초록 ▼

An electro-pneumatic or electro-hydraulic safety system for shutting in a well or the like in the event of unusual pressure conditions in the production line of the well. The safety system includes a pressure transducer (30) which senses the flowline pressure and provides a corresponding electrical

An electro-pneumatic or electro-hydraulic safety system for shutting in a well or the like in the event of unusual pressure conditions in the production line of the well. The safety system includes a pressure transducer (30) which senses the flowline pressure and provides a corresponding electrical signal to a digital controller (34). When the signal applied to the controller is outside of a preset range defined between low and high settings of the controller, a control circuit deenergizes a solenoid valve which bleeds fluid from a fluid actuator in order to close a surface safety valve (10). Once the safety valve has closed, the controller is latched out of service and must be manually reset before the safety valve can be opened. For protection of a subsurface safety valve (155), the safety system provides a time delay between opening of the subsurface valve and opening of the surface valve and also between closing of the surface valve and closing of the subsurface valve.

대표청구항 ▼

In a safety system for a fluid flowline having a safety valve movable between open and closed positions to respectively open and close the flowline, the improvement comprising: pressure transducer means for sensing the fluid pressure in the flowline and providing an electrical signal indicative of t

In a safety system for a fluid flowline having a safety valve movable between open and closed positions to respectively open and close the flowline, the improvement comprising: pressure transducer means for sensing the fluid pressure in the flowline and providing an electrical signal indicative of the sensed fluid pressure; electrical control means having a low setting corresponding to a preselected low pressure level in the flowline and a high setting corresponding to a preselected high pressure level in the flowline, said control means receiving the electrical signal from said transducer means and detecting when said signal is within a predetermined range defined between said low setting and said high setting; valve actuator means for maintaining said safety valve in the open position when the signal detected by said control means is within said predetermined range and for moving the safety valve to the close position when the signal detected by said control means is outside of said predetermined range; means for maintaining said safety valve in the closed position when the signal provided by said transducer means returns to said predetermined range after having been detected outside of said predetermined range; manually operated means to override said means for maintaining said safety valve in the closed position for reopening said safety valve; and manually operated shutdown means effective to close said safety valve independently of said electrical control means.