The article describes the result of theoretical research aimed at assessing the loads and operating conditions of a Coiled Tubing pipeline injecting water, suspended to the mining platform of Lotos Petrobaltic. For this purpose, appropriate calculation models have been developed using the Finite Element Method (FEM), taking into account the nature of the analyzed object and its loads. The analyzes were carried out for two pipes (previously operated and newly proposed) differing in geometrical and strength parameters. The research was carried out for selected directions of load on the pipeline (originating from sea waves) and various variants of attaching the suspended pipeline to the mining platform.

The article presents the analysis, project, and experimental examination of an original rigid riser for Coil Tubing Pipes. The principle of riser operation is based on the use of friction forces. The research included the FEM analysis of the designed riser, calculations of the required bolt tensions, and checking the effect of the clamping force on stress distribution in the pipeline. The results of computer simulation were verified on a specially designed test rig. The described riser design was implemented on the LOTOS Petrobaltic platform, thus eliminating the need for purchase and installation of expensive elastic risers.

The aim of the article is presenting of the preliminary results of simulations showing behaviour of paraffin deposits in submarine pipelines. The described parameters for changing the deposition of the solid paraffin phase with the flow of crude oil through the submarine pipeline inside the subsea system: subsea wellhead – platform processing system. The research includes considerations of the behaviour of paraffins in the presence of the injected gas phase. Author recommends using of phenomenon as an alternative way of securing submarine pipelines operating on the Baltic Sea. This analyse informs that the paraffin’ deposit is possible to adjust of it’s thickness buy using agents other than purely chemical paraffin point temperature depressants. It is supposed here that main impact on paraffin deposition behaviour get decreasing of sediments thickness on the walls of the submarine pipeline in the analysed sections. The reservoir fluid composition used in the simulation was taken from B3 fluid PVT analysis owned by LOTOS Petrobaltic S.A. General composition was used in Leda Flow 2.5 computer analysis in courtesy of Kongsberg Company.