TABLE OF CONTENTS This program calculates the required gas injection volumetric flow rate in order to obtain a bottom hole annulus pressure of 3360 psig while drilling at 10,000 ft of depth. Assumes homogeneous multiphase flow.
| q a := 1263 | air volumetric flow rate trial and error value (acfm) |
| q f := 191 | mud flow rate (gpm) |
| ? f := 10 | specific weight of mud (ppg) |
| ? air := 0.012 | viscosity of air (centipoises) |
| ? mud :=30 | viscosity of mud (centipoises) |
| | aerated fluid flow loss coefficient through nozzles |
| D c := 7000 | total depth of cased hole (ft) |
| D oh := 3000 | total length of open hole (ft) |
| alt:= 4000 | elevation of drilling site (ft) |
| p o := 12.685 | pressure from table for elevation (psia) |
| t o := 60 | temperature from table for elevation ( F) |
| p at := 12.685 | actual given atmospheric surface pressure (psia) |
| t at := 60 | actual given atmospheric surface temperature ( F) |
| ROP:= 60 | estimated rate of penetration (ft/hr) |
| d bh := 7.875 | borehole (drill bit) diameter (in) |
| od dc := 6.25 | outer diameter of drill collar (in) |
| id dc := 2.8125 | inner diameter of drill collar (in) |
| od dp := 4.5 | outer diameter of drill pipe (in) |
| id dp := 3.826 | inner diameter of drill pipe (in) |
| od tj := 6.25 | outer diameter of drill pipe tool joint (in) |
