A TEST ON UTILIZING DIRECTIONAL SURVEYS

 

1) A well is deviated 5o from surface to bottom hole.  Its measured depth is 10,000'.

Question A) What is the wells TVD?

a) 9961
b) 9826
c) 9653
d) 9215

Question B) What is the total offset for this well?

a) 120'
b) 234'
c) 578'
d) 871'

2) If you are currently working on a 3D interpretation, what is the projection the 3D project was loaded in?

3) What is the definition of True (Geodetic) North?


4) What is the definition of Grid North?

5) Is there any place in the Gulf of Mexico where True North and Grid North directional survey coordinates (X-Y offset values) are the same.

6) You are a geologist doing an interpretation on a block in High Island SE. A well with a 5000' of closure does not tie with the seismic data. You are ready to have it out with your geophysicist. Your mapping expert suggests that you check the north reference for the directional survey. You find that the north reference is not specified.

Question. For this well what is the possible magnitude of error in location at bottom hole that may exist if the north reference is not assumed correctly.

a) 2-3'
b) 20-30'
c) 200-300'

7) In the Gulf of Mexico today, most contractors adjust the survey azimuth and X-Y coordinates to:

a) True North
b) Grid North
c) Magnetic North

8) For the onshore United States, most contractors adjust the survey azimuth and X-Y coordinates to:

a) True North
b) Grid North
c) Magnetic North

9) You are mapping horizontal drilling in the Austin Chalk using Map. You need to load the directional surveys. Would they be loaded:

a) As is.
b) Require some corrections prior to loading.

10) What percent of wells in an onshore Louisiana 3D seismic project will require modification (if any)?

11) What is the definition of magnetic declination.

12) In the Gulf of Mexico, the magnetic declination is:

a) East
b) West

13) You have a 3D project overlapping the High Island Southeast and West Cameron South areas. Since each side has its own map projection, what projection should you use for the 3D project?

a) Use Texas South Central on the Texas side and Louisiana South on the Louisiana side.
b) Use Texas South Central.
c) Use Louisiana South.
d) Use UTM zone 15.
e) Either b,c,d.
f) All of the above
g) None of the above.

14) If you used Louisiana South, do any of the directional surveys need adjusting prior to loading the 3D project?

a) All of the surveys.
b) Louisiana surveys.
c) Texas surveys.
d) None of the surveys.

 

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© 1999 John Sharry
e-mail: jsharry@ix.netcom.com
2/22/99