Please show work, thanks ! The rate of penetration (ROP) is a very important pie
ID: 2270954 • Letter: P
Question
Please show work, thanks !
The rate of penetration (ROP) is a very important piece of information for drilling engineers. It is the number of feet drilled for a given amount of time. One can have an actual ROP, that is, the ROP as determined only when the bit is rotating; or, one can have an average ROP, that is, the ROP averaged over time which includes any non-rotating time such as a connection. In this problem, you are to determine the following: The length of a joint of drill pipe is usually between 29 to 31 foot. Use an average length of 30 ft. It is taking 21 minutes for kelly down (the time it takes after a connection to drill to the time another connection is needed). A connection takes 6 minutes to accomplish. Find: a) The average ROP in feet per hour. The actual instantaneous ROP in feet per hour. If another 1,152 feet of hole are needed before reaching TD (total depth), assuming no change in ROP (highly unlikely but what the hey, it's only an exam) and no trips, and it is 8:55 am, when should the drilling engineer show up on location (get out to the rig) to see the rig reach TD?Explanation / Answer
a) It drills 30 feet in 21 minutes,
a connection time = 6 minutes.
so total time for drilling 30 feet = 21+ 6 = 27 minutes.
so average ROP = 30 / 27 = 10/9 ft /min
In ft/ hr , (10/9) * 60 = 600/9 ft/hr.
avergae ROP in ft/hr = 600/9 ft/hr. = 66.666 ft/hr
b) instantaneous ROP = 30 / 21 = 10 /7 ft/minute
In ft/hr , instantaneous ROP = (10/7) * 60 = 600/7 ft/hr
instantaneous ROP in ft/hr = 600/7 ft/hr = 85.714 ft/hr
c) time required to drill 1152 feet = 1152/avg. ROP = 1152/66.666 = 17.28 hours.
so, 17.28 hours = 17 hours and 16.81 minutes.
adding this to 8 .55 a.m
the drilling engineer should show up at 2 . 12 a.m the next day.