EXECUTIVE SUMMARY

1.1This document describes anode requirement calculations for galvanic anodes that will be used as supplement protection of casings on projected HP gaslines in TCO Drilling Base.

1.2 HP gasline with diameter of 114mm comprises of two joints, one of which is 6,3m from the tie-in point to the shut-off valve and 155m from the shut-off valve to the AGDS;HP gasline – crossings 1 to 3.

1.3 Above-ground sections of pipelines and valves are protected from outdoor corrosion by paint coating with thickness not less than 0.2 mm, applied over the degreased surface cleaned from rust and scale according to SNiP RoK of 2.01-19-2004. Underground sections of pipelines covered by heavy type insulation according to GOST of 9.602-2005 on the basis of adhesive PUF (polyurethane foam) coatings. Insulation design: is the primer “Primer” NC -50 according to TU 5775-001-01297859-95-1 layer; adhesive polythene tape «Polylene» according to TU 2245-003-01297859-99-2 layers; outer wrapper is polyethylene tape «Polylene-OB» according to TU 2245-004-01297859-99-1 layer. Isolation kit is provided on block valve station aboveground.

1.4 How and for how long the short section of 4” HP pipeline,located between the block valve tie-in point and the existing steel construction U/G 8” (200 mm) will be protected. These recommendations shall be issued by the TCO Operations service

1.5 Although the gasline is located within TCO Industrial Base area it is used to supply gas to consumers rather than participate in gas production/processing process. Therefore CP parameters calculation has been made on the basis of the calculation methods described in RD 153-39.4-091-01