Understand Boyle’s Gas Law
Boyle’s gas law states that at constant temperature, the absolute pressure and the volume of a gas are inversely proportional in case of constant temperature within a closed system. Bolye’s law can be illustrate in the graph shown in figure 1.
Figure 1 – Boyle’s Law
Well, we can describe the statement above into simple mathematics as following formula:
Boyle’s Gas Law
P x V = constant
Or express Boyle’s law in another term:
P1 x V1 = P2 x V2
Where;
P1 = Pressure at condition # 1
V1 = Volume at condition # 1
P2 = Pressure at condition # 2
V2 = Volume at condition # 2
Note: You can use any unit for Bolye’s gas law as long as P1 and P2 are the same unit and V1 and V2 are the same unit.
Let’s apply Boyle’s law into our drilling business
Calculate the volume of gas you will have on the surface, 14.7 psi for atmospheric pressure, when 1 bbl of gas kick is circulated out from reservoir where has formation pressure of 3,000 psi. Figure 2 and 3 shows the condition of this well.
Figure 2 – Gas Kick 1st condition at the bottom
Figure 3 – Gas Kick 2nd condition
Apply the Boyle’s Gas Law:
P1 x V1 = P2 x V2
P1= 3000 psi (reservoir pressure)
V1 = 1 bbl (volume at bottom hole)
P2 = 14.7 psi (atmosphere pressure)
V2 = ? (volume at surface)
P1 x V1 = P2 x V2
3000 x 1 = 14.7 x V2
V2 = 204 bbl
Figure 4 – Gas
References
Cormack, D. (2007). An introduction to well control calculations for drilling operations. 1st ed. Texas: Springer.
Crumpton, H. (2010). Well Control for Completions and Interventions. 1st ed. Texas: Gulf Publishing.
Grace, R. (2003). Blowout and well control handbook [recurso electrónico]. 1st ed. Paises Bajos: Gulf Professional Pub.
Grace, R. and Cudd, B. (1994). Advanced blowout & well control. 1st ed. Houston: Gulf Publishing Company.
Watson, D., Brittenham, T. and Moore, P. (2003). Advanced well control. 1st ed. Richardson, Tex.: Society of Petroleum Engineers.
