| 摘要 |
A hydraulic control system can be used on a downhole choke and has the feature of moving a travel stop for a sliding sleeve using discrete j-slot mechanisms for selectively moving the stop in either one of two opposed directions. The valve can be incrementally opened further with pressure cycling on an opening chamber. The valve can be immediately put to the closed position with pressure on a closing chamber. After closing, the valve can assume its former open position or other selected less open positions by reconfiguring the travel stop while the valve stays in the closed position In order to achieve a higher open percent after closing, one or more pressure cycles must be applied to the open chamber after the valve is reopened to the position it was in before it was closed. |
