A comparison of bitumen sands and bitumen carbonates: Measured data

作者:Yuan, Hemin*; Han, De-hua; Li, Hui; Zhang, Weimin
来源:Geophysics, 2017, 82(1): MR39-MR50.
DOI:10.1190/GEO2015-0657.1

摘要

Bitumen is a very important hydrocarbon resource, which exists in enormous amounts all over the world. Bitumen sands and bitumen carbonates have large percentages of bitumen content. However, the differences in lithology, porosity, and bitumen content cause them to have distinct properties, which can further lead to different production methods. Therefore, it is significant to study the different properties between bitumen sands and bitumen carbonates, so as to further analyze the factors causing the differences and to provide guidance for production. To study the basic properties of the bitumen rocks, we have developed a method to measure the rock samples' true porosity, which can estimate the porosity even for "as is" samples. The method involves injecting water and can provide relatively accurate estimation of the porosity. Then, we compared the porosities and bitumen content of the bitumen sands and bitumen carbonates from the same area. Due to different rock formation mechanisms, mineral composition, and compaction, bitumen sands and bitumen carbonates show different porosity and bitumen saturation. Based on the differences in porosity and bitumen content, the responses of the bitumen sands and bitumen carbonates under different pressure and temperature conditions are also compared and analyzed. The bitumen sands are more sensitive to pressure and temperature than are the bitumen carbonates, owing to the larger porosities and higher bitumen content. Bitumen carbonates show distinct behaviors from bitumen sands-the velocities drop faster at the high temperature range. In the end, the waveforms of the signals of the bitumen sands and bitumen carbonates are also compared, and the attenuation is calculated. Bitumen sands and bitumen carbonates display stronger attenuation in the middle temperature range, which is related to the bitumen properties. Comparatively stronger attenuation occurs in bitumen sands because of its loose frame and higher bitumen content.