Is oil-based mud environmentally friendly?
Palm oil and groundnut oil are highly biodegradable and have better eco-toxicological properties compared to diesel. Most environmental protection regulations are favourably disposed to vegetable oil-based mud because of their high biodegradability and minimal impact on the ecosystem and its organisms.
What is compressibility in oil and gas?
Compressibility of Oil Oil compressibility (also called isothermal oil compressibility) is defined as the change in fluid volume with respect to the change in pressure at isothermal conditions. A point of sudden increase in compressibility therefore exists at the bubble-point pressure.
Why 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.
Is oil-based mud flammable?
Oil-based mud is a drilling fluid used in drilling engineering. The oil base can be diesel, kerosene, fuel oil, selected crude oil or mineral oil. The requirements are a gravity of 36–37 API, a flash point of 180 °F (82 °C), fire point of 200 °F (93 °C) and an aniline point of 140 °F (60 °C).
What is synthetic based mud?
1. n. [Drilling Fluids] 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 drilling fluid made of?
Drilling muds are traditionally based on water, either fresh water, seawater, naturally occurring brines, or prepared brines. Many muds are oil-based, using direct products of petroleum refining such as diesel oil or mineral oil as the fluid matrix.
What is compressibility of gases?
Gas compressibility factor is also called “deviation factor” or “z-factor.” Its value reflects how much the real gas deviates from the ideal gas at a given pressure and temperature.
Why is oil not compressible?
In other words, the dissolved air decreases the bulk modulus of mineral oils and therefore decreases the resistance to compression. This effect is especially present at low operating pressures, as a fluid is pressurized, the entrained air is compressed and has less influence on the compressibility.
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 is the difference between drilling fluid and drilling mud?
Both liquid and mud are used to drill boreholes but the composition is different. One term is often used for the other, but strictly speaking gaseous drilling fluid, using an array of gases, is a fluid. But fluids that are water or oil based are called mud.
Is drilling mud hazardous?
Drilling muds are composed of numerous chemicals, some of which are toxic, and which are harmful to the environment and its flora and fauna.
Why is bentonite used for drilling mud?
The most common use of bentonite is in drilling fluids. The bentonite in the flush fluid lubricates and cools the cutting tools whilst protecting against corrosion. As the drilling fluid generates hydrostatic pressure in the borehole, it hinders fluid and gas penetration.
How is mud compressibility determined in a formation test?
Mud compressibility is then estimated from the measured pressure. A method for determining mud compressibility is disclosed. The method comprises capturing wellbore fluid in the formation tester, the wellbore fluid being in fluid communication with a pretest chamber containing a movable piston.
What are the advantages and disadvantages of oil based mud?
3. Water-based mud can easily block the layers of very low permeability and influence the capability. 4. Oil-based mud can support the shale formation and its oil molecules cannot penetrate into tiny organic and non-organic pores under the capillary pressure.
How is the compressibility of oil measured in isothermal conditions?
Oil compressibility (also called isothermal oil compressibility) is defined as the change in fluid volume with respect to the change in pressure at isothermal conditions. Oil compressibility is expressed in psi−1. Another unit (microsip) is also used.
Which is the best definition of oil compressibility?
Isothermal compressibility. Oil compressibility is a measure of change in volume as a result of change in prevailing pressure. It is defined as the rate of change in the volume of crude oil per unit change in pressure divided by the volume of oil.