A MOL hazai hagyományos és nem hagyományos tárolóiban végzett hidraulikus repesztéseinek kihívásai és az erre adott válaszaink

Székely - Szabó Tamás 2017 - 01 - 10

Reservoir Quality vs. Stimulation type

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Highly conductive flow path - Highway

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Creating a Highway

Increase well productivity by altering the flow pattern in the formation near the wellbore from radial flow to linear flow

Succesful only if the fracture is significantly more conductive than the formation

Stimulation Objectives

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Stimulation Treatments

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Why it works - Flow area

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Vertical single stage to Horizontal Multistage

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Reservoir Characterization

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Simplified Workflow – Design and Optimization

Clean up and Flowback Considerations

Presenting to [name] 12

Damage Mechanisms

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Engineered Transition to Production

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ALS selection - For the life of the Well

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The Future - More Integrated Engineering Approach

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The Future: Real - time fracture control

Integrated Approach - Result

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Cost reduction alone will not sustain the industry.

MOL „Unconventional” Fracturing

Békés

Derecske

MakóDráva-Zala

T V D ( m )

1 8 5 /8 "1 5 0 m

1 3 3 /8 "8 1 0 m

T O C1 8 0 0 m

9 5 /8 "2 3 0 0 m

7 "4 1 0 0 m

4 1 /2 "4 4 1 2 m

Mud/HeavyBrineSG: ~ 1.47

Potassium Chloride

SG: ~ 1.02

InhibitedFreshwater

Fracture Stimulation & Completion Operations:

Mud change Perforation of deepest interval & Fracture Treatment Run 4 ½” Drillable Bridge Plug Perforation of middle interval & Fracture Treatment Run 4 ½” Drillable Bridge Plug Perforation of highest interval & Fracture Treatment Drill out Bridge Plugs & clean-up well bore via CT Run 4 ½”Permanent Packer w/ plug on WL Circulate Brine inRig up Workover Rig Run 2 ⅞” tubing Circulate inhibited freshwater into the annulus Sting tubing string in & tree upRig down Workover Rig Lift well, if necessary, via Coiled Tubing Clean up flow (commingled) Test flow (commingled) Run PLT / Sampling Secure the well

Tight Gas Fracturing and Completion Concept - combined rig with rigless intervention

Derecske Tight play condition - Main Challenge of temperature

Made by ExxonMobil and provided to MOL for Makó partnership in 2008 - Confidential

Temperature (F)

0

10

20

30

0 100 200 300 400 500

Pre

ssur

e (K

psi)

Limit of Industry Demonstrated Production Capabilities Ultra

HPHT

Sample EMOP ProspectsSample OBO Prospects

Near-Critical Fluid

Tested in MakóHPHT

Conventional PT

Beru - 4 & 6

Coiled Tubingskidding tower

Frac Fleet

PumpingSlurry(high and low pressure)

Mixing fluids, chemicals and

proppant in storage

HPHT frac challenges• Reservoir and stress field parameters predictability • Reliable Pressure and Temperature working envelope of equipment and technology• TSA and appropriate annulus pressure protocoll at given pressure rated equipment• Stable and robust fluid system and fluid efficiency at elevated Temperature• Achievable fracture geometry - height control , xf • Validation and calibration of fracture model ( chemical tracers , NRT proppant , PLT )

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Fracturing Fluids

Aqueous polymer viscosifiedMetal Crosslinked

zirconate/titanateBorate Crosslinked

mono-borateorgano-borate (most used in Europe)low-polymer borates

Acidscrosslinked acidpH controlled viscosified acidEmulsified Acid

Non-aqueous polymer viscosifiedcrosslinked methanolcrosslinked hydrocarbon

Non-polymer based fluidsvisco-elastic surfactantsvisco-elastic surfactant gelled acid100% CO2 Frac

Energized systemsN2, CO2, and Binary foams

24Fracturing fluids and proppants

Polymer Nomenclature

• Guar gum• Hydroxypropyl Guar• Carboxymethylhydroxypropyl Guar• Carboxymethyl Guar• Hydroxyethyl Cellulose• Carboxymethylhydroxyethyl Cellulose• Xanthan Gum• Polyacrylamide (Friction Reducer)

GuarHPGCMHPGCMGHECCMHECXC PolymerPA

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Delayed Cross-linked Systems

• Cross-linking agent is delay-released• Cross-link time is sensitive to temperature and pH• Delay time can span several minutesAdvantages:I. Reduced friction

I. lower treating pressureII. less hydraulic power required for the operation

II. Reduced exposure to excessive shear in tubulars and surface equipmentI. conserve fluid’s viscosity and sand-carrying capacityII. avoid premature screenout

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BreakersI. Break viscosity in a controlled mannerII. Optimise fluid cleanupIII. Maximise frac conductivity & well productivity

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Types of breakers

• Oxidisers

• Conventional enzymes

• Polymer-linkage-specific enzymes

• Encapsulated breakers

• Breaker catalysts

Fracturing Fluids

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Synthetic polimer fluid - fast-hydrating synthetic copolymer and a metal crosslinker

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Presenting to [name] 30

Beru - 6 :Treatment summary

Presenting to [name] 31

Way Forward

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MOL Conventional Frac Challenges

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• Well Head pressure rating and production casing scheme of mature wells• Frac completion - high Pressure loss & treating pressure• Data quality - production history matching , SWT • Fluid and job redesigned onsite as per actual fluid efficiency • NWB issues • Refrac in previously not really successfully treated field / well

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Treatment Summary

Well Test Data vs. DFIT Data – Design and Redesign

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Fibers ( Prop NET )

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Doing more with less - Channel Fracturing (HiWAY)

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Ruzsa - 28 Fiber PAD + HiWAY

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• All wells successfully stimulated • Zero Screen out• 100% proppant placement as per calibrated design

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Fracture Treatment Geometry Summary

Designing Hydraulic Fracturing Treatments( The Three Golden Rules)

• Candidate selection - Get the right data before fracturing a well

• Keep it simple ( It is already harder than it seems!! If possible consider vertical wells to start with.)

• Set the right expectations

Keep it simple - What does it mean ?

• Do not over design a job ( placement , reservoir )

• Get the right people with field experience

• Place emphasis on ‘on location’ analysis and design, rather on designing a job to death in the office.( Mother nature will always fool you!! )

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Do not let the situation confuse you …

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References

Jonathan Abott (Schlumberger) - A Review of Modern Fracturing Techniques (presentation 2016, Herceghalom)

Jonathan Abott (Schlumberger) - MOL Stimulation workshop (presentation 2016 ,Szeged)

Kevin Mauth ( Schlumberger ) - From Pore to Pipe (presentation 2016, Herceghalom)

Kevin Mauth ( Schlumberger ) - Responsible Production Enhancement (presentation 2016, Hereceghalom)

Max Engels( Fracture Technologies ) - MOL In - house Fracturing Training Course (2013, Szeged)

Various MOL fracturing project post evaluation documents

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Thank you for your attention !