Unformatted text preview: th (UCS), even when Eq. 6 is used. It has also been observed, from lab data under confined bottomhole pressure, that
MSE is often substantially higher than the rock confined compressive strength (CCS), even when the bit is apparently drilling
It is common knowledge in the industry that bit hydraulic improves the drilling operations by increasing the ROP. Even
though MSE does not directly contain any bit hydraulic-related term, it has been observed that bit hydraulic increases the
drilling efficiency by reducing MSE. 3, 10 Including a bit hydraulic-related term on the specific energy correlation is
paramount to the improvement of drilling operations. This is the main task of this publication.
Drilling Specific Energy (DSE)
Drilling specific Energy (DSE) can be defined as the work done to excavate and remove, underneath the bit, a unit volume of
rock. Teale’s original equation was modified to include a bit hydraulic-related term on the MSE correlation. DSE can be
calculated as follows: DSE = WOB 120 * π * RPM * T 1,980,000 * λ * HPB
AB * ROP
ROP * AB (8) The first two terms on the right side of the equation are the same terms included...
View Full Document
- Spring '13
- Strength of materials, DSE, Compressive strength, ROP