Well Drilling Process Optimization in the Verkhnechonskoye Oil and Gas Condensate Field

1.

SPE-181928-MS.
Well Drilling Process Optimization in the
Verkhnechonskoye Oil and Gas Condensate Field
Andrey Dubrovin, Andrey Klabukov, Nikolay Abaltusov, Weatherford.
Vladimir Shulga, PAO"VCNG"

2.

Slide 2
Verkhnechonskoye Oil and Gas Condensate Field
VCOGCF
VCOGCF is located in the north of the
Irkutsk Region, in the Chone river’s head
It is one of the largest in Eastern Siberia
Irkutsk
Region
Oil reserves total 200 million tons
Gas reserves total 95.5 billion m3
Irkutsk
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

3.

Slide 3
Verkhnechonskoye Oil and Gas Condensate Field
Field discovery
1978
VCNG field
development
2005
Connected to the
ESPO pipeline September of
2008
40 million
tons of oil
2012
486
wells
2016
230
wells
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

4.

Slide 4
VCOGCF Geological Structure
Vch-2 pay
zone
Salt
Dolomites
Argillites
thickness
10 m
bed, TVD
1660 – 1670 m
washingout
Slide drilling challenges
hard
formations
low ROP
cavings
risk of sticking; problems when
running the casing string
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

5.

Slide 5
Pay Formations in VCOGCF
1300
Osinskiy horizon
Ust-Kutskiy horizon
Preobrazhenskiy horizon
1650
VCh-1
Verkhnechonskiy horizon
VCh-2
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

6.

Slide 6
Well Drilling Process Optimization in VCOGCF
Conductor
1 day
Surface casing
2.5 days
Production
casing
Production casing
11.5– –13.5
13.5days
days
11.5
7 – 9 days
Drilling
Wiper trip and casing
4.5 days
Liner
Horizontal well
5.5 days
19 – 22 days
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

7.

Slide 7
Production Casing Section Drilling
DP
MWD
XO
Sonic
NMDC
MWD +
gamma +
vibrations +
borehole
annulus
pressure
NMDC
Motor with
stabilizer
PDC bit
resistivity +
gamma
density +
porosity
Spectral gamma
Float sub
XO
PDC bit
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

8.

Slide 8
Experiment #1. Drilling over 2 Runs
Run 1
Trip out
Run 2
• Bit replacement
DP
• Motor replacement
MWD
XO
Sonic
NMDC
MWD +
gamma +
vibrations +
borehole
annulus
pressure
resistivity +
gamma
density +
porosity
NMDC
MWD (inc only)
Middle Moti suite
Motor with
stabilizer
Motor with
stabilizer
PDC bit
PDC bit
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

9.

Slide 9
Production Casing Section Drilling over 1 run
Water based mud
Oil based mud
Stator elastomer wears out much faster
Motor with an oil-resistant elastomer is required
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

10.

Slide 10
Motor with an Oil-Resistant Elastomer
Drilling mud samples
Motor manufacturing
NBR-HR-37 elastomer
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

11.

Slide 11
Experiment #2. Drilling over 1 Run
Run 1
MWD
Sonic
resistivity +
gamma
density +
porosity
ROP = 17,3 m/h
MWD (inc only)
Motor with
stabilizer
147 hours
of circulation
PDC bit
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

12.

Slide 12
depth, m
Time for Drilling Production Casing Section
days
Conventional drilling of production casing section
Drilling over 2 runs
Drilling over 1 run
12-30 h
≈ 45 hours
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

13.

Slide 13
Restrictions
Azimuth change is to be less than 60°
MWD
Production casing setting depth is
to be less than 2700 m
< 60
Sonic
Side view
> 60
resistivity +
gamma
density +
porosity
MWD (inc only)
< 2700
Motor with
stabilizer
Top view
PDC bit
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov
> 2700

14.

Slide 14
The Results of Production Casing Section Drilling Optimization
LWD suite is included in BHA
Production casing section is drilled per one run
The bit design is optimized
An optimal size of the motor stabilizer is selected
Water based mud is replaced by oil based mud
Oil resistant elastomer is selected based on drilling fluid sampling
MWD pulser is adjusted based on defined borehole conditions
o Data transmission speed increase
o ROP increase
An individual approach to each well
o
Preliminary calculations of hydraulics, WOB, tensions and torques
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

15.

Slide 15
Record well
Drilling over 1 run
Start drilling of production casing section
Production casing
interval is drilled and
depth, m
cased for 7
Start drilling of liner section
days
Total well construction
time
14 days
days
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

16.

Slide 16
The Results of Production Casing Section Drilling Optimization
8 wells drilled with Drilling optimization
250 hrs of total well-construction time saving
15 000 000 RUB – Value to Client
SPE-181928-MS • Well Drilling Process Optimization in the VCOGCF • Nikolay Abaltusov

17.

Slide 17
Acknowledgements / Thank You / Questions
The authors express thanks to the management groups of PAO “VCNG”
(PAO “NK Rosneft”) and Weatherford companies for the permission to
publish and submit the results of this paper.
We also express thanks to the drilling crew and the service specialists who
were involved in the well drilling and were gathering the field data for
analysis.