What is a trip tank?

Trip Tank is a small metal tank with small capacity about 20-40 bbls with 1 bbl divisions inside and it is used to monitor the well. There are several operations that we can use the trip tank to monitor the well as follows;

1. Trip Out Of Hole (TOOH): While tripping out of hole, the trip tank is used to track volume of mud replacing volume of drill string. The volume of mud should be equal to displacement volume of any kind of tubular tripped out of hole.

2. Trip In Hole (TIH): While tripping in hole, the drilling string (bit, BHA and drill pipe) is ran back in the hole, the trip tank must be use to keep track volume gain. The expected volume gain should be equal to the displacement volume of whole string.

Learn more about pipe displacement

3. Flow check: The trip tank is utilized to determine well condition in order to see if the well is still under static condition.

The importance of trip tank is as follows:

1. Provide sufficient hydrostatic pressure to prevent influx from reservoir. When TOH, mud hydrostatic will be lost because mud volume must substitute drill pipe volume pulled out of hole. If hydrostatic pressure decreases too much, influx from reservoir can come into the hole and make a trouble in well control. For this reason, mud in trip tank must be filled into hole to maintain hydrostatic pressure.

2. Kick Indicator: Volume of mud from the trip tank is pumped in the hole can be an indicator that relates to a situation occurring in wellbore as kick. If the volume of mud measured by trip tank is less than the expected volume of drill pipe volume tripped out of hole, the suspect problem is kick because volume of kick substitutes volume of mud.

The circulation system while tripping

I would like to show the circulation system while tripping out of hole therefore you will be more understanding about how trip tank works.

While Tripping Out of Hole (TOH), a trip tank pump will circulate mud into a bell nipple in order to keep the hole full all the time and the over-flow mud will return back to the trip tank. Once every stand is pulled, the mud volume in the well will decrease because the drill pipe is pulled out of hole. Since the trip tank pump is always run while tripping, the annulus will be full all the time (see figure below).

Reference book: Well Control Books

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17 Responses to What is a trip tank?

  1. man says:

    Hi RJ,

    What about the circulation system during TIH?

    From my current knowledge, during drilling, mud is pumped downhole through drill string and return to the pit through the bell nipple through gumbo shaker etc. But here you mentioned that “a trip tank pump will circulate mud into a bell nipple….”. So my understanding now is the circulation is the other way round during tripping?? Correct me if i am wrong.


    • During tripping in hole, your trip tank circulating system is still the same as when you trip out of hole.

      It is different from when you are drilling the well. While tripping out, we don’t circulate any down into drill string unless you pump out of hole. It is not the other way around because the trip tank pump just only fill the mud into the annulus in order to keep the well full.

      Rachain J.

  2. man says:

    Is the trip tank pump still on during tripping in hole?


  3. mohand says:

    HI RJ.
    about trip tank i need to know during total loss can you use trip tank to fill annulas with water . also can we use trip tank in the reverse circulation. and what about
    pump? is it gust to pump mud during trip out , i heard that during circulation we use mud pump to pump mud into drill string and not trip tank pump..


    • It depends on how severe of losses is.
      You can line up your trip tank and try to fill the annuals with it but if the level in the trip tank indicates high loss rate, you may need to fill via mud pump into the choke / kill line because it can provide more volume.
      I’ve never used the trip tank for reverse circulation. You just line up to normal pit volume and track gain loss from total pit volume
      During circulating, you line up from mud pump ->drillstring-> out into annulus-> back to surface and mud pit. Trip tank will not use during circulation. Mud pits are the one that you will use.

  4. Ghamdan Alqadie says:

    Any negative detcted from the trip tank immdetiliy shut in your well and strat try to fing out the propelity of cick.


    • If you get the negative detection, it means losses down hole. You need to monitor the well to see how much you lose. If the lost rate is too much, you must fill the hole with drilling mud. There is no point to shut the well in.

  5. Joe says:

    Hello all… Could somebody give examples how to fill a trip tank sheet?

    Thank you

  6. Nasir says:

    respected sir,
    Can you please tell me how the following formula is driven? i am unable to understand about the “1029.4” constant.. please derive it.. thanking you in anticipation..
    formula…. {(OD)2 – (ID)2} / (1029.4)= (answer) bbl/ft

  7. Carlos de Jesus says:

    What is the advantage, if any, of having more than one trip tank? Is it more precise volume control??

  8. rafeek says:

    can we do flow check during RIH?

  9. Jonas says:

    Greetings RJ

    This question pertains to monitoring for kicks. You mentioned:

    “If the volume of mud measured by trip tank is less than the expected volume of drill pipe volume tripped out of hole, the suspect problem is kick because volume of kick substitutes volume of mud.”

    However to my understanding, if you are tripping out of hole and your trip tank volume reads less than expected, it would mean than the trip tank sent more mud into the wellbore than the expected displacement volume. Wouldn’t that therefore indicate a loss in mud instead of a gain in formation fluid (kick)

    Please correct me if I’m wrong.
    Thanks in advance.


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