Method and apparatus for hydraulically controlling subsea equipment

Apparatus for remote individual control of a relatively large number of hydraulically-actuated operators using a smaller number of hydraulic lines between a surface control center and a subsea device containing said operators, said apparatus comprising:

• means for connecting said apparatus to a source of hydraulic fluid under pressure;
• a plurality of hydraulic AND-gates each having an output and a pair of inputs, said gates being arranged in rows and columns;
• a plurality of series-connected valve-pairs for conducting fluid from an input to an output when the pressure applied to a predetermined valve-pair is between a predetermined lower limit and a predetermined upper limit, said valve-pairs being segregated into first and second groups;
• first and second signal pressure lines;
• means for connecting said first signal line to said input of each of said valve-pairs in said first group;
• means for connecting said second signal line to said input of each said valve-pairs in said second group;
• means for coupling pressurized fluid from said fluid source to said first and said second signal lines;
• means for coupling the output of each of said first group of valve-pairs to a first input of each of said gates in a corresponding row;
• means for coupling the output of each of said second group of valve-pairs to a second input of each of said gates in a corresponding column;
• and
• means for coupling the output of each of said gates to a corresponding one of said subsea operators.

Apparatus for remote individual control of a relatively large number of hydraulically-actuated operators using a supply line and a pair of hydraulic signal lines between a surface control center and a subsurface device containing said operators, said apparatus comprising:

• means for connecting said apparatus to a source of hydraulic fluid pressure;
• a plurality of hydraulic AND-gates each having an output, a pressure input lead and a pair of enabling inputs, said enabling inputs operating said gate in response to signals on said enabling inputs, each of said AND-gates providing an output pressure only when a pressure is simultaneously applied to both of said enabling inputs, said gates being arranged in a matrix of rows and columns;
• first and second signal pressure lines;
• control means for coupling predetermined values of fluid pressure from said fluid source to said first and said second signal lines;
• means for applying signals from said first pressure line to a first enabling input of each of the gates in a predetermined row when the pressure in said first pressure line is within a corresponding predetermined range;
• means for applying signals from said second pressure line to a second enabling input of each of the gates in a predetermined column when the pressure in said second line is within a corresponding predetermined range;
• and
• means for coupling the output of each of said gates to a corresponding one of said operators, said plurality of AND-gates providing an output pressure to a maximum of one operator at any time in response to said signals from said first and said second pressure lines.