What is fenestral porosity?
What is fenestral porosity?
fenestral porosity Porosity developed in carbonates due to the presence of fenestrae. Rocks with fenestral porosity will not form good reservoir rocks unless the fenestrae are interconnected to permit a good permeability to be established. See CHOQUETTE AND PRAY CLASSIFICATION. A Dictionary of Earth Sciences.
What are fenestrae geology?
The fenestrae lie between lithified laminae formed in surface algal layers. The crusts consist of pellets, skeletal fragments, and cryptocrystalline aragonite. Deposits of mud and pellets form floors in some fenestrae.
What causes Fenestral fabric?
Tubular fenestrae probably formed by burrowing organisms in soft, wet intertidal and/or shallow subtidal sediments. Irregular and laminoid fenestrae formed by desiccation/lithification in more frequently exposed sediments resulting in hard, indurated surfaces in tidal flats, which inhibited further burrowing.
What is porosity in reservoir?
Porosity determines reservoir storage capacity. It is defined as the ratio of void space, commonly called pore volume, to bulk volume and is reported either as a fraction or a percentage. (Also see Reservoir quality.)
What is primary porosity?
Primary porosity describes the pore spaces between grains that are formed during depositional processes, such as sedimentation and diagenesis. Total porosity is the sum of the primary and secondary porosities. The porosity of a soil sample or unconsolidated sediment is determined as follows.
What is porosity in geology?
More specifically, porosity of a rock is a measure of its ability to hold a fluid. Mathematically, it is the open space in a rock divided by the total rock volume (solid and space). A rock may be extremely porous, but if the pores are not connected, it will have no permeability.
What is intercrystalline porosity?
Intercrystalline Porosity. This type of porosity is formed in the existing space among the dolomite crystals (Figure 3(a)) and their geological origin is from sabkha to open marine. This porosity is one of the best spaces for gas reserves in the gas field.
What is vuggy porosity?
Vuggy porosity is gas- or fluid-filled openings in rock matrix that are large enough to be seen with the unaided eye. Well-connected vugs can form major conduits for flow of ground water, especially in carbonate rocks.
What is Fenestral limestone?
Fenestral fabric: pores that are large compared to the size of expected intergranular pores, forming an elongate or domal shape parallel with bedding plane; often associatated with cyanobacterial mats. These fabrics are know as laminar birdseye limestones too. May be cement-filled.
What is porosity geology?
How do you define porosity?
Porosity is defined as the ratio of the volume of pores to the volume of bulk rock and is usually expressed as a percentage.
What is the difference between porous and permeable?
More specifically, porosity of a rock is a measure of its ability to hold a fluid. Permeability is a measure of the ease of flow of a fluid through a porous solid. A rock may be extremely porous, but if the pores are not connected, it will have no permeability.
What is the definition of fenestra?
Definition of fenestra 1 : a small anatomical opening (as in a bone): such as 2 : an opening cut in bone 1 : a small anatomical opening (as in a bone): as
What is the antorbital fenestra?
Recent Examples on the Web In most meat-eating dinosaurs, a ridge of bone provides a roof over an opening in the skull in front of the eye sockets known as the antorbital fenestra.
What is the dorsotemporal fenestra?
— Fox News, 6 Sep. 2019 The specialized pocket sits within an opening on the top rear of the skull called the dorsotemporal fenestra.
What are the characteristics of Stromatactis fenestria?
Basic features of stromatactis fenestrae The stromatactis-type fenestrae (Figs 3–6) have relatively smooth and sharp (horizontal or slightly bent) bases, but the roofs are clearly arched and have friable fabrics. The upper sides of individual stromatactis chambers are den- sely ornamented by cuspate or digitate protrusions.
