Function Description
Submersible Rigs
Submersible rigs, suitable for shallow water, come in contact with the ocean or lake floor. These rigs consist of platforms with two hulls positioned on top of one another. The upper hull contains the living quarters for the crew, as well as the actual drilling platform. The lower hull works much like the outer hull in a submarine - when the platform is being moved from one place to another, the lower hull is filled with air - making the entire rig buoyant. When the rig is positioned over the drill site, the air is let out of the lower hull, and the rig submerses to the sea or lake floor. This type of rig has the advantage of mobility in the water, however once again its use is limited to shallow …ver más…

The effective viscosity can be determined from following simple formula. μ = ρ (t - 25)
Where:
μ = effective viscosity in centipoises ρ = density in g/cm³ t= quart funnel time in seconds
Important: If water is used, the time should be 26 +/- 0.5 seconds. If the time is less than this the tube is probably enlarged by erosion, if more it may be blocked or damaged, and the funnel should be replaced.
Definition Paragraph
Bentonite is an absorbent aluminium phyllosilicate, in general, impure clay consisting mostly of montmorillonite. There are different types of bentonites, and their names depend on the dominant elements, such as potassium (K), sodium (Na), calcium (Ca), and aluminum (Al). As noted in several places in the geologic literature, there are some nomenclatorial problems with the classification of bentonite clays. However, the term bentonite, as well as a similar clay called tonstein, has been used for clay beds of uncertain origin.
Classification Paragraph
There are several types of drilling fluids used depending on the drilling conditions encountered: -Water-based muds are used most frequently. The base may be either: fresh water, or salt water. -Oil-based muds. -Synthetic materials. The oil and gas extraction industry has developed many new oleaginous (oil-like) base materials from which to formulate high-performance drilling fluids. - Air and