**Exhibit4.70**

**Execution Version**

**Notice ofAssignment in relation to Nexen Parent**
| To:    |   | Nexen Inc.              |
|--------|--------|-------------------------|
|   |   | 2900, 801-7th Avenue SW |
|   |   | Calgary                 |
|   |   | Alberta                 |
|   |   | T2P 3P7                 |
|   |   | Canada                  |

 

**The vessel m.v. “AOKA MIZU”registered in The Netherlands Antilles at the port of Willemstad, Curacao withregistration number 1999 - C - 1615, which is to be converted into a floatingproduction, storage and offloading unit**

We refer to the guaranteegiven and delivered by you, Nexen Inc., to us, Bluewater Ettrick Production(UK) Limited (the “**Assignor**”)dated 31 March 2006 (the “**Guarantee**”)relating to an Agreement for the provision of a Floating Production, Storageand Off-loading Vessel for the Ettrick Field with an effective date of 27February 2006 (the “**Contract**”).

Wehereby give you notice:

## 1.               that, by a GeneralAssignment (the “**Assignment**”)dated 29 June 2006, made between (inter alios) us and ING Bank N.V. (in itscapacity as security trustee) (the “**Assignee**”),we have assigned to the Assignee all of our rights, title, interest, andbenefit (present and future, actual and contingent) in, to, under and pursuantto (inter alia) the Guarantee including (but without prejudice to thegenerality of the foregoing) our rights to receive monies and make claims fordamages under and pursuant to the Guarantee;

# 2.               that, unless anduntil you receive notification from the Assignee or ING Bank N.V. ascontemplated by paragraph 4 below, you are irrevocably authorised andinstructed to pay all such amounts payable to us under and pursuant to theGuarantee which are Operating Costs and Insurance Costs (as defined in theContract) to such account as we may from time to time direct;

# 3.               that you areirrevocably authorised and instructed to pay all other amounts payable to usunder and pursuant to the Guarantee to account name “BEP Assigned Account”,account number 02.01.42.692 with ING Bank N.V., acting through its Amsterdamhead office, or with effect from the receipt by you of written instructionsfrom ING Bank N.V., acting for these purposes as agent of the Assignee, to sucheffect, to such other account as ING Bank N.V. (in such capacity) may from timeto time direct;

# 4.               that at all timesafter you have received written notice from the Assignee or ING Bank N.V.,acting for these purposes as the agent of the Assignee, that the Assignment hasbecome enforceable, you are irrevocably authorised and instructed to pay allamounts payable to us under and pursuant to the Contract (including all amountsreferred to in paragraphs 2 and 3 above) to account name “BEP Assigned Account”,account number 02.01.42.692, with ING Bank N.V., acting through its Amsterdamhead office, or, with effect from the receipt by you of written instructionsfrom ING Bank N.V., acting for these purposes as agent of the Assignee, to sucheffect, to such other account as ING Bank N.V. (in such capacity) may from timeto time direct; and

# 5.               that each amountpaid by you in accordance with paragraph 2, 3 or 4 above shall discharge, by acorresponding amount, your payment obligations under the Guarantee.

Please acknowledgereceipt of this notice by signing the acknowledgement endorsed on the enclosedduplicate of this notice and returning that duplicate direct to the Assignee atthe address shown, with a copy to us.

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For and on behalfof**Bluewater Ettrick Production (UK) Limited**by its duly authorised attorney-in-fact
|                    | /s/ [ILLEGIBLE] |   |
|--------------------|-----------------|--------|
|               |            |   |
| Dated 29 June 2006 |

 

 

Confirmed andagreed.**ING Bank N.V.**by its duly authorised attorney-in-fact
|                    | /s/ [ILLEGIBLE] |   |
|--------------------|-----------------|--------|
|               |            |   |
| Dated 29 June 2006 |

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Acknowledgement ofAssignment - Nexen Parent Guarantee
| To:   |   | ING Bank N.V.                             |
|-------|--------|-------------------------------------------|
| Copy: |   | Bluewater Ettrick Production (UK) Limited |

 

We acknowledge receipt ofthe notice set out above and consent to the assignment referred to therein.

For and on behalfof**NEXEN INC.**by its duly authorised officer
|                         | /s/ [ILLEGIBLE] |   |
|-------------------------|-----------------|--------|
|                    |            |   |
| Dated July 20/06  2006. |

 

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