Crude oil wax remediation using enhanced chemical formulations

Research output: ThesisMaster's Thesis

Abstract

In this thesis, a chemical approach was taken to improve the hot water treatment carried out in Aldorf, Bockstedt and Düste fields in Northern Germany. The existing hot water treatment (via annular injection) is incapable of fully removing the wax deposition in production wells and requires the aid of compatible solvents to improve the overall treatment. The thesis describes step by step the experimental development of chemical formulations enhanced with surfactants/dispersants. The compositions were chosen based on the wax solvency, flash point, toxicity, manufacturing costs and compatibility with elastomers of the PCPs. Moreover, a polymer recipe consisting of a special polymeric Asphaltene dispersants + ethylene vinyl acetate copolymer (EVA) was investigated as a potential wax inhibitor for the type of crude oil produced. Experimental comparison of different readily biodegradable solvent is also presented as green alternative to conventional petroleum solvents. The developed solvents were tested using a modified cold finger experiment for comparison with conventional solvents. The created solvent (mixed with water) showed superior wax removing performance compared to pure solvents and fresh water at a lower temperature than the wax melting point. The wax inhibiting polymer recipe was tested using cross-polarized microscope for wax appearance temperature (WAT) and Rheometry for viscosity measurements. The novel polymer recipe showed comparable results in depressing the WAT and superior viscosity reduction compared to a commercial product. This polymer combination can also be integrated with the enhanced solvent formulation to create an effective wax inhibitor additive. The green solvent’s wax solvency results obtained were promising as well as providing cost effective green alternative to petroleum solvents. The presented chemical formulations can be used to enhance existing hot water treatment practices with low added costs. The treatment can eliminate the need of workover and frequent scrapping to reduce the overall operational costs.

Details

Translated title of the contributionRohölwachssanierung durch Verwendung von verbesserter chemischer Formulierungen
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date25 Jun 2021
Publication statusPublished - 2021