The Monitor

Production Process Insights

Implementing safe and cost efficient chemical injection & sampling

Posted by Lance Witt on 2/9/16 9:45 AM

Oil and gas plant pipelines

Much of the world's energy comes from the petroleum industry. Especially in this industry, it is critical that operations are run safely and efficiently with controlled, real-time data. Since oil and gas drilling, refining and pipeline operations often are located in sparsely inhabited, remote areas with temperature extremes, oil & gas operators need a partner to provide full solutions with rugged, reliable products that can provide the best in corrosion monitoring and mitigation, chemical optimization and representative sampling to help them maintain seamless and safe operations.


One of the world’s largest independent oil & gas exploration and production companies has operations in 25 countries with more than 17,000 employees. The company is focused on exploration, production and transportation of oil and natural gas.

In the South Texas and Gulf Coast regions, where extensive production takes place, all equipment used in the field must be rated to a maximum allowable operating pressure (MAOP) rating of 5000 psi (345 bar) to handle all variations in pipeline and system pressures. This reduces the complexity of equipment selection and operational procedures. Reduced complexity improves operator safety, lowers environmental risks and increases operational efficiencies.

Hydrogen sulfide (H2S) gas is a colorless, transparent gas found in petroleum and natural gas. It is a huge safety concern for personnel as well as a major contributor to corrosion.


To mitigate levels of H2S, scavenger chemicals must be injected into the oil or gas stream. For this customer, each line at the wellhead required two atomizers to disperse chemicals. Typically, the chemicals are introduced into the process near the top of the line, using variations of open drip tubes. However, this customer believed that a more effective method was possible. The customer chose Sentry® patented Saf-T-Vise™ MM-50 chemical atomizers, with the injection point placed on the pipe centerline. A unique 90° elbow at the tip of the injection point, combined with a low flow atomizing nozzle, provided optimal chemical placement in the pipeline. The customer realized more even chemical dispersal and efficient usage provided by this solution.

Chemical injection

To inject viscous chemicals such as corrosion inhibitors and defoamer agents into the pipelines, and for sampling gas and liquids from the lines, the customer chose Sentry patented Saf-T-Vise MM-50 chemical injection & sample quills. The quills can both inject chemicals and collect samples. Whether in a liquid or gas line, for injection the quill tip is placed in the center of the line where maximum velocity exists. For sampling, the flexibility of the product design allows a sample to be obtained from any point between the bottom of the line and the top, depending on the sample to be collected.

Corrosion measuring

For measuring corrosion in the pipeline, the company uses rod-style corrosion coupons in the bottom of the lines. Corrosion coupons are used to measure pitting and metal loss that might occur due to the corrosive content in the gas or liquids. These coupons are cathodically isolated and are used to indicate the effectiveness of the anti-corrosion chemicals. The customer chose Sentry patented Saf-T-Vise MM-50 corrosion coupon holders to place the coupons in the lines.

All the Sentry Saf-T-Vise MM-50 products have a MAOP of 5000 psi (345 bar) at 100°F (37.7°C) and a maximum operating temperature of 450°F (232.2°C) or 1000°F (537.7°C) depending on the seal chosen. With its ability to operate easily in all applications, even extreme high-pressure environments, this product was the right choice for the customer.

Learn more information about our corrosion monitoring & chemical injection product portfolio.

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Topics: Upstream & Midstream

Written by Lance Witt

With over 25 years in the hydrocarbon industry, Lance Witt brings a unique perspective to Sentry Equipment as the Regional Sales Manager. He is a wealth of industry knowledge as an author and presenter for ASGMT, ISHM, AFMSC and Gas Well Deliquification Workshops. He also a technological expert with 3 patents on chemical optimization and an active NACE member.

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