Controlled Vibro-Impact Drilling for Suppressing Stick-Slip Oscillations in Oilwell Drill-Strings. Self funded PhD in Engineering Ref: 3089

About the Research Project

Streatham Campus, University of Exeter, EX4 4QJ

Academic Supervisors:
Dr Yang Liu

Project description:
The Oil and Gas Industry is a key player in supplying the worlds energy needs and the methods for searching and obtaining these important hydrocarbons has been continuously progressing since is first discovery. As seismic and radioactive surveying was developed an abundance of oil reservoirs were discovered offshore around the UK in the North Sea.

Drilling in such deep conditions with long slender pipe tools and high loading introduces complex downhole conditions that are difficult to monitor and can have critical repercussions if not controlled.

This leads to the integration of computer systems to detect and manage small oscillations before they transmit up the drill-string and damage components. Also the mitigation of these vibrations improves drilling efficiency allowing for a greater rate of penetration, this is a huge benefit especially in today’s financial climate where expenses are being reduced in every possible process.

In conventional drilling the rotational energy to the drill-string is provided by the rotary table or top drive, actuated by an electrical motor. The drill-string is comprised of a series of interconnected hollow pipes leading to the what I known collectively as the bottom hole assembly. Here there is a number of stabilizers, drill collars and the drill bit. It is at the bottom end there is the majority of frictional forces interacting that causing the destructive vibrational phenomena like stick-slip, bit bounce and whirl.

Motivated by the Resonance Enhanced Drilling, this project aims to adopt the vibro-impact technique for suppressing stick-slip oscillations in drill-strings. This will be done by (1) developing a mathematical model of the vibro-impact rotary drilling; (2) investigating the influence of vibro-impact loading on stick-slip oscillations and drill-string dynamics; (3) designing a control system for modulating the vibro-impact loading; (4) building a laboratory small-scale vibro-impact rotary drilling rig; and (5) conducting experimental studies to verify the effectiveness of the proposed control system.

For more information about the project and informal enquiries, please contact the primary supervisor: Dr Yang Liu -

Information about current fees can be found here:

Information about possible funding sources can be found here:

Entry requirements

Applicants for this research project must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology.

If English is not your first language you will need to meet the English language requirements and provide proof of proficiency. Click here for more information and a list of acceptable alternative tests.

How to apply

You will be asked to submit some personal details and upload a full CV, covering letter and two academic references. Your covering letter should outline your academic interests, prior research experience and reasons for wishing to undertake this project. You may also be asked to upload verified transcripts of your most academic qualification.

If you have any general enquiries about the application process please email

Please quote reference 3089 on your application and in any correspondence about this project.


Application deadline:24th September 2018
Value:This project is self-funded
Duration of award:Not applicable
Contact: EMPS PGR Team