Gas hydrates are a major flow assurance problem in the oil & gas industry. If not treated well, they pose a major threat to pipeline failure. In this work, a simple statistical correlation is developed for the prediction of gas hydrate formation temperature. For this, initially, the thermodynamic equilibrium conditions for various gas mixtures are gathered from the literature. This is done to maintain the accuracy with the real-time conditions that could encounter in the pipelines. These data points are used for the development of a statistical model. This model is validated with the latest literature data and its reliability for the prediction of gas hydrate formation temperature is confirmed. Further, the performance of the improved model is compared with some of the well-known statistical models to evaluate its efficiency.

Introduction and Background

Gas hydrates are crystalline compounds formed when gas molecules get trapped inside the hydrogen-bonded cages formed by water molecules [1]. These gas hydrates are formed at low temperatures and high pressure considering the suitable size of the guest molecules that matches the cavity's size [2]. Water from the reservoirs is usually used to make petroleum reservoir fluids. As a result of the combination of water and hydrocarbons, gas hydrate formation can occur, causing flow restriction and blockage, as well as major operational, economic, and safety issues. The ongoing development of many petroleum fields raises the danger of encountering gas hydrates, which might pose operational challenges. Low seabed temperatures and high operation pressures enhance the likelihood of blockage due to gas hydrate formation in multiphase transfer lines from the wellhead to the production platform. Hydrate formation can also occur in other facilities, such as wells and process equipment [3]. Oil and gas corporations are constantly setting new water depth records in their search for hydrocarbon riches in deep waters. Water-based drilling fluids are generally preferred over oil-based drilling fluids due to environmental concerns and regulations, particularly in offshore exploration. However, the development of gas hydrates in the event of a gas kick is a well-known concern in deep water offshore drilling employing water-based fluids. The hydrostatic pressure of the drilling fluid column, together with the comparatively low bottom temperature, could create ideal thermodynamic conditions for the formation of gas hydrates in deep-water drilling. During the confinement of the kick, this might generate major well safety and control issues.

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