Update: We released the guidelines on 20 Nov but later discovered several errors. Revsion 3 is now available. The FAQs explain the main changes. This is a recap … note the info on the bit.
A new version of the 2018-2019 Guidelines dated 26 Nov 2018 was posted. Minor changes were included. Additional changes that are considered more significant follow:
3.1 The problem statement was changed from drilling a horizontal well to drilling a deviated well.
3.2 Eliminated redundancies and added references to the sections with specific instructions.
3.4.3 Depth measurements shall use the rig floor as the depth datum.
3.5 Reorganized
3.6 Renumbered this section, and …
3.6.2 Indicated where the well center will be when drilling commences.
3.6.3 Teams drill a pilot hole prior to the test, not to exceed 1” deep, as per previous competitions. [Comment: This hole will be extended when the test commences – see Section 3.16.]
3.7 [Comment: Teams have an option of which bit they will use at the Phase II test. They may use the DSATS bit (1.25 inch diameter), or a bit they provide, not to exceed 1.50 inch diameter]
3.7.3 An error when posting information about the bit diameter may have led to confusion and could affect teams who designed equipment based on the erroneous diameter. Therefore, teams may substitute a bit of their own design or a purchased bit not to exceed 1.5 inches in diameter and not more than 2 inches long. While this may allow some additional space for building the downhole equipment, it could also affect the build rate of the directional wellbore. It may also induce additional torque that could affect drillstring forces. Teams must evaluate the benefits and drawbacks of each and are encouraged to provide this analysis in their Phase I design report that describes what different forces are expected and their impact on drilling operations.
3.8 [Comment: Note that the pipe/tubing provided by DSATS will be aluminum, as per previous competitions. Although there were some discussions of replacing this with stainless steel due to excessive bending if the well were horizontal, with the directional well requirements, aluminum tubing is adequate.]
3.16 Reorganized
7.0 Revised timeline to reflect the two test sites instead of tests at each school.
Previous Post
The latest version of the 2018-2019 Guidelines were released today. Instead of a horizontal well, the challenge this year is to drill a directional well. The bit will not create enough build to get fully horizontal in this small rock sample.
The DSATS provided pipe will be the same aluminum tubing provided last year. The additional flexibility of aluminum over stainless steel should help build angle.
Please, where is the new guideline ?
Further explanation is needed about which dimension would be along North/South direction, Is it the 24 in or the 12 in?
I am confused about the first directional scoring Figure; it is showing the axes are N/S and E/W which make me think that the well is vertical and that is a top view for horizontal plan . I think it should be a front view facing north or south but still the dimension confuses me.
The above points leads to confusion about the horizontal departure as well as the best score TVD in directional calculations.
Note that you will exit the bottom of the rock, not one of the sides, since the wellbore is no longer horizontal.
As I commented on the older guidleines, We can still exit from the side with an angle through a continous build profile without having to reach 90 deg. (horizontal). Even if exiting from the bottom of the sample, from my underestanding, on the first figure the target is just the center of the sample with coordinates (0,0) which is the same as top cooridnates which means that well profile is vertical.
For Group A
The target is to build as much angle as possible along the best path. (0,0) would score zero points. If you can exit the side, then you have reached the maximum offset due to the size of the sample. In the unlikely event that more than one team exited the side and had the same point score, we would then measure the TVD to determine the winner.
For Group B
The well will be vertical, as per the 2017-2018 Guidelines.
So the maximum horizontal departure regardless of the TVD is 6 in along N/S direction?
Yes. Please let the committee know the results of your testing during the next few months. Are you able to exit the side of the rock and at what TVD? Are you able to maintain trajectory? Also provide brief details on your design of the bit and BHA that gives you these high build rates.
I haven’t started yet, and I doubt that I would a build up rate that would be high enough, but based on the older version of the guidelines the maximum inclination needed was around 40 so the BUR would be higher than 2 deg/in. So the only thing I was saying is a continuous profile doesn’t need to be horizontal (90 deg).
Lately, I was wondering if N/S is still along the 12 dimension after changing the sample dimensions as I didn’t understand the point of changing the length dimension (along E/W) when it won’t increase the horizontal departure (target is to keep along N/S) . It might be giving a chance for correction actions, but I am not sure if it will.
Thanks for you patience!