Kick Detection (Warning Sign) and Shut in Quiz

Three positive well control indicators are flow with pump off, pit gain and increase in flow out.

Ref: Positive Kick (Wellbore Influx) Indications

If the short fill is seen, you should stop and install the safety valve as soon as possible before flow check the well.

Ref: Shut-In Procedure while Tripping

The purpose of space out is to avoid tool joint in the BOP stack.

Ref: What is space out in drilling (especially in well control)?

For hard shut in, the HCR and choke must be closed while drilling.

Ref: 2 Types of Shut-In (Hard Shut In and Soft Shut In)

Several factors contributing to swabbing effect are high viscosity of drilling mud, bit balling, pull pipe too fast and small clearance between BHA and hole.

The pumps are shut down after space out and right before closing the BOP because it is the best way to have the ECD to minimize influx. Less influx in the well means less hassle.

When drilling break is observed, it is good practice to flow check because high drilling break can be a high formation pressure zone.

Drilling break is one of possible well control indicators.

Ref: What are differences between possible and positive well control indicators?

There are two purposes of shutting the well in. The first purpose is to stop influx and the last purpose is to determine pressure to kill the well.

Less influx will create less surface pressure and shoe pressure therefore it will not create damage in the well while performing well control operation.

Permeability of formation affects time to get stabilized and pit volume gain. The formation with high permeability will get stabilized quicker and pit volume will increase faster too. On the other hand, the low permeability formation will not flow into the wellbore very quickly and it takes longer time to get stabilized.

Right mud weight is controllable so personnel must ensure that mud weight used for drilling must be sufficient. For some reason, mud weight is less than the plan, personnel must stop and weight up the system prior to continue drilling ahead.

Short fill while tripping out indicates that there is influx into the wellbore due to swabbing.

The best practice is to go back to bottom and circulate the influx out.

The signs show that well cannot flow due to Equivalent Circulating Density; however, once the pump is shut down, the mud weight is less than formation pressure resulting flow when pumps off. Therefore, the weight should be increased to amount of pressure loss in the annulus.

When the amount of cutting increases without any changes in flow rate or drilling parameters, it is the possible sign of abnormal pressure zone. The good practice is to do the flow check first. If the well is static, circulate bottom up to clean the well. It may be a good idea to increase mud weight prior to drilling ahead.

The best way to kill the well off bottom is to secure the well and strip back to bottom. It is NOT recommended to kill off bottom.

In this case, the well is not flowing because annular pressure loss stops wellbore influx. Therefore, new mud weight should be high enough to cover annular pressure loss.

Mud weight = current mud weight + (annular pressure loss ÷0.052÷TVD)
Mud weight = 11.0 + (330 ÷0.052÷8,000)= 11.8 ppg

Ref: Kill Weight Mud

The action is called “Surge” which can increase bottom hole pressure and sometimes result in lost circulation.

Does not matter how well of the crew is, it is better to have unscheduled well control drill from time to time.

If the possible well control indicator(s) is observed, it is good drilling practice to space out, shut down and perform flow check.

Ref: Possible Kick (wellbore influx) Indications Part1

Possible Kick (wellbore influx) Indications Part2

The hard shut in minimizes influx from the reservoir but the soft shut in will allow more influx into the well before the well is secured. With this reason, most of oil companies and drilling contractors utilize this method.

Ref: 2 Types of Shut-In (Hard Shut In and Soft Shut In)

You should go back to the bottom to kill the well. In order to do that, you need to following these steps: Space out, stab safety valve + iBOP and run or strip back to bottom.