Origins and differences in condensate gas reservoirs between east and west of Tazhong uplift in the Ordovician Tarim Basin, NW China

Abstract

The Ordovician of the Tazhong area in the Tarim Basin has suffered multi-cyclic hydrocarbon charging, making Tazhong a typical condensate gas district. In this paper, production and test data were gathered and a detailed comparison was conducted on the geology and the fluid distribution and characteristics between the eastern and western Tazhong area. Eastern and western regions exhibit significant differences in tectonic structure, fluid distribution, and physical-chemical properties of oil and gas. Compared with the eastern region, the western part has a greater development of discordogenic gas associated with strike-slip faults which, combined with the Tazhong No. 1 fault zone, control the fluid distribution. The eastern region is mainly controlled by the Tazhong No. 1 fault zone. Fluid have markedly homogeneous properties in the east, but are heterogeneous in the west. The origins of oil and gas are different between the east and the west. In the east, hydrocarbons are mainly from Ordovician source rocks and natural gas is mostly derived from kerogen pyrolysis. In the west, the hydrocarbons mainly originated from Cambrian source rocks, and the gas was mostly generated by crude oil cracking. In sum, the east region is dominated by primary condensate gas reservoirs, and the western region is dominated by secondary condensate gas reservoirs. Because of the different geological settings and fluid physical properties, differences in the condensate gas reservoirs in the eastern and the western Tazhong area have been analyzed, and appropriate formation mechanisms for condensate gas origins are established.

Keywords

condensate gas reservoir / origin / Ordovician / carbonate / Tazhong area

References

[1] Chen Z. N. Oil and Gas Geology, 2005 Beijing: Geological Publishing House, 36.

[2] Dzou L. I., Hughes W. B. Geochemistry of Oils and Condensates, K Field, Offshore Taiwan: A Case Study in Migration Fractionation. Organic Geochemistry, 1993, 20(4): 437-462.

[3] Guo L. J., Xiao X. M., Tian H. Laboratory Studies of Differences between Oil-Derived and Kerogen Maturation Gases. Petroleum Geology & Experiment, 2011, 33(4): 428-436.

[4] Guo X. W., Liu K. Y., Song Y., . Relationship between Tight Sandstone Reservoir Formation and Petroleum Charge in Dabei Area of Kuqa. Earth Science, 2016, 41(3): 394-402.

[5] Han J. F., Mei L. F., Yang H. J., . The Study of Hydrocarbon Origin, Transport and Accumulation in Tazhong Area, Tarim Basin. Natural Gas Geoscience, 2007, 18(3): 426-435.

[6] Huang H. P., Zhang S. C., Su A. G. Geochemical Processes in Petroleum Migration and Accumulation. Petroleum geology & Experiment, 2001, 23(3): 278-284.

[7] Jiang N. H., Zhu G. Y., Zhang S. C., . Detection of 2-Thiaadamantanes in the Oil from Well TZ-83 in Tarim Basin and Its Geological Implication. Chinese Science Bulletin, 2007, 53(3): 396-401.

[8] Jin Z. J. Particularity of Petroleum Exploration on Marine Carbonate Strata in China Sedimentary Basins. Earth Science Froniters, 2005, 12(3): 15-22.

[9] Kvenvolden K. E., Claypool G. E. Origin of Gasoline-Range Hydrocarbons and Their Migration by Solution in Carbon Dioxide in Norton Basin, AK. American Association of Petroleum Geologists Bulletin, 1980, 64(7): 1078-1106.

[10] Larter S., Mills N. Phase-Controlled Molecular Fractionations in Migrating Petroleum Charges. Geological Society, London, Special Publications, 1991, 59(1): 137-147.

[11] Li D. S., Liang D. G., Jia C. Z., . Hydrocarbons Accumulations in the Tarim Basin, China. AAPG Bulletin, 1996, 80(10): 1587-1603.

[12] Li X. D. Genetical Types and Formation Model of Condensate Gas Pool. Geological Review, 1998, 44(2): 200-205.

[13] Losh L., Cathles L., Meulbroek P. Gas-Washing of Oil along a Regional Transect, Offshore Louisiana. Organic Geochemistry, 2002, 33(6): 655-663.

[14] Lü X. X., Jiao W. W., Zhou X. Y., . Paleozoic Carbonate Hydrocarbon Accumulation Zones in Tazhong Uplift, Tarim Basin, Western China. Energy Exploration & Exploitation, 2009, 27(2): 69-90.

[15] Meulbroek P., Cathles L., Whelan J. Phase Fractionation at South Eugene Island Block 330. Organic Geochemistry, 1998, 29(1): 223-239.

[16] Peters K. E., Moldowan J. M. The Biomarker Guide: Interpreting Molecular Fossils in Petroleum and Ancient Sediments, 1993, 160-170.

[17] Roberts H. H., Carney R. S. Evidence of Episodic Fluid, Gas and Sediment Venting on the Northern Gulf of Mexico Continental Slope. Economic Geology, 1997, 92: 863-879.

[18] Schoell M., Durand B., Oudin J. L. Migration of Oil and Gas in the Mahakam Delta, Kalimantan: Evidence and Quantitative Estimate from Isotope and Biomarker Studies, 1985, 49-56.

[19] Thompson K. F. M. Classification and Thermal History of Petroleum Based on Light Hydrocarbons. Geochimica et Cosmochimica Acta, 1983, 47(2): 303-316.

[20] Thompson K. F. M. Fractionated Aromatic Petroleums and the Generation of Gas-Condensates. Organic Geochemistry, 1987, 11: 573-590.

[21] Thompson K. F. M. Gas-Condensate Migration and Oil Fractionation in Deltaic Systems. Marine and Petroleum Geology, 1988, 5: 237-246.

[22] Tian H., Xiao X. M., Li X. Q., . Comparison of Gas Generation and Carbon Isotope Fractionation of Methane from Marine Kerogenand Crude Oil-Cracking Gases. Geochimica, 2007, 36(1): 71-77.

[23] van Graas G. W., Gilje A. E., Isom T. P., . The Effects of Phase Fractionation on the Composition of Oils, Condensates and Gases. Organic Geochemistry, 2000, 31: 1419-1439.

[24] Yang D. B., Zhu G. Y., Liu J. J., . Distribution of Global Condensate Gas Field and Major Factors Controlling Its Formation. Earth Science Frontiers, 2010, 17(1): 339-349.

[25] Yang H. J., Wu G. H., Han J. F., . Characteristics of Hydrocarbon Enrichment along the Ordovician Carbonate Platform Margin in the Central Uplift of Tarim Basin. Acta Petrolei Sinica, 2007, 28(4): 26-30.

[26] Zhang S. C., Liang D. G., Zhang B. M., . Generation of Marine Oil and Gas in Tarim Basin, 2004 Beijing: Petroleum Industry Press, 299-344.

[27] Zhang S. C., Huang H. P. Geochemistry of Palaeozoic Marine Petroleum from the Tarim Basin, NW China: Part 1. Oil Family Classication. Organic Geochemistry, 2005, 36(8): 1204-1214.

[28] Zhang S. C., Liang D. G., Zhu G. Y., . Fundamental Geological Elements for the Occurrence of Chinese Marine Oil and Gas Accumulations. Chinese Science Bulletin, 2007, 52: 28-43.

[29] Zhang S. C., Zhu G. Y., Yang H. J., . The Phases of Ordovician Hydrocarbon and Their Origin in the Tabei Uplift, Tarim Basin. Acta Petrologica Sinica, 2011, 27(8): 2447-2460.

[30] Zhao M. J., Zeng F. G., Qin S. F., . Two Kinds of Cracking Gas Are Discovered and Approved in Tarim. Natural Gas Industry, 2001, 21(1): 35-39.

[31] Zhao W. Z., Zhu G. Y., Zhang S. C., . Relationship between the Later Strong Gas-Charging and the Improvement of the Reservoir Capacity in Deep Ordovician Carbonate. Chinese Science Bulletin, 2009, 54(17): 3076-3089.

[32] Zhou X. Y., Jiao W. W., Han J. F., . Tracing Hydrocarbons Migration Pathway in Carbonate Rock in Lunnan-Tahe Oilfield. Energy Exploration & Exploitation, 2010, 28(4): 259-277.

[33] Zhu C. Q., Qiu N. S., Cao H. Y., . Paleogeothermal Reconstruction and Thermal Evolution Modeling of Source Rocks in the Puguang Gas Field, Northeastern Sichuan Basin. Journal of Earth Science, 2016, 27(5): 796-806.

[34] Zhu G. Y., Zhang S. C., Liang Y. B., . Isotopic Evidence of TSR Origin for Natural Gas Bearing High H₂S Contents within the Feixianguan Formation of the Northeastern Sichuan Basin, Southwestern China. Science in China, 2005, 48(11): 1960-1971.

[35] Zhu G. Y., Zhang S. C. Hydrocarbon Accumulation Conditions and Exploration Potential of Deep Reservoirs in China. Acta Petrolei Sinica, 2009, 30(6): 793-802.

[36] Zhu G. Y., Yang H. J., Zhu Y. F., . Study on Petroleum Geological Characteristics and Accumulation of Carbonate in Hanilcatam Area, Tarim Basin. Acta Petrologica Sinica, 2011, 27(3): 827-844.

[37] Zhu G. Y., Jiang N. H., Su J., . The Formation Mechanism of High Dibenzothiophene Series Concentration in Paleozoic Crude Oils from Tazhong Area, Tarim Basin, China. Energy Exploration & Exploitation, 2011, 29(5): 617-632.