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 are the advantages of oil-based muds over water-based muds?
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.
When should we use oil-based mud?
Oil-based mud is a drilling fluid used in drilling engineering. It is composed of oil as the continuous phase and water as the dispersed phase in conjunction with emulsifiers, wetting agents and gellants. The oil base can be diesel, kerosene, fuel oil, selected crude oil or mineral oil.
Why do we use water-based mud?
Water-based fluids (WBFs) are used to drill approximately 80% of all wells. For example, the surface interval typically is drilled with a low-density water- or seawater-based mud that contains few commercial additives. These systems incorporate natural clays in the course of the drilling operation.
What is synthetic oil 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.
Why is barite used in drilling mud?
Barite increases the hydrostatic pressure of the drilling mud allowing it to compensate for high-pressure zones experienced during drilling. The softness of the mineral also prevents it from damaging drilling tools during drilling and enables it to serve as a lubricant.
What are the disadvantages of adding solids to the water based mud?
Excessive massive solids will increase pressure more than formation pressure, and drilling mud will permeate into strata while fine particles will enter into oil channel which results in blockage causing damage of oil reservoir.
What does continuous phase in mud mean?
1. n. [Drilling Fluids] The continuous phase of an emulsion. The internal phase is the dispersed droplets of emulsified fluid. Synonyms: external phase.
Which type of clay is used as a drilling mud?
bentonite clay
Water-based drilling mud most commonly consists of bentonite clay (gel) with additives such as barium sulphate (barite), calcium carbonate (chalk) or hematite.
What are the advantages using polymer mud?
Polymer-based drilling fluids used in the Bashkortostan fields of Russia can increase penetration rates, improve core recovery, minimize formation damage, retain a near-gauge hole, and reduce transportation and preparation costs.
What’s the difference between oil based and water based MUDs?
Drilling muds are actually the life blood of a drilling system, keeping the wellbore clean and all operations running smoothly while avoiding formation damage. The two most common types are oil-based muds and water-based muds, with both having many variations designed to meet the demands of specific drilling applications.
What kind of mud is used for drilling?
Oil-based mud is a drilling fluid used in drilling engineering. It is composed of oil as the continuous phase and water as the dispersed phase in conjunction with emulsifiers, wetting agents and gellants. The oil base can be diesel, kerosene, fueloil, selected crude oil or mineral oil. – wiki emulsified within the oil.
What’s the difference between oil based and water based drilling fluids?
Water-Based vs. Oil-Based Drilling Fluids. Water-Based vs. Oil-Based Drilling Fluids. These two types of drilling fluids have very different behavior. In recent years, the oil-based drilling fluid has gained popularity, but the present environmental movement brings water-based drilling fluids back.
Is it safe to use oil based mud?
Oil-Based mud can be damaging to the rubber parts of the circulating system and preclude the use of special oil resistant rubber. It has posed potential fire hazards due to low flash points of vapors coming off the oil. Additional rig equipment and modifications are necessary to minimize the loss of Oil-Based mud [5].