BAKER HUGHES - Drilling Fluids Reference Manual

RESERVOIR APPLICATION FLUIDS
(These above categories are called residual sediments)
Biological: Biochemical solution and physical fracturing (result of vegetation).
Erosion has four agents: Gravity, glacial action, running water and wind.
Note that soil is the product of biological weathering. It consists of rock debris and decaying
organic matter.
Figure 6 - 1
Rock Cycle
Classification of Sedimentary Rocks
Five generic classes are recognized; chemical, organic, residual, ferruginous and volcanoclastic.
1. Chemical sediments are formed directly by precipitation in a sub-aqueous environment.
Types of evaporates and some types of lime muds.
2. Organic sediments are composed of organic matter, both of animal and vegetable origin.
3. Residual sediments are those left in place after weathering.
4. Ferruginous sediments are the derivatives of the land mud rocks, and siliclastics.
5. Volcanoclastic sediments are the product of volcanic activity.
The above classes are sometimes divided into those which have been transported into the
depositional environment (allocthonous) and those which are formed within the depositional area
(autochthonous).
This classification is important in order to establish some idea about the rocks’ origin.
All possible mixtures of compositions and textures occur among sediments and these are studied by
proper selection of compositional and textural end members.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 6-3