How can hidrocarbon have been form at the reservoir ?
The answer is with petroleum system : petroleum system is system to accumulate hydrocarbon, this need a process start from organic material accumulate on source rock generation, migration, until accumulate on reservoir rock.
Before the answer will be given we must know the part of petroleum system including :
1.Bedrock (Source): rock that has a lot of organic material content. These rocks, are rocks that have a nature capable of preserving the content of organic material such as stone or clay content of rocks that have a lot of organic material such as limestone.
2. Rock storage (Reservoir): rock that has the ability to store fluid such as sandstone where oil or gas can be between grains of sandstone. Or it could be in a lot of limestone cavity-sockets. Essentially a rock cavity and the cavities are connected with each other.
3. Cap rock (Seal): an impermeable rock or rock that is not easy to penetrate because it is very fine grained which the grains each other very tightly.
4. Migration (Migration): migration of oil or natural gas that is formed from parent rock to rock storage until the oil and gas which can not move anymore.
5. Trap (Trap): the form of a geometry that can hold oil and gas to be able to gather.
The process is also important to the constituent elements of crude oil. If we have the element but not support or otherwise process the crude oil will also not be formed.
The process to accumulate hydrocarbon can also be divided into 5 stages.
1. Formation (Generation): The pressure from above rocks host rock makes the temperature and pressure becomes greater and can cause changes of source rock organic material into oil or natural gas.
2. Migration or migration (Migration): The compound hydrocarbon (oil and gas) will tend to move from the source rocks (source) to the rock storage (reservoir) because its density is lighter than water.
3. Collection (accumulation): A number of hydrocarbon compounds which move faster than the parent rock to rock trap storage than the loss of time will make the oil and gas accumulated.
4. Storage (Preservation): Oil or gas is still stored in the rock storage and unchanged by other processes such as biodegradation (changed because there are microbes that can damage the quality of the oil).
5. When (Timing): The trap must be formed before or during the switch from petroleum source rocks to the rock storage.
Well if all conditions are met then chances are we can find oil or gas traps.
So now we know about how can hydrocarbon can be find at the reservoir.
Thanks for read Petroleum System to Accumulate Hydrocarbon we will continue discuss about petroleum system on next article.