Abaco Drilling Technologies LLC

Basintek, LLC

Timothy Mark Miller

Peter Thomas Cariveau

Jing Lu

Jorge A Gonzalez

Jonathan Jared McCalip

Minor diameter enlargements are engineered into a stator in a positive displacement motor (PDM) power section to relieve stator stress concentrations at the lower (downhole) end of the power section in the presence of rotor tilt. The minor diameter enlargements may include one or more contoured stress relief lengths according to various tapered or step functions.

Rotor tilt compensation in PDM stators

Tapered stator designs are engineered in a positive displacement motor (PDM) power section to relieve stator stress concentrations at the lower (downhole) end of the power section in the presence of rotor tilt. A contoured stress relief is provided in the stator to compensate for rotor tilt, where the taper is preferably more aggressive at the lower end of the stator near the bit.

High modulus liners in PDM stators with diameter reliefs compensating for rotor tilt

Tapered stator designs are engineered in a positive displacement motor (PDM) power section to relieve stator stress concentrations at the lower (downhole) end of the power section in the presence of rotor tilt. A contoured stress relief (i.e. a taper) is provided in the stator to compensate for rotor tilt, where the taper is preferably more aggressive at the lower end of the stator near the bit.

Positive displacement motor stators with diameter reliefs compensating for rotor tilt

An adapted elastomer compound, in which the adaptation is based at least in part on load performance data of a rotor/stator test coupon as evaluated on a test apparatus. The test coupon's stator section includes the original elastomer compound before adaptation thereof. The test apparatus includes a motor, a brake, and at least one sensor disposed to evaluate load performance data of the test coupon. The load performance data is the product of the process comprising the steps of: (a) rotating either the rotor section or the stator section on the test apparatus, wherein such rotation section actuates corresponding rotation of the other of the rotor section and the stator section; (b) applying a braking torque to the actuated rotor section or stator section; and (c) responsive to step (b), evaluating load performance data of the test coupon.

Tested products of PDM performance testing device

Tapered stators in positive displacement motors remediating effects of rotor tilt

A method for evaluating load performance of a rotor/stator test coupon tested within a sealable test chamber containing test fluid. The test coupon preferably includes at least a partial length of a PDM stage. Alternatively, the test coupon may include a splined rotor/stator. The method includes rotating either the rotor section or the stator section in order to actuate corresponding rotation of the other of the rotor section and the stator section. Non-linear torque in the form of an acceleration torque and/or a braking torque may be applied to either the rotor section or the stator section. Downhole stall conditions may be simulated by selectively engaging and disengaging a second motor and flywheel to vary rotational torque applied to the test coupon. Load performance of the test coupon may be evaluated over time in such simulated stall conditions.

Stall simulator for PDM performance testing device

A method for evaluating load performance of a rotor/stator test coupon, advantageously within a sealable test chamber comprising test fluid. In some embodiments, the test coupon comprises at least a partial length of a PDM stage, and in others the test coupon comprises a splined rotor/stator. The method includes rotating either the rotor section or the stator section, wherein such rotation actuates corresponding rotation of the other of the rotor section and the stator section. A braking torque is applied to the actuated one of the rotor section and the stator section such that load performance of the test coupon may be evaluated. Embodiments include selectively applying non-linear torque to load the test coupon, and evaluating load performance of the test coupon with reference to relative angular positions of the rotor section and the stator section over time.

Enhanced PDM performance testing device

A method for measuring load performance of a positive displacement motor (PDM) test coupon. The test coupon comprises a partial length of a PDM stage and is received inside a sealable test chamber. In some embodiments, the test coupon may be cut from a failed PDM stage. The test chamber is filled with test fluid. In some embodiments, the test fluid may be drilling fluid sampled from a live well. Rotation of the rotor on the test coupon actuates rotation of the stator. A braking torque is applied to the stator rotation, enabling evaluation of, for example, fatigue load performance of test coupon. Additional embodiments comprise the rotor axis and the stator axis being offset in order to simulate rotor/stator eccentricity in a full size PDM stage.

PDM performance simulation and testing

A method for measuring load performance of a positive displacement motor (PDM) test coupon. The test coupon includes a partial length of a PDM stage and is received inside a sealable test chamber. In some embodiments, the test coupon may be cut from a failed PDM stage. The test chamber is filled with test fluid. In some embodiments, the test fluid may be drilling fluid sampled from a live well. Rotation of the rotor on the test coupon actuates rotation of the stator. A braking torque is applied to the stator rotation, enabling evaluation of, for example, fatigue load performance of test coupon. Additional embodiments comprise the rotor axis and the stator axis being offset in order to simulate rotor/stator eccentricity in a full size PDM stage.

Growing community of inventors

Klein, TX, United States of America

Timothy Mark Miller