Solvent Treating Basics

7/31/2019 Solvent Treating Basics

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Solvents

Uses

Types and Selection

Application Handling

Disposal

3/14/2009 1George E. King EngineeringGEKEngineering.com


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Solvent Types

Checks:

Flash point (safety issues for pumping)

Solubility of damage in solvent

Stability of solvent

Seal stability in solvent

Disposal ease



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Solvent Types and Uses

Xylene removes most wax, asphaltene, sludges

Toluene, same uses as xylene, but has lower flashpoint and harder on seals.

Lemonol may be a passable xylene substitute,safer, but test on the deposit at well conditions.

Kerosene removes wax, some sludges

Crude oil removes some wax, but generally poor

response or very slow #2 diesel not recommended unless filtered to 5

microns with beta of 1000.



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First Treatment

BP

Begin pumping

xylene @ 3bpmPumping xylene @ 7 bpm

Slowdown pump & swap to diesel tank.

Begin pumping diesel @ 8 bpm

Note: Pressure increasing on

wellhead @ ~8,000 gals of ???

Completed

pumping diesel @ 8

bpm

SD and begin

flushing ofequipment.

Start breaking over @ 8 bpm



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Second Treatment

BP

A-5

3500

4000

4500

5000

5500

6000

6500

7000

1/15/06 14:30 1/15/06 15:00 1/15/06 15:30 1/15/06 16:00 1/15/06 16:30 1/15/06 17:00 1/15/06 17:30

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

BHP

BPM

start xylenestart diesel

xylene at perfs



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Solvents, Instead of Acids

use for removal of:

Sludges best solvent depends on composition

Emulsions solvent depends on composition

Paraffins - xylene, kerosene, condensates, some oils Asphaltenes xylene, toluene, lemonol dispersants

Poorest solvents? - #2 diesel (loaded with wax) and

dead crude oils (asphaltic growth issues and wax

loadings)



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Solvent Volumes

paraffin removal

10 to 15 gal/ft of affected zone.

asphaltene removal

10 to 25 gal/ft - and this wont dissolve much!

100 grams of xylene dissolves 9 grams of

asphaltenes



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0

1000

2000

3000

4000

5000

6000

7000

8000

0 1000 2000 3000 4000 5000

BottomH

olePressure(ps

ig)

Total Liquid Rate (stbf/d)

1 - Hydraulics B ase

2 - PRSS 770.000

3 - PRSS 1050.000

1 - IPR Base

2 - SKN 2.000

3 - SKN 16.000

Boqueron 0 2

Reservoir Data

Pres sure = 7100

kh = 1092.0

Skin = 16.00

Boqueron 02 (1 3march01)

Density = 4.000

Perf Diam = 0.50

Penetration = 8.00

Rate vs. Press ure

27-Mar-01 11 :42:54

Depth (MD) = 17276

WHPres (psia) = 770

Tubing I.D. = 2.750 (s1)

Before:

Oil: 2200 bopd

WHP: 770 psiBHFP: 3660 psi

Skin: 16

After:Oil: 3100 bopd

WHP: 1050 psi

BHFP: 5000 psiSkin: 2

Oil(bopd) GOR(scf/bbl) WHP(psi) BHFP(psi) WHT(F) H2S(ppm) GAS(mmscfd) APIGrav SepPress(psi)

Before 2200 2080 770 3660 187 10 4.3 31.5 420

After 3200 1830 1050 5100 198 10 5,92 31.3 200

?

Boqueron Field in Maturn - Venezuela Source Jose Soto

Example of

a solvent

job.



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Event Oil(bopd) GOR(scf/bbl) WHP(psi) BHFP(psi) WHT(F) H2S(ppm) GAS(mmscfd) APIGrav SepPress(psi)

Before 2200 1950 770 3660 195 10 4.3 31.4 420

After 3100 1950 1050 5000 195 10 5.92 31.4 420

With correction of Separator pressure, the data becomes:

Treatment Summary

100 gal per foot perforated of 100% Xylene -> Total:21,000 gals Soak time: 6 hours

Injection rate: 1,1 bpm w/ CT annulus pressure:2000 psi.

Calculated Xylene penetration with 10% porosity @6,5 ft.

Estimated Cost Real Cost

$ 255,000 $ 191,5003/14/2009 9George E. King EngineeringGEKEngineering.com


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Problems with Solvents

rubber/elastomer seal deterioration

density problems (hard to get to and hold onbottom)

getting reasonably pure solvents ie., xylene b.p. is 138-144 C

naphta not nearly as good

just what is a xylene bottom? no real definition



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Solvent migration through a standing brine

column

Xylene will come back to surface fast (fast or

faster than gas?)

Migrates at 5 - 10,000 feet per hour in

seawater.

If you're soaking a pill on bottom, it won't stay

there long.



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Disposal

Most solvents are sold with crude.

Some aromatics may affect oil price, but may

not be a factor in large oil volumes.

Care must be taken not to expose personnel

or the environment to returning solvent.


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Solvent Treating Basics