The permanent miniature bridge plug is designed to set in coiled tubing or drill collars. It is designed to withstand differential pressures of 10,000 psi at 350 ° F. In house, the bridge plug is successfully pressure tested at 7,500 psi. The bridge plug is available in four sizes: 0.750″, 0.875″, 1.25″ and 1.375″, which can be set on slickline or electric line.
The permanent miniature bridge plug has opposed, case hardened slips located above and below a tl1ree piece rubber pack-off system, manufactured out of either HSN (Highly Saturated Nitrile) or Viton. The pack-off elements are contained by rocker action metal back-up rings that eliminate extrusion of tl1e elements at high temperatures and pressures. A ratchet lock ring retains the setting force applied to the slips and pack-off to maintain a constant sealing pressure.
To assure centered setting of the small diameter plug in coiled tubing and/or drill collars, special ribbed cones direct the slips to evenly spaced positions against the pipe. Should it be necessary to remove a permanent bridge plug after setting, a milling process is recommended as the plug is constructed of mild steel and is not considered drillable.