Concept and Framework to Asses the Energy Losses Along the Drillstring

Research output: ResearchMaster's Thesis

Abstract

For the time being the O&G industry relies on simple procedures and models to get an idea if the way it operates is to some extend reasonable respectively efficient or not. The application of an energy balance that could help to evaluate the efficiency of the total drilling system is for now constrained as it is not account for all the energy consuming physical processes going on downhole along the entire drillstring. Missing knowledge about wellbore geometries, string and borehole interaction and drilling dynamics along the whole string limits the informative value of current models. A possible approach is a breakdown of the system and the processes occurring along the drillstring and an itemization of the single processes helps to have a proper discussion. Based on the lack of appropriate models describing each process sufficiently it is further suggested to analyze the system with the help of additional data gained trough measurements along the whole drillstring becoming doable with new telemetry systems. Reasonable predictions where such downhole measurement subs may be positioned along pre defined vertical-, tangential- and horizontal well paths are stated based on the capabilities and resolution of different sensors deployed as well as a minimalistic torque and drag and hydraulic model conducted for the corresponding well paths. As a final result the setup of the drillstring and measurement subs are presented for each of the three suggested well profiles. The layout of the drillstring is chosen in a way to achieve the maximum resolution possible under given constrains. An optimum resolution is achieved trough a uniform allocation of multiple subs along different sections of the wellbore that is based upon the sensor with the worst resolution at the point of interest.

Details

Original languageEnglish
QualificationDipl.-Ing.
Supervisors/Advisors
Award date18 Dec 2015
StatePublished - 2015