GEOG 4891 Lecture Notes - Lecture 9: Neal Adams, Pennwell, Directional Drilling
Course description: pressure profile, casing design, cementing, well control, directional drilling, fishing. Petroleum engineering, drilling and well completion prentice-hall inc. Formation pressure or pore pressure (pf: matrix stress or lithostatic pressure (pm) The summation of formation pressure and matrix stress is total overburden pressure (pob) Hydrostatic pressure is conceptually to be refreshed before going though abnormal pressures. Hydrostatic pressure (ph): function of average unit weight of the fluid ( ), gravity acceleration (g) and vertical height (d) of the fluid column in open system. Hydrostatic pressure gradient is function of: dissolved solids, dissolved gasses, temperature gradient. Increasing dissolved solids (such as higher salt concentration) in fluid column increases hydrostatic pressure gradient, while increasing dissolved gas and or temperature as well, decreases it. Sg: average specific gravity of the water column (1) Overburden pressure (pob) is the total weight of rock matrix and fluids in the pores overlaying concerned underground formation. In general, overburden pressure increases uniformly by depth.