Depth activated downhole adjustable bend assemblies

A downhole mud motor positionable in a wellbore, comprising:

• a driveshaft housing;
• a driveshaft rotatably disposed in the driveshaft housing;
• a bearing mandrel coupled to the driveshaft;
• a bend adjustment assembly comprising an offset housing and an adjustment mandrel having a first relative angular orientation associated with a first configuration of the bend adjustment assembly and a second relative angular orientation associated with a second configuration of the bend adjustment assembly;
• wherein the first configuration of the bend adjustment assembly provides a first deflection angle between a longitudinal axis of the driveshaft housing and a longitudinal axis of the bearing mandrel, and the second configuration of the bend adjustment assembly provides a second deflection angle between the longitudinal axis of the driveshaft housing and the longitudinal axis of the bearing mandrel that is different from the first deflection angle, and wherein the bend adjustment assembly is configured to shift between the first configuration and the second configuration when positioned in the wellbore;
• and
• a locking assembly comprising a locking piston configured to lock the offset housing and the adjustment mandrel in the first relative angular orientation when in a first position, and to unlock the offset housing and the adjustment mandrel from the first relative angular orientation when in a second position that is spaced from the first position whereby the offset housing and the adjustment mandrel are shiftable from the first relative angular orientation to the second relative angular orientation.

A downhole mud motor positionable in a wellbore, comprising:

• a driveshaft housing;
• a driveshaft rotatably disposed in the driveshaft housing;
• a bearing mandrel coupled to the driveshaft;
• a bend adjustment assembly comprising an offset housing and an adjustment mandrel having a first axial position associated with a first configuration of the bend adjustment assembly and a second axial position, spaced from the first axial position, and associated with a second configuration of the bend adjustment assembly;
• wherein the first configuration of the bend adjustment assembly provides a first deflection angle between a longitudinal axis of the driveshaft housing and a longitudinal axis of the bearing mandrel, and the second configuration of the bend adjustment assembly provides a second deflection angle between the longitudinal axis of the driveshaft housing and the longitudinal axis of the bearing mandrel that is different from the first deflection angle, and wherein the bend adjustment assembly is configured to shift between the first configuration and the second configuration when positioned in the wellbore;
• and
• a locking assembly comprising a locking piston configured to lock the adjustment mandrel in the first axial position when in a first position, and to unlock the adjustment mandrel from the first axial position when in a second position that is spaced from the first position whereby the adjustment mandrel is shiftable from the first axial position to the second axial position.