Cable head with cable shear mechanism for attaching to a wireline to support oilfield equipment in a wellbore

摘要

A cable head with cable shear mechanism for attaching to a wireline to support oilfield equipment in a wellbore formed from a housing with a cable bore. The housing comprises a tapered sleeve with a tapered sleeve cable bore, a sliding bell with a sliding bell cable bore, a drive pinch cylinder, a linear biasing mechanism positioned between the tapered sleeve and the drive pinch cylinder, a plurality of shear pins disposed partially into the housing and though the drive pinch cylinder, wherein each shear pin is adapted to withstand from 100 pounds to 2000 pounds of shear load, a pair of slidable cutting segments and a pair of slidable cutting segment guides. When cable load exceeds a preset limit, the shear pins shear allowing the slidable cutting segments to be moved up the slidable cutting segment guides to impact and shear the cable.

主权项

1. A cable head with a cable shear mechanism for attaching to a wireline cable to support oilfield equipment in a wellbore, comprising:
a. a housing with a cable bore having a central axis; b. a tapered sleeve with a tapered sleeve cable bore within the housing; c. a sliding bell with a sliding bell cable bore disposed within the housing, wherein the sliding bell cable bore receives a cable end of the wireline cable and pinches together a plurality of cable strands of the cable end between the tapered sleeve and the sliding bell when the sliding bell is pulled by the wireline cable into the tapered sleeve; d. a drive pinch cylinder positioned in the housing; e. a linear biasing mechanism positioned in the housing between the tapered sleeve and the drive pinch cylinder; f. a plurality of shear pins, each shear pin disposed partially into the housing and through the drive pinch cylinder to shear pin bore holes, wherein each shear pin is adapted to withstand from 100 pounds to 2000 pounds of a shear load; g. a pair of slidable cutting segments within the housing, each slidable cutting segment having a sliding surface, each slidable cutting segment having a cutting face, wherein the pair of slidable cutting faces slide from an open non-cutting orientation to a closed cutting orientation when a cable load exceeds a shear strength of the plurality of shear pins, wherein the pair of slidable cutting segments have a pair of radially based spring mechanisms separating the pair of slidable cutting segments under static conditions prior to breaking of the plurality of shear pins; and h. a pair of slidable cutting segment guides in the housing, each slidable cutting segment guide having a sliding guide surface for interfacing in a sliding engagement with one of the slidable cutting segments sliding surfaces; and wherein when the cable load exceeds a preset limit, the plurality of shear pins shear allowing the pair of slidable cutting segments to be moved up the pair of slidable cutting segment guides to impact and shear the wireline cable aided by the linear biasing mechanism.