Introduction to Natural Gas Engineering and Its Challenges

🔍 Exploration and prediction techniques play a crucial role in the natural gas industry.

🌱 Natural gas is a clean fossil fuel source with less harm to the environment compared to coal and oil.

💡 The origin of natural gas involves the conversion of organic material into coal, oil, and gas over a geological time scale.

🔥 Natural gas is measured in terms of energy content, not just volume.

🛢️ Gas reservoirs can be classified based on the gas-to-oil ratio and different well types: gas well, condensate well, and oil well.

💡 Understanding the phase behavior of natural gas under different temperature and pressure conditions is crucial for reservoir classification and hydrocarbon recovery.

🔍 Reservoir fluids can be classified as oil reservoirs or gas reservoirs based on composition and temperature-pressure conditions.

⚙️ Understanding phase behavior helps in predicting production and designing systems based on composition changes.

🌡️ By changing temperature and pressure, the phase of a single component system can be altered from liquid to vapor or vice versa.

💡 The phase envelope represents the region where both liquid and gas phases coexist in a two-component system. Quality lines within this envelope indicate the percentage of liquid and gas phases.

🔍 The bubble point curve separates the pure liquid region from the two-phase region, where liquid and gas coexist. The dew point curve represents the transition from gas to liquid phase.

📊 The shape of the phase diagram, including the envelope, depends on the composition of the hydrocarbon mixture. Reservoir classification is determined by the temperature and pressure at the critical point.

📈 The behavior of reservoir fluids can be determined based on temperature and pressure conditions.

💧 Classification of natural gas reservoirs can be done based on dew point, gas-to-oil ratio, and fluid color.

🌡️ The phase envelope for natural gas can vary depending on composition, pressure, and temperature.

🔑 In a dry gas reservoir, reducing pressure without changing temperature results in the production of methane without any liquid substances.

🌊 In a wet gas reservoir, reducing pressure and changing temperature causes the gas to reach the dew point curve and produce liquid drops along with gas.

🔄 Retrograde condensation occurs in reservoirs between the critical point and cricondentherm temperature, where reducing pressure causes a mixture of liquid and gas to alternate.

Near the wellbore region, the accumulation of oil reduces the permeability for gas, hindering gas recovery and production.

Liquid loading occurs when gas lacks the energy to carry over accumulated liquid, requiring actions such as gas injection or shutting the well.

Understanding the behavior of gas condensate flow near the wellbore is crucial for optimizing gas condensate reservoir production.