Module 10. Well Control

Question 1

Describe Driller’s method

Answer 1

• Step 1 - circulate out influx with original mud density

- Step 2 - circulate well with kill mud weight

Question 2

Wait & Weight Method

Answer 2

• simultaneous circulation of both the invading fluid (influx) and kill density mud

Question 3

Well control systems permits the following:

Answer 3

1) Detecting the kick
2) Closing the well at surface
3) Circulating the well under pressure to remove the formation fluids and increase the mud density
4) moving the mud density
5) diverting the flow away from the rig personnel and equipment

Question 4

What will happen if HP is higher than FP?

Answer 4

In the porous intervals wells fluids will not flow into the well and the formation is “overbalanced” by the Mud Density

Question 5

Formulas for EMD?

Answer 5

EMD = BHP/(0.00981 x Depth)
EMD = MWD + SIDPP/ (0.00981 x TD)

Question 6

Rule of thumb for gas contribution for HP?

Answer 6

2.25 kPa/m

Question 7

What is velosity for gas rising relative to mud?

Answer 7

800 m/hr

Question 8

Primary well control?

Answer 8

HP from the column of fluid in the wellbore

Question 9

Secondary well control?

Answer 9

BOOP components bring wellbore under control

Question 10

Terturay well control?

Answer 10

External means are required to kill the well

• relief wells
• capping the wbore with larger BOPs
• dynamite blasting to put out burning well

Question 11

Describe SIDPP

Answer 11

This is the pressure recorded at the drill pipe pressure gauge on the remote choke control panel on the rig floor after a kick has been taken and the well has been shut in by closing BOP rams

Question 12

Describe SICP

Answer 12

Pressure recorded by the casing pressure gauge on the remote choke control panel after the well is shut in on a kick and the pressure have stabilized

Question 13

Three reasons why influx enters annular space?

Answer 13

1) the cross sectional area of the annulus is usually much larger than cross sectional area of the bit nozzles. The larger area offers less resistance of fluid flow
2) the direction of mud flow during drilling is always from the pipe to the annulus, which pushes the influx into the annulus
3) the drill string pressure may contain a float, which prevents any flow up the string

Question 14

Determine pit gain

Answer 14

Pitgain - increase in the total pit volume, which must be equal the influx volume unless there is a loss somewhere

Question 15

what is Kill rate(KR) or Slow circulating rate(SCR)?

Answer 15

It is the pump speed in strokes/minute (SPM) at which a kick will be controlled. The resultant ciculating pressure is called kill rate pressure(KRP)

Question 16

formula for Kill mud weight(KMW)

Answer 16

KMW = OMW(old mud weight) + SIDPP/(depth x 0.052)

Question 17

What is Kick Tolerance(KT)?

Answer 17

the kick volume which can be safely taken nwithout breaking down the shoe while circulating out the kick by the driller’s method

Question 18

Describe tge Concurrent Method

Answer 18

• circulate the kick out and partually kill the well in the first circulation

Question 19

Low Choke Method

Answer 19

outruning a kick by attemting to bad the annulus w/weightened mud faster than well flow and using choke pressure and a higher pump rate to increase ECD

Question 20

Volumetric Method

Answer 20

bottomhole pressure is maintained slightly higher than formation while the gas is allowed to expand in a controlled manner to surface

Question 21

ICP?

Answer 21

The pump pressure at drill pipe pressure gauge on the remote choke control panel at the start of pumping the kill mud into the string

Question 22

FCP

Answer 22

The pump pressure after kill mud reaches the bit