Bit Run Optimization through Simulation: A Case Study

Abstract:

The usual objective when drilling a well is to drill for the lowest overall cost. At first sight, this may seem like a requirement to drill as fast as possible, since many of the costs, such as the rig day rate, wages etc., are time dependent. However, some costs are fixed, for example the cost of the bit, and it may not always be economic to pay a very high cost for a bit that drills somewhat faster, particularly if the other costs are low.In this paper, some first 3465 feet of a reservoir lithology including four bit runs are analyzed so that factors affecting penetration rate are optimized and the lowest possible well cost is achieved. The effects of using other bit types, WOB, RPM and bit hydraulics are simulated in an attempt to determine the optimized parameters, which result in the lowest drilling cost. In this study, reducing both nozzle sizes and mud flow rate, the horse power dissipated at the bit is increased, hence reducing cost per foot of drilled interval. As it is noted, by using this simulator, 17% of the original well cost is saved, which is a considerable amount of money.

• Periodical: Advanced Materials Research (Volumes 433-440)
• Pages: 2387-2393
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.433-440.2387
• Online since: January 2012
• Authors: E. Novieri, S. Torfi
• Keywords: Bit Hydraulics, Bit Run Optimization, Rotary Speed, Simulation, Weight on Bit

References

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DOI: 10.2118/9781555630010

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[6] Abouzeid, A.A. and Cooper G.A., (2001).

[30] Shorijeh 222.

[6] 8. 5 T.C. I.

[35] [60] [87] 180-400 220 Abderaz.

[54] [28] 12. 25 T.C. I.

[10] 190.

[81] Table II Well #2 Parameters. Thickness Depth(ft) Formation Cf(cost/ft) ROP Bit Size Bit Type W(Ibf) N(RPM) ρ(pcf) 130-190.

[60] Shorijeh 220.

[8] 8. 5 T.C. I.

[40] [58] [87] 190-400 210 Abderaz.

[56] [27] 12. 25 T.C. I.

[10] 190.

[81] Table III Original Bit Runs. Table IV Final Optimization of Bit Types. Table V Final Optimization of WOB and Rotary Speed. Table VII Final Optimization of Bit Hydraulics.