PETE 411 Well Drilling

1. PETE 411Well Drilling Lesson 35 Wellbore Surveying Methods

2. Wellbore Surveying Methods Average Angle Balanced Tangential Minimum Curvature Radius of Curvature Tangential Other Topics Kicking off from Vertical Controlling Hole Angle

3. Read:Applied Drilling Engineering, Ch.8 (~ first 20 pages) Projects:Due Monday, December 9, 5 p.m.( See comments on previous years’ design projects )

4. Homework Problem #18 Balanced Cement Plug Due Friday, December 6

5. I, A, DMD

6. Example - Wellbore Survey Calculations The table below gives data from a directional survey. Survey Point Measured Depth Inclination Azimuth along the wellbore Angle Angle ft I, deg A, deg A 3,000 0 20 B 3,200 6 6 C 3,600 14 20 D 4,000 24 80 Based on known coordinates for point C we’ll calculate the coordinates of point D using the above information.

7. Example - Wellbore Survey Calculations Point C has coordinates: x = 1,000 (ft) positive towards the east y = 1,000 (ft) positive towards the north z = 3,500 (ft) TVD, positive downwards C C N (y) N Dz Dz D D Dy Dx E (x)

8. Example - Wellbore Survey Calculations I. Calculate the x, y, and z coordinates of points D using: (i) The Average Angle method (ii) The Balanced Tangential method (iii) The Minimum Curvature method (iv) The Radius of Curvature method (v) The Tangential method

9. The Average Angle Method Find the coordinates of point D using theAverage Angle Method At point C, x = 1,000 ft y = 1,000 ft z = 3,500 ft

10. The Average Angle Method C N (y) C Dz D N Dz D E (x) Dy Dx

11. The Average Angle Method

12. This method utilizes the average of I1 and I2 as an inclination, the average of A1 and A2 as a direction, and assumes the entire survey interval (DMD) to be tangent to the average angle. The Average Angle Method From: API Bulletin D20. Dec. 31, 1985

13. The Average Angle Method

14. The Average Angle Method

15. The Average Angle Method At Point D, x = 1,000 + 99.76 = 1,099.76 ft y = 1,000 + 83.71 = 1,083.71 ft z = 3,500 + 378.21 = 3,878.21 ft

16. The Balanced Tangential Method This method treats half the measured distance (DMD/2) as being tangent to I1 and A1 and the remainder ofthe measured distance (DMD/2) as being tangent to I2 and A2. From: API Bulletin D20. Dec. 31, 1985

17. The Balanced Tangential Method

18. The Balanced Tangential Method

19. The Balanced Tangential Method

20. The Balanced Tangential Method At Point D, x = 1,000 + 96.66 = 1,096.66 ft y = 1,000 + 59.59 = 1,059.59 ft z = 3,500 + 376.77 = 3,876.77 ft

21. Minimum Curvature Method b

22. Minimum Curvature Method This method smooths the two straight-line segments of the Balanced Tangential Method using the Ratio Factor RF. (DL= b and must be in radians)

23. Minimum Curvature Method The Dogleg Angle, b, is given by: cos b = 0.9356 b = 20.67o = 0.3608 radians

24. Minimum Curvature Method The Ratio Factor,

25. Minimum Curvature Method

26. Minimum Curvature Method

27. Minimum Curvature Method

28. Minimum Curvature Method At Point D, x = 1,000 + 97.72 = 1,097.72 ft y = 1,000 + 60.25 = 1,060.25 ft z = 3,500 + 380.91 = 3,880.91 ft

29. The Radius of Curvature Method

30. The Radius of Curvature Method

31. The Radius of Curvature Method

32. The Radius of Curvature Method At Point D, x = 1,000 + 95.14 = 1,095.14 ft y = 1,000 + 79.83 = 1,079.83 ft z = 3,500 + 377.73 = 3,877.73 ft

33. The Tangential Method

34. The Tangential Method

35. The Tangential Method

36. Summary of Results (to the nearest ft) xyz Average Angle 1,100 1,084 3,878 Balanced Tangential 1,097 1,060 3,877 Minimum Curvature 1,098 1,060 3,881 Radius of Curvature 1,095 1,080 3,878 Tangential Method 1,160 1,028 3,865

39. Building Hole Angle

40. Holding Hole Angle

42. CLOSURE (HORIZONTAL) DEPARTURE LEAD ANGLE

43. b

44. Tool Face Angle