Halliburton Energy Services, Inc.

University of Minnesota

Ganesh Ramakrishnan

Zhijie Sun

Ketan Chimanlal Bhaidasna

Emmanuel Detournay

Kaixiao Tian

The disclosure provides a solution for monitoring stick-slip vibrations without using any surface torque measurements. Instead, the disclosure provides a method to monitor stick-slip vibrations based on rotational speed. A stick-slip monitor, a top drive controller and a method of operating a drill string are provided herein that use rotational speed for monitoring stick-slip vibrations. In one example, the method of operating a drill string includes: (1) performing a frequency domain analysis of an RPM signal associated with a top drive that is used to rotate a drill string, and (2) determining a presence of torsional oscillations of the drill string based on the frequency domain analysis of the RPM signal.

Monitoring drilling vibrations based on rotational speed

Systems, methods, and computer-readable media are provided for simulating the coupled axial/torsional dynamics of drilling systems. An example method can include calculating a profile of a bit including cutters, the profile including a cutter layout representing cutter faces of the cutters; based on the profile of the bit, determining cutter interactions between cutters, a cutter interaction being determined when at least two cutters interact with a same surface portion; approximating a cutter geometry of each cutter using polygon approximation; based on the cutter interactions and approximated cutter geometry of each cutter, calculating an engagement surface for each cutter using polygon approximation; and based on geometric parameters associated with the engagement surface for each cutter, simulating reaction forces on the bit at a plurality of time steps corresponding to constant increments of an angular position of the bit during each revolution of the bit, the reaction forces including weight-on-bit and torque-on-bit.

Fast algorithm to simulate the response of PDC bits

The disclosure addresses mitigating stick-slip in drilling systems. In one example, a method of operating a drill string is disclosed for stick-slip mitigation. The method can include: 1) monitoring operation of a drill string, wherein the drill string is rotated via a top drive that is controlled by a speed controller, and (2) changing the value of at least one speed controller parameter of the speed controller in response to torsional oscillations of the drill string during the operation, wherein the value is based on a stability model for the drill string. A stick-slip mitigation advisor for drilling systems is also disclosed herein.

Growing community of inventors

Houston, TX, United States of America

Ganesh Ramakrishnan