Failsafe control system for a safety valve having a condition sensing and chemical injection feature

• Main Authors: Miller Wade A, Jones Brett C
• Format: Patent
• Language: English
• Published: 13.06.2017
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

A control system for a Subsurface Safety Valve (SSSV), includes an actuating piston mounted in a housing with at least one seal and connected to the SSSV. The actuating piston having a first end and a second end, the first end in fluid communication with a control line; a primary pressure reservoir in fluid communication with the second end of the actuating piston, the reservoir configured to contain a fluid under an amount of pressure selected to act against a prospective hydrostatic pressure expected in the control line based upon the selected position of the control system in a downhole environment. An equalizing piston in fluid communication with both the control line and with the second end of the actuating piston, the equalizing piston remaining in a closed position during shifting of the actuating piston with pressure applied or removed from the control line, the equalizing piston movable to an open position upon a control system failure that reduces pressure in the primary reservoir to below a threshold value; and a condition sensing and chemical injection assembly in fluid communication with the primary reservoir. A method for operating a control system for a Subsurface Safety Valve (SSSV).