Annulus operated test valve

In a well annulus operated valve for drill string test tools having a ball rotatable between an open position to allow flow through the drill string for testing and a closed position to block flow through the drill string during placement and retrieval operations, wherein the improvement comprises:

• a pair of shifting linkages extending from opposite sides of said ball, said linkages being adapted to shift in opposite relative directions to open and close said ball;
• a pressure operated inner mandrel slidably engaging the first of said shifting linkages, said mandrel being movable between extended and retracted positions responsive to pressures in the well annulus, thereby shifting said first linkage to rotate said ball;
• a spring sleeve surrounding said inner mandrel and slidably engaging said second shifting linkage so that movement of said inner mandrel and first shifting linkage causes opposite relative movement of said spring sleeve and second shifting linkage;
• pressure balancing means movable between an active position responsive to pressures in the well annulus to prevent movement of said inner mandrel and a static position to allow movement of said inner mandrel;
• and
• actuating means for moving said pressure balancing means between said active and static positions.

In a well annulus operated valve for drill string test tools having a ball rotatable between an open position to allow flow through the drill string for testing and a closed position to block flow through the drill string during placement and retrieval operations, wherein the improvement comprises:

• a pair of shifting linkages extending from opposite sides of said ball, said linkages being adapted to shift in opposite relative directions to open and close said ball;
• a pressure operated inner mandrel slidably engaging the first of said shifting linkages, said mandrel being movable between extended and retracted positions responsive to pressures in the well annulus, thereby shifting said first linkage to rotate said ball;
• a spring sleeve surrounding the upper extent of said inner mandrel and slidably engaging said second shifting linkage so that movement of said inner mandrel and first shifting linkage causes opposite relative movement of said spring sleeve and second shifting linkage;
• a spring positioned about the lower extent of said inner mandrel below said spring sleeve, said spring being compressed when said inner mandrel is extended;
• pressure balancing means movable between an active position responsive to pressures in the well annulus to prevent movement of said inner mandrel and a static position to allow movement of said inner mandrel;
• and
• actuating means for moving said pressure balancing means between said active and static positions.