Abstract：In order to investigate quantitative grain fluorescence responding to residual oil zones and palaeo-oil zones, samples from sandstone reservoirs in well TZ421 in Tazhong area, Tarim Basin, NW China, were used to carry out quantitative grain fluorescence (QGF and QGF-E) measurement and analysis. A palaeo-oil zone can be delineated in well TZ421 between 3 720 and 3 620 m with strong QGF responds. A residual oil zone was discovered in well TZ421 between 3 680 and 3 620 m with strong QGF-E responds. The presence of a residual oil zone and a palaeo-oil zone in well TZ421 below the current oil-water contact indicates that some oils were lost after the initial charge. The reservoir is believed to have been charged initially down to 3 720 m at the depth of the palaeo-oil-water contact. The presence of a 60 m residual oil zone below the current oil-water contact, as delineated by QGF-E, suggests that the palaeo-oil zones leaked in two epochs and part of the oil lost quite recently. The strong QGF responds in the current condensate gas interval indicates that the initially charged oil was partly displaced by gas and formed an oil zone with a gas cap.
[1] Coble P G, Green S A, Blough N V, et al. Nature, 1990, 348: 432. [2] Downare T D, Mullins O C. Applied Spectroscopy, 1995, 49: 754. [3] Barwise T, Hay S. American Association of Petroleum Geologists Memoir, 1996, 66: 363. [4] Liu K, Eadington P J. Journal of Geochemical Exploration, 2003, (78-79): 389. [5] Liu K, Eadington P J. Organic Geochemistry, 2005, 36：1023. [6] Liu K, Eadington P J, Middleton H, et al. Journal of Petroleum Science and Engineering, 2007, 57: 139. [7] LIU Ke-qi, SU Zhen-ge(刘克奇，苏振阁). Journal of China University of Petroleum(Edition of Natural Science) (中国石油大学学报·自然科学版), 2005, 29(2): 6. [8] JIANG Zhen-xue, YANG Jun, PANG Xiong-qi, et al(姜振学，杨 俊，庞雄奇，等). Oil & Gas Geology(石油与天然气地质), 2008, 29(2): 159. [9] YANG Chu-peng, ZHANG Bao-min, WANG Fei-yu, et al(杨楚鹏，张宝民，王飞宇，等). Oil & Gas Geology(石油与天然气地质), 2008, 29(2): 181. [10] Jiang Z, Pang X, Yang H, et al. Petroleum Science, 2010, 7(2): 201. [11] Pan C, Liu, D. Organic Geochemistry, 2009, 40: 387. [12] Jiang Z, Yang H, Li Z, et al. Acta Geologica Sinica(English Edition), 2010, 84(5):1116. [13] Li S M, Pang X Q, Jin Z Q, et al. Organic Geochemistry, 2010, 41(6): 531. [14] YANG Chu-peng, GENG An-song, LIAO Ze-wen, et al(杨楚鹏，耿安松，廖泽文，等). Science in China(Series D: Earth Sciences)(中国科学D辑：地球科学), 2009, 39(1): 51.
