For those involved in the production side of the upstream business, the reality of using EOR techniques on mature fields and ever-rising water cuts is a continual rise year-on-year in the global volume of produced water.

As a result, both the management of the produced water to ensure the environment remains protected and the need for enhanced economic efficiency is one of the oil and gas industry’s biggest challenges at present.

How to maximize water reuse and minimize the costs is a high-priority concern for operators as they continue to look for better ways to enhance mature reservoir recovery rates, extend field lives and achieve the stringent environmental targets and regulations that set the boundaries for them.

200 Projects

Houston-based process solutions provider ProSep has been working with the U.K.’s Industry Technology Facilitator (ITF), a not-for-profit organization that has been involved in facilitating the launch of more than 200 projects worldwide from early-stage concepts to field trials and commercialization. ITF has member companies from the operator and service sectors and works closely with the technology development community and government bodies.

ProSep designs, manufactures and commercializes technologies to separate oil, water and gas generated by oil and gas production, and through ITF it started collaborating in 2015 with Middle East national oil companies (NOCs) Qatar Petroleum and Petroleum Development Oman (PDO).

The company’s Osorb Media is a water treatment technology that selectively removes hydrocarbons from produced water and has the ability to be regenerated in situ and reused for reinjection or discharge without a loss in efficiency. Under the ITF’s stewardship a joint industry project (JIP) was formed with the two NOCs aimed at enhancing and proving the regeneration and reuse of the media under realworld situations.

This before-and-after image shows the instantaneous effect of Osorb on hydrocarbons. (Source: ITF)

Difficult Water Streams

Both Qatar Petroleum and PDO had similar requirements for treating difficult produced water streams, according to ITF.

The former was seeking to replace existing water treatment technologies with one that could reduce the amount of waste generated, utilities required and size of systems. The latter was searching for a technology that was suitable for treating the produced water generated during chemical EOR in operations such as polymer floods and alkali surfactant polymer floods.

The JIP enabled ProSep to put a full-scale Osorb Media unit through a two-phase field trial on PDO’s Marmul oil field, about 200 km (124 miles) northeast of Salalah in Oman, to demonstrate the offshore-capable technology’s water treatment and regeneration capabilities.

Regenerable Media

Osorb Media is a regenerable organosilica that adsorbs free, dispersed and water-soluble hydrocarbons as well as many oilfield chemicals from produced water. Spent Osorb Media can be regenerated using a variety of techniques and resources, and operators often have different options available for this process. The two phases of the project compared regeneration methods through a rigorous test schedule to ensure that regeneration process options were created that were both economically and operationally practical for all operators.

The field trial got underway in July 2016, with the Osorb system designed, engineered and built to complete the testing at the Marmul Field’s water treatment plant. The system was installed to treat the water coming into the plant directly from the production separators. A small slipstream of the produced water was treated for nine hours each day. Samples of the inlet and outlet produced water were collected twice each day and analyzed in the operator’s laboratories at Marmul.

JIP Trial Phase Concluded

ProSep has now concluded the final first stage of the ITF-led JIP with the two NOCs and other JIP members. This involved successfully regenerating the media using steam over four water treatment cycles. The final phase of the trial will aim to demonstrate natural gas regeneration and further optimize the system.
The data gathered in the trial is now being used to optimize the design and system process to reduce capital costs as well as the operational costs for owning such a system. The purpose built 750 bbl/day system that is currently being used for the trial will be available to other operators for further testing on the conclusion of the JIP.

According to PDO’s corporate technology adviser, Wail Saif Salim Al-Harrasi, the JIP “has the potential to resolve some of the challenges associated with EOR activities such as de-oiling of polymer-contaminated water and enabling the reuse of spent polymer, which in turn reduces the overall cost of EOR.”

ProSep’s Middle East general manager, Ryan McPherson, added that being part of a JIP with two NOCs in the Middle East “has been a tremendous experience, with all parties truly collaborating toward a shared goal. The ability to regenerate the media in situ is fundamental to full-scale technology implementation. The field trial will enable ProSep to create a regeneration process that is both economically and operationally practical for operators.”

ITF’s first truly collaborative Middle East JIP was to develop an offshore-capable oil-in-water removal and media regeneration package. (Source: ITF)

Optimized System

According to ProSep, the field trials have produced a significant amount of information from several water treatment and regeneration cycles. Data also are being analyzed to verify the water treatment capabilities, validate prediction models and identify means to optimize the system moving forward.

The end goal for the JIP is to see a commercial unit integrated into a customer-produced water stream for extended trials.

Editor’s note: The ITF’s annual Technology Showcase event— focused on bringing the technology R&D community together with key industry decision makers—will be held March 1 in Aberdeen, Scotland.