1. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ A method of determining seismic statics from gravity data. An OEX Technology Registered in the U.S. Patent and Trademark Office offered through Lockhart Geophysical.

2. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical What is the goal of GravStat™? To determine seismic statics through the interpretation of high spatial frequency gravity anomalies caused by lateral changes in near surface geology.

3. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ Model

4. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Datum Velocity & Bouguer Density

5. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Pb = 1.7 g/cc Pb = 2.6 g/cc Nettleton Density Profile Pb = 2.2 g/cc Pw = 2.2 g/cc; Vw = 8370 ft/sec Vw = 2550 m/sec

6. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Bouguer Density Analysis in Sandunes

7. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Density and Velocity are related by Gardner's Equation: V (feet/sec) P (g/cc)

8. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ Model Weathering Layer 4000 ft/sec 1219 m/sec Sub Weathering Layer 8000 ft/sec 2438 m/sec

9. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical ms/mGal Nomogram 28 ms/mGal 17 ms/mGal 6000

10. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Bouguer Density Analysis in Sandunes

11. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ Statics in Sandunes

12. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat™ Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

13. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat™ Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

14. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Spatial Aliasing of Gravity Data

15. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Typical 3D Survey Designs

16. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Survey Design-1 (660 feet)

17. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Survey Design-2 (660 feet)

18. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Survey Design-3 (660 feet)

19. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Survey Design-4 (440 feet)

20. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Survey Design-5 (300 feet)

21. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat™ Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

22. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Bouguer Gravity Map (Delaware Basin)

23. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat™ Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

24. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ Static Map (Delaware Basin)

25. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

26. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Shot Record Only elevation statics applied

27. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical 3D Shot Record Elevation and Gravstat™ statics

28. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical The GravStat Method Acquire un-aliased gravity data coincident with the seismic source and receiver locations. Remove elevation, topographic and regional effects from the gravity data. Invert the high frequency residual gravity data into a surface consistent static correction. Calculate and apply the statics optimizing the regional gravity and the GravStat™ inversion. Analyze the processed seismic data for clarity and accuracy to known geology.

29. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction Statics Section (glacial till)

30. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ Statics Section (glacial till)

31. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Set A - Refraction Statics without Autostatics

32. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Set B - GravStat Statics without Autostatics

33. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Set C - Final Refraction Static Section

34. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Set D - Final GravStat Static Section

35. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Advantages of GravStat™ High velocity over low. Not dependent on the quality of the seismic first breaks. Automatically compensates for velocity variations in the weathering and sub-weathering. Long period statics are resolved. Subtle features such as faults are more clearly imaged with GravStat™ reason less autostatic smear.

36. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Advantages of GravStat™ High velocity over low. Not dependent on the quality of the seismic first breaks. Automatically compensates for velocity variations in the weathering and sub-weathering. Long period statics are resolved. Subtle features such as faults are more clearly imaged with GravStat™ reason less autostatic smear. THE SEISMIC WILL NOW TIE TO THE WELLS

37. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical A Kansas example how GravStat™ was used to tie to known well control. This example is a comparison of two interpretations; one using seismic data processed with refraction, and the other using seismic data processed using GravStat™.

38. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Interpretation The following three slides show a structural interpretation using seismic data processed with refraction statics. The survey is over a producing field - well control is shown by the green dots. Note how much the refraction velocity map must be distorted to tie to the known well control.

39. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Time Structure Contour interval = 1ms

40. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Velocity to Depth Contour interval = 5’/sec.

41. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Depth Map Contour interval = 4 feet

42. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Interpretation The following three slides show a structural interpretation using seismic data processed with GravStat™ statics. As before, the well control is shown by the green dots. Note how well-behaved and generally-flat the calculated velocity map is compared to the refraction velocity map. Also note the similarities between the GravStat™ Time and Depth Maps.

43. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Time Structure Contour interval = 1ms

44. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Velocity to Depth Contour interval = 5’/sec.

45. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Depth Map Contour interval = 4 feet

46. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Depth Map Contour interval = 4 feet

47. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Depth Map Contour interval = 4 feet

48. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical GravStat™ - Time Structure Contour interval = 1ms

49. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Refraction - Time Structure Contour interval = 1ms

50. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Conclusions The GravStat™ time structure map mimics the actual well control more accurately than the refraction time structure map. The GravStat™ velocity map is flatter, allowing for greater confidence in predicting prospects away from the existing well control. The time structure on the refraction static interpretation in the SW corner of the survey is probably not a valid prospect.

51. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Predicted Well Tie Results GravStat Refraction

52. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical ZEN........... ZEN........... and the Art of Small, Prospect Specific 3D Seismic Surveys in Oil and Gas Exploration William A. Miller, CPG, PE

53. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical AN ATTEMPT TO QUANTIFY CONFIDENCE IN MAPPING STRUCTURES Confidence Assuming Vint=7 ft/msec and picking accuracy of 1 msec, then express Confidence as: 1-(accuracy in ft/structural relief) –for 10’ of structure: Confidence=1-7/10 or 30% –for 14’ of structure: Confidence=1-7/14 or 50% –for 21’ of structure: Confidence=1-7/21 or 66% –for 28’ of structure: Confidence=1-7/28 or 75% William A. Miller, CPG, PE

54. GravStat™ A OEX Technology Registered in the U. S. Patent and Trademark Office and offered through Lockhart Geophysical Economics of GravStat™ A typically GravStat™ survey only adds 10% to the 3D seismic survey. The true cost of a GravStat™ survey is considerably less if one considers the cost of drilling a dry hole!