Formulas for Wait and Weight Well Control Method

There are some well control formulas that you need to know for wait and weight method.

 

1. Kill Weight Mud

KWM = OMW + [SIDPP ÷ (0.052 x TVD)]

Where;

KWM is kill weight mud in ppg.

OMW is original mud weight in ppg.

SIDPP is shut in drill pipe pressure in psi.

TVD is true vertical depth of the well in ft.

Note: Read more about it>> Kill Weight Mud


2. Determine barite required to wait up to KWM

Where;

Barite Require is in sack.

Total Mud Volume is in bbl.

KWM is kill weight mud in ppg.

OMW is original mud weight in ppg.

Note: Read more about it>> Increase mud weight by adding barite

3. Slow Circulating Rate (SCR)

SCR = ICP – SIDPP

Where;

SCR is slow circulating rate in psi.

ICP is initial circulating pressure in psi.

SIDPP is shut in drill pipe pressure in psi.

 

4. Final Circulating Pressure (FCP)

FCP = SCR x KWM ÷ OMW

Where;

FCP is final circulating pressure in psi.

SCR is slow circulating rate in psi.

KWM is kill weight mud in ppg.

OMW is original mud weight in ppg.

 

5. Drill string volume (strokes)

Drill string volume = Drill pipe capacity x TD ÷ Pump output

Where;

Drill string volume is in strokes.

Drill pipe capacity is in bbl/ft.

TD is well measured depth in ft.

Pump output in bbl/stroke.

Note: read more about pipe capacity and pump output >> Inner Capacity of Pipe and Pump Output

6. Drill pipe schedule for a vertical and non taper-string

Drillpipe pressure drop/stroke increment = (ICP – FCP) x increment strokes ÷ surface to bit (strokes)

Where;

ICP is initial circulating pressure in psi.

FCP is final circulating pressure in psi.

Increment strokes are how many strokes for pressure drop certain psi.

surface to bit (stokes) is stokes require from surface to bit.

The detailed calculation can be find in the following topics:

Drill Pipe Pressure Schedule Calculation for Wait and Weight Well Control Method

Pressure Profile of Drillpipe and Casing Pressure while killing a well with wait and weight method

Have a nice day.

Reference book: Drilling Formula BookFormulas and Calculations for Drilling, Production and Workover, Second Edition

Related Post

Lag Time and Its Importance for Well Control Opera... Drilling personnel need to fully understand about the lag time. Lag time is time delay from pressure adjustment made on a choke valve or a choke HCR t...
Do you have too much slug in the well? Slug is heavy drilling mud that is used to pump when you want to pull pipe dry. However, excessive volume of slug in the well can create higher mud we...
Driller’s Method Quiz No. 3 Before starting 1st circulation of driller's method, you have this following information Original Shut in Drill Pipe Pressure = 500 psi Shut in ca...
Cement Transition Period in The Oil Well Can Cause... When cement is in transition period (forming the bond), you will lose some hydrostatic pressure because cement becomes solid phase therefore water in ...
Share the joy
  • 3
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
    3
    Shares
Tagged , , , . Bookmark the permalink.

About DrillingFormulas.Com

Working in the oil field and loving to share knowledge.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.