What Does Synthetic-Based Drilling Mud (SBM) Mean?
Synthetic-based drilling mud (SBM) also known as low toxicity oil-based mud (LTOBM) is an invert emulsion mud with synthetic oil as the external phase instead of oil. This has made SBM's more environmentally acceptable than oil-based muds for use in offshore drilling in spite of the high initial cost.
These muds have performance, as good as oil-based muds, but comply with environmental regulations. SBM drill cuttings are approved to be disposed of into the water because they biodegrade faster.
Trenchlesspedia Explains Synthetic-Based Drilling Mud (SBM)
Synthetic-based drilling mud (SBM) was developed as a result of meeting stringent environmental regulations to minimize the environmental impact from oil-based drilling muds. Petroleum derived mineral oils do not sufficiently biodegrade and therefore pose a risk to marine species.
However; there was a need to develop a drilling fluid that could match the high performance of oil-based muds. This led to the development of SBM that was formulated with greater biodegradability and reduced toxicity.
The cost of SBM per barrel is high but their fast rate of penetration and less mud related non-productive time make them an economical choice for offshore applications. Similar to oil-based muds, SBM's can maximize the rate of penetration (ROP), increase lubricity in directional and horizontal wells, and reduce problems related to wellbore instability such as in reactive shales.
The performance of SBM is comparable to diesel and mineral-oil based fluid.