Shenjia Hydraulics

Release Date:

2023-03-31

Natural gas hydrates are a mixture whose primary component is natural gas; they form as liquid phases under pressure. Because natural gas hydrates have a lower density than liquid natural gas, they enable the transportation of natural gas over longer distances at lower costs and reduced pressures.

Natural gas hydrates possess the ability to decompose hydrocarbons, thereby helping to mitigate environmental pollution and promote a cleaner environment. They can also be used to purify natural gas, enhancing its quality, improving combustion efficiency, and conserving energy. Furthermore, they are applicable in oil and gas processing and storage, as they safeguard the integrity of these resources by protecting them from oxidative degradation by atmospheric oxygen. With a lower specific gravity than liquid natural gas, they reduce storage and transportation costs while saving energy. Given their significant contributions to environmental remediation, quality enhancement, and energy conservation, natural gas hydrates represent an invaluable resource that should be actively harnessed. Also known as gas hydrates, they refer to a complex system in which petroleum, natural gas, and water coexist within the same geological formation. This intricate layered structure exhibits remarkable diversity and broad potential, capable of meeting diverse technical, economic, and environmental requirements.

The formation of natural gas hydrates is primarily attributable to two factors: first, the physical and chemical interactions among oil, gas, and water give rise to a composite oil–gas–water layer; second, the movement of groundwater drives the incorporation of oil and gas, leading to the formation of oil–gas–water hydrates. Based on the compositional characteristics of oil, gas, and water, these can be classified into three types: the oil–gas–water composite layer, the oil–gas–water mixed layer, and the oil–gas–water seepage layer. In the oil–gas–water composite layer, the compositions of oil and water remain stable; in the oil–gas–water mixed layer, these compositions vary; and in the oil–gas–water seepage layer, the compositions are unstable. Three key technical attributes—porosity, flow behavior, and production characteristics—are also identified. Porosity refers to the spatial distribution of oil and water within the hydrate; flow behavior describes the interactions and movement of oil and water in the hydrate; and production characteristics pertain to the production rate or output of the hydrate.

The development and utilization of natural gas hydrates can be categorized into two approaches: one is hydrocarbon‑driven, in which the flow of oil and gas propels a mixture of hydrocarbons and water, ultimately yielding gas hydrates; the other is water‑driven, where groundwater flow facilitates the mixing of hydrocarbons and water, leading to gas hydrate formation. This technology holds significant application potential, as it can enhance the economic viability of oilfields, increase recovery rates, boost production, and improve key technical and economic indicators. Moreover, gas hydrates can be employed to upgrade the technological capabilities of oil‑production facilities, mitigate environmental impacts, and reduce the consumption of oil and natural gas, making them a highly promising emerging energy source.

As evident from the foregoing, natural gas hydrates exhibit remarkable diversity, immense potential, and promising application prospects. They can meet a wide range of technical, economic, and environmental requirements, making them a highly valuable energy resource.