Table of Contents
What are characteristics of a reservoir?
As a rock to be named a reservoir has to be a porous and permeable lithological structure. It encompasses sedimentary rocks. These sedimentary rocks may be made of sandstones (quartz sand or arksosic sandstone), carbonates mud or dolomite.
What is reservoir quality?
1. n. [Formation Evaluation, Well Completions, Shale Gas] A prediction of the likelihood of a rock to yield commercial quantities of hydrocarbons. Reservoir quality (RQ) is a geologic, engineering and economic assessment of a resource, its reserves and their producibility.
What are the most important characteristics of reservoir rock?
The most prominent features of reservoir rock are porosity, permeability, and fluid saturations. These properties related to the pore media system and its fluid distribution and flow forms. By carrying out laboratory analyses, using core samples, reservoir rock properties can be investigated.
What kind of rock makes a good oil reservoir?
If you are referring to oil reservoirs then limestones (carbonates) contain >60% of the world’s hydrocarbon reserves; therefore limestones make very effective reservoir rocks. A good reservoir rock is one that contains significant porosity and permeability to store the hydrocarbons and allow them to flow.
What is a good permeability for a reservoir?
The typical reservoir permeability range of 0.001 md (1 μD) to 0.1 md (100 μD) is considered.
What should be the main characteristics of a good underground reservoir?
Underground reservoirs are geological structures that have unique features. There is a porous medium having some degree of permeability. The porosity allows natural gas to be contained within the medium. The permeability allows the gas to move from point to point within the medium.
Why is clay good for a reservoir?
Clay minerals, used as a rock and particle term, describe an earthy, fine-grained, natural material which develops plasticity when mixed with a small amount of water. Such clay minerals significantly affect important reservoir properties such as porosity, water saturation, and permeability.
How do you calculate reservoir quality?
The quality of a reservoir is defined by its hydrocarbon storage capacity and deliverability. The hydrocarbon storage capacity is characterized by the effective porosity and the size of the reservoir, whereas the deliverability is a function of the permeability.
What is good porosity in reservoir rock?
2 Reservoir porosity. Fluid-productive sandstones display porosities ranging between 0.05 and 0.4, or 5%–40%. Although the porosity of carbonate base material is practically zero, the overall porosity of carbonate rocks can be significant due to natural fractures within the rocks.
What is good permeability?
Good permeabilities are observed for polyimides such as 6FDA-Durene, which have high fractional free volume allowing significant amounts of hydrogen to easily diffuse (Powell and Qiao, 2006).
How is a reservoir made?
A reservoir is an artificial lake where water is stored. Most reservoirs are formed by constructing dams across rivers. A reservoir can also be formed from a natural lake whose outlet has been dammed to control the water level. People build reservoirs because the amount of water in a river varies over time.
What is reservoir and examples?
Reservoirs can be natural or artificial (human-made). Examples of natural reservoirs include hydrocarbon reservoirs in rock formations (Figure 1) and water reservoirs that occur behind naturally occurring dams. Artificial dams mostly involve water, such as the reservoirs behind hydroelectric dams (Figure 2).
What makes a reservoir rock a good reservoir?
The shale also contains organic matter, which is why it’s black. The sandstone and the limestone are conventional reservoir rocks in that they have both good porosity and good permeability. This can be demonstrated simply by pouring water on the two rocks. In both cases, the water is quickly absorbed into the rock.
What makes a dolomite a good reservoir rock?
Dolomites mostly form good reservoirs because the common reason behind it is that there is Mg, 13% smaller than Ca in a way that during dolomitization, there is a total decrease in volume of the material by 13%, here by 13% porosity is gained. The term sand refers to a specific grain with sizes between (62 µm – 2 mm).
How is the content of a reservoir determined?
Significant part of their scientific studies on particular petroleum system is on estimating the possible quantity of hydrocarbons (crude oil) that may be present there. The reservoir content is estimated by means studying rock properties which can be determined in a direct way or indirectly.
How does size of grains affect reservoir properties?
Sorting or uniformity of size of the grains: size of grains has an effect on reservoir properties; the more uniform the grains are sized, the great proper volume of voids spaces. Thereby mixing grains of different sizes tends to decrease total volume of void space.