How is oil based mud made?
Many muds are oil-based, using direct products of petroleum refining such as diesel oil or mineral oil as the fluid matrix. In addition, various so-called synthetic-based muds are prepared using highly refined fluid compounds that are made to more-exacting property specifications than traditional petroleum-based oils.
What is the difference between oil based mud and water-based mud?
Oil-Based muds can be formulated to withstand high temperatures over long periods of time, however, Water-Based mud can break down and lead to loss of viscosity and fluid loss control. The initial cost of Oil-Based mud is high, especially those formulations based on mineral or synthetic fluids.
What is the percentage of water in oil based mud?
OWR is calculated directly from the retort analysis of an oil mud. For example, if a mud contains 60 vol. % oil and 18 vol. % water, the oil percentage is [60/(60 + 18)]100 = 77% and the water percent is [18/(60 +18)] = 23%.
Why do we use oil based mud?
Oil-based muds have become more widely used because of their distinct advantages over water-based muds. Boyd el al. list (1) thermal stability in deep, high-temperature wells, (2) increased lubricity in deviated offshore wells, and (3) hole stability in thick, water-sensitive shales as advantages of oil-based muds.
What is NDF mud?
Nonaqueous, water-internal (invert) emulsion muds in which the external phase is a synthetic fluid rather than an oil. This and other more minor changes in formulations have made synthetic fluids in muds more environmentally acceptable for offshore use.
What is Sobm in drilling?
In 2014, synthetic oil based mud (SOBM) was used to drill the Telisa section as a way to. improve the drilling performance and reduce drilling. cost.
How do you clean oil based mud?
you can use any detergent (e.g. Fairy) to remove the oil based mud from the cuttings and washed it many times with clean water and then dry it at up 110 degrees in oven or you can dry it in room temperature. Be careful to not dry it in high temperatures as you may affect the organic content of the samples.
What makes up an oil based mud system?
An oil based mud can be defined as a drilling fluid which has oil as its continuous external phase and the water, if present, is a dispersed or internal phase. The solids in an oil-based fluid are oil-wet, all additives are oil dispersible and the filtrate of the mud is oil.
Why are oil based muds used for shale drilling?
Oil muds are most suited for drilling water sensitive shales. Formulated with the proper salinity, oil muds can prevent water movement from the mud into the shale. In some cases, water can actually be drawn from the shale and could result in strengthening.
What’s the ratio of oil to brine in an invert mud system?
As the name implies, an invert is an emulsion mud utilizing oil as the continuous or external phase. Brine constitutes the discontinuous or internal phase of the mud. Typical oil/brine ratios range from 95/5 to 50/50 in invert emulsion systems.
Why are oil MUDs called relaxed invert emulsions?
Invert emulsions are usually tightly emulsified, low fluid loss oil muds. An improvement in drilling rates has been seen when the fluid loss control of the system is relaxed, thus the name “relaxed” invert emulsion. Also, the relaxed invert emulsions fluids do not use as much emulsifier as the regular invert emulsion systems.