Unformatted text preview: in2 is needed to have efficient drilling conditions. This value is 50% higher than the one
normally used by the industry (HSI = 2.0 hp/in2) to optimize the drilling operations.
DSE and Rock Compressive Strength: The rock confined compressive strength (CCS) is added to the information on Fig.
3 and presented on Fig. 5 to compare the DSE model with the CCS. As per Teale’s observation, the system would be at
efficient conditions when the DSE is close to the CCS.1 It is shown on Fig. 5 that all the WOB curves tend to the rock
compressive strength value when the bit hydraulic (HSI) energy is progressively increased. The hydraulic contribution for the
20,000 lbs WOB is too high when the HSI is higher than 4.7 hp/in2 generating DSE values lower than the CCS. The 30,000
lbs and 40,000 lbs WOB data seems to be operating at efficient conditions with HSI equal to 7.5 hp/in2. Nonetheless; ROP is
higher when WOB is 40,000 lbs, even though, the DSE value is similar for both WOB values (30,000 lb and...
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- Spring '13
- Strength of materials, DSE, Compressive strength, ROP