ECONOMIC EFFICIENCY OF VACUUM ANCHOR DEVICES APPLICATION FOR FIXING SUBSURFACE PIPELINE IN SOFT SOIL CONDITION

Abstract

Background Subsurface pipelines operating experience in swamps and the flooded area prove that water force (buoyancy in water) is a key factor, which causes pipeline stability loss. Under this force, steel pipeline shell receives larger movements in water-saturated soils, which leads to sharp increase in tension in a pipeline wall and to decrease in a capacity of the pipeline. That is why the providing of steady subsurface pipeline design position in a soft soil condition is a recent problem for Russian oil and gas industry. The main objectives are new materials and designs using for fixing pipelines on design marks, material carrying capacity decreasing, construction cost and cargo transportation decreasing, building speed increasing. Aims and Objectives The purpose of the article is an economic efficiency analysis of vacuum anchor devices application for fixing subsurface pipeline in a soft soil condition. The main contents of an economic analysis are: o an estimated cost calculation of pipeline construction with application of the covering type reinforced concrete weighting compounds, the ring type reinforced concrete weighting compounds, the screw anchor devices, the vacuum anchor devices; o a calculation of net present value, profitability index, internal rate of return, pay-back period. Methods А comparative analysis was used as the main method. The economic efficiency determination is estimate by comparing theу following indicators: net present value, profitability index, internal rate of return, pay-back period. Results It is defined that pipeline anchoring by vacuum anchor device is economically expedient way to achieve stable pipeline position on design marks.