Washout Drill Pipe Experience

We would like to share experience about washout drill pipe. We observed pressure gradually dropped from 4,100 psi to 3,600 psi (500 psi pressure loss) with same pumping rate 800 GPM. There was no mud weight or mud properties change at that time. Then, we tried to switch to another pump but the same problem still occurred so there must be something wrong down hole or surface.

When we observed pressure loss, we stopped rotating and drilling, just only circulating, and figured out where the washout was.

Note: It’s a good practice not to rotate while we are losing pressure because you can snap drill pipe easily due to washout.

At this stage, when we saw the pressure loss, we needed to know where pressure loss occurred.

1. Check surface equipment: Closed IBOP on the top drive, pressure up surface equipment with mud pump to 5000 psi and held for 5 mins. Everything was OK, no pressure loss. Therefore, there was nothing wrong with surface line and it should be down hole.

2. Check MWD signal: You may not see the change in signal so you need to recycle pump to ensure whether signal was  good or not. We found that the signal generated by tool was weaken at the same flow rate of 800 GPM. This indication showed us that washout location was above MWD tool.

We were quite sure that we had washout drill pipe downhole and we decided to pull out of hole to find washout. This was what we found. Internal washout at pin end of drill pipe resulted in pressure loss.

washout-pipe---new washout-pipe-new2

We laid down washout drill pipes and made up TDS and attempted to circulate with 800 GPM to see if pressure continued dropping. Pressure came back close to where it was before. Everything was OK then we ran back in hole to continue drilling operation.

Please remember that if you pull several stands of drill pipe before you see washout when you make up TDS and circulate pressure may not be like what you previously have due to less length of pipe.

Note: You can calculate depth of washout via this topic, Depth of Washout

If you have any experience regarding this issue, please feel free to share with us.

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8 Responses to Washout Drill Pipe Experience

  1. Humphrey says:

    I have a well with section azimuth at 230deg and Kick off point at 3000ft along 110deg azimuth. where do I place my tool face?

  2. Natalie Roberts says:

    Useful info!

  3. George B. Heckler says:

    The best thing to do is immediately come out of the hole if the pumps check out OK. Additional circulating only increases the size of the washout and possible parting of the string. Stoppping rotation is also advised.

  4. Bharada Indrajaya says:

    Could you please share the root cause of the string wash out and lesson learned. It’s because the pipe condition or drilling parameter or formation /lithology.

  5. Edmon Salloum says:

    Please allow me to add a little notice for drilling string wash out.

    Actually beside to the steps you mentioned about investigation of wash out- surface of down hole 

    there is another important value can helps us to approximately determine the depth of  wash out, can take it from mud logger report, friction- pressure loss- values can find where could the wash has happened 

    for example 500 psi pressure loss will approximately equal to pressure loss in drill pipe and two stands of HWDP. where is could be the wash out. 

    I hope this could be useful

  6. Raul zevallos says:

    Mwd of slb have TRPM (turbine RPM) if a drop in it ocurred less flow is passing through mwd which mean a washout above mwd.

    Other sign is if you pooh wet the level of mud on drillpioe drops as you get closer to the wahsout

    Several cases occurred behind nrdpp

    Other signs is ecd drop

    Some people drop paint insed drillpioe and count the strokes until get the pain in the shakers but is very dificult to see the paint and you waste time and the washout get larger.

  7. Kaser says:

    Hi all…it happened to me also but in packed hole bha…pressure decrease from 2500 psi to 2300 psi while drilling …i stop drill …i seen pressure on btm and off btm…i find it 1rst on less than 2 nds one by 5o psi…not logical…what confused us is mud enginner transfer 10m3 obm by d 1.25 but in well 1.3…..hmmm….guess what i do…i try find solution by weight…i resume drilling with wob 10t ..then pressure decrease 70 psi…i added wob to 15 t …spp decrease 100 psi…i directly pull out….thank for reading…

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