Part III - Well stimulation methods
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Modern
Well Stimulation
Methods
Anatoly Zolotukhin
Part III - Well stimulation methods |
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Part III
Well Stimulation Methods
Part III - Well stimulation methods |
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Syllabus
Well stimulation
Reservoir justification of stimulation treatments
Hydraulic fracturing
Matrix stimulation
Acid fracturing
Performance comparison between vertical and horizontal wells
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Well stimulation methods
Methods of stimulation treatment
There are two major areas of interest for a stimulation treatment:
Well bore zone and its proximity
Rest of a reservoir
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Well stimulation methods
Methods of stimulation treatment
Depending on the zone of interest different kinds of stimulation technology can be used:
Acid washing
Matrix acidizing
Acid fracturing
Hydraulic fracturing
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Well stimulation methods
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SITUATION |
STIMULATION DESIGN |
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Options |
Acid |
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CARBONATE ACIDIZING |
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Acid washing |
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Perforating fluid |
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5% CH3COOOH (Acetic) |
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Damaged perforations |
(a) |
9% HCOOH (Formic) |
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(b) |
10% Acetic |
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(c) |
15% HCl |
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Deep wellbore damage |
(a) |
15% HCl |
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(b) |
28% HCl |
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(c) |
Emulsified HCl |
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SANDSTONE ACIDIZING |
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HCl solubility |
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Use HCl only |
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High permeability (>100 md) |
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High Quartz (80%), Low Clay (<5%) |
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12% HCl + 3% HF (1) |
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High Feldspar (>20%) |
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13.5% HCl + 1.5% HF (1) |
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High Clay (>10%) |
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HCl + 1% HF (2) |
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High Iron Chlorite Clay |
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3% HCl + 0.5% HF (2) |
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Low permeability (<10 md) |
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Low Clay (<5%) |
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6% HCl + 1.5% HF (3) |
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High Chlorite |
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3% HCl + 0.5% HF (4) |
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(1) Preflush with 15% HCl |
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(2) Preflush with sequestered 5% HCl |
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(3) Preflush with 7.5% HCl or 10% Acetic |
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(4) Preflush with 5% Acetic |
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Well stimulation methods
Hydraulic fracturing
Stress conditions of rock media
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Hydraulic fracturing
Linear elastic theory (1D)
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z |
l z |
z |
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l z |
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E |
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l z |
– absolute deformation |
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– relative deformation |
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– normal vertical stress (compression stress) |
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E – Yong’s modulus (elasticity modulus)
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Hydraulic fracturing
For an isotropic medium:
x y |
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l x, y |
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l x, y |
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x, y z
– Poisson’s ratio
For a reservoir rock 0.25
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Hydraulic fracturing
d1 d 2
h d1
h
z
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