Patent ID: 7762333

Claim:
A ported sub comprising: a tubular body including a wall and ends formed for installation in a wellbore tubular string; a first port through the wall; a second port through the wall; a first hydraulically openable sliding sleeve for controlling the open and closed condition of the first port; a second hydraulically openable sliding sleeve for controlling the open and closed condition of the second port; a first pressure release connection for securing the first hydraulically openable sliding sleeve in a position on the tubular body and being releasable by application of a selected hydraulic pressure to the first hydraulically openable sliding sleeve; and a second pressure release connection for securing the second hydraulically openable sliding sleeve in a position on the tubular body and being releasable by application of hydraulic pressure at least substantially similar to the selected hydraulic pressure to the first hydraulically openable sliding sleeve, the first pressure release connection including a first type of pressure release mechanism and the second pressure release connection including a second type of pressure release mechanism different than the first type of pressure release mechanism.