Solids Removal by Mechanical Separation
Of all the problems that could conceivably occur during the drilling of a well, mud contamination from drilled solids is a certainty. The volume and type of solids present in drilling mud exert a considerable influence over mud treating costs, drilling rates, hydraulics, and the possibility of differential sticking, kicks, and lost returns.Solids control is one of the most important phases of mud control – it is a constant issue, every day, on every well. If drilled solids can be removed mechanically, it is almost always less expensive than trying to combat them with chemicals and dilution.

The primary reason for using mechanical solids control equipment is to remove unwanted drilled solids particles fro the mud in order to prevent drilling problems and reduce mud and waste costs, thereby reducing overall drilling costs. The benefits of solids removal by mechanical separation can best be seen in terms of two outcomes:

1) Reduced total mud solids
2) Reduced dilution requirements

Click here to learn more about the solids removal equipment offered by Mud Control Equipment, Corp.

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Mechanical Separation vs. Dillution

 

A common method of trying to offset the build-up of drilled solids is the addition of more liquid.This is known as dilution and does not remove cuttings but reduces their concentration in a drilling mud, thereby reducing the percent of total solids in the mud.

 

However, it is important to note that dilution is expensive. Every barrel of dilution water (or oil) added requires and additional amount of chemicals, barite or other materials in order to maintain desired mud properties. The lower the drilled solids content to be maintained, the greater the dilution required. In the case of an oil-base mud, oil must be used for dilution – which can become extremely expensive.

 

Effective solids removal by mechanical separation can maintain a minimum solids level in drilling mud and greatly reduce the need for dilution. Reducing the need to dilute the mud can drastically decrease the cost of having to purchase mud products such as weight material (barite) and chemicals.These materials are expensive – mud costs can be 10% of the total cost of drilling a well.

Dilution Ratio Chart

The Dilution Ratio Chart below can be used indirectly to approximate the amount of dilution that can be eliminated by use of solids removal equipment. For example, suppose a drilling engineer required that no more than 5% solids were to be maintained in an unweighted mud. The chart shows that at 5%, each barrel of mud would contain about 45 pounds of drilled solids. If solids control equipment were removing 1 ton (2000 lbs) of solids per hour, then the equipment would save 2000 ÷45 = 44 barrels of dilutions per hour. If the chemicals and additives were worth only $10 per barrel, the mud treating costs would be reduced by approximately $440 per hour! Over the life of a drilling operation, $440 per hour adds up to a very significant cost savings.