N2 for offshore oil industry

How Nitrogen membranes tackle all challenges

N2 is used for a variety of applications in the onshore oil industry. The inert gas is indispensable in all three phases of the oil & gas supply chain: from increasing the pressure of the oil reservoir to reducing the risk of explosions. 

Nevertheless, the use of nitrogen also poses many challenges. Think about logistics, safety and unexpected shutdowns. In this blog post we will indicate how nitrogen membranes can overcome these challenges.

27 Февруари 2019

N2 in oil & gas supply chain

Filling up your car with gasoline or heating your house is just the final step in a long supply chain.

The supply chain of the oil and gas industry is divided into three segments: Upstream, Midstream and Downstream, and nitrogen plays an important role in all these segments.

1. Upstream

Upstream is the exploration and production of crude oil and natural gas. N2 can be used for different upstream applications, one of them being nitrogen injection.

Normally when hydrocarbons are recovered from a new reservoir, the typically high reservoir pressure ensures that these hydrocarbons easily flow to the production wells. Over time, however, the pressure in the reservoir drops. In order to increase the pressure, oil companies inject nitrogen into the well.

Another possibility is that hydrocarbons get stuck and need flushed. Nitrogen is the perfect gas to extricate these hydrocarbons, since it does not mix with oil and water. A nitrogen injection will enhance the flow rate of oil and increase the hydrocarbon production.

2. Midstream

Midstream is the processing, storage and transportation of crude oil and natural gas via pipelines. Before a pipeline can be put into operation, it needs thorough cleaning. Nitrogen is often used for the pigging and purging of a pipeline. After pigging, nitrogen is pushed several times through the pipeline until it is completely oxygen free and has reached the desired dew point. During this process multiple stoppages can occur for various reasons (e.g.: pig stuck in the pipeline, valve leaking, etc…).

3. Downstream

Downstream includes refining crude oil into finished products such as gasoline, fuel oils, and petroleum-based products. One of the various applications of nitrogen in the Downstream Industry is nitrogen blanketing.

The inert gas is used to blanket hydrocarbon storage tanks, insuring inert conditions are maintained. The main goal of this operation is to prevent explosions, discoloration, polymerization and other undesirable changes in quality. The entire process is monitored through the flow rate and pressure of the inert gas stream and/or the oxygen level in the exhaust gas.

Petrochemical plants also deploy N2 to perform leak tests. Using water or air is not recommended for these types of test. When companies detect leaks, they need to be repaired  before a leak test is performed once again after the repair.

Challenges of N2 in onshore oil industry

Nitrogen is a challenging product to work with. In our previous blog post, we reviewed the challenges liquid nitrogen poses to the offshore oil industry, but what are the difficulties for onshore industry? And is a new technology, such as nitrogen membranes, able to overcome these challenges?

1.   Logistical challenge

Oil and gas industry is usually located in remote areas. Transporting liquid nitrogen to these remote areas is quite problematic. It takes too much time and is costly.

Nitrogen membrane technology eliminates such hassles. The equipment is compact, safe and can remain on site with one-time mobilization until job completion.

2.   Safety issues

Serious precautions are required when transporting and using liquid nitrogen on site, because of its cryogenic nature. There is a big risk posed by nitrogen leaks, which can cause a lot of damage to the site and puts the lives of employees at risk.

When you work with nitrogen membrane generators, this risk is reduced to zero. The membrane separates the gaseous nitrogen from other molecules by using compressed air stream.

3.   Availability of LIN during shutdown/turnaround

Shutdowns and turnarounds occur frequently in existing oil and gas facilities. When these unexpected events occur, the facility urgently needs additional volumes of nitrogen. LIN suppliers have difficulties meeting this last-minute demand. On the other hand; nitrogen membranes form a very reliable partner when it comes to mobilizing N2. The equipment can meet such urgent demands much easier, because it can remain on site as long as needed.

4.   Evaporation losses during transport

Nitrogen can only be kept in its liquid form at an extremely low temperature. When liquid nitrogen is transported, N2 will start to evaporate due to an increase in temperature, constantly reducing the volume of LIN. This is also an issue when transporting N2 to offshore platforms.

All of this proves that nitrogen membranes are a safe, easy and reliable solution for operators, contractors and end users in the oil & gas industry, both onshore and offshore.

Syed Faiyazuddin

Regional Business Development Manager at Atlas Copco Rental - Middle East & Key Accounts - Specialized Applications, Flow & Power

N2 for offshore oil industry

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