Operational impacts and benefits of determining Methanol Concentration by Gas Chromatography

Gas hydrates are a common problem within the oil and gas industry. Methanol hydrate inhibition is one of the most cost-effective methods to prevent hydrate formation, but the process to determine the Methanol concentration ratio can be complicated. Element can determine the current quantity of Methanol present in your systems to help you determine if your Methanol concentration is high enough to prevent hydrate formation.

What Are Gas Hydrates? 

Gas hydrates are ice-like crystals containing large amounts of a low molecular weight gas that builds up and restricts flow in pipeline systems. Gas hydrates form when low molecular weight gasses such as methane, ethane, or carbon dioxide combine with water and freeze into a solid. This freezing can happen at low temperatures or under high-pressure conditions. When gas hydrates begin to build up within a pipelines system, they can reduce the diameter of the pipe, ultimately blocking the pipeline. These blockages can be challenging to locate and expensive to remove, costing you significant losses in production and revenues.

How does Methanol hydrate inhibition work? 

When Methanol is injected into a water-based liquid, it lowers the freezing point of the water. This property makes Methanol a common anti-freeze agent. When Methanol is injected into a pipeline system, it goes through three phases: aqueous, vapor, and hydrocarbon, losing an amount of the Methanol during the vapor phase. In order to prevent hydrate formations, there must be enough Methanol left in the system to act as an anti-freeze agent once it has reached the hydrocarbon phase. It is therefore critical to test for Methanol concentration to ensure that the injection will be effective.  We can determine the current Methanol concentration in your sample through Chromatographic analysis.

Determining Methanol concentration by Chromatographic Analysis

Chromatographic analysis is one of the most cost-effective and straightforward methods of examining Methanol concentration. Accurate validation of Methanol concentrations can significantly impact BTU determination and measurement, whereas inaccurate measurements can result in lost profits due to product noncompliance and supply flow disruption. ASTM D7423, the standard test method for chromatographic analysis with a flame ionization detector (GC-FID), allows for 0.5ppm lower detectable limit in C2-C5 streams. As Methanol has low BTU content, even very low levels of Methanol concentration can dilute the real BTU and create measurement error.

Why do you need to test for methanol concentration? 

Stringent regulations require companies to obtain regular quality and process control measurements for methanol concentration. Routine testing for Methanol concentration levels supports optimal production, with fewer upsets, and provides a low-cost alternative to expensive equipment failures and process shut-downs. 

The Element Advantage    

Element has been at the forefront of analytical method development and best laboratory practices for more than 38 years. Element’s analytical procedures conform to the Gas Processors Association (GPA), American Standard Test Methods (ASTM), and the American Petroleum Institute (API) protocols. Element’s global platform of labs supports the natural gas, offering advance services designed to test and qualify materials intended for use within the environments of the future. In working with Element, you have direct access to some of the best Oil and Gas materials scientists and engineers within the industry.

To learn more about methanol injection and other hydrate preventative measures, contact an expert today.