Johannes Liljenhjerte


Johannes Liljenhjerte


Project title: Extended reach interventions

Project description:
When very long pipes/rods are subjected to a significant compressive load, instabilities can occur in the form of buckling. A phenomenon that can be observed by placing a long slender ruler vertically on a table and then press down its top edge until it starts bending.

This project is focusing on the oil and gas industry where kilometers long coiled tubings (CT) are injected into oil wells (of length up to 12km) for various operations such as removing scales or releasing chemicals. A build-up of compressive forces form due to friction between the CT and well casing. This build-up of compressive forces can initiate different buckling modes along the length of the tubes that eventually end up in a helical shape on the inside of the well. When this happens, friction between the tube and well increases to an extent where the tube locks up inside the well and thus can reach no further.

In this project, a novel solution to reduce friction and provide increased structural integrity for the tube is proposed. The desired properties and viability of the solution is investigated computationally and later experimentally before introducing it in the field.

Instabilities in pipes/rods appear across various length scales and industries, thus the investigation can find its usefulness in other contexts as well, for example when inserting catheters into the body, jamming nanorods into confined channels or DNA packing inside viral capsules.

Supervisor: Assoc. Prof. Jens Vinge Nygaard

ID: 129318628