ATMATM PETE 689 UBD ATMATM ATMATMATMATM Lesson 9 Gasified Liquid Hydraulics Read: UDM Chapter 2.7 pages

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Gasified Liquid Hydraulics Reynolds Number Multi-phase flow Pressure prediction –HSP –Circulating pressure –Bit pressure drop Hole Cleaning

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Reynolds Number In practice the flow of gasified liquid is almost always turbulent (Reynolds number > 4000) Example water flowing up an 8 1/2” hole with 5” drillpipe. AV of 7 ft/min would be turbulent AV’s > 100 ft/min are common

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Reynolds Number Equation 2.58

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Reynolds Number The consequenses of turbulance in the annulus is that the rheology of gasified fluids has little effect on the annular pressure profile. This is at least true with un-viscosified base fluid.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Multi-phase flow At least three phases are present in the wellbore –Liquid, gas, and solids Liquids could be: –Mud –Oil –Water

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Flow Regimes

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Flow Regimes

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Flow Regimes

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Pressure prediction HSP Annular Friction Bit pressure drop –Mud –Gasified mud Drillstring pressure drop –Mud –Gasified mud

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering HSP

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering HSP

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering HSP

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Gas Volume

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Friction forces

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Fanning Friction Factor

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Reduced Reynolds Number

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Gas volume This correlation and equation 2.66 were used to compute the required air injection rate to give a BHP of 2497 psi at 6000’ in an 8 1/2” X 4 1/2” annulus at 350 gpm. Required 14.9 scf/bbl

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Gas volume Equation 2.63 was used to calculate the volume of air to give the same BHP static. Required 13.4 scf/bbl. Poettmann and Bergman concluded that the difference is insignificant and a reasonable calculation of air rate for the desired BHP could be done assuming a static fluid column.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Bit pressure drop Mud Gasified Mud

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Bit pressure drop - Mud Red book

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Bit pressure drop - Gasified Mud This relationship neglects any energy loss through the nozzles due to frictional effects and any change in potential energy.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Bit pressure drop - Gasified Mud Substituting equation 2.44 for the density of a lightened fluid this becomes

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Fig. 2.41

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Hole Cleaning Settling velocity Critical velocity Settling Velocity Cuttings Transport ratio

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Settling velocity

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Critical velocity Guo assumed that the cuttings concentration in the annulus should not exceed some critical value if hole cleaning problems were to be avoided. v c = ROP/60C c v c = critical velocity, ft/min ROP = Rate of penetration, ft/hr C c = Cuttings concentration, fraction

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Critical velocity Taking the critical concentration as 4%, cuttings would need to travel uphole with a velocity 25 times greater than the penetration rate. For a penetration rate of 30 ft/hour, this corresponds to a velocity of 12.5 ft/min.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Settling Velocity With a large annulus, the AV may not be such that turbulent flow can be achieved. We would then need to alter the viscosity of the fluid.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Settling Velocity For a 0.25” cutting with a density of 21 ppg falling through a fluid of density of 5 ppg. Maximum AV = 15 ft/min. Settling velocity would have to be restricted to 17.4 ft/min at a penetration rate of 30 ft/hr. This would require an effective viscosity of 160 cP.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Cuttings Transport Ratio

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Cuttings Transport Ratio The velocity of the system is normally the mean velocity in the annulus determined by dividing the total flow rate of the various phases of the fluid by the cross-sectional area of the annulus.

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Cuttings Transport Ratio The CTR should be calculated throughout the annulus to ensure that adequate hole cleaning takes place at all points and that the cuttings are not packing off in the hole somewhere. A CTR of 1.0 implies perfect hole cleaning. If CTR>0 cuttings are moving upward. CTR should be >0.55

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering Example

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering

ATMATM PETE 689 UBD ATMATM ATMATMATMATM Harold Vance Department of Petroleum Engineering