21. Natamam quyuların növləri və natamamlığın quyu hasilatına təsiri (Not sure)

Şəkil 7.5. Elastik qravitasiya su basqısı rejimində layın
əsas göstəricilərinin zamandan asılılığı
Su basqısı rejimlərinin һamısında layın neftlilik zonasında onun neftlə doyma əmsalı sabit qalır, lakin o, su-neft kontaktında dəyişir.


29. Qaz quyuları üçün optimal texnoloji rejimlərin seçilməsi. (Kitabda yox idi)
There are various drive mechanisms that play a crucial role in the extraction of natural gas from reservoirs. These mechanisms help in moving the gas from the reservoir to the surface. The primary drive mechanisms include:
Primary Depletion (Natural Water Drive): In this mechanism, the pressure within the reservoir decreases naturally over time as gas is produced. The gas is pushed to the wellbore by the pressure difference between the reservoir and the wellbore. This is the initial driving force in many gas reservoirs.
Gas Cap Drive: Some gas reservoirs have a layer of gas accumulated above the liquid hydrocarbons (oil or condensate). As gas is produced from the reservoir, the gas cap expands and pushes down on the liquid hydrocarbons, aiding in their upward movement. This gas expansion helps maintain reservoir pressure and enhances gas recovery.
Water Drive: In some reservoirs, water is present in an aquifer below the hydrocarbons. As gas is produced, the aquifer water moves into the reservoir, maintaining pressure and assisting in gas movement toward the wellbore. This mechanism is common in gas reservoirs that also contain oil.

Gravity Drainage: This mechanism relies on the difference in density between the gas and the liquid hydrocarbons. As gas is produced, the heavier liquids are displaced downward, and the gas rises to the top of the reservoir, creating a natural flow toward the wellbore.

Injection Methods (Water or Gas Injection): In some cases, injection of fluids, such as water or gas, is used to maintain reservoir pressure and enhance gas recovery. Water or gas can be injected into the reservoir to re-pressurize it and displace gas toward the producing wells.
Miscible Gas Injection: This method involves injecting a gas (often nitrogen or carbon dioxide) that is miscible (mixes well) with the natural gas in the reservoir. The injected gas helps maintain pressure, reduces viscosity, and enhances gas mobility, leading to improved recovery.
Hydraulic Fracturing: In unconventional gas reservoirs, such as shale gas, hydraulic fracturing is used to create fractures in the rock formation. This increases the surface area for gas flow and allows gas to flow more easily into the wellbore.
Determining the most suitable drive mechanism for a gas reservoir involves a comprehensive reservoir engineering analysis that considers a range of factors. Reservoir engineers and geoscientists use various methods and tools to evaluate and predict the behavior of the reservoir and its fluid dynamics. Here are some methods and considerations used to assess and define the optimal drive mechanism:
Reservoir Simulation: Numerical reservoir simulation models are used to simulate the behavior of the reservoir over time, taking into account the different drive mechanisms. These models incorporate geological, petrophysical, and fluid data to predict how gas and fluids will flow within the reservoir under various scenarios. By running simulations with different drive mechanisms, engineers can compare the performance and recovery rates to determine which mechanism is better suited for the reservoir.
Material Balance and PVT Analysis: Material balance calculations and pressure-volume-temperature (PVT) analysis help determine the initial reservoir conditions, fluid properties, and changes over time. This information is crucial for understanding how the reservoir will respond to different drive mechanisms and production strategies.
Well Testing and Pressure Transient Analysis: Well tests, such as pressure buildup and pressure drawdown tests, provide valuable data about reservoir properties and behavior. Pressure transient analysis helps interpret well test data to estimate reservoir parameters, including permeability, skin factor, and reservoir boundaries. This information informs drive mechanism selection.
Core Analysis: Laboratory analysis of core samples from the reservoir can provide insights into rock and fluid properties, including permeability, porosity, and fluid saturations. This data is used to validate and refine reservoir models and drive mechanism predictions.
Historical Production Data: Analyzing historical production data from similar reservoirs can provide valuable insights into the performance of different drive mechanisms. Comparing recovery rates, pressure decline curves, and other production metrics can help engineers make informed decisions.

Economic Analysis: Economic factors play a significant role in selecting the optimal drive mechanism. Engineers consider the costs associated with implementing and maintaining each mechanism, as well as the potential revenue from gas production. The economic analysis helps determine the feasibility and profitability of each option.

Sensitivity Analysis: Engineers often conduct sensitivity analyses to assess how changes in various parameters, such as reservoir permeability, gas saturation, or injection rates, impact the performance of different drive mechanisms. This helps identify key sensitivities and uncertainties that could influence the choice of mechanism.
Field Pilot Tests: In some cases, pilot tests or field trials may be conducted to evaluate the effectiveness of different drive mechanisms on a smaller scale before full-scale implementation.