### Water Breakthrough Time in a Vertical Oil Well

Consider an oil reservoir with an underlying water zone. An oil well that is producing from this reservoir will experience the phenomenon of water breakthrough if the well produces above its critical rate. Since economic considerations often demand high flowrates, this can be a real risk.

This Excel spreadsheet uses the Sobocinski-Cornelius method to calculate the water breakthrough time.  This method was published in 1965, and was derivied from laboratory tests. It uses these equations.

where

• Bo is the oil formation volume factor
• μo is the oil viscosity (cp)
• μw is the water viscosity (cp)
• φ is the porosity
• h is the oil column thickness (ft)
• hp is the perforated interval (ft)
• Qo is the oil production rate (STB day-1)
• α is 0.5 if M <=1, or 0.6 otherwise
• M is the water-oil mobility ratio
• tBT is the time to breakthrough
• tD is the dimensionless time (Sobocinski-Cornelius method)
• Z is the dimensionless cone height
• ρw is the water viscosity (lb ft-3)
• ρo is the oil density (lb ft-3)

### Binary Distillation with McCabe-Thiele Method

This Excel spreadsheet uses the McCabe-Thiele method to calculate the number of theoretical stages needed for binary distillation.

Binary distillation is a common unit operation that separates two liquids (with one being more volatile, or "lighter"). The concepts are encountered in many branches of chemical and petroleum engineering.

Simply enter your parameters at the top of the spreadsheet, including the
• feed flowrate,
• mole fraction of the light component (or more volatile component) in the feed,
• mole fraction of light component in the top product,
• mole fraction of light component in the bottom product,
• reflux ratio,
• relative volatility of the light component
• and the q-line value.
The spreadsheet will automatically calculate flowrates throughout the column, the number of theoretical plates, the feed plate position, the minimum reflux ratio (from the Underwood equation), and the minimum number of theoretical plates (from the Fenske equation)

The spreadsheet also automatically draw the traditional McCabe-Thiele plot. This is a classic Chemical Engineering diagram and shows the number of theoretical stages, the position and slope of the q-line, and the relative volatility curve, and the purity of the top and bottom products.