What is a solution gas drive?
Solution gas drive is a mechanism by which dissolved gas in a reservoir will expand and become an energy support to produce reservoir fluid. Because compressibility of oil and rock is very low, only a small amount of fluid can be produced and typically the volume is around 1-2% of oil in place.
Which is the most efficient recovery mechanism for a gas reservoir Why?
Waterdrive is the most efficient drive mechanism, followed by gasdrive and gravity drainage. Reservoir-drive mechanisms are also called natural drives.
Which drive mechanism gives highest recovery?
Water drive and gas cap expansion are both displacement type drive mechanisms and have relatively high recoveries. Solution gas drive is a depletion type drive and is relatively inefficient.
What is Waterdriver mechanism?
1. n. [Well Completions] A reservoir-drive mechanism whereby the oil is driven through the reservoir by an active aquifer. As the reservoir depletes, the water moving in from the aquifer below displaces the oil until the aquifer energy is expended or the well eventually produces too much water to be viable.
What are examples of drive mechanism?
There are five common drive mechanisms:
- Water drive.
- Gas expansion.
- Solution gas.
- Rock or compaction drive.
- Gravity drainage.
How do you maintain reservoir pressure?
To maintain the reservoir pressure, gas has to be injected into the gas-cap. The amount of injected gas depends on the size of the gas cap and other reservoir properties. Some options of injected gases includes the produced gas, lean gas, inert gas or any other gas that may be locally available.
What are the sources for most common drive mechanism?
How do you calculate gas recovery factor?
Boi = formation volume factor = 1.05 + (N × 0.05), where N = number of ft3 of gas produced per bblbarrels of oil (gas-oil ratio or GOR). For example, if a well has a GORgas-oil ratio of 1,000, then Boi = 1.05 + (10 × 0.05) = 1.1.
What is gas recovery factor?
The recoverable amount of hydrocarbon initially in place, normally expressed as a percentage. The recovery factor is a function of the displacement mechanism. An important objective of enhanced oil recovery is to increase the recovery factor.
Why does reservoir pressure decrease?
The reason for the small decline in reservoir pressure is that oil and gas withdrawals from the reservoir are replaced almost volume for volume by water encroaching into the oil zone. Figure 11-9. Pressure-production history for a water-drive reservoir.
What is solutionsolution gas drive?
Solution gas drive is the mechanism whereby the lowering of reservoir pressure through production in an undersaturated reservoir causes the oil to reach the bubble point where gas starts to evolve from solution.
How is additional energy obtained from a solution gas drive reservoir?
Additional energy is obtained from the expansion of the rock and its associated water. Depending on its discovery pressure, a solution gas drive reservoir can be initially either undersaturated or saturated. In an undersaturated reservoir, the reservoir pressure is greater than the bubblepoint of the oil.
Are black- and volatile-oil reservoirs amenable to solution gas drive?
Both black- and volatile-oil reservoirs are amenable to solution gas drive. Other producing mechanisms may, and often do, augment the solution gas drive. Solution gas drive reservoir performance is used as a benchmark to compare other producing mechanisms. Pure solution gas drive reservoirs are subject to four stages of idealized production.
How effective is water drive in oil and gas reservoirs?
A strong water drive is more effective in oil reservoirs than in gas reservoirs. On a semi-log plot of production decline, the curve tends to be flat. In fields where the aquifer is smaller and/or has lower quality, there is limited expansion of water into the reservoir as oil or gas is withdrawn.