Well P&A Tubing Compaction Method Evaluation and Modelling

Abstract

The number of aged fields in the North Sea is increasing, and in few years, and there will be a significant increase in number of wells that need to be permanently plugged and due to low oil prices and other reasons, there is a push from the industry to reduce the cost of P&A operations as much as possible, and using rig-less equipment for P&A has proven to be a reliable alternative to drilling rigs, but this solution requires the development of new technologies to overcome the challenges that come up with it. The presence of tubing in the area where the permeant plug should be set is still a thorny issue for P&A rig-less operation for many reasons. Recently there are many approaches for removing tubing in place without pulling it to surface, one of these alternative ideas is downhole tubing disposal (DHTD). The main scope of this thesis is to give an insight into DHTD method, its advantages and the challenges to translate this idea into practice. In this work as well, different approaches are incorporated to estimate the required tubing crushing force, including FEM, analytical estimation and experimental work. Results are reported for an analytical estimation and FEM (ABAQUS) analysis of a slotted tubular subjected to compression axial load. The results showed different kinds of correlations with experimental test data. On the other hand, they showed that FEM is a powerful method to solve this kind of problems.