Petroleum Engineering 405 Drilling Engineering 1 Well Drilling Engineering Drilling Hydraulics Hydrostatics Dr DO QUANG KHANH 2 Drilling Hydraulics Hydrostatics Hydrostatic Pressure in Liquid Columns[.]
Well Drilling Engineering Drilling Hydraulics - Hydrostatics Dr DO QUANG KHANH Drilling Hydraulics - Hydrostatics Hydrostatic Pressure in Liquid Columns Hydrostatic Pressure in Gas Columns Hydrostatic Pressure in Complex Columns Forces on Submerged Body Effective (buoyed) Weight of Submerged Body Axial Tension in Drill String σ A = FA / A Read: Applied Drilling Engineering, Ch.4 (Drilling Hydraulics) HW #4 ADE # 4.3, 4.4, 4.5, 4.6 WHY? Drilling Hydraulics Applications Calculation of subsurface hydrostatic pressures that may tend to burst or collapse well tubulars or fracture exposed formations Several aspects of blowout prevention Displacement of cement slurries and resulting stresses in the drillstring Drilling Hydraulics Applications cont’d Bit nozzle size selection for optimum hydraulics Surge or swab pressures due to vertical pipe movement Carrying capacity of drilling fluids Well Control ppore < pmud < pfrac Fig 4-2 The Well Fluid System Forces Acting on a Fluid Element F1 = FWV = specific wt of the fluid pA dp ∆D)A F2 = (p + dD F3 = Fw v A∆D Pressures in a fluid column At equilibrium, ΣF=0 = F1 + F2 + F3 dp ∑ F = = pA − (p + dD ∆D)A + Fw v A∆D ∴ dp = FwvdD (p = ρgh) Incompressible Fluids dp = Fw v dD Integrating, p = Fw v D + p [p = p when D = 0] Incompressible Fluids In field units, Fw v ρ 62.4 = * 144 8.33 = 0.433 * ρ 8.33 Fw v = 0.052 ρ 1’ x 1’ x 1’ cube 10