Abstract A reamer for use in a drilling string for enlarging, scraping or smoothing a well bore, and having extensible and retractable cutting members operable by the pressure of the drilling fluid circulated through the string during the drilling operation. The cutting members may include a plurality of telescopingly arranged elements movably positioned on the body of the tool for radial movement inwardly and outwardly thereof relative to window openings in the body and having seal forming means positioned to prevent leakage through the openings. The cutting members and body are formed with inwardly and downwardly sloping end faces positioned for coaction to allow the cutting members to move inwardly toward their retracted position, aided by gravity, when the internal pressure in the string is shut off, and the members are also formed with beveled external, upper end faces, positioned for engagement with irregularities in the well bore to move the members toward their retracted positions upon upward movement of the string during the removal of the same from the bore.
A well reamer comprising a tubular body adapted to be connected into a well string for rotation and lowering with the string in a well bore, and having peripherally spaced window openings, cutter members movably mounted in the window openings for radial movement to extended positions projecting outwardly from the body under the influence of the pressure of fluid in the body and to retracted positions substantially flush with the external surface of the body, said body being formed with upper and lower downwardly and inwardly sloping end faces in said window openings, and said members being formed with end surfaces shaped for coaction with said end faces to cause the members to move radially inwardly and downwardly away from said wall upon movement of said members away from said extended positions.
Claim 2
Dependent Claim
132 words
A well reamer comprising a tubular body adapted to be connected into a well string for rotation and lowering with the string in a well bore, and having peripherally spaced window openings, cutter members movably mounted in the window openings for radial movement to extended positions projecting outwardly from the body under the influence of the pressure of fluid in the body and to retracted positions substantially flush with the external surface of the body, said body being formed with upper and lower downwardly and inwardly sloping end faces in said window openings, and said members being formed with end surfaces shaped for coaction with said end faces to cause the members to move radially inwardly and downwardly away from said wall upon movement of said members away from said extended positions.
Claim 3
Dependent Claim
46 words
The well reamer as claimed in claim 1 wherein each of said members includes an inner part and an outer part detachably secured together and means on said inner part positioned for coaction with said body to limit outward movement of the member in the opening.
Claim 4
Dependent Claim
44 words
The well reamer as claimed in claim 1 wherein each of said members includes telescopingly arranged parts slidable relative to each other radially of the body and means on said parts positioned for coaction to limit movement of the parts toward said extended position.
Claim 5
Dependent Claim
44 words
The well reamer as claimed in claim 3 including seal forming means for each of said parts positioned for coaction with the parts and body to prevent the outflow of fluid from the body through said window openings in all positions of the members.