QUESTION $1$

A horizontal well with a measured depth $($MD$)$ of $15,000ft.$ can be approximated as being

vertical to $2,500ft,$ then a $7,000-ft$ segment inclined from vertical at $60$ deg $($from vertical$),$

and a horizontal $5,500-$ ft section. The drill string is composed only of drill pipes. The bit is

at $15,000ft(MD).$ Given:

Open hole diameter $($ constant $)=9in$

Drill pipe outside diameter $(OD)=5in$

Drill pipe inside diameter $(ID)=4in$

Mud weight $=10ppg$

Flow rate $=400gpm$

Pore pressure $at$ bottom $=3,220$

a$)$ Compute the pipe capacity in $f\frac{t^3}{f}t.$

Ans. $0\mathrm{.}087f\frac{t^3}{f}t$

b$)$ Compute the pipe displacement in gal$/$ft$.$

Ans. $0\mathrm{.}367ga\frac{l}{f}t$

c$)$ Compute the total annular volume.

Ans. $816$ bbl

d$)$ Compute the time necessary to bring the cuttings from the bit to the surface.

Ans. $85\mathrm{.}7$ min

e$)$ Compute the mud velocity inside the drill string.

Ans. $613f\frac{t}{m}in$

f$)$ Compute the mud UNDERBALANCE $(P)$ at the bottom of the well with mud at rest.

Ans. $-100$ psi

THE ANSWERS ARE GIVEN, CAN YOU EXPLAIN EACH QUESTION STEP BY STEP PLEASE