Regulation concerning the disposal of produced water is necessarily stringent, with environmental bodies setting targets for the reduction of pollution by oil and other substances discharged into the sea.

Some regions such as the Persian Gulf suffer from water shortage problems. Earlier this year, the United Arab Emirates (UAE) banned the export of groundwater as a report by its Ministry of Environment and Water estimated freshwater reserves will have depleted within the next five decades.

A variety of technologies have been tested but with inconclusive results. They also do not meet the requirements as laid down by legislation. New technologies or custom approaches need to be investigated to provide a definitive solution to address the issue in the Middle East region.

Industry Technology Facilitator (ITF) launched a call for proposals in May this year to urge technology developers to come forward with solutions to tackle the challenges of managing produced water in Middle East oil and gas production.

Shaybah facility

Produced water management is a crucial issue for oil and gas production in the Middle East at developments such as Saudi Aramco’s Shaybah facility. (Image courtesy of Saudi Aramco)

There was significant interest in the call, which generated 13 submissions from international technology developers and academics. These proposals currently are being reviewed by members, with successful proposals anticipated to be launched as joint industry projects during 1Q 2013.

The main challenges identified by ITF’s members are treating produced water with back-produced polymer in polymer flood projects as well as the treatment of water for reinjection and other applications.

Polymer injection in oil fields has been practiced in only a few regions around the world. Due to the different requirements and fields being exploited, there is a lack of knowledge with regard to the technique, and the requirements vary over the producing fields and regions. Different fields require different polymer concentrations to reduce oil-in-water (OIW) to safe levels for disposal.

There is a need for technologies that have a wide range for dealing with viscosity of up to 60 cp that can achieve OIW specification without degradation of polymer if possible. Solutions also need to operate efficiently with conditions of water quality at inlet being OIW 200 parts per million by volume (ppmv), 20 mg/l (0.02 kg/cu m) total suspended solids (TSS), and outlet of 5 ppmv OIW and 2 mg/l (0.002 kg/cu m) TSS.

Another challenge is the lack of detection and characterization of back-produced polymer in produced water. Without this, it is difficult for operators to identify the best possible treatments. Desalination of water with back-produced polymer is another issue for consideration, as is the degradation of back-produced polymer without shearing the OIW.

Local legislation

In terms of treatment of water for reinjection and other applications, local legislation is a major factor. The development of a coalescence technology to adequately treat produced water so it can be reinjected or disposed of safely to comply with local legislation is key.

The Regional Organization for the Protection of the Marine Environment (ROPME) Protocol for overboard discharge standard is 15 mg/l (0.015 kg/cu m), and the UAE’s Ministry of Environment and Water standard for disposal into the sea is 40 ppmv. It is critical to reduce salinity and develop cost-effective techniques without the need to change cartridges frequently, with a target OIW concentration of less than 2 ppm.

It also is essential to bear in mind those technologies being sought should be suitable for a range of water cut in the region of 30% to 90%. There also is a need to ensure that water content in the crude oil after separation is minimal, at least less than 1%.

Developing a system that does not use a compressor or a pump to separate gas from liquids (gas, crude, and water mixture) with the gas and crude oil returned to the flowline is important since it could allow a system to be automated and reliable for use in unmanned and remote locations.

Reuse water challenge

Produced water with low salinity, less than 8,000 mg/l (8 kg/m cu m), is a strong candidate for treatment and potential reuse. The main challenges are treatment to achieve reuse water specifications such as irrigation, industrial use, steam generation, and polymer mixing.

The requirement is to achieve de-oiling to less than 5 ppm and have salinity, silica, water hardness, boron, TSS, and other chemicals to the required specification. Finding a cost-effective way to transport produced or treated water is another key factor with a need for alternatives to carbon steel-lined pipelines.

Treatment of high-salinity produced water (salinity more than 50,000 mg/l or 50 kg/cu m) for reuse in steam generation can prove costly. There are limitations with current technology as in some cases maximum salinity can be more than 120,000 mg/l (120 kg/cu m). Solutions need to address these extreme cases. A large number of current technologies have high power requirements; therefore, applications with minimal power requirements that are able to tolerate OIW would be the ideal consideration.

ITF opened an office in Abu Dhabi in 2011, and this challenge is the first to emerge from the regional managers group that it established with its Middle East members this year. The initial meeting brought together 30 of the region’s largest oil and gas players to focus on a collaborative vision for solving regional technology challenges and identified produced water management as a priority area to tackle.

ITF’s Middle East-based members pushed for this challenge to be addressed first because of its significance to oil and gas production in the region. Technology needs to become more effective in order to meet legal requirements.

There is a clear requirement for new technologies to provide a definitive solution to the problem of managing produced water, particularly in the Middle East. ITF aims to bring such innovative technologies to market by acting as the honest broker between operators, service company members, and technology developers.