The situations in the field are various, which is a challenge in both design and logistics for drilling mud treatment and management. After the core treating process such as solid-liquid separation, it is essential to combine some different operational modules to fulfill the rapid and full handling. The following section will briefly discuss the on-site and off-site treatment/management based on chemical separation according to previous experience.
The use of “dewatering units,” as a regular part of the drilling fluid treatment process on drilling rigs, continues to increase. A dewatering unit, the final phase of a solids control program, is designed to discard no free liquid. A solids control program in which a dewatering unit is used is referred to as a “closed-loop system” (CLS), “sump-less system,” or “chemically enhanced centrifugation” (CEC).
Offshore drilling rigs operate in very sensitive environments surrounded by water. Waves can wash seawater onto the rig. Monsoons can completely cover the deck with a thick layer of water within a couple of minutes. Oil spillages can end up on the drill floor because of a mistake or a mechanical failure.
Use of traditional cuttings handling systems based on washing the cuttings. By cleaning the cuttings, the oil content in the cuttings can be brought down to approximately 100g oil content per. kg drilled cuttings, which is the average allowable discharge of oil per. well. This again means that the cleaned cuttings can be dumped to sea after cleaning is performed.