Using formate brine and water based fluids drilling fluids to improve drilling performanceA case study in PipestoneRyan Siemens and Elie MeyerDrilling EngineersCalgary | September 16 | 2014

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Agenda

• Pipestone well design• 2013 Invert performance summary• Introduction to brine fluids• Why use potassium formate brine• Special operational considerations• Design and results of field trial• Potassium formate 1.0 performance• Potassium formate 2.0 performance• Cost of utilization• Challenges and limitations

Sour service pipe design

Halfway 18 % - Doig 11% - Montney 8%

Mud 90/10 invert (oil-based mud) for hole stability and lubricity

LWD resistivity utilized to geosteer

244.5mm J-55 Surface Casing

~600m

177.8mm L-80 Intermediate Casing

Set at ~70°(Surface to ~2550m)

TVD 2400-2700 m

222mm intermediate hole

Liner Hanger Packer Set at ~35°

2200m leg~41 days Spud to RR

Pipestone well designHorizontal open hole set packers

2013 Invert performance summary

Introduction to brine fluids• Salt

– Ionic compounds that result from the neutralization reaction of an acid and a base

• Brine– Dissolved solution of salts, most commonly solvent is water

• pH– The ratio of hydroxide ions to hydronium ions determines a

solution pH • Formate Brine

– Formate brines are the aqueous solutions of the alkalimetalsalts of formic acid. These salts are readily soluble in water, yielding high-density brines

• Sodium formate• Potassium formate• Cesium formate

What is the brine advantage?

Solids (%)

Yield Pt.(Pa)

Plastic Vis.(mPa.s)

Thermal Cap.(J/g.°C)

ThermalCond. (W/m.K)

Water/brine 0-1 0 -1 1 - 2 0.6 4.2

Oil/invert 10-18 4 - 8 10 - 40 0.2 2

Why potassium formate brines?Corrosion & lubricity

Halide brine corrosion damageW. Canadian examples

Corrosion testing results

Formation compatibility testing

distilled water – potassium formate – calcium bromide – calcium chloride

Solids control setupBead recovery unit & davelin tank

FluidSolidsBeads

Temperature limitation

Temperature limitationResults

Potassium formate trial pad

Potassium formate parametersRate of penetration, length of runs

13 m/hr. vs. 24 m/hr.236 m vs. 850 m

Potassium formate parametersStandpipe pressure

~6000 kPa25%

Potassium formate parametersRotary torque

Increase bead concentration

Potassium formate trial pad

8-11 days

Potassium formate trial padNormalized lateral meterage

4-7 days~40%

Potassium formate 1.0 performance2014 Q2 time depth vs. 2013 invert

Potassium formate 1.0 performance2014 Q2 time depth vs. 2013 invert

10 days~30%

Potassium formate 1.0 performance2014 Q2 time depth vs. 2013 invert – normalized lateral

Potassium formate 1.0 performance2014 Q2 time depth vs. 2013 invert – normalized lateral

10 days~40%

Potassium formate 2.0 performanceFloc/formate vs. invert in intermediate section

2.5 days~30%

But isn’t formate too expensive?Comparing fluid cost

125 %

250 %

320 %

360 %

100 %

Cost of serviceMud cost & total service cost

• tank farm• bead unit• davlin tank• agitator

• Invert surcharge

17 %

27 %

Total drilling well costInvert vs. formate 2013 - 2014

11 %

27 %

Total drilling well costLaterals greater than 2000 m invert vs. formate

27 %

Total drilling well costFormate in lateral vs. floc/formate in intermediate

12 %

Challenges & limitations

Lubricity

Increased drag

Limitation to well length

Switching to invert at toe

Using invert for

liner install

Key Contributors & References

Encana drilling team– Nathan Gullacher– Don Poffenroth– James Highet– Ryan Siemens– Bill Mulloy– Elie Meyer– Lois McCorriston

External– Nick Legacy (DMK)– Chris Kostiuk (DMK)– Kelly Burake (DMK)– Wade Wondrasek (Paramount)

Formate Technical Manual (Cabot)Pertrofrom Technical Manual (ADDCON)SPE 27143 – 105733 – 145562

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Questions?