schizophyllan as biopolymer for eor lab and field … polymer flooding/20… · confidential...

Schizophyllan as biopolymer for EOR Lab and field results

Stephan Hatscher

05th of April 2016

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Schizophyllan as biopolymer for EOR

Schizophyllan and its properties

Production of Schizophyllan

Field trial in Bockstedt

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Agenda

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Schizophyllan and its properties Production of Schizophyllan


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Agenda

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Motivationwater injectorwater injector production

wellproductionwell polymer injectorpolymer injector

irregular displacement

(“water fingering”)

irregular displacement

(“water fingering”)more uniformdisplacement more uniformdisplacement

waterwaterpolymersolutionpolymersolution

1TDS = Total Dissolved Solids

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The biopolymer Schizophyllan is a polysaccharide with an average molecular weight of 2-3 MM Daltons (single strain)

Primary structure is a linear -1,3:-1,6 glucan without functional groups

Fully salt tolerant

Low adsorption to rock

The tertiary structure is a triple helix

High temperature tolerance

Excellent mechanical stability, e.g. to shear

The biopolymer is produced by a fungus calledSchizophyllum commune

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General Details On Schizophyllan

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Highly efficient viscosifier

Pronounced shear thinning

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Rheology Of Schizophyllan

Measured in typical North-German reservoir brine:186 g/L TDS* (pH 6)CaCl2 42,6MgCl2 10,5NaCl 132,0Na2SO4 0,3NaBO2 0,4

*TDS = Total Dissolved Solids

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Schizophyllans Temperature Tolerance

No loss of viscosity found so far after about 300 days at 110°C under anaerobic conditions.

Experimental setup for anaerobic long-term storage at temperatures above 100°C is challenging and had to be solved beforehand

Schizophyllan retains its viscosity up to temperatures of 135°C

Viscosities shown were normalized at T=30°C to account for different viscosifying efficiencies

0,0

0,2

0,4

0,6

0,8

1,0

0 50 100 150 200

Temperature / °C

Nor

mal

ized

vis

cosi

ty @

100

s-1

Schizophyllan

Xanthan

sulfonated PAAM

concentration = 3000 ppmshear rate = 100 s-1

dT/dt = 1 K/min

0

5

10

15

20

25

30

35

40

0 20 40 60 80 100 120 140 160

Time [days]

Visc

osity

@ 7

/s [m

Pas]

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

pH

Viscosity pH

SchizophyllanT = 110°Cconc. 350 ppm

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Comparison To Commercial EOR Polymers

Comparison of mechanical stability with commercially available EOR polymers shows excellent resistance to shear compared especially with synthetic polymers

Comparison of viscosity vs. concentration relationship with commercially available EOR polymers shows excellent viscosifying efficiency

0

20

40

60

80

100

120

0 1 2 3 4 5 6 7 8 9

Time of Shear / min

rel.

Visc

osity

(@7s

-1) /

%

SchizophyllanXanthansulfonated PAAMPAAM

Sweetwater (0,1 g/L TDS)Shear Rate of 35 000 s-1

T = 25°C

1

10

100

1000

0,1 1 10concentration / g·L-1

visc

osity

@ 7

s-1

/ mPa

·s

SchizophyllanXanthansulphonated PAAM

T = 54°C186 g/L TDS

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Production of Schizophyllan Field trial in Bockstedt

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Agenda

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Biopolymer From A Fungus

Schizophyllum commune One of the most wide-spread fungi

Produces biopolymer from carbon source

Glucose + O2 + SubstratesSchizophyllan

Glucose source is hydrolyzed corn starch.

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Biopolymer is produced at an expanded biotech-plant at BASF in Ludwigshafen, Germany

The liquid mother solution contains 0.5% to 1% active ingredient

Transport to operation site is in tank cars via rail and road transport

At operation site biopolymer is diluted down to 300 ppm

300 ppm Schizophyllan equivalent to~25 cP @ 7s-1 at reservoir conditions

186,000 ppm reservoir brine used as make-up water

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Biopolymer Production Plant

Picture from Google Maps (taken during re-construction)(https://maps.google.com/maps)

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Production of Schizophyllan


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Agenda

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Reservoir: Valanginian Sandstone Geologic Age: Lower Cretaceous Depth: ~1280m Net pay: 6-35m (18m pilot area) Average porosity: 24% Average permeability: 2,000 mD

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Location and Pilot Area

Bo 83

Bo 56

PILOT AREAPILOT AREA

Bo 81

Bo 85

~140m

Previously waterfloodedcompartment, now being polymer flooded with biopolymer

~260m

~70m

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The Polysaccharide Schizophyllan for EORPilot Plan Operation Site

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production wells

injection well

injection pumpsmixing units/viscosimeter

water pre-treatmentbiocide station

offloading pumpspolymer storage

3-phase separator

I&Celectricity

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Tank cars for transport and storage on site

High shear rotor-stator unit for on-the-fly mixing

Injection via standard oil field pumps

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Some On Site Pictures

AT2

Folie 15

AT2 Ana Todosijevic; 18.01.2016

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Schizophyllan as biopolymer for EOR Schizophyllan: Long Term Injectivity

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>100,000m³ of polymer solution injected after ca. 36,000m³ of produced water

Initial injectivity challenges before the polymer injection overcome with several stimulations and improved water quality

Good continuous injectivitymaintained

Expected change in Hall plot slope with start of polymer injection

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Bockstedt field trial

Trial is approved by mining authorities until at least June 2017

Positive trend of incremental oil in observation Bo 81 well

Further testing of Schizophyllan in single well test mode on Bo 83

Confirm performance of Schizophyllan in the reservoir

Improve reservoir modelling for cEOR processes

Schizophyllan project

Further develop logistics concepts for offshore

Further develop and improve manufacturing processes

Check opportunities for other pilot trials

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Current status and outlook

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schizophyllan as biopolymer for eor lab and field … polymer flooding/20… · confidential...

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