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Exhibit 10.6 CONFIDENTIAL
 AMENDMENT NO. 2
TO  MASTER LICENSE AGREEMENT
   Recitals
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Licensor
SYNTROLEUM CORPORATIONBy:
    /s/ Larry J. WeickLarry J. Weick, Vice PresidentLicensee
IVANHOE ENERGY INC.By:
    /s/ E. Leon DanielE. Leon Daniel, President & CEO 2




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Exhibit A to Amendment Number 2   ATTACHMENT 3     License Fee Calculation
 I.
    
    For purposes of this Attachment 3, the following terms shall have the meanings
ascribed thereto:A.
    
    Licensed Plantmeans the Licensed Plant in which a Site License Agreement for such plant is
issued to and remains in the name of the Licensee who has executed this Agreement with
Licensor and, in which the Participating Interest held by Licensee, or collectively by
Licensee and any other Person who has executed a license agreement (which is applicable to the
Licensed Plant) with Licensor, represents at least 10% of the entire Participating Interest
not held by a governmental authority regardless of operatorship of the Licensed Plant.B.
    
    Large Licensed Plantmeans a Licensed Plant under a single Site License Agreement with a
maximum daily design capacity, as defined in a single Process Design Package, of nominally
180,000 or more barrels of Synthetic Product per day and which may be constructed in two
phases of nominally 90,000 or more barrels per day for each phase and with the second phase
constructed either concurrently with the first phase or in a separate consecutive period
starting no more than 1 year following the start of construction of the first phase.C.
    
    Royalty Rateshall mean (i) the lowest royalty rate per Barrel of Synthetic Product
accepted by Licensor for a Site License Agreement with a non-Affiliate for a facility of
comparable size, in the Licensed Territory, which is not under a master preferred license
agreement, during the twelve (12) months immediately preceding the execution date of the
applicable Site License Agreement under this Agreement, or (ii) if no such Site License
Agreement has been executed during the twelve (12) months immediately preceding, then the
royalty rate per Barrel of Synthetic Product in the last Site License Agreement with a
non-Affiliate, in the Licensed Territory, executed by Licensor, which is not under a master
preferred license agreement, or (iii) if none of the foregoing applies, then US$0.50 per
Barrel of Synthetic Product. Market Royalty Rate does not include the catalyst price as
provided for under Section 2.03 of this Agreement.D.
    
    BLS Indexshall mean the index for January of the year in question represented by the
Producer Price Index for Industrial Commodities as published by the Bureau of Labor
Statistics, U.S Department of Labor, using the year 1982 as the base index equal to 100. If,
at any time, the above index should cease to be published, then
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another suitable index published by the U.S. Government or other authoritative organization and
generally recognized by the trade as authoritative with respect to changes in the U.S. of
equivalent commodity costs shall be used.II.
    
    For each Site License Agreement executed under this Agreement for a Licensed Plant with a
maximum daily design capacity, as defined by the Process Design Package, of less than 30,000
barrels of Synthetic Product per day, Licensee agrees to pay License Fees to Licensor on a
prepaid license basis as follows:
 A.
    
    Licensee agrees to pay Licensor a one-time, prepaid License Fee calculated in
accordance with the following formula:License Fee = C x 350 x 7.5 x R wherein:
 C
    
    =
    
    the maximum daily design capacity, as defined by the
Process Design Package, of such Licensed Plant to produce Marketable Products
measured in Barrels of Synthetic Product per day for which such Licensed Plant
is originally designed and constructed, andR
    
    =
    
    the Royalty Rate.
 and payable in installments as follows:
 (i)
    
    20% within thirty (30) days after the execution of the Site
License Agreement for such Licensed Plant;(ii)
    
    30% within thirty (30) days after delivery of the Process
Design Package or within one hundred twenty (120) days after the execution of
the Site License Agreement for such Licensed Plant, whichever first occurs;(iii)
    
    20% within thirty (30) days after the commencement of field
construction move-in:(iv)
    
    30% within one-hundred and twenty (120) days after the
Start-Up Date of the Licensed Plant or a successful Performance Test as
specified in the Process Guarantee and Performance Test Agreement, whichever
first occurs.
 B.
    
    Notwithstanding any other provision of this Agreement, payments made by
Licensee to Licensor under Section 5.01 of this Agreement and Section 5 of Amendment
No. 1 to Volume License Agreement between Licensee and Licensor dated October 11,
2000, shall be fully credited against the License Fees payable by Licensee to Licensor
under Section II.A.
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C.
    
    In the event the actual production capacity of any Licensed Plant, under
II.A. above, is determined to have either exceeded the original maximum daily design
capacity established in its Site License Agreement or is increased through major
equipment modification, by more than five percent (5%) or by more than 500 barrels per
day, at any time after the Start-up Date, Licensee shall pay Licensor an additional
License Fee, on a prepaid basis, equal to the difference between (a) the prepaid
License Fee as would have been calculated with the higher production capacity for such
Licensed Plant substituted for C in the calculation method set forth in II.A. above,
and (b) the License Fee as would have been calculated for such Licensed Plant by the
method set forth in II.A. above using the original maximum daily design capacity
established in each Site License Agreement. The incremental License Fee due will be
reduced by any previous incremental adjustments. Such additional License Fee shall be
payable within thirty (30) days after the end of the calendar year in which such
increase in production capacity of such Licensed Plant occurs. Incremental License
Fees for increased production capacity in any Licensed Plant shall not be due if the
increased production capacity is the result of the initial use of Licensee Patent
Rights or Licensee Technical information. The total cumulative incremental capacity
adjustments under each Site License Agreement will be limited to 50 percent of the
initial maximum daily capacity under such Agreement.D.
    
    Upon payment of all fees due under the Site License Agreement for each
Licensed Plant under this Section II, Licensee shall be deemed to have acquired a
fully paid license for such Licensed Plant up to the original maximum daily design
capacity or any adjusted daily design capacity made under the provisions of Section
II.B. above. Any additional incremental increases in the Licensed Plant capacity will
be subject to additional License Fees as calculated under incremental adjustments
pursuant to this Section II.
 III.
    
    For each Site License Agreement executed under this Agreement for a Licensed Plant with a
maximum daily design capacity, as defined in the Process Design Package, equal to or more than
30,000 barrels but less than nominally 180,000 barrels of Synthetic Product per day, Licensee
agrees to pay License Fees to Licensor as follows:
 A.
    
    Prepaid License Fee.
   C
    
    =
    
    the maximum daily design capacity, as defined by the
Process Design Package, of such Licensed Plant to produce Marketable Products
measured in Barrels of Synthetic Product per day for
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which such Licensed Plant is originally designed and constructed, andR
    
    =
    
    the Royalty Rate.
 and payable in installments as follows:
 (i)
    
    20% within thirty (30) days after the execution of the Site
License Agreement for such Licensed Plant;(ii)
    
    30% within thirty (30) days after delivery of the Process
Design Package or within one hundred twenty (120) days after the execution of
the Site License Agreement for such Licensed Plant, whichever first occurs;(iii)
    
    20% within thirty (30) days after the commencement of field
construction move-in;(iv)
    
    30% within one-hundred and twenty (120) days after the
Start-Up Date of the Licensed Plant or a successful Performance Test as
specified in the Process Guarantee and Performance Test Agreement, whichever
first occurs.
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B.
    
    Running Royalty License Fees.
 1.
    
    In addition to the prepaid License Fee payable by Licensee to
Licensor in accordance with Paragraph A above, Licensee agrees to pay Licensor, on
or before thirty (30) days after the end of each calendar month, a monthly running
royalty license fee based on the actual operation of the Licensed Plant and
calculated in accordance with the following formula:Monthly Running Royalty License Fee = MP x (R x .50) x BLSwherein:
 MP
    
    =
    
    the total monthly production in Barrels of
Synthetic Product during a calendar quarter as measured in a manner
specified in the Process Design Package,R
    
    =
    
    the Royalty Rate, andBLS
    
    =
    
    the factor equal to (a) the BLS Index for the
calendar year in which the payment is being made divided by (b) the BLS
Index applicable as of the Effective Date of the Master License Agreement.
 IV.
    
    For each Site License Agreement executed under this Agreement for a LargeLicensed
Plant, Licensee agrees to pay License Fees to Licensor as follows:
 1.
    
    First Phase
 A.
    
    Prepaid License Fee25% of the Prepaid License Fee for the first nominal 90,000 barrels per day of a
Large Licensed Plant (First Phase) will be paid in accordance with the
installment payment schedule set forth in Section III.A. aboveANDB.
    
    Running Royalty License FeesThe remaining License Fee in respect to the First Phase of a Large Licensed Plant,
will be paid, on or before thirty (30) days after the end of each calendar month,
as a running royalty license fee (First Phase
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Running Royalty License Fee) per barrel of actual production of Marketable
Products for the life of the project. The First Phase Running Royalty License Fee
rate, will be equal to 75% of the standard Royalty Rate for a Licensed Plant
current at the time of execution of the Site License Agreement and escalated
annually thereafter based upon the Bureau of Labor Statistics published inflation
index, calculated as follows:First Phase Running Royalty License Fee = MP x (R x 0.75) x BLSWherein:
 QP
    
    =
    
    total monthly production in Barrels
of Marketable Products during a calendar monthR
    
    =
    
    the Royalty RateBLS
    
    =
    
    the factor equal to (a) the BLS
index for the calendar year in which the payment is being made
divided by (b) the BLS Index applicable as of the Effective Date
of the Master License Agreement.
 2.
    
    Second PhaseFor the second nominal 90,000 barrels per day minimum or more for the Large Licensed Plant
under the same Site License Agreement referenced above (Second Phase) that will be
included in a combined design with the First Phase as a single project for purposes of
preparation of the Process Design Package, with the Second Phase constructed either
concurrently with the First Phase or in a separate consecutive period starting no more than
1 year following the start of construction of the First Phase, the License Fee associated
with the Second Phase of the Large Licensed Plant shall be paid as follows:
 A.
    
    Prepaid License Fees
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B.
    
    Running Royalty License FeesThe remaining License Fee in respect to the Second Phase of the Large Licensed
Plant, will be paid, on or before thirty (30) days after the end of each calendar
month, as a running royalty license fee (Second Phase Running Royalty License
Fee) per barrel of actual production of Marketable Products for the life of the
project. The Second Phase Running Royalty License Fee rate, will be equal to 50%
of the standard Royalty Rate for the Licensed Plant current at the time of
execution of the Site License Agreement and escalated annually thereafter based
upon the Bureau of Labor Statistics published inflation index, calculated as
follows:Second Phase Running Royalty License Fee = MP x (R x 0.50) x BLSWherein:
 MP
    
    =
    
    total monthly production in Barrels of
Marketable Products during a calendar monthR
    
    =
    
    the Royalty RateBLS
    
    =
    
    the factor equal to (a) the BLS index
for the calendar year in which the payment is being made divided by
(b) the BLS Index applicable as of the Effective Date of the Master
License Agreement.
 3.
    
    Accumulated credits, if any, to which Licensee is entitled against the
License Fee under the Site License may be applied at Financial Closing and any
remaining credits may be applied the thirty (30) days after commencement of field
construction move-in.
 V.
    
    All payments required hereunder shall include a statement showing the details supporting the
calculation of the License Fees being paid. Licensee shall keep accurate and complete records
of all natural gas feedstock processed (volume and composition) and all Synthetic Product
produced at and either used internally within or removed from each Licensed Plant to enable
verification of statements and payments rendered to Licensor hereunder. Licensee agrees to
permit Licensor, at Licensors expense, to inspect such records on reasonable notice and at
reasonable
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intervals during normal business hours to verify the license fees paid and payable under this
Agreement.VI.
    
    If the Licensee can not achieve financing on commercially reasonable terms for the Licensed
Plant or if the project is terminated for any reason prior to such time, Licensee shall retain
25% of the License Fee payments made to Licensor for the project up to that date and the
remaining 75% shall be credited to any future Licensed Plant that is initiated within 15 years
from the Effective Dates of the Master License Agreement.
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