Sonatrach - First Calgary Petroleums Algeria

摘要

By definition the oil & gas industry is used to handling fluid phases, vapour and liquid, as the wells produce always water gas and oil in very different proportions. But in addition under certain circumstances solid phases could appear in different locations (reservoir, pipe-lines or in the process facilities), for instance we could have appearance and deposit of ice, gas hydrates, wax, mercury, sulfur or solid CO2. Most of the time the operating conditions of the fields will be chosen in order to avoid any solid particle in the fluids that could have dramatic consequences on the installations but it is not always possible. Anyway, the simulators used for designing the future installations or assisting the engineers in charge of the production should detect the presence of solid phases. It means that there is a crucial need of predictive, reliable and robust thermodynamic models that can perform calculations of complex equilibrium with 3 fluid phases combined with several solid phase and provide their properties (density, thermal conductivity, heat capacity,...), for instance gas-oil water-gas hydrates-wax. We will present the situations where solid phases can appear in the oil & gas installations their impacts, the current available thermodynamic models and our expectations for the future. In addition, we will imagine how we could react to this problem to avoid any accident that can be happened and can be with fatal consequences, and to avoid unproductive time. Properties of crude oil and natural gas are fundamental for Designing and analysing oil and gas production systems in Petroleum engineering: Pressure, Temperature (t), Bubble point pressure, Stock tank oil gravity, Solution gas oil ratio (Rs), Gas specific gravity .... Hydrate formation in one of the most problem occurred in gas production, caused by the transformation of water to glace with the decreasing of temperature, this example illustrate the importance to avoid the appearance of solid particles in the fluid phase. Once formed, hydrates can block pipeline and processing equipment. They are generally then removed by reducing the pressure, heating them, or dissolving them by chemical means (methanol is commonly used). Care must be taken to ensure that the removal of the hydrates is carefully controlled, because of the potential for the hydrate to undergo a phase transition from the solid hydrate to release water and gaseous methane at a high rate when the pressure is reduced. The rapid release of methane gas in a closed system can result in a rapid increase in pressure. Salt formation during production is a serious problem occurred in Oil and Field, caused by the temperature and pressure change during production of gas and oil. We will try to focus to this two principal problem, identify the problem and try to find solution will be our objective.