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Oilfield Technology
January
2016
measurements can also be furnished at the request of the
customer.
If further analysis is needed, data will then be collected and
sent to a third party for QA by an industry-trained and qualified
survey analyst. There, surveys will be analysed at a high level
by advanced survey management experts using real time data,
surface data, and tool memory data. Also, corrections can be
made to adjust for any axial and/or cross-axial biases on the data.
A full certification letter and survey report with detailed
description of the QA performed and the survey corrections
applied will be delivered to the customer. This data will then
be filed with the appropriate regulatory body as per area
requirements. Other data can be provided to the customer upon
request, and reports can be tailored to meet specific reporting
requirements or preferences as directed by the customer.
Proofofperformance
This technology was recently used in a field trial in the
Middle East. In this particular application, the customer was
using a standard MWD tool in the 12 ¼ in. section from surface
all the way to total depth. Furthermore, this was a vertical
application, where there were no planned directional objectives
for the well. One of the customer’s primary expectations was
to reduce the amount of nonproductive time (NPT) with regard
to taking surveys versus the MWD solution. In this particular
application, the customer had historically run with an MWD
tool, and then used a gyro or other
high-precision tool post-run to validate
the primary survey tool. Based on this
information it was agreed to run the
FloSurvey tool and then use a gyro
tool post-run to validate the tool’s
performance against the gyro tool.
The results of the run were that
the tool provided each survey within
75 seconds from the time the pumps
came on from each connection event.
The rig took approximately 48 surveys
from 6562 to 11 942 ft (2000 to 3640 m)
true vertical depth. The total rig time
required to take all of the 48 surveys was
approximately 60 minutes, consuming
0.2% of the total rig time for this drilling
campaign of 17 days. As a comparison,
an alternative system has reported a
survey transmission time of five minutes.
If this solution had been used in this
application with the same number of survey points collected, it
would have represented approximately 1% of the same rig time, or
an increase of more than 75% versus the FloSurvey tool.
A comparison between the FloSurvey tool and the gyro tool
was also considered. After the FloSurvey tool run, the customer
ran a gyro in the well. Table 1 shows the resulting comparison
of the two tools. As shown at 11 942 ft (3640 m), the total
difference of the bottomhole location was only 6.86 ft (2.09 m).
The customer was extremely pleased with both the performance
of the Flosurvey tool and the overall operational savings offered
with this solution.
The driller indicated that his operational efficiency increased
significantly because he was able to receive surveys far more
rapidly versus the MWD tool. Additionally, the knowledge that
the tool only required 75 seconds from pumps on to gather
information enabled the driller apply more weight on bit due to
his confidence in the speed of the survey.
Conclusion
In challenging and demanding applications, operators who are
keen to increase the efficiency of their operations and wells will
agree that having a built-for-purpose solution for the vertical
sections of wells makes fiscal and operational sense. This
technology aims to enable operators to maximise every minute
on their rigs by reducing the time wasted waiting on surveys to be
transmitted to the surface.
Figure 3.
Surface systemcomponents.
Table 1. The difference in the FloSurvey run versus the gyro tool run.
Gyro
FloSurvey
Difference
Total difference
(m)
Depth (m)
+N/-S (m)
+E/-W (m
)
+N/-S (m)
+E/-W (m)
Northing (m)
Easting (m)
2000
-13.53
-21.13
-13.30
-21.39
0.23
0.26
0.35
2500
-14.17
-20.71
-13.96
-20.71
0.21
0.00
0.21
3000
-17.30
-19.56
-15.99
-18.96
1.31
0.60
1.44
3500
-17.83
-19.59
-16.60
-18.66
1.23
0.93
1.54
3640
-18.39
-19.01
-17.25
-17.26
1.14
1.75
2.09
