SURGE ANALYSIS FOR SUBSEA PIPELINE

iFluids Engineering has conducted Surge Analysis for subsea pipeline for Petrocil Engineers & Consultants Pvt Ltd.

Vedanta Limited (VL) installed crude oil tanks at Bhogat terminal to export neat crude oil to coastal refineries. A Single Point Mooring (SPM) is installed for marine tanker loading near Salaya in Gujarat. It is installed to export Mangala crude oil into heated tankers of 120000 tonnes deadweight (Aframax type). A crude oil storage and export pumping terminal is installed at Bhogat, approximately 8 km from the Landfall point. There is a significant amount of wax in the crude oil from Mangala. It is expected to gel at temperatures below 50°C.

The export pipelines from Bhogat to SPM are being flushed by flushing oil (currently Diesel) using the export pump /export booster pumps. The flushing oil is being imported at Bhogat Terminal through the same marine export lines.

To optimize OPEX, it is suggested to replace present flushing oil with stabilized Gas Condensate transported from Raageshwari Gas Terminal (RGT) to Bhogat through road tankers.

Scope

The scope of this document is to perform steady state hydraulic study and surge analysis for the export pipeline during flushing operation with condensate as flushing fluid to establish the adequacy.

Objective

The purpose of this study is,

  1. To develop steady state model and perform Hydraulic study of the existing Export pipeline and confirm the adequacy for the light Gas Condensate as handling fluid.
  2. Perform Transient State Analysis and estimation of surge pressure for Export Pipeline due to closure of XV/XSV and closure of valves during emergency shutdown and Pump Trip during pipeline flushing operation using condensate as flushing oil.
  3. To provide the surge mitigation measures, when the surge pressure exceeds the allowable surge pressure.