Preventing the Formation of Methane Hydrates in Natural Gas Transmission Pipelines–A Comprehensive Review

Abstract

Hydrates are usually formed during the transportation and treatment of natural gas, resulting in hydrate plugging of pipelines. Hydrates are crystal like structure being formed from the mixture of gas and water. They occur at low temperature and highpressure conditions. These hydrate plugs cost the oil and gas industry significant amounts in revenue cuts and is a major problem for the industry. There are many preventive measures that can be implemented such as inhibitors to avoid the formation of hydrates. This paper aims to highlight the different measures and analyse their effectiveness for hydrate-plug prevention. One such method for the reduction of hydrate formation is the removal of existing hydrates by using different types of inhibitors. The most common method of hydrate prevention in deep-water developments is injection of thermodynamic inhibitors, which include methanol, glycols, and others. If hydrate prevention methods are unsuitable and hydrates are liable to form, the process of dehydration can be used wherein the water gets removed from the gas stream. Electrical heating is also used as a way to dehydrate the pipe. This paper compares a variety of inhibitors and various hydrate preventive methods and discusses their influence in the mitigation of hydrate formation in gas pipelines.