A Novel Technique for Removing Wax Deposition in the Production System Using Thermochemical Fluids

Abstract

In the petroleum industry, deposition of hydrocarbon wax is one the critical problems. Wax can deposit and accumulate inside the well completion, surface facilities and transportation pipelines. Wax deposition can lead to significant pressure drop in the production system and may result in stopping the hydrocarbon production. Several treatments are used to remove the deposited wax and improve the hydrocarbon flow. This paper presents a new and cost-effective technique for removing the wax deposition from the production system. In this work, inexpensive and environmentally-friendly fluids have been used for wax removal. Chemicals that able to generate heat and pressure at certain condition were used. In this study, thermochemical fluids were utilized to remove the accumulate wax in the production tubing. Actual wax from Arabian oil field was used to mimic the real condition of wax deposition. Thermochemical solutions that consist of two chemical reagents were used to remove the accumulated wax in a production tubing. The used chemical can react at certain condition and generate significant amount of heat and pressure. Temperature up to 500°F and pressure up to 2000 psi can be in-situ generated due to the thermochemical reaction. The chemical reaction can be triggered using acetic acid as an activating agent, to reduce the operational time for wax removal. The results showed that, more than 95% of the deposited wax can be removed using thermochemical solutions. The in-situ generated heat is able to liquefy the precipitated wax, then, the induced pressure due to the chemical reaction can flush the wax out of the production tubing. The used chemicals did not result in any damage in the pipeline, no corrosion or precipitation was observed in the production tubing. Also, the generated pressure due to thermochemical treatment did not reduce the pipe integrity, no pipe enlargement or damage was induced in the treated samples. This study presents a novel and high-performance treatment for wax removal using thermochemical fluids. The used chemicals can remove the wax from production tubing, surface facilities, and transportation pipelines; without affecting the integrity of the production system. The thermochemical fluids can be used at harsh situation of high temperature and high salinity condition. The obtained results show that there is a good potential for field application of this work in the next few months.