نمایش نتیجه 1 تا 2 از 2 نتیجه یافت شده برای donut type drill collar:
n: a type of drill collar with big and heavy circular weighting block to increase the drilling pressure
n: a ring of wedges or a threaded, tapered ring that supports a string of pipe.
n: refer to donut type drill collar
a hanger, usually screwed onto the end of the top tubing joint and lowered into the slip bowl of the wellhead.
© ۱۳۹۲-۱۳۹۷ این اثر شامل قانون حمایت از مولفین بوده و هرگونه کپی برداری از آن ممنوع است.
