Calculate Specific Gravity (SG) in oilfield unit

You may need to calculate specific gravity from different density or pressure gradient units. This post demonstrates you about specific gravity calculation and specific gravity formulas frequently used in oilfield business.

1. Calculate specific gravity using mud weight in PPG

 

Specific gravity formula : Specific Gravity (SG) = mud weight in ppg ÷ 8.33

Example: 
Fluid = 13.0 ppg
Specific Gravity (SG) = 13.0 ppg ÷ 8.33
Specific Gravity (SG)= 1.56

2. Calculate specific gravity using pressure gradient in psi/ft

 

Specific gravity formula : Specific Gravity (SG) = pressure gradient in psi/ft ÷ 0.433

Example: pressure gradient = 0.50 psi/ft
Specific Gravity (SG) = 0.50 psi/ft ÷ 0.433
Specific Gravity (SG) = 1.15

3. Calculate specific gravity using mud weight in lb/ft3

 

Specific gravity formula : Specific Gravity (SG) = mud weight in lb/ft3 ÷ 62.4

Example: Mud weight = 90 lb/ft3
Specific Gravity (SG)= 90 lb/ft3÷ 62.4
Specific Gravity (SG) = 1.44

Please also find the Excel Sheet: Specific Gravity Calculation Sheet

Ref books: Lapeyrouse, N.J., 2002. Formulas and calculations for drilling, production and workover, Boston: Gulf Professional publishing.

Bourgoyne, A.J.T., Chenevert , M.E. & Millheim, K.K., 1986. SPE Textbook Series, Volume 2: Applied Drilling Engineering, Society of Petroleum Engineers.

Mitchell, R.F., Miska, S. & Aadny, B.S., 2011. Fundamentals of drilling engineering, Richardson, TX: Society of Petroleum Engineers.

Related Post

Starting volume of original mud (weight up with Ca... You know how much volume will be increased due to adding calcium carbonate into the system; however, you sometimes are limited to total volume due to ...
Increase oil/water ratio The concept of increase oil water ratio is to increase oil volume in the system without any changes in water to meet new oil water ratio. How can ...
Calculate Pressure Gradient and Convert Pressure G... This article describes about how to calculate and convert pressure gradient in different units. Please see simple oil field formulas shown each topic ...
Determine surge and swab pressure for close-ended ... I would like to show more calculation about surge and swab pressure. In this article, I will show how to use the previous formulas (Surge and swab pre...
Share the joy
  • 448
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
    448
    Shares
Tagged . Bookmark the permalink.

About DrillingFormulas.Com

Working in the oil field and loving to share knowledge.

Comments are closed.