Thermochemical Process To Remove Sludge From Storage Tanks

Abstract

ThermoChemical Process To Remove Sludge From Storage Tanks Nelson de Oliveira Rocha; Nelson de Oliveira Rocha Petrobras Cenpes Search for other works by this author on: This Site Google Scholar Carlos Nagib Khalil; Carlos Nagib Khalil Petrobras S.A. Search for other works by this author on: This Site Google Scholar Lucia Ferreira Leite; Lucia Ferreira Leite Petrobras Search for other works by this author on: This Site Google Scholar Andre Manoel Goja Ferreira Andre Manoel Goja Ferreira Petrobras Search for other works by this author on: This Site Google Scholar Paper presented at the International Symposium on Oilfield Chemistry, Houston, Texas, U.S.A., February 2007. Paper Number: SPE-105765-MS https://doi.org/10.2118/105765-MS Published: February 28 2007 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Rocha, Nelson de Oliveira, Khalil, Carlos Nagib, Leite, Lucia Ferreira, and Andre Manoel Goja Ferreira. "ThermoChemical Process To Remove Sludge From Storage Tanks." Paper presented at the International Symposium on Oilfield Chemistry, Houston, Texas, U.S.A., February 2007. doi: https://doi.org/10.2118/105765-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Conference on Oilfield Chemistry Search Advanced Search AbstractThe periodic cleaning of the bottom of crude oil storage tanks in vessels, terminals and refineries has become a big problem for industrial maintenance, principally due to the temporary inoperability of the equipment and the high environmental impact caused by the conventional treatments used. The storage of crude oil in large tanks invariably creates a gradual deposition process of organic sediments of high molecular weight.PETROBRAS has developed a thermochemical method aimed at removing wax deposits in submersed oil pipelines, wax damage in production reservoirs and petroleum sludge removal from storage tanks.This work presents the chemical treatment performed inside an oil storage tank located onboard an oil tanker as well as the laboratory methodology for the organic deposit physical-chemical characterization, kinetics of reaction, physical simulation, treatment dimensioning and operational treatment, aimed at the removal of 800 M3 of organic deposit.The thermochemical method consists of a chemical reaction between two nitrogen salts that produce a strong exothermic chemical reaction. The heat produced by the reaction, together with the turbulence due to the generation of a large volume of nitrogen and the solvency, dispersed the initially solid compacted sludge at the bottom of the tank. The heat of the solution, estimated at 90oC, in contact with the sludge, irreversibly melted the organic fractions according to the previously studied phases diagram.The method demonstrated itself to be efficient, safe and of low cost, when compared to existing classic methods. The process financial balance showed that the cost of the oil recovered from the organic deposit paid for the investment in chemical reagents and operational facilities.IntroductionSince 1990, PETROBRAS has been performing thermochemical treatment aimed at the removal of oil sludge in storage tanks for oil and its derivatives, desalinators, separator vessels, flotators and related equipment.The oil sludge found at the bottom of storage tanks for oil and its derivates is defined as a multiphase water-oil-solid system with high stability, possessing a semi-solid physical state, produced from the gradual process of the sedimentation of heavy oil fractions, when submitted to the classic storage conditions. It appears in the form of an emulsion, varying in consistency, density, thickness and composition across the whole bottom of the tank.Inorganic