Economic benefits from using formate brines - Latest paper

Economic benefits from using formate brines - Good well performance and recovery of reserves “High production rates with low skin” * “ We selected formate brine to minimise well control problems and maximise well productivity”* * Quotes by Statoil relating to Kvitebjoern wells (SPE )

Economic benefits from using formate brines - More efficient and safer drilling “ a remarkable record of zero well control incidents in all 15 HPHT drilling operations and 20 HPHT completion operations” Better/safer drilling environment saves rig-time costs Stable hole: see LWD vs. WL calipers in shale Elimination of well control* and stuck pipe incidents Good hydraulics, low ECD Good ROP in hard abrasive rocks * See next slide for details

Formate Brines : Allow fast solids-free drilling Solids-free formate brines drill deep horizontal well sections much faster than muds like OBM – and cause less formation damage

Economic benefits from using formate brines - Improved well control and safety Elimination of barite and its sagging problems Elimination of oil-based fluids and their gas solubility problem Low solids brine  Low ECD (SG ) and swab pressures Inhibition of hydrates Ready/rapid surface detection of well influx Elimination of hazardous zinc bromide brine

- Drill-in and completing with formate brine allows open hole completion with screens - Clean well bores mean no tool/seal failures or blocked screens - Completion time 50% lower than wells drilled with OBM “ fastest HPHT completion operation ever performed in North Sea (12.7 days)” Economic benefits from using formate brines - More efficient/faster completions

No differential sticking Pipe and casing running speeds are fast Mud conditioning and flow-check times are short Displacements simplified, sometimes eliminated Duration of flow back (minutes) Fluid Gain (bbl) Flow check fingerprint for a Huldra well Economic benefits from using formate brines - Operational efficiencies

Economic benefits from using formate brines - Good reservoir definition if Cs present in fluid High density filtrate and no barite Filtrate Pe up to 259 barns/electron Unique Cs feature - makes filtrate invasion highly visible against formation Pe of 2-3 b/e LWD can “see” the filtrate moving (e.g. see the resistivity log on far right – drill vs ream Good for defining permeable sands (see SAND-Flag on log right ) Consistent and reliable net reservoir definition from LWD and wireline

Economic benefits from using formate brines - Good reservoir imaging Highly conductive fluid Clear resistivity images Information provided: - structural dip - depositional environment - geological correlations

Formate brines – Summary of economic benefits provided to users Formate brines improve oil and gas field development economics by : Reducing well delivery time and costs Improving well/operational safety and reducing risk Maximising well performance Providing more precise reservoir definition

SPE (2012) “ Experience with Formate Fluids for Managed Pressure Drilling and Completion of Sub-Sea Carbonate Gas Development Wells” Managed pressure drilling and completion of fractured carbonates with formate brine Petronas - Kanowit field – 2 sub-sea gas wells Managed pressure drilling in fractured carbonate with K formate brine improved economics by: - Minimising fluid losses - Reducing fluid cost (use K formate instead of Cs formate) - Improving production by 50% - Eliminating need for stimulation (no acidising)

Kanowit SS-1 : Production profile from start-up - natural clean-up – no stimulation 100 MMscfd gas and 4,000 bpd condensate after 5 hours >150 MMscfd gas and > 6,000 bpd condensate after 9 hours

Kanowit SS-1 : Multi-rate well test results Both wells can produce > 150 MMscfd gas and > 6,000 bpd condensate The maximum potential flow rate figures are 50% higher than the technical potential predicted in the original field development plan.

OPERATORLOCATION Packer Fluid (ppg) BHT (°C) BHT (°F) Start Date End Date Comments DevonWC 165 A-78.6 KFo /2005 DevonWC 165 A-88.6 KFo /2006 Devon WC 575 A-3 ST2 9.5 KFo /2005 WOG/DevonMO 862 #112.0 NaKFo /20055/2006 Well P&A – H 2 O production – G-3 in excellent condition BP/ApacheHI A-5 #111.5 NaKFo /20024/2008 Well P&A - Natural depletion – S13Cr in excellent condition ExxonMobilMO 822 #712.0 NaKFo EPLST 42 #111.5 NaKFo EPLST 41 #F113.0 NaKFo EPLEC 109 A NaKFo EPLST 42 #212.8 NaKFo Dominion WC 72 #3 BP NaFo EPL WC 98 A-3 ST NaKFo EPLWC 98 A NaKFo Formate brines as packer fluids in GOM

177ºC, 14,000 psi S13Cr tubing failed from CaCl 2 packer fluid Well worked over and re- completed with Cs formate 1.4 g/cm 3 Na/K formate used as packer fluid Tubing retrieved 6 years later Tubing was in excellent condition. BP High Island – Formate brine used as a packer fluid for 6 years