris deflection tube and a screen for separating the debris from the fluid. Fluid is drawn into the tool by either a set of eductor nozzles or a downhole motor and pump.

Claims

1. An apparatus for removing milling debris from a well bore during milling operations, said apparatus comprising:

a rotatable tubular separator housing, said separator housing being connectable to a lower end of a work string;

a milling tool connectable to a lower end of said separator housing;

at least one fluid ejection port through a wall of said separator housing, said at least one ejection port being positioned and adapted to eject fluid to an area of a well bore adjacent said separator housing;

at least one intake port on said milling tool, said at least one intake port being positioned and adapted to take in debris-laden fluid from an area of a well bore adjacent said milling tool;

a debris deflector tube within said separator housing, said debris deflector tube being in fluid flow communication between said at least one intake port in said milling tool and said at least one fluid ejection port; and

a downhole pump positioned and adapted to pump debris-laden fluid from said at least one intake port, through said debris deflector tube, to said at least one fluid ejection port.

2. An apparatus as recited in claim 1, wherein said debris deflector tube comprises:

an inlet connected in fluid flow communication with said at least one intake port in said milling tool;

an end cap on said deflector tube for deflecting debris; and

at least one side port on said deflector tube for directing debris-laden fluid to an annular space between said deflector tube and said separator housing.

3. An apparatus as recited in claim 1, further comprising a downhole motor connected to the workstring, said downhole pump being driven by said downhole motor.

4. An apparatus as recited in claim 3, further comprising a surface pump at the well site for pumping fluid downhole through the workstring to said downhole motor, wherein said downhole motor is a fluid driven motor.

5. An apparatus as recited in claim 1, further comprising a screen within said separator housing, an inlet side of said screen being positioned to receive fluid from said deflector tube, an outlet side of said screen being in fluid flow communication with said at least one ejection port.

6. An apparatus for removing milling debris from a well bore during milling operations, said apparatus comprising:

a tubular separator housing, said separator housing being connectable to a lower end of a rotating work string;

a milling tool connectable to a lower end of said separator housing;

at least one fluid ejection port through a wall of said separator housing, said at least one ejection port being positioned and adapted to eject fluid to an area of a well bore adjacent said separator housing;

at least one intake port on said milling tool, said at least one intake port being positioned and adapted to take in debris-laden fluid from an area of a well bore adjacent said milling tool;

a screen within said separator housing, an inlet side of said screen being positioned to receive fluid taken in by said at least one intake port, an outlet side of said screen being in fluid flow communication with said at least one ejection port;

a debris deflector within said separator housing between said at least one intake port in said milling tool and said screen;

a downhole motor connected to said separator housing;

a surface pump at the well site for pumping fluid downhole through the workstring to said downhole motor, wherein said downhole motor is a fluid driven motor; and

a downhole pump driven by said downhole motor, said downhole pump being positioned and adapted to pump debris-laden fluid from said at least one intake port in said milling tool, through said debris deflector, to said inlet side of said screen;

wherein said debris deflector comprises;

a deflector tube within said separator housing;

an inlet on said deflector tube connected in fluid flow communication with said at least one intake port in said milling tool;

an end cap on said deflector tube for deflecting debris; and

at least one side port on said deflector tube for directing debris-laden fluid to an annular space between said deflector tube and said separator housing.

7. A method for removing milling debris from a well bore during milling operations, said method comprising:

providing a separator housing connected to a lower end of a work string, and a milling tool connected to a lower end of said separator housing, said separator housing containing a fluid ejection port, a downhole pump, and a debris deflector tube;

rotating said separator housing and said milling tool with said workstring to perform a downhole milling operation;

ejecting fluid with said downhole pump through said fluid ejection port to an area of a well bore adjacent said separator housing to entrain milling debris created by said milling tool;

drawing debris-laden fluid into an intake port on said milling tool, from an area of a well bore adjacent said milling tool, with said downhole pump; and

conducting said debris-laden fluid through said debris deflector tube within said separator housing and back to said fluid ejection port.