摘要 |
A system and method for controlling drilling mud density at a location either at the seabed (or just above the seabed) or alternatively below the seabed of wells in deep water and ultra deep water applications. A base fluid of lesser density than the drilling mud required at the wellhead is used to produce a diluted mud in the riser. By combining the appropriate quantities of drilling mud with base fluid, a diluted riser mud density at or near the density of seawater may be achieved. The present invention also includes a wellhead injection device for injecting the base fluid into the rising drilling mud. The riser charging lines are used to carry the low density base fluid to the injection device for injection into the return mud. At the surface, the diluted return mud is passed through a treatment system to cleanse the mud of drill cuttings and to separate the heavier drilling mud from the lighter base fluid. The present invention further includes a control unit for manipulating drilling fluid systems and displaying drilling and drilling fluid data.
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