This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Contribution = ⎜
⎟ * 100
⎠ (9) MSE was calculated using Eq. 1 (Teale’s original correlation). Fig. 9 shows the bit hydraulic contribution vs. bit HSI for
WOB equal to 20,000 lb, 30,000 lb and 40,000 lb, respectively. Fig. 9 shows a linear relationship between the bit hydraulic
contribution and HSI, it also shows that the bit hydraulic contribution reduces with WOB. A common practice in the industry
is to use HSI equal to 2.0 hp/in2 to “optimize” the field operations. For HSI equal to 2.0 hp/in2, the bit hydraulic contribution 4 SPE 116667 reduces from 22% to 9% when the WOB increases from 20,000 lb to 40,000 lb. This reduction on the bit hydraulic
contribution could explain why all the data with HSI lower than 1.7 hp/in2 fits on the inefficient drilling region (High DSE
and low ROP) on Fig. 3.
Fig. 10 shows the bit hydraulic contribution vs. ROP for the same WOB values mentioned on the previous paragraph. Fig.
10 shows that the relationship of bit hydraulic contribution and ROP is not linear; it is a power function. This means that the
View Full Document
- Spring '13