Abstract: Embodiments of a sleeve assembly, used for stimulating multiple stages in a completion string has a lower shifting sleeve and an upper shifting sleeve and stimulation ports formed therebetween. The sleeves are caused to shift by progressively larger objects pumped through a bore of the completion string and engaging seats formed thereon. The seat on the lower sleeve is a releasable seat. When shifted the lower sleeve opens the stimulation ports. The seat on the upper sleeve is sized to accept the same size object as is required to engage and shift the lower sleeve on the stage uphole therefrom to close the ports. Thereby, stimulation ports are opened and closed without increasing a number of objects required to stimulate the wellbore. Further, as the ports at each stage below the stage being stimulated are closed, the objects are not required to isolate the bore therebelow.

Abstract: A flow-actuated pressure equalization valve, for use with a downhole tool such as a treatment tool, for use in stimulating a subterranean formation. The equalization valve allows the pressure of treatment fluid above and below an isolation device to be equalized so the treatment tool can be moved. The valve can be closed when fluid flow exceeds a certain threshold and the treatment tool is set in the wellbore. While running in or pulling out of hole, the valve will not close regardless of the rate of fluid flow. The valve can be opened by stopping fluid flow and then bleeding off pressure above the isolation device, or by pulling up on the treatment tool.

Abstract: Embodiments of a sleeve assembly, used for stimulating multiple stages in a completion string has a lower shifting sleeve and an upper shifting sleeve and stimulation ports formed therebetween. The sleeves are caused to shift by progressively larger objects pumped through a bore of the completion string and engaging seats formed thereon. The seat on the lower sleeve is a releasable seat. When shifted the lower sleeve opens the stimulation ports. The seat on the upper sleeve is sized to accept the same size object as is required to engage and shift the lower sleeve on the stage uphole therefrom to close the ports. Thereby, stimulation ports are opened and closed without increasing a number of objects required to stimulate the wellbore. Further, as the ports at each stage below the stage being stimulated are closed, the objects are not required to isolate the bore therebelow.

Abstract: A flow-actuated pressure equalization valve, for use with a downhole tool such as a treatment tool, for use in stimulating a subterranean formation. The equalization valve allows the pressure of treatment fluid above and below an isolation device to be equalized so the treatment tool can be moved. The valve can be closed when fluid flow exceeds a certain threshold and the treatment tool is set in the wellbore. While running in or pulling out of hole, the valve will not close regardless of the rate of fluid flow. The valve can be opened by stopping fluid flow and then bleeding off pressure above the isolation device, or by pulling up on the treatment tool.