Exhibit 99
Suite 800 East
February 16, 2021
925 N. Eldridge Parkway
Ladies and Gentlemen:
Pursuant to your request,
DeGolyer and
MacNaughton
has performed a process review of the
processes and
controls used by ConocoPhillips in preparing its internal estimates
of proved reserves,
as of December 31, 2020. This
process review,
which is contemplated
by Item 1202 (a)(8) of
Regulation S–K of
the United States Securities
and Exchange
Commission (SEC), has been performed
specifically to address the adequacy
and effectiveness of ConocoPhillips’ internal processes
and
controls relative to
its estimation
of proved reserves in compliance
with Rules 4–10(a)
(1)–(32) of
Regulation S–X
of the SEC.
DeGolyer and
MacNaughton
has participated as an independent
member of the internal
ConocoPhillips Reserves
Compliance
Assessment Team
in
reviews and
discussions with each
of the
relevant ConocoPhillips
business units relative to SEC
proved reserves estimation.
DeGolyer and
MacNaughton
has participated in the review of all major
fields in all countries in which
ConocoPhillips holds proved
reserves worldwide. ConocoPhillips
has indicated
that
these reserves
represent over 90 percent of
its estimated
total proved reserves as of December 31, 2020.
The reviews with ConocoPhillips’
technical staff
involved presentations
and discussions of a) basic
reservoir data,
including
seismic data,
well-log
data,
pressure and production
tests, core analysis,
pressure-volume
-temperature data, and production
history, b) technical methods
employed in SEC
proved reserves estimation,
including performance
analysis,
geology, mapping,
and volumetric
estimates, c) economic
analysis, and d) commercial assessment,
including
the legal
basis for the
interest in the reserves, primarily
related to lease agreements
and other petroleum
license
agreements,
such as concession
and production
sharing
agre
ements.