Process: Produced Water Treatment using OPUS™ Technology
Client: Chevron
Location: San Ardo, California
Country: United States
Completion Date: November 2008
Flowrate: 50,000 barrels per day
Client Needs:
This project involves treatment of produced water for the purposes of discharge to recharge basins and production of Once Through Steam Generator (OTSG) make-up water. The raw produced water temperature is 200°F, and it contains about 25 ppm free oil, 80 ppm TOC, 240 ppm silica, 26 ppm boron, 240 ppm hardness and 6,500 ppm Total Dissolved Solids (TDS).
The project goal was to reduce the feed water TDS to less than 510 ppm and boron to less than 0.64 ppm for recharge basins discharge, while achieving 75% water recovery across the treatment system and minimizing the volume of produced water requiring re-injection. For OSTG make-up, the project goal was to reduce the feed water hardness to less than 2 ppm as CaCO3.
Our Solution:
The treatment process includes a common pretreatment step for free oil removal followed by OPUS™ technology to achieve the discharge water quality and a Series Softening System for generation of OSTG make-up water.
The free oil removal system consists of an induced gas floatation system and a PowerClean walnut shell filtration system to reduce the free oil to less than 0.5 ppm.
The OPUS™ technology consists of multiple treatment steps such as heat exchange, degasification, chemical softening, media filtration, ion exchange softening, and a double-pass RO system to meet the effluent water quality requirements. The solids generated from the system are dewatered and disposed in a landfill.
The Series Softening System involves a two-stage strong acid cation softeners to reduce hardness in the feed water to acheive the water quality specification.
