End Notes for:

Perforating for Heavy Oil Cold Production In North West Saskatchewan and North East Alberta, Canada

by Kirby Hayes,

1. Cold production is a relatively new production technique. It is subjected to the cyclic market conditions of heavy oil. As such, it has not had the opportunity, in some situations, to establish or apply, what might be deemed, as good engineering or science.

2. It is important to notice whether API specifications are being compared to API. There is significant differences between API specifications and QC specifications. QC specs are not necessarily comparable due to the difference between QC testing targets and test designs.

3. Reversing sand control strategies to enhance cold production is a way to apply sand control literature and techniques to cold production put forward by S. Tariq. In his presentation, he noted N. Morita, SPE 16989, 1997 and Santarelli, SPE 22797, 1991 theoretical models indicated higher shot densities led to more sanding, Morita also indicated a smaller EHD is more unstable and Santarelli observed that sand production risk is unaffected by perforation depth. Veeken, et al, SPE 22792, 1991 saw in his field measurements that erosion was the primary mechanism in sand production and fluid velocity was the main factor in this phenomena.

4. 50%BH and 50%DP

5.  It is imperative that most of these carriers be shot in fluid to avoid splitting

6. It was previously an accepted practice to reduce the fluid head to an under balanced level before perforating, shoot the first carrier experience inflow and proceed with the subsequent perforating runs thinking they would still be subjected to the same under balanced situation as the first run.

7. The fear of bottom water became less as drainage geometry and water encroachment became better understood.

8. It is not recommended to use wire line conveyance when 127mm carrier lengths exceed 4m. The shock of detonation and the greater mass of these carriers often times creates enough momentum to exceed the weak point of the cable head.

9. A line truck is not required but a previously recorded correlation log is.

10. See re- perforating section

11. Recent studies into casing damage are being conducted by Wascana, Husky Oil, Noetic Engineering and C-FER.

12. There have been cases where wells have been perforated and re-perforated several times until the casing has been shot to 91 SPM using BH and EBH charges.

13. This study attempted to normalize geology and pay thickness

14. It is conceivable that the completion strategy chosen, after reviewing all the considerations listed, may well be different from the one being recommended here.

Bibliography

  1. S.Chugh et al, Mainstream Options For Heavy Oil Part 1
  2. S. Tariq, Big Shot 21 presentation
  3. Dusseault et al, Practical Requirements for Cold Production
  4. G. E. King, Factors Effecting Perforating Charge Performance
  5. A. Squires, Inter-well Tracer Results and Gel Blocking Program
  6. M. B. Geilekman, M. B. Dusseault, Dynamics of Wormholes and Enhancement of Fluid Production
  7. M. B. Geilekman et al, Dynamic Effects of Foamy Fluid Flow in Sand Production Instability
  8. S. Solanki et al, Heavy Oil Reservoir Mechanisms, Lindbergh and Frog Lake Fields, Alberta Part 1 and
  9. G. E. King, Casing Crush Resistance Loss to High Density Perforating
  10. W. K. Godfrey et al, Casing Damage Caused by Jet Perforating
  11. G. E. King, Casing Crush Resistance Loss to High Density Perforating
  12. D. Brownlee, Chemical Stimulation in Heavy Oil Wells
  13. Wai Ma, Chem Frac Results Update

Acknowledgements

Editorial suggestions by:

Dr. Franklin Foster, Foster Learning Inc.

Chris Wallin, Wascana

Greg Calpas, Husky

Jordan Wiess, Arco

Dave Metcalfe, Explosives Limited

Brett Davidson, Subterranean Technologies