Retort Analysis

A mud retort with an “oven” heating feature is used to measure the amount of liquids and solids in drilling fluid. Here’s how it works: A small sample of mud (using a 10 ml, 20 ml, or 50 ml retort) is placed in a cup, and a lid is added to push out some fluid, ensuring the correct volume. The sample is then heated until the liquid parts turn into vapor. The vapor is cooled in a condenser and collected in a measuring cylinder, which shows the results in percentages. The amounts of oil and water are measured directly as percentages. The solids, both suspended and dissolved, are calculated by subtracting the liquid percentages from 100% or by checking the empty space at the top of the cylinder. This helps determine the exact composition of the drilling fluid

The calculation of oil-to-water ratio requires retort values as follows.

$oil ratio = (\frac{% oil}{% oil + % H_{2} O}) 100$

$Water ratio = (\frac{% H_{2} O}{% H_{2} O + % oil}) 100$

Oil, Water, and Solids Percentage Calculator

Total Volume (mL): Total Liquid Collected (mL): Volume of Water (mL):

Percent Oil: Percent Water: Percent Solids:

Oil must be added to raise the oil-to-water ratio. No water will be added to the system.
To Calculate the barrels of oil required to increase O/W ratio:

Record the retort volume % oil as % oil
Record the retort volume % water as % H₂O
Record the water ratio of the desired O/W ratio as W_R

Calculate the barrels of oil to add:

$Oil to add (\frac{bbl}{bbl} mud) = \frac{% H_{2} O}{W_{R}} - \frac{(% oil + % H_{2} O)}{100}$

in this equation

$New liquid volume (\frac{bbl}{bbl} &#xA0 mud) = \frac{% H_{2} O}{W_{R}}$

$Original liquid volume (\frac{bbl}{bbl} mud) = \frac{(% oil + H_{2} O)}{100}$

New liquid volume = Original liquid volume + oil to add

Example:

Volume % oil (retort)=51%
Volume % water (retort) = 9%
Original O/W ratio = 85/15
Desire O/W ratio = 90/10
To increase the O/W ratio from 85/15 to 90/10, calculate how much oil must be added:

$oil to add (\frac{bbl}{bbl} mud) = \frac{9}{10} - \frac{51 + 9}{100} = 0.9 - 0.6 = 0.3 bbl oil per bbl of mud$

Inreasing oil-to-water ratio

	Given	Required
% Oil
% Water
Oil Ratio
Water Ratio
Oil to Add (bbl/bbl mud)

Decreasing oil-to-water ratio

	Given	Required
% Oil
% Water
Oil Ratio
Water Ratio
Oil to Add (bbl/bbl mud)