Abstract: A multi-layer downhole drilling tool designed for drilling a wellbore including a plurality of formations is disclosed. The drilling tool includes a bit body including a rotational axis extending therethrough. A plurality of blades are disposed on exterior portions of the bit body. A plurality of primary cutting elements and a plurality of back-up cutting elements are disposed on exterior portions of the plurality of blades. The back-up cutting elements are track set with corresponding primary cutting elements, and each back-up cutting element is disposed on a different blade than the corresponding primary cutting element.

Abstract: An extended life seal is incorporated into a drill bit used for drilling a wellbore. The drill bit can include a seal surface, a seal which engages the seal surface, and a groove which compresses the seal greater on opposite axial sides than at a central portion of the seal. The drill bit may include the seal having a cylindrical surface which engages the seal surface, and another cylindrical surface opposite the first surface, and the groove having a third cylindrical surface which engages the second surface, and wherein the groove simultaneously biases the seal toward the seal surface on opposite axial sides of the third surface. The drill bit may include the seal having right cylindrical shaped inner and outer surfaces, and a contact pressure between the seal surface and the seal being greater at each opposite side of the seal than at a central portion of the seal.

Abstract: A multi-layer downhole drilling tool designed for drilling a wellbore including a plurality of formations is disclosed. The drilling tool includes a bit body including a rotational axis extending therethrough. A plurality of blades are disposed on exterior portions of the bit body. A plurality of primary cutting elements and a plurality of back-up cutting elements are disposed on exterior portions of the plurality of blades. The back-up cutting elements are track set with corresponding primary cutting elements, and each back-up cutting element is disposed on a different blade than the corresponding primary cutting element.

Abstract: Systems and methods are provided for swellable material activation and monitoring in a subterranean well. A sensor system for use in a subterranean well includes a swellable material, and at least one sensor which is displaced to a wellbore surface in response to swelling of the swellable material. Another sensor system includes a sensor which detects swelling of a swellable material. A swellable well tool system includes a base pipe, a swellable material on an exterior of the base pipe, and eccentric weighting for inducing rotation of the swellable material about a longitudinal axis of the base pipe.