| 摘要 |
A subsurface test tree so compact in its vertical dimension that the entire tree can be positioned below the blind rams in a blowout preventer stack. When the stinger is removed the remaining valve section of the tree will be below the blind rams in any conventional blowout preventer stack. The valve operators are split, one carried by the stinger and one carried in the valve housing with the arrangement of operator and valve in the housing providing an extremely small vertical dimension. A dome charge is effective on a piston to drive a ball valve to closed position to cut a line extending through the ball valve and to provide sequential operation between the ball valve on bottom and the valve thereabove which may be a flapper valve so that the lower valve closes and the line is cut before the upper valve closes. In one form the invention includes a subsurface safety valve below the test tree operated by one of control or balance pressure fluid. |
