Saudi Aramco use of formate brines, 2003-2009 7 deep gas fields 44 HPHT wells drilled 70,000 ft of reservoir drilled at high angle 90,000 bbl of brine recovered and re-used Good synergy with ESS, also OHMS fracturing

Summary from Aramco’s OTC paper 19801 Aramco still consume around 300 m3/month of K formate brine

Potassium formate brine with Micromax® Good results in Saudi Arabia and Kuwait (9 HPHT wells so far) SPE 132151 (2010) “Successful HPHT Application of Potassium Formate/Manganese Tetra-Oxide Fluid Helps Improve Drilling Characteristics and Imaging Log Quality” SPE/IADC 147983 (2011) “Utilization of Non-damaging Drilling Fluid Composed of Potassium Formate Brine and Manganese Tetra Oxide to Drill Sandstone Formation in Tight Gas Reservoir SPE 163301 (2012) “Paradigm Shift in Reducing Formation Damage: Application of Potassium Formate Water Based Mud in Deep HPHT Exploratory Well”

Pakistan - OMV use potassium formate brine for HPHT deep gas well drilling and completions

Extracts from OMV’s SPE papers and SPE presentations – note 1,700 psi overbalance, and 350oF

North Sea - Formate brines used as combined HPHT drill-in and completion fluids 33 development* wells drilled and completed in 7 HPHT offshore gas fields Huldra (6 ) Tune (4) Devenick (2) Kvitebjoern (8 O/B and 5 MPD) Valemon (1) Kristin (2) – Drilled only Vega (5) * Except Valemon (appraisal well) Mostly open hole stand-alone sand screen completions

Tune field – HP/HT gas condensate reservoir drilled and completed with K formate brine, 2002 4 wells : 350-900 m horizontal reservoir sections. Open hole screen completions. Suspended for 6-12 months in formate brine after completion

Tune wells - Initial Clean-up – Operator’s view (direct copy of slide) June 2003 Wells left for 6-12 months before clean-up Clean-up : 10 - 24 hours per well Well performance Qgas 1.2 – 3.6 MSm3/d PI 35 – 200 kSm3/d/bar Well length sensitive No indication of formation damage Match to ideal well flow simulations (Prosper) - no skin Indications of successful clean-up Shut-in pressures   Water samples during clean-up Formate and CaCO3 particles Registered high-density liquid in separator Tracer results A-12 T2H non detectable A-13 H tracer indicating flow from lower reservoir first detected 5 sd after initial clean-up <-> doubled well productivity compared to initial flow data No processing problems Oseberg Field Center

Tune – Production of recoverable gas and condensate reserves since 2003 (NPD data) Good early production from the 4 wells - No skin (no damage) - 12.4 million m3 gas /day - 23,000 bbl/day condensate Good sustained production - 90% of recoverable hydrocarbon reserves produced by end of Year 7 NPD current estimate of RR: - 18.3 billion m3 gas - 3.3 million bbl condensate Rapid and efficient drainage of the reservoir

Huldra field – HPHT gas condensate reservoir drilled and completed with formate brine, 2001 6 production wells 1-2 Darcy sandstone BHST: 147oC TVD : 3,900 m Hole angle : 45-55o Fluid density: SG1.89-1.96 230-343 m x 81/2” reservoir sections Open hole completions, 65/8” wire wrapped screens Lower completion in formate drilling fluid and upper completions in clear brine

Huldra – Production of recoverable gas and condensate reserves since Nov 2001 (NPD data) Plateau production from first 3 wells - 10 million m3 gas /day - 30,000 bbl/day condensate Good sustained production - 78% of recoverable gas and 89% of condensate produced by end of Year 7 - Despite rapid pressure decline..... NPD current estimate of RR: - 17.5 billion m3 gas - 5.1 million bbl condensate Rapid and efficient drainage of the reservoir

Kvitebjørn field – HPHT gas condensate reservoir drilled and completed with K/Cs formate brine, 2004-2013 13 wells to date – 8 O/B, 5 in MPD mode 100 mD sandstone BHST: 155oC TVD : 4,000 m Hole angle : 20-40o Fluid density: SG 2.02 for O/B 279-583 m x 81/2” reservoir sections 6 wells completed in open hole : 300-micron single wire-wrapped screens. Remainder of wells cased and perforated

A few of the highlights from Kvitebjoern Fast completions and high well productivity Kvitebjoern well Completion time (days) A-4 17.5 A-5 17.8 A-15 14.8 A-10 15.9 A-6 12.7 * Operator comments after well testing (Q3 2004 ) “The target well PI was 51,000 Sm3/day/bar This target would have had a skin of 7” “A skin of 0 would have given a PI of 100,000” “THE WELL A-04 GAVE A PI OF 90,000 Sm3/day/bar (ANOTHER FANTASTIC PI)” The Well PI was almost double the target * Fastest HPHT well completion in the North Sea

Kvitebjørn– Production of recoverable gas and condensate reserves since Oct 2004 (NPD data) Good production reported from first 7 wells in 2006 - 20 million m3 gas /day - 48,000 bbl/day condensate Good sustained production (end Y8) - 37 billion m3 gas - 17 million m3 of condensate - Produced 70% of original est. RR by end of 8th year NPD : Est. RR have been upgraded - 89 billion m3 gas (from 55) - 27 million m3 condensate (from 22) Note : Shut down 15 months, Y3-5 - To slow reservoir pressure depletion - Repairs to export pipeline

Economic benefits of using formate brines SPE 130376 (2010): “A Review of the Impact of the Use of Formate Brines on the Economics of Deep Gas Field Development Projects” SPE 145562 (2011): “Life Without Barite: Ten Years of Drilling Deep HPHT Gas Wells With Cesium Formate Brine”