Borehole Collapse
Borehole Collapse
(OP)
Can anyone suggest some references or formulas for determining when borehole collapse will occur when drilled in certain type of rocks?
I am trying to figure out at what depth will I need a liner if at all.
Thanks
I am trying to figure out at what depth will I need a liner if at all.
Thanks





RE: Borehole Collapse
Having said that, you may hit brecciated zones within the rock that might cause a problem - again, in blocking the retrieval of the core barrel. In such cases, you would grout the brecciated region of the rock, let it set and then drill it out. Similarly, there may be clay seams that might wash out but I doubt it would leave to 'cave' - perhaps in sandstones, you might run into sandy seams.
The point is that unless you know the geology quite well, how would you know what is there that might cause a 'cave'?
Anyway - that's my take for now! Chou and
RE: Borehole Collapse
When rock quality is bad, you are more likely to get fluid loss than collapse. Fluid loss indicates voids in rock structure, particularly in poor quality limestone or areas of none solution cavities.
RE: Borehole Collapse
your concern is a typical issue in oil drilling engineering, where stability of holes located in significant stress fields (thousands of feet of lithostatic burden)
may be critical, expecially in horizontal drilling.
While BigH and Ron said just about everything we need to know, if you want to pursue the subject further I think you have to post your question in some petroleum or drilling engineering forum (sorry, I don't know any).