Abstract: A skinned rotor 201 or skinned stator 305 of a progressive cavity apparatus is described. A rotor 201 can be skinned by threading a sleeve 210 with a profiled helical outer 212 and profiled helical inner 214 surface onto a core 202 with a profiled helical outer surface 204. A rotor (1301, 1401) can also be skinned by inserting a non-helical core (1302, 1402) into a non-helical longitudinal bore (1314, 1414) of a sleeve (1310, 1410) with a profiled helical outer surface (1312, 1412). A stator 305 can be skinned by threading a tubular liner 310 with profiled helical inner 314 and profiled helical outer 312 surfaces into a profiled helical bore 308 of a tube 306. A stator (2405, 2505) can also be skinned by inserting a tubular liner (2410, 2510) with a non-helical outer surface (2412, 2512) into a non-helical bore (2408, 2508) of a tube (2406, 2506).

Abstract: A Moineau style stator includes a helical reinforcement component that provides an internal helical cavity. A resilient liner is deployed on an inner surface of the helical reinforcement component. The helical reinforcement component includes a solder or braze material and is typically metallurgically bonded to an inner wall of a stator tube. In exemplary embodiments, the helical reinforcement component includes a composite mixture of solder and aggregate. Exemplary embodiments of this invention address the heat build up and subsequent elastomer breakdown in the lobes of prior arts stators by providing a helical reinforcement component. Solder reinforced stators tend to be less expensive to fabricate than reinforced stators of the prior art.

Abstract: A method to control borehole fluid flow includes detecting a drilling condition and operating at least one valve in the drill string to place an exterior of the drill string in fluid communication with an interior of the drill string in response to detecting the drilling condition.

Abstract: Systems and methods for drilling a multilateral well using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a multilateral well includes drilling and casing a mother wellbore, installing a multilateral junction, drilling and casing a first lateral well from the multilateral junction, and drilling a second lateral well from the multilateral junction using magnetic ranging while drilling such that the second lateral well has a controlled relationship relative to the first lateral well. The first and second lateral wells may form a SAGD well pair, in which case the first lateral well may be a producer well and the second lateral well may be an injector well.

Abstract: A system and method for communicating with a downhole tool is disclosed. In one embodiment, a telemetry system for communicating with a downhole tool in a wellbore includes a first electrode. A modulated electric current flows from the first electrode through a formation to the downhole tool. The telemetry system also includes a downlink box, which provides the modulated electric current to the first electrode. The downhole tool comprises a sensor unit, which detects the modulated electric current. The telemetry system includes a second electrode that allows the modulated electric current to return to the downlink box. The telemetry system also includes an uplink telemetry, wherein the uplink telemetry does not comprise electromagnetic telemetry. In some embodiments, the downlink may be operated while mud pumps are turned off. The downlink may also be operated while the downhole tool is sending uplink telemetry by a method other than electromagnetic current.