Formate brines – Production and first field use - Milestones Start of deep HPHT gas well drilling with formates in Germany (Mobil, RWE, BEB) Potassium formate brines used in USA, Canada, Mexico, Venezuela, Brazil, Ecuador First field use of sodium formate: Shell drills and completes first Draugen oil wells First field use of potassium formate (with Micromax) : Statoil drills and completes Gullfaks oil well First use of formate brine as packer fluid: Shell Dunlin A-14 1993 1994 1995 1996 1997 1998 Sodium formate powder available throughout, but no anti-caking additive. Draugen wells each produce 48,000 bbl oil /day 1995 - Potassium formate brine becomes available from Hydro Chemicals (now Addcon) in Porsgrunn – sold thru Forbrico Ltd 1997 - Cesium formate brine becomes available from Cabot Potassium formate from Addcon

Potassium formate brine has been produced at Porsgrunn since 1994 Production Site ADDCON NORDIC AS Storage tanks for raw materials Potassium formate from Addcon

Cesium formate produced by Cabot in Canada from pollucite ore Cs0.7Na0.2Rb0.04Al0.9Si2.1O6·(H20) Mined at Bernic Lake, Manitoba Processed on site to Cs formate brine Cs formate brine production 700 bbl/month Potassium formate from Addcon

Germany : Potassium formate brine has been used to drill deep HPHT gas wells since 1995 First use : ExxonMobil’s Walsrode field, onshore northern Germany - high-angle deep HPHT slim hole low perm gas wells TVD : 4,450-5,547 metres Reservoir: Sandstone 0.1-125 mD BHST : 157o C Section length: 345-650 m Drilling fluid: SG 1.45-1.55 K formate brine Potassium formate from Addcon

Potassium formate from Norway used in 15 deep HPHT gas well constructions in Germany ,1995-99 Further wells drilled for BEB and RWE-DEA in Germany with Porsgrunn’s potassium formate brines via Baroid (1997 onwards) Well Name Application Fluid Type Density s.g. (ppg) Horizontal Length(m) Angle (°) BHST (°F) BHCT (°F) TVD (metres) MD (metres) Permeability (mD) Walsrode Z5 W/C K Formate 1.55 (12.93) 345 26 315 na 4450 - 4632 4815 - 5151 0.1 - 125 mD Wasrode Z6 420 40 Walsrode Z7 Drill-In 1.53 (12.77) 690 59 295 4541 - 4777 5136 - 5547 Söhlingen Z3A Formix 1.38 (11.52) 855 89 300 270 4908 5600 Söhlingen Z3a Na Formate 1.30 (10.85) Volkersen Z3 1.40 (11.68) 512 52 320 Kalle S108 1.45 (12.10) 431 60 220 6000-6500 6200-6600 Weißenmoor Z1 1.35 (11.27) 634 31 Idsingen Z1a 645 61 321 290 4632 - 4800 5257 - 5821 Söhlingen Z12 Na Formate/Formix 452 28 313 285 4736 - 4937 4846 - 5166 1.0 - 75 mD Simonswolde Z1 K Formate/Formix 1.52 (12.68) 567 35 293 275 4267 - 4572 4236 - 4648 0.1 - 25 mD Walsrode NZ1 1.51 (12.60) 460 34 265 4632 - 4815 4541 - 4693 Idzingen Z2 Voelkersen NZ2 1.40 (11.680 Söhlingen Z13 Drill-In/Frac 1.30 (-1.56)(10.85) 1200 90 4724 5486 - 6400 0,1 - 150 mD Potassium formate from Addcon

Summary of potassium formate brine use in HPHT gas wells in Germany,1995-99 Potassium formate from Addcon

Formate brines – Some further important milestones : 1999-2004 First use of K/Cs formate brine : Completion job in Shearwater well (Shell UK) First drilling jobs with K/Cs formate brine: Huldra and Devenick First use of K/Cs formate brine as HPHT well suspension fluid (Elgin G-3) First use of Cs-weighted LSOBM as perforating completion fluid (Visund) First production of non-caking crystalline K formate at Porsgrunn Cs-weighted LSOBM used as OH screen completion fluid (Statfjord) First of 14 Kvitebjørn HPHT wells drilled and completed with K/Cs formate brines 1999 2000 2001 2002 2003 2004 Formate brines used as packer fluids for HPHT wells in GOM. First well : ExxonMobil’s MO 822#7 (215oC BHST) in 2001 Use of Cs-weighted oil-based completion fluids for oil reservoirs : Visund, Statfjord, Njord, Gullfaks, Snorre , Oseberg, Rimfaks 2001 – present Individual Draugen oil wells (1993) and Visund oil wells (2003) have similar flow rates of around 50,000 bbl oil/day Potassium formate from Addcon

The first sustained use of K/Cs formate brine was in the world’s largest HPHT gas field development Elgin/Franklin field – UK North Sea Cesium formate brine used by TOTAL in 34 well construction operations in 8 deep gas fields in period 1999-2010 Potassium formate from Addcon