Water treatment in the oil & gas industry

Introduction

Any disruption to operating performance is problematic for oil and gas producers. With rising energy demands, the need to be more considerate of the environment, and volatile prices, it’s crucial every step of the process is efficient.

The average platform runs at only 77% of the maximum production potential, leaving a big gap to recover. This shortfall comes at a price – a day’s downtime for a company producing 220,000 barrels per day would cost 25 million USD in lost revenue. And on average, producers experience 27 days of downtime every year.

27 days of downtime = $675m in lost revenue

That leaves plenty of opportunities to improve the production process.

*Based on current prices and 220,000 daily barrels

The role of water in oil production

Water processing is pivotal to the upstream process. It’s injected to enhance oil recovery and produced as a by-product of extraction.

Energy producers generally use and filter two types of water.

Produced water: water that comes out of the well with the crude oil during crude oil production. Produced water contains soluble and non-soluble oil and organics, suspended solids, dissolved solids, and various chemicals used in the production process.

Seawater: a complex mixture of water, salt, chemical compounds, and dissolved oxygen. Seawater has a lot of organic matter in it, including algae and bacteria.

Energy producers pump more water than oil every day, so improving the water treatment process will impact oil production levels.

Why do energy producers need to get water treatment right?

Water treatment is vital for protecting downstream membranes, pumps, and other processing equipment. It prevents blockages in the well formation and is a crucial part of adhering to changing legislation around extraction.

Having an optimised filtration system increases runtime and reduces money lost on filter cartridge replacements, equipment maintenance, and downtime.

This can deliver an OPEX benefit that cancels out CAPEX expenditure within the first year of operation. As facilities can operate for more than 25 years, it’s well worth the investment.

Water treatment techniques and applications

Seawater Injection

Water needs filtering before injection to prevent the well from getting damaged or blocked. The level of filtration required depends on the formation water is being injected into. Where sulphate reduction is required, membrane protection is critical. Protecting membranes with filters maximises plant uptime and increases the volume of injection water produced so more oil can be extracted.

Produced Water

Produced water is filtered to remove residual oil before it’s injected or disposed of. With increasingly stringent environmental regulations limiting overboard disposal, reinjection is common both as a more environmentally friendly solution and as a useful source of water for enhanced oil recovery. Effective filtration is critical as a final processing stage to protect the rock formation, and to protect coalescing filters as they remove residual oil from the water.

Drinking water

To operate offshore, employees need a constant supply of drinking water. Producers supply this via tanker or by purifying seawater through a reverse osmosis plant.

Where reverse osmosis systems are used, effective pre-filtration is vital to ensure enough drinking water is produced and to avoid frequent and expensive membrane replacements.

Key water treatment challenges

Seawater/drinking water – biological materials such as bacteria and algae

Produced water – waxy crudes, chemicals to help the upstream process, coagulation

Rig worker in an orange high-vis jacket and white hard hat, reviewing the facility's water treatment equipment

5 ways to improve your water treatment process

Follow these tips and you'll...

Suffer less downtime

Change filters less often

Improve filtrate quality

Save on unnecessary OPEX

1. Focus on cost vs. benefit

Budgets and CAPEX are important to protect. But that doesn’t mean the cheapest filtration solution is the best one for the job, will be cheaper overall, or will deliver the lowest carbon footprint. It’s worth taking time to research and understand what’s going to give you a better ROI. Some filters are cheap but have a short life – that means more changeouts, downtime, and replacements.

2. Choose the right filter

As contaminants in water, extraction legislation, and filtration specifications are so changeable, using optimal filter technology is crucial. If the filtration solution isn’t right and you don’t consider the whole process, including upstream and downstream equipment, then production performance can severely suffer.

In some cases, energy producers end up with poor quality filters that don’t deliver the efficiency they promise. This can result in 50% less operating capacity.

For seawater filtration, look for filters with anti-algal or antibacterial coatings to combat biofouling. This helps the filter last longer so you have fewer changeouts, saving time and money. It can also help to protect reverse osmosis membranes meaning they need cleaning and replacing less often.

Using the right filter also helps to protect operational equipment and rock formations while recovering oil reserves. If you don't filter injection water properly, contaminants can block the pores of the rock formation. This will reduce the flow rate of injection water or block the well entirely, meaning little to no water can get in to extract the oil.

3. Don’t underestimate housing design

Poorly designed and sized filter housings can lead to high year-on-year operating costs and impact production levels.

Unsuitable internal supports can cause filters to operate at high differential pressures when they’re clean. This leads to higher energy and pumping costs and limits the differential pressure available for cartridge fouling. Other issues like flow impingement or unseating of cartridges can compromise filter integrity and reduce efficiency.

Access closures can make the cartridge change-out process inefficient. You’ll need more people and, in some cases, cranes. This can take 20+ times longer than a well-designed access closure.

These all have a negative impact on production and OPEX.

A good supplier will offer bespoke housing design or consultation to ensure you have the right combination for your job.

Water treatment equipment at an gas production facility

4. Get help from your specialists

Work with a supplier who’ll collaborate well with your process and mechanical engineers. They can recommend the most appropriate technology, micron rating, and cartridge construction based on:

Particle loading and size distribution
Other contaminants present
Equipment used upstream and downstream

5. Choose the right filter partner

Suppliers don’t always understand the oil production process enough to offer the best solutions, but it’s crucial they do. This is especially true when downtime comes at such a high price. A lack of knowledge of the entire process can cause:

Filters to be sized based on flow rate only, rather than taking the whole process and application into consideration
An imbalance of CAPEX and OPEX
Upstream pre-filtration equipment not to be considered in the solution
A solution that’s not durable enough to withstand challenging operating conditions and will not last for as long as the plant is operational
You to have no expert advice available if something goes wrong during commissioning or production

Two oil rig workers in yellow high-vis jackets and white hard hats talking to a filtration supplier

Getting the best from your supplier

Not all suppliers are created equal. Service continuity and levels vary, and product quality differs too. Here are some traits to look for to get the most from your investment.

Product and industry expertise

A good supplier will design, manufacture, and install filters for you. They’ll also know your industry and processes inside out so they can recommend you the most suitable products.

Accessible team

Look for problem-solvers with a proactive culture who want to communicate and work with you to offer the best solutions.

Quick, agile, and customisable service

Choose a supplier who can be flexible with your demands and provide a quick turnaround. A supplier who can customise their products to suit your needs is even better.

Focused on performance

The best suppliers focus on improving their products. For example, maximising effectiveness and minimising your filtration spending.

Proven and trusted

They should have lots of experience with customers of all sizes, markets, and locations. Complying with regulations shouldn’t be a problem for them.

Close up of green waste water with a thick film of scum

Case study

Improving process economics for sulphate reduction plant (SRP) membrane protection

The challenge

The service life of a prefilter in the sulphate reduction process is directly related to inlet water conditions. These conditions can vary by location, season, and weather.

Biological contaminants such as algae reduce filter lifetime and increase downtime and cost.

The solution

To combat the build-up of biological contaminants, we developed and launched a filter range called KilBac®.

KilBac uses micron-sized particles containing active silver, zinc, and copper to combat the growth of bacteria and algae. This extends cartridge life and improves performance.

Due to the rapidly changing conditions of inlet seawater, it’s difficult to trial filters in a standard test environment. So, we partnered with a global energy producer and launched a rigorous test programme.

We tested three different filters in parallel with the same quality seawater and biological exposure.

5-micron anti-algal SupaSpun KilBac®
5-micron antibacterial SupaSpun KilBac®
5-micron untreated standard SupaSpun II filter

The results

Our testing showed that KilBac® technology can significantly improve the seawater filtration process.

Compared to the untreated standard SupaSpun II:

The KilBac filters exhibited half the differential pressure
The anti-algal SupaSpun KilBac had a 39% higher dirt holding capacity
The antibacterial SupaSpun KilBac had a 125% higher dirt holding capacity

Having KilBac technology on filters:

Can double the service life of a cartridge, reducing annual filter costs along with the carbon footprint reduction from lower logistics costs, fewer man hours required for maintenance, and reduction in the amount of waste to be disposed of
Offers greater protection of the downstream membranes, reducing downtime and the expense of cleaning and regenerating
Reduces frequency of change-outs, minimising downtime
Keeps filters operational under increased levels of organic contaminants from unexpected occurrences, e.g., localised algae blooms

Shot of the ocean just below the surface, with numerous bubbles of different shapes and sizes rising to the top

Save time and money with Amazon Filters

Optimising your water treatment process is critical to reducing downtime and increasing revenue. We can assess your existing water filtration systems and offer expert advice and manufacturing to improve your process.

Why us?

For over 35 years, our team of experts has designed, manufactured, and installed innovative filtration solutions for businesses worldwide.

Today, we’re one of the world’s leading filter manufacturers supported by years of industry knowledge, we deliver high-quality, reliable, and accredited filtration solutions to your exact specifications.

We help you focus on producing high-quality products and services, and worry less about the filtration process.

Exceptional project turn-around times
Competitive, cost-effective pricing
Industry-leading technology

The importance of effective water treatment in the oil and gas industry