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- Titre : "spectrasphere-eni-gom-cs.pdf"
- Submitted by : Anonymous
- Description : a complete formation evaluation in a single run while also reducing acquisition time and rig cost.” Gian Luca Atzeni. Operations Geology Manager, Eni Identify new sampling method to save time and money in future operations. Eni US Operating Co. wanted to optimize formation testing processes to save time and money in future wells.
Transcription
CASE STUDY
Eni Receives Industry-First While-Drilling Analysis
of Hydrocarbon Composition, Gulf of Mexico
PVT lab testing validates results of fluid-profiling method
CHALLENGE
Determine capability of new formation testing
method to optimize formation pressure testing
and sampling processes.
SOLUTION
Use SpectraSphere* fluid mapping-while-
drilling service to obtain reservoir-repre-
sentative downhole samples in a wildcat
exploration well and provide in situ fluid
properties in real time.
RESULTS
■ Transmitted fluid compositions for
C1, C2, C3, C4, C5, C6+, and CO2 in
real time for first time while drilling.
■ Delivered lab-quality, in situ fluid
property analysis, which would save
an estimated 10 weeks of lab time
in future sampling operations.
“The SpectraSphere service will soon
give us the possibility to perform
a complete formation evaluation in
a single run while also reducing
acquisition time and rig cost.”
Identify new sampling method to save time and money in future operations
Eni US Operating Co. wanted to optimize formation testing processes to save time and money in future
wells. The operator conducted a field test while drilling an exploratory well in the Mississippi Canyon
area of the Gulf of Mexico in Miocene turbiditic sands. The target zone was located at a water depth
of about 5,800 ft with uncertain reservoir characteristics and fluid properties. A new reservoir fluid
mapping method would need to be capable of acquiring pretests, capturing clean downhole samples,
and fully describing reservoir fluids at a cost and time savings.
Acquire individual fluid composition analysis up to C5 with SpectraSphere service
Schlumberger recommended using the SpectraSphere service to measure formation pressures, acquire
samples, and analyze the fluid characteristics in real time from the exploratory Mississippi Canyon
well. This service is added to the downhole drilling assembly and collects reservoir-representative
samples while performing accurate fluid analysis before sampling while drilling. Traditionally,
sampling happens about a day after drilling, which often results in deeper invasion of the reservoir
by the drilling fluid filtrate. The SpectraSphere service accurately delivers the following in situ
hydrocarbons properties: individual compositions from C1 to C5, C6+, GOR, fluid color, hydrocarbons
and water fractions, flowline fluid resistivity, temperature and pressure, and CO2.
Transmitted individual hydrocarbon analysis in situ, delivered lab-quality fluid profiling
The SpectraSphere service analyzed and collected six samples downhole in real time, setting an
industry first for the transmission of detailed in situ fluid properties. The SpectraSphere service
estimated contamination and time to clean up, performed fluid identification and typing and
measured GOR and fluid composition (C1 to C5, C6+, and CO2).
These results were verified 10 weeks later by lab results. Contamination was estimated in real time to
within ±2% of the laboratory-determined values. Pressure measurements and fluid gradients were also
successfully obtained during the operation. A total of 28 pretests were taken—17 while drilling and 11
while pulling out—that provided Eni a full description of the reservoir pressure and fluid gradients.
Gian Luca Atzeni
Operations Geology Manager, Eni
By delivering lab-quality results while drilling, SpectraSphere service proved its capability of
gathering good measurements and clean samples, saving Eni about 10 weeks.
Fluid mapping
PVT lab results
Error bar
%
t
w
,
t
n
e
n
o
p
m
o
C
80
70
60
50
40
30
20
10
0
2,000
1,500
l
b
b
/
f
c
s
1,000
500
C1
C2
C3
C4
C5
C6+
C02
0
GOR
PVT lab analysis results show good agreement with real-time, in situ analysis of fluid properties.
Drilling
CASE STUDY: SpectraSphere service delivers in situ fluid sampling and testing in real time, Gulf of Mexico
12,000
10,000
8,000
6,000
4,000
2,000
i
s
p
,
e
r
u
s
s
e
r
P
%
,
n
o
i
t
c
a
r
f
i
d
u
l
F
100
80
60
40
20
0
200
180
160
140
120
100
80
60
40
20
D
i
s
p
l
a
c
e
m
e
n
t
u
n
i
t
r
a
t
e
,
c
m
3
/
s
P
u
m
p
e
d
l
v
o
u
m
e
,
L
Annular pressure, psi
Displacement unit inlet pressure, psi
Displacement unit outlet pressure, psi
Volume pumped, L
Displacement unit flow rate, cm3/s
0
20.0
40.0
60.0
80.0
120.0
140.0
160.0
180.0
200.0
100.0
Elaspsed time, min
At 31 min
At 79 min
At 125 min
At 183 min
20.0
40.0
60.0
80.0
120.0
140.0
160.0
180.0
200.0
100.0
Elaspsed time, min
C1
C2
C3
C4
C5
C6+
CO2
Oil fraction
Water fraction
Eni determined that the quality and amount of real-time data (shown above) from the SpectraSphere service would enable it to accurately determine pressures, fluid composition,
and fluid fraction in future wells.
* Mark of Schlumberger.
Other company, product, and service names are the properties of their respective owners.
Copyright © 2017 Schlumberger. All rights reserved. 17-DR-265263
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