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| FEATURES AND ASSESSMENT OF OIL SAND IN SHALLOW HEAVY OIL RESERVOIRS |
| WU Zhao-hui1,2, WU Ying-hao1, GUO Jin-hui3, ZHAI Lin-xiu4, WU Ying-xin5, XU Shou-yu1 |
1. Geology Science and Technology Institute, China University of Petroleum, Qingdao 266580, Shandong Province, China;
2. Geology Exploration and Development Institute, Shengli Oilfield, Dongying 257015, Shandong Province, China;
3. Shengli Changan Co., Ltd., Dongying 257000, Shandong Province, China;
4. Technology Supervisor Institute, Shengli Oilfield, Dongying 257000, Shandong Province, China;
5. Shengji Petroleum Equipment Co., Ltd., Dongying 257067, Shandong Province, China |
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Abstract Oil sand and shallow heavy oil are low-cost unconventional resources, which greatly impact the oil prices. In Chunfeng Oilfield, which is the combination of both kind resources, the rich oil sand in shallow reservoirs is loose due to weak compaction. Therefore, it is difficult to carry out some routine experiments, such as physical properties and oil saturation. Beside conventional tests, some new experiments are necessary for these unconventional resources, i.e. thermal properties, high-temperature permeability analysis, NMR saturation test, etc. Thermal experiments show that both muddy and limy interlayers in reservoirs are usually high thermal conductivity, indicating a high thermal efficiency during development. Phase permeability experiment, which reflects pore sizes and connectivity, shows great difference between the ending values of Kro and Krw, with a wide range of 2-phase covers and low irreducible water saturation. The evener the pore sizes are, the higher the oil phase relative permeability is. NMR can directly obtain the value of Swi and original oil saturation, and then calculate the oil displacement efficiency. The potential assessment result shows that after many rounds of steam stimulation, the inter-well oil saturation is still high, which reflects the low oil displacement efficiency, suggesting a great potential of the oil sand.
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Received: 03 June 2015
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2016, Vol. 25 
