24 - Candidate Selection For Acidizing

Production Technology for All (Candidate Selection f or Acidizing)

Manuel Bramao PE-STM-02

Learning Objectives

1



Purpose of Matrix Acidizing



Skin effect



Rules for candidate selection

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Importance of Candidate Selection – Most of the Matrix Treatment failures are due to wrong selection of wells. – To select a Good Candidate it to choose a well where a potential gain is possible after a Matrix Treatment.

– Identify low-productivity wells and stimulation candidates.

2

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Identifying Low-Productivity Wells and Stimulation Candidates – Comparison between productivity pattern of wells of same reservoir – Identification of under-performers

PI PI / h BPD BPD /

3

ft

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Wells

Reasons for Under-Performing – – – – –

Restriction in completion Perforations plugged Small size completion Unconsolidated formation (sand control candidate) Low permeability (fracturing candidate)

– Formation damage  Matrix Treatment candidate

4

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Skin Effect

q

k h Pr  Pwf 141 .2

B



  

ln

 re  s  rw 

s  s perf  s form

Matrix Treatments

5

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Candidates and Objectives – Candidates: 

sform reduction up to 90%



Economy

– Objectives 

Sandstone sform = 0 to 1 (typically < 5)



Carbonates sform = -1 or -2

Very high skin (>20) leads preferably to fracturing 6

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Matrix Treatment Candidate Additional diagnosis required yes start Well with Form. damage

Mech. problems

no

PTA available

yes

no qactual 20

Consider fracturing

yes Frac possible

no no

yes

s is the formation skin no

Economic evaluation

No Candidate

yes NO CANDIDATE

8

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MATRIX CANDIDATE

Economic evaluation yes

FRAC CANDIDATE

Any Questions?

9

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