Drilling Technology

1.

Pressure Gradient psi/ft =

Mud Weight ppg x 0.052

Pressure Gradient psi/ft ^ 0.052

3.

Hydrostatic Pressure psi =

Mud Weight ppg x 0.052 x True Vertical Depth ft

4.

Formation Pressure psi =

Hydrostatic Pressure in Drill String psi + SIDPP psi

(with bit on bottom)

Weight ppg =

1. Pump Output bbls/min =
2. Annulus Velocity ft/min =
3. Initial Circulating Pressure psi =
4. Final Circulating Pressure psi =
5. Kill Weight Mud ppg =
6. Shut in Casing

Pressure psi =

12. Equivalent circulating density ppg =

Pressure psi ^ True vertical Depth ft ^ 0.052 Pump Output bbls/stk x Pump Speed spm Pump Output bbls/min ^ Annulus Volume bbls/ft

SCR psi + SIDPP psi

SCR psi x (Kill Mud Weight ppg ^ Original Mud ppg)

• SIDPP psi + TVD ft + 0.052) + Original Mud ppg
• Mud Grad psi/ft - Influx Grad psi/ft) x Influx Height ft] + SIDPP psi
• a title="Annular Pressure Losses Drilling Engineering" href="/engineering-4/annular-pressure-losses.html">Annulus Pressure loss psi ^ TVD ft ^ 0.052) + Original Mud ppg

1. Height of influx ft =
2. Gradient of Influx psi/ft =
3. Trip Margin/safety = factor ppg
4. Pump Pressure/Pump Stks Relationship psi

Kick size bbls ^ Annulus Volume bbls/ft

• SICP psi - SIDPP psi)
• Mud weight ppg x 0.052)

Influx Height ft

Present Pressure psi x (New SPM ^ Old SPM)2

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

17. Max. Allowable Mud Weight ppg

(Surface Leak Off psi ^ Shoe TVD ft ^ 0.052) + Test Mud ppg

1. New MAASP psi
2. Barite to raise mud weight lbs/bbl
3. Percolation Rate ft/hr
4. Kick Tolerance ppg

Kick tolerance in feet

• Max. Allowable Mud Weight ppg -Current Mud Weight ppg)
• Kill mud weight ppg - Old mud weight ppg) x 1500
• 35.8 - kill weight mud ppg)

Drill pipe pressure increase psi/hr ^ Mud gradient psi/ft

(MAASP - (Mud gradient psi/ft - Influx Grad ft)) x Influx Height ft

TVD x 0.052

MAASP - SIDPP

GM- GI

1. Boyle's Law:
2. Pressure drop per ft. tripping dry pipe
3. Pressure drop per ft. tripping wet pipe
4. Level drop for pulling collars out of hole ft
5. Length of pipe to pull before well starts to flow ft
6. Hydrostatic Pressure loss if casing float fails

P2V2 P2

2 2 Mud grad psi/ft x Metal Disp bbls/ft

Casing cap. bbls/ft - Metal Disp bbls/ft

Mud grad psi/ft x (Metal disp bbls/ft + Pipe disp bbls/ft)

Annulus Volume bbls/ft

Length of collars ft x metal disp bbls/ft

Casing cap. bbls/ft

Overbalance psi x (casing cap. bbls/ft - pipe disp bbls/ft)

Mud gradient psi/ft x pipe Disp bbls/ft

Mud grad psi/ft x Casing Cap bbls/ft x differential height ft

(casing capacity + Annulus capacity bbls/ft)

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS

r W21

28. Volume displace by slug = Slug Vol x I--11

W1 AP

R TVD

Riser Sea-water

or the total increase in mud Wt required before disconnected.

1. Conversion of pipe diameter to bbls/ft =-= bbls/ft
2. 42

or -= bbls/ft

1. 42
2. Max Mud Wt [Offshore]

32. Estimated Casing setting depth beneath sea floor

33. 'U' Tube formula

SECTION 10 : FORMULAE, CONVERSION FACTORS & GLOSSARY OF TERMS