1. Shale Gas Research Group (SGRG), Universiti Teknologi PETRONAS, Bandar Seri Iskandar 32610, Perak Malaysia
2. Department of Petroleum Engineering, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak Malaysia
3. Department of Geoscience, Faculty of Geoscience and Petroleum Engineering, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia
4. Western Australia School of Mines, Minerals, Energy and Chemical Engineering, Curtin University, 26 Dick Perry Avenue, Kensington, 6151 WA, Australia