Analysis and use of drilling bit parameters for better well design

1. MONITORING DRILLING BIT
PARAMETERS
ALLOWS
OPTIMIZATION OF DRILLING RATES
V.C. KELESSIDIS - P. DALAMARINIS
vaskel1@hotmail.com
sk l1@h tm il m
Technical University of Crete
Mineral Resources Engineering
SGEM 2009
Albena, June 14-19, 2009

2. Research aim
Optimization of drilling rates
Less expensive and safer drilling practices
Hydrocarbon, geothermal, mining, water well
H d b th l i i t ll
drilling
Multitude of parameters affecting drilling
performance
Availability of data and proper modeling
software
Optimum combination better drilling rates
2

3. The problem
Drilling allows for access to subsurface
target areas
Pythagoras saying ‘whoever digs, finds, he who
never digs, will never find’
digs find
Drilling is expensive
Optimum drilling practice arrive to target
in the most economical way, but with safety
y y
Main monitoring parameter – Penetration Rate
(m/ )
(m/h)
Depends on two main groups
Formation
Drilling parameters 3

4. Main parameters
FORMATION
Local stresses
Rock compaction
Mineralogical content
Flu d
Fluid pore pressure
DRILLING
Weight on bit and torque
Rpm
Hydraulic parameters
y p m
Bit condition 4

5. Modeling drilling process - Teale
Rock-bit interaction
Energy to the bit
Efficiency of energy transfer
ff y f gy f
ENERGY PER WOB 8(RPM )(μD )(WOB / Abit )
SEt = +
UNIT VOLUME Abit ROP
UCS
ROCK-BIT MODEL = SEt
eff
ROP =
(8)( RPM )(μD )(WOB / Abit )
UCS WOB
−
eff Abit 5

6. Payzone simulator
Developed by G. Cooper, UCB
Similar to Teale’s model predictions
Adjustable p
j parameters
m
Use of historical data for tuning
SPE 30213 36660
30213,
ROP = ( flow _ factor )(C )(aggressivity )( RPM )(tooth _ length)(G )
⎡ ⎛ WOB ⎞ curv ⎛ 12 ⎞⎤
G = 1 − exp ⎢− ⎜ ⎟ ⎜ 2 .5 ⎟⎥
⎢ ⎝
⎣ UCS ⎠ ⎜ D (0.4 * tooth _ length ) ⎟⎥
⎝ g ⎠⎦
6

7. Comparison of models with lab data
7

8. Use of historical data
8

9. Data needed
Lithology
Bit records and bit types
Casing schedule
Drilling parameters
WOB, RPM, FLOW RATE,
PRESSURE
ROP
Drilling fluid
9

10. Adequate simulation
10

11. Case study analysis
Drilling in Norwegian Continental Shelf
Reconstruct drill time log
1917 – 2414 m
Four main lithologies, 18 formation intervals
11

12. Base case and two scenarios
1.Normal drilling curve
2.Drilling curve with
RPM+50 rpm
3.Drilling curve with
WOB+45 kN
12

13. Full scenarios
1.Base drilling time plot
1B d illi ti l t
2.Simulated drilling time
plot b having extra 4.5
l t by h i t 45
tons, extra 50 RPM and
extra 200 lpm
t l
13

14. Increase in UCS by 50%
Increase may range between 58
y g
and 96%, giving an overall
increase in total drilling time for
g
the sections chosen for the
14
simulation of 82%

15. Conclusions
Penetration rate – the most sought after
parameter f d i of well d illi
t for design f ll drilling
Attempts to simulate the process – none very
successful
Recent advances, flexible simulators that
,f
could be used on site
Payzone,
Payzone is one of them (G Cooper)
(G.
Drilling advance model, few adjustable
parameters
Can be tuned via use of prior historical data
from the region and the field
f th i d th fi ld
15

16. Conclusions
Data: WOB, RPM, Flow, well geometry, drill
bit record, ROP, Lithology
gy
Normally monitored – need to monitor in non-
critical wells also
Can be used to effectively model and describe
the drilling process
Re-engineering and re-drilling possible, no
great difficulties
reat
Increase in WOB, RPM, Flow -> beneficial
effect, need to worry about bi wear
ff d b bit
Increase (error) of UCS by 50%
y decrease
in ROP by 82%
16