DEEP CASING TOOLS LIMITED

Pnc Bank, National Association (As Agent)

The "existing intellectual property" (as defined in the instrument).

Pnc Bank, National Association (As Agent)

The "existing intellectual property" (as defined in the instrument).

Pnc Bank, National Association (As Agent)

This new york law governed instrument creates a security interest over the collateral (as defined therein) including, but not limited to the intellectual property listed in schedules a to c of the instrument.

Pnc Bank, National Association (As Agent)

N/A.

ENERGY VENTURES III L.P. (REGISTERED IN GUERNSEY, NUMBER 901) (AS SECURITY TRUSTEE)

ENERGY VENTURES III L.P. (REGISTERED IN GUERNSEY, NUMBER 901) (AS SECURITY TRUSTEE)

SCOTTISH EQUITY PARTNERS LLP

MAVEN CAPITAL PARTNERS UK LLP

BOND & FLOATING CHARGE

SCOTTISH EQUITY PARTNERS LLP

FLOATING CHARGE

THE ROYAL BANK OF SCOTLAND PLC

BOND & FLOATING CHARGE