Mud cake (also mudcake) is the layer of particulates from drill mud coating (caking) the inside of a

borehole A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petro ...

after the suspension medium has seeped through a porous

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

. Similar to

filter cake A filter cake is formed by the substances that are retained on a filter. Filter aids, such as diatomaceous earth or activated carbon are usually used to form the filter cake. The purpose is to increase flow rate or achieve a smaller micron filtra ...

. Mud cake provides a physical barrier to prevent further penetration and loss of drilling fluid, as well a later loss of produced fluids, into a permeable formation.Schlumberger Oilfield Glossary, 'formation damage

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References

{{reflist Drilling technology Fluid dynamics