Tham khảo tài liệu 'orr, f. m. - theory of gas injection processes episode 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | . EXERCISES 71 Binary Displacement with Mutual Solubility. The discussion of the application of the velocity constraint and entropy condition to eliminate nonphysical solutions follows that of Johns 54 Chapter 3 for the Buckley-Leverett problem. Examples of solutions for displacement of C10 by CO2 are given by Pande 95 Chapter 4 . The description of the dependence of solutions on initial and injection conditions was given first by Helfferich 32 . Effects of Volume Change on Mixing. A comparison of binary solutions with and without volume change as components change phase is given for CO2 C10 displacements by Dindoruk 19 Chapter 6 . Exercises 1. Characteristic curves. Consider the equation -CC. C 0 4 n CdX - The initial composition is Cinit and the injection composition is Cinj . Derive expressions for the characteristic curves. Plot the appropriate characteristic curves on a t-x diagram. Determine whether shocks would occur in this displacement. 2. Gas dissolution. Consider a laboratory core which contains initially water that is saturated with CO2 in equilibrium with gas at the critical gas saturation Sgc . The equilibrium volume fraction of CO2 dissolved in the saturated water phase is and the volume fraction of water in the gas phase is . At time T 0 injection of pure water into the core begins. Assuming that effects of volume change as components change phase can be neglected calculate the saturation profile at T pore volumes injected. Determine how much pure water would have to be injected to remove all the gas present initially in the core. 3. Calculate the saturation profile at T and pore volumes injected for the relative permeability functions of Eqs. with Sgc Sor and M 10 for a displacement in which gas displaces oil. The volume fraction of the light component required to saturate the liquid phase is and the volume fraction of light component in the equilibrium vapor phase is . The
