Ingeniería

G

R

O

U

P

(Matrix Stimulation and Hydraulic Fracturing)
Alberto Casero

Production Enhancement

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 1 of 41

Eni – E&P Division

Well Stimulation
Eni Corporate University – Eni E&P Division
Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 2of 41

Production Enhancement

REMOVE DAMAGE

MAX PRODUCTIVITY

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 3 of 41

FORMATION DAMAGE

•Filter cake

•Formation

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 4 of 41

FORMATION DAMAGE
HOLEFormation

FRACTURE Filter Cake
Zone invaded by mud spurt Formation

Bridging Zone

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 5 of 41

PERFORATIONS

#2 A downside perforation #4 A topside perforation Multiple Perforations in Sandstone block

Eni Corporate University – Eni E&P Division

Junior ProductionEngineering/Stimulation Rev. 00 - Jan. 05/EP Page 6 of 41

Production Enhancement in Limestone
Formation type i Good K ii Medium K or Low K with existed micro fractures CT Jetting HCl Main treatment technique With the help of Pulsonix® Hydra Blast Pro® Gelled HCl

CT Spotting+ Bullheading Gelled HCl using MAPDIR StimGun® – StimStick®

iii Low K iv Very Low K and closure stress problem

AcidGelled Frac with Closure Fracture Acidizing Proppant Frac

Mechanical barrier in CH SurgiFrac in OH

Proppant bridge Mechanical barrier
Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 7 of 41

Eni Corporate University – Eni E&P Division

PURPOSE OF MATRIX STIMULATION

To remove formation damage from the ENTIRE producing sections of Vertical Wells & Horizontal WellsEni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 8 of 41

TRADITIONAL APPROACH PROBLEM :
Fluid naturally tend to follow the path of least resistance (higher permeability / undamaged zones )

SOLUTION :
Effective diversion methods

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev.00 - Jan. 05/EP Page 9 of 41

UNIFYING CONCEPT FOR DIVERSION TECHNIQUES

To be effective , any Diversion Technique must be able to provide sustained , planned Dp levels during matrix stimulation

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 10 of 41

UNIFYING CONCEPT FOR DIVERSION TECHNIQUES
Darcy’s equation shows howdifferent diversion techniques help maximize ∆p in radial flow conditions :

141.2 qi µw ∆p = Kwh
Mechanical Isolation Ball Sealers Chemical ( Particulate ) Diverters Viscosified Fluids , Foams

[ ( ) ]
In rb rw +s

(1)

Reduction of h (Kh) Reduction of h (Kh) Increase of s Increase of µ

New Diversion Technique

Increase of qi

Eni Corporate University – Eni E&P DivisionJunior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 11 of 41

MAXIMIZED PRESSURE DIFFERENTIAL INJECTION RATES ( MAPDIR ) TECHNIQUE
Injection rate is the key for sustained , planned Dp levels Stimulation fluids must be placed downhole so as to cover the total interval to be treated Applicable wherever Darcy’s law holds Sandstones Poorly consolidated sands Unfractured ormicrofractured limestones / dolomites

Eni Corporate University – Eni E&P Division

Junior Production Engineering/Stimulation Rev. 00 - Jan. 05/EP Page 12 of 41

MAPDIR TECHNIQUE GUIDELINES FOR FIELD APPLICATION
1) Set ∆pmax in matrix conditions

∆pmax = 0.8 ∆pf = 0.8 ( pf - pe ) pf = 2

(

ν 1- ν

p )(

o

- pp + pp

)

Eni Corporate University – Eni E&P Division

Junior Production...