Rod lock for ram blowout preventers

摘要

A blowout preventer to hydraulically seal a wellbore includes a housing configured to be positioned above a wellhead and to surround a drillstring, a plurality of rams positioned perpendicular to an axis of the drillstring to engage the drillstring and hydraulically isolate an annulus between the wellbore and the drillstring when in a closed position, and a roller lock positioned about a thrust rod of each ram configured to maintain the rams in the closed position.