Selectively locking locator

A downhole tool comprising:

• a locator key disposed between a housing and a mandrel and radially extendable through a window of the housing between an engagable position and a retracted position;
• a support ring disposed between the housing and the mandrel, the support ring preventing movement of the locator key from the engagable position to the retracted position until the support ring is axially displaced relative to the mandrel;
• and
• an engagement mechanism at least partially disposed within a radial bore of the mandrel and including a c-ring, the engagement mechanism selectively engagable with the support ring in response to a first differential pressure between the interior and exterior of the mandrel, thereby selectively preventing axial displacement of the support ring relative to the mandrel and selectively preventing movement of the locator key to the retracted position.

A method for selectively preventing relative axial movement between a first tubular member and a second tubular member slidably disposed relative to the first tubular member in a downhole tool, the method comprising the steps of:

• disposing an engagement mechanism at least partially within a radial bore of the second tubular member, the engagement mechanism including a c-ring;
• applying a first differential pressure between the interior and the exterior of the second tubular member;
• and
• selectively engaging the engagement mechanism with the first tubular member in response to the first differential pressure, thereby selectively preventing axial displacement of the first tubular member relative to the second tubular member.

A method for selectively preventing passage of a locator device through a nipple profile within a wellbore comprising the steps of:

• engaging a locator key of the locator device with the nipple profile;
• providing a first differential pressure to the locator device to act on an engagement mechanism at least partially disposed within a radial bore in the sidewall of a mandrel and including a c-ring;
• and
• radially shifting the engagement mechanism to engage a support ring and prevent axial displacement of the support ring relative to the mandrel, thereby preventing retraction of the locator key from the nipple profile and preventing passage of the locator device through the nipple profile in a first direction.