| Autor: |
Sameer Punnapala, Maryam Abdul Rahman, Sanjay Misra |
| Rok vydání: |
2014 |
| Předmět: |
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| Zdroj: |
Day 2 Tue, November 11, 2014. |
| DOI: |
10.2118/171766-ms |
| Popis: |
Horizontal wells have become a norm in ADCO for effective and efficient reservoir recovery. At present ADCO is embarking on development of tight carbonate reservoirs where permeability ranges from 0.2 – 10 mD. While carrying out a review of the 214 acidization jobs conducted from 2005 to 2013 in two of ADCO's fields, it was found that conventional acid stimulation with 15% hydrochloric acid in horizontal wells in tighter parts of the reservoirs did not seem to provide expected results. Use of selective stimulation in segmented completion and diversion also did not yield the desired results. The reaction rate of 15% hydrochloric acid is too fast to create effective wormholing when tightness of the reservoir exceeds certain degree. A thorough survey of market and the published literature was carried out to analyze the root cause of the poor performance. Wormholing is the desired mechanism for carbonate stimulation, which is governed by the reaction kinetics and rate of transport. Optimal wormholing is obtained at a right balance between these two mechanisms. Literature is abundant with references on use of weak acids and non-acid stimulation chemicals like acetic acid, chelating agents and nano emulsions for stimulation of carbonate reservoirs. These chemicals have an advantage over 15% hydrochloric acid in terms of wormholing potential owing to slower rate of reaction. The study revealed that in a field, permeability and length of treatment are the main parameters in deciding the optimal stimulation chemical. A correlation was developed based on the kinetic parameters of various chemicals and field experience which can act as a guide in selecting the right acidization formulations. Such correlations will go a long way for ADCO in acid stimulation of horizontal wells in tight carbonate formations. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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