Capillary pressure correlation was developed by Brooks and Corey, which is frequently used to study and analyze the capillary pressure behavior in porous media, including hydrocarbon bearing formations. It was proposed more than 40 years ago and since then has been implemented during various studies in different ways. This paper gives a brief overview of Brooks and Corey correlation and its usage, which shows its significance in reservoir engineering studies. Also, in this study a correlation has been proposed between reservoir characteristic constant and change in maximum displacement pressure.