This article is a summary of how to free stuck pipe caused by three main mechanisms which are wellbore geometry, differential sticking and packing/bridging off. It will give you some ideas which you can apply for your operation.

Free Stuck Pipe Caused By Wellbore Geometry

These following instructions are guide lines on how to free the stuck drill string caused by wellbore geometry.

What should you  do to free the stuck pipe caused by wellbore geometry ?

• If the drill string gets stuck while moving up, jar down with maximum trip load and torque can be applied into drill string while jarring down. Be caution while applying torque, do not exceed make up torque.

• On the other hand, if the drill string gets stuck while moving down, jar up with maximum trip load. DO NOT apply torque in the drill string while jarring up.

• Flow rate must be reduced while attempting to free the drill string. Do not use high flow rate because it will make the stuck situation became worse and you will not be able to free the pipe forever.

• To free the string, jarring operation may take long time so please be patient.

• If a formation you get stuck is limestone or chalk, acid can be spotted to dissolve cuttings around the pipe.

• If the drill string is stuck in a salt formation, spotting fresh water is another choice to clear the salt in the annulus.

• Please always seriously consider regarding well control prior to spotting light weight stuff (acid or fresh water) around the drill string. You must ensure that you are still over balance formation pressure otherwise you will be dealing with well control too.

What should you  do after the string becomes free?

• Increase flow rate and circulate to clean wellbore. Flow rate must be more than cutting slip velocity in order to transport cuttings effectively.

• Reciprocate and work pipe while cleaning the hole.

• Ensure that the wellbore is clean prior to continuing the operation.

• Back ream or make a short trip the section that causes the problem.

Free Stuck Pipe Caused By Differential Sticking

These following instructions are guide lines on how to free the stuck drill string caused by differential sticking.

• Apply maximum flow rate as much as you can.

• Apply maximum torque in the drillstring and work down torque to stuck depth. Torque in the string will improve chance of free the pipe.

• Slack off weight of string to maximum sit down weight.

• Jar down with maximum trip load. Torque may be applied with jarring down with caution. The chance of freeing the pipe by jarring down is more than jarring up. Please be patient when a hydraulic jar trips because it may take around 5 minutes each circle.

The secondary actions to free the pipe that you may try

• Reduce hydrostatic pressure by pumping low weight mud/pill. You must ensure that overall hydrostatic pressure is still able to control reservoir fluid to accidentally come into the wellbore.

• Continue jarring down with maximum trip load and apply torque into drill string.

• It may take long time to free the pipe therefore personnel must be patient.

What should you  do after the string becomes free?

• Circulate at maximum allowable flow rate. Flow rate must be more than cutting slip velocity in order to transport cuttings effectively.

• Reciprocate and work pipe while cleaning the hole. Ensure that you can work pipe with full stand or joint while circulating.

• Condition mud prior to drilling ahead because if you still drill with poor mud properties, the differential sticking will be re-occurred.

Free Stuck Pipe Caused by Pack off / Bridging

These following instructions are guide lines on how to free the stuck drill string  cause by packing off or bridging off.

What should you  do to free the stuck pipe caused by Pack off / Bridging?

• Circulate with low flow rate (300 – 400 psi pumping pressure). This is very important to apply low flow rate because if high flow rate is applied, the stuck situation becomes worse.

• If the drill string gets stuck while moving up or with the string in static condition, jar down with maximum trip load and torque can be applied into drill string while jarring down. DO NOT JAR UP. Be caution while applying torque, do not exceed make up torque.

• On the other hand, if the drill string gets stuck while moving down, jar up with maximum trip load. DO NOT apply torque in the drill string while jarring up.

• To free the string, jarring operation may take long time (10 hours +) so please be patient.

What should you do after the string becomes free?

• Increase flow rate and circulate to clean wellbore at maximum allowable flow rate. Flow rate must be more than cutting slip velocity in order to transport cuttings effectively.

• Reciprocate and rotate while circulating to improve hole cleaning ability. Work the drill string with full stand if possible.

• Ensure that the wellbore is clean prior to continuing the operation. You can see from the sale shaker whether the hole is clean or not.

• Sweep may be utilized to improve hole cleaing.

• Back ream or make a short trip through the area where causes the stuck pipe issue.