When Shell began an ultraheavy-oil development in Alberta, Canada, the field
plan was based on manual pad positioning without consideration for surface
hazards, trajectory constraints, or injector/producer slot requirements arising
from the prefabricated-pad configuration.
Shell teams were challenged to investigate alternative field-development
plans to reduce the initial investment. The volume of wells, surface hazards,
trajectory constraints, and pad slot configuration requirements for
injector/producer ratios made this a formidable task. Shell leveraged the
expertise of third-party consultants and powerful software to generate numerous
development scenarios, which enabled the Shell staff to focus on the economics
of each plan.
An aerial image that delineated surface hazards, an elevation grid, and
injector/producer targets were loaded into the 3D subsurface-visualization
environment of the software to generate pad-placement simulations, including
trajectory designs. The software followed the Shell planning constraints and
avoided all surface hazards.
The analyses were conducted for the highest, lowest, and median number of
pads. From these three scenarios, a value analysis was plotted. This value
analysis enabled the planning team to identify the optimal surface-to-reservoir
configuration and to maximize the value of the field by delivering all of the
reservoir targets, while minimizing the number of pads needed to drill. The
output also yielded field cumulative values, including total and nominal well
length, to support future economic analyses.
The analysis determined that 87 pads maximized the value of the field when
42-slot configured pads were considered. Additional studies determined that
when 50-slot configured pads were considered, more than 99% of the planned
reservoir targets could be drilled from 72 major and four or fewer minor pads.
In either case, a significant reduction from the original 98 pads was realized.
Through the combined efforts of Shell engineers and third-party consultants, as
well as the use of state-of-the-art software, this optimization was completed
in only 8 worker-weeks.
This paper describes the software and processes used to reduce Shell's
estimated field-development costs and to minimize the environmental effect of
the field by reducing the number of pads required.
© 2010. Society of Petroleum Engineers
View full textPDF
- Original manuscript received:
18 September 2009
- Meeting paper published:
5 October 2009
- Revised manuscript received:
24 November 2009
- Manuscript approved:
2 April 2010
- Published online:
26 August 2010
- Version of record:
11 October 2010