PEFTEC 2019 - Abstract

Abstract Title: Advanced foam separation for efficient treatment of produced water for reuse
Abstract Type: Oral
Session Choice: Water Treatment
Presenter Name: Prof Yoram Oren
Co-authors:Prof Eilon Adar
Prof Jack Gilron
Dr Michael Weisman
Mr Roey Ashkenazi
Company/Organisation: Ben Gurion University
Country: Israel

Abstract Information :

Produced water (PW) is the major waste in exploration and production of oil and gas operations on inland, onshore and offshore platforms. PW is composed of organic compounds, dissolved salts, heavy metals and suspended compounds which, if released without treatment, may cause severe damages to the aquatic and marine environments. The most abundant inorganic compounds are calcium, magnesium, sodium and chloride. The major organic chemicals in most PW are low molecular weight organic acids and polycyclic-aromatic hydrocarbons with different solubility. The composition and the physio-chemical properties of the PW depend on the organic compounds, mineralogy and the thermodynamic conditions prevailing in the geological formation, and on the stage and history of oil and gas production. As water becomes scarce in many places around the globe and regulations for disposal and reinjection of PW to the original subsurface formation become stringent, recycle for reuse of PW is the most recommended solution, which also reduce PW adverse effect on the environment. The most essential step is the removal of dissolved and suspended hydrocarbon from the PW.

In this work we focus on the removal of dissolved organic and suspended material from oil and gas PW using foam-separation driven by a new Venturi type the eductor-injector nozzle.

PW samples were collected from Heletz 5 oil well (Israel). This water contains ˜ 30 ppm TOC and ˜ 55gr/L TDS. Study was done in two stages. In the first stage removal of the organic content using a specially designed 3-D printed nozzle with Venturi air inlet with different diameters positioned at the critical flow point in the centered streamline was tested. Up to 64% TOC removal after 120 minutes processing of 25L raw PW could be achieved, while the volume of the collected foam phase was found less than 4% of the original raw PW volume.

In the second stage, the effect of the organic content in raw and treated PW on reverse osmosis (RO) membranes was studied as an attempt to reduce salt content. Desalination of treated PW using a RO system didn't show a structural damage to the membrane sheet in short operation durations. However, it was found that membrane blocking by the organic content occurs to some extent upon long term exposures of the membranes to these types of water.