Characteristics and significance of the penecontemporaneous karst in lacustrine carbonate, Da'anzhai Member, Lower Jurassic, Beibei area, eastern Sichuan Basin

Abstract

There are few reports about the penecontemporaneous karst of the lacustrine carbonate of Da'anzhai Member which developed on the top of Lower Jurassic Ziliujing Formation, eastern Sichuan Basin. Based on the analysis of the macroscopic and microscopic characteristics of Heping Reservoir section in Beibei area, It is discovered that the penecontemporaneous karst in the lacustrine carbonate, Da'anzhai Member, and its characters as follows: (1) The dissolved fractures and karrens are common, which have been filled with vadose silts, bioclasts, terrigenous quartzes, crystal and intergrown calcites; (2) The penecontemporaneous karstification mainly occurs in the micrites and shell limestones of the middle and upper part of the shallowing-upward sequence, and the desiccation cracks occur in some shallowing-upward sequences; (3) Three meteoric-water diagenetic lenses are identified in this section. By further study we also find the factures, stylolite and burial dissolution pores occur along the karst system (tubes, conduits and caves of the karst). And the asphalt not only fills the stylolites and fractures, but also is mixed with the vadose silt in the karst system, although the pore space formed by penecontemporaneous karstification is filled with vadose material and cements. Therefore it is concluded that the development and modification of the tight lacustrine carbonate reservoir of Da'anzhai Member, to some extent, are relevant with the penecontemporaneous karstification, and the penecontemporaneous karst reservoir may develop in the buried Da'anzhai carbonate of the basin.

Keywords

Sichuan Basin / Da'anzhai Member / Lacustrine carbonate / Penecontemporaneous karst / Tight reservoir

Acknowledgements

Professor Jingshan Chen of Southwest Petroleum University and Dr. Jiangang Wang of Institute of Geology and Geophysics, CAS offer me valuable guidance and help in the research. I would like to give my sincere gratitude to them! This study was Supported by Unconventional Oil & Gas, Scientific Research Innovation Team Building Project, Universities Affiliated to Sichuan Province (Provincial Teaching Designed 127 Education Office of Sichuan Province).

References

[1] S.J. Chen, H.X. Zhang, J.G. Lu, et al., Controlling factors of Jurassic Da’anzhai member tight oil accumulation and high production in central Sichuan basin, SW China, Petrol. Explor. Dev. 42 (2) (2015) 206-214.

[2] R.C. Feng, Y.Y. Wu, S.Z. Tao, et al., Sedimentary microfacies characteristics and their control on reservoirs in daanzhai member, lower Jurassic, Sichuan basin, Pet. Geol. Exp. 37 (3) (2015) 320e327 (in Chinese).

[3] D.H. Li, J.Z. Li, S.Y. Wang, et al., Fine dissection of Jurassic tight oil calibrated area and key parameters research in Sichuan basin, China, Nat. Gas. Geosci. 27 (9) (2016) 1666e1678 (in Chinese).

[4] H.Q. Huang, Relationship between diagenesis and reservoir properties in Jurassic Da’anzhai Member, northern Sichuan, Exp. Pet. Geol. 11 (1) (1989) 62e76 (in Chinese).

[5] C.J. Li, Oil-gas prediction and characteristics of reservoir bodies for Da’anzhai-1 Submember in Baiya of north Sichuan, Oil Gas Geol. 23 (1) (2002) 81e83 (in Chinese).

[6] L. Xie, X.Z. Wang, F. Zhang, et al., A study of the reservoir of Da’anzhai member in WenjingddMingyue area of Sichuan basin, Geol. China 37 (5) (2010) 1393e1398 (in Chinese).

[7] D.R. Shi, T. Zhang, Y.H. Hu, et al., Research on predicted hydrocarbon enrichment zone of Da’anzhai section in LangzhongddSouth area of north Sichuan, Pet. Geol. Eng. 27 (1) (2013) 12e17 (in Chinese).

[8] J.M. Du, X.L. Zhang, F. Zhang, et al., Sedimentary facies and reservoir prediction of the lower Jurassic Da'anzhai member, Longgang area, central Sichuan basin, J. Palaeogeogr. 17 (4) (2015) 493e502 (in Chinese).

[9] K.L. Deng, Geologic setting of hydrocarbon accumulation for Da’anzhai member of Ziliujing formation in Baiya-Shilongchang area of Sichuan basin, Pet. Geol. Recovery Effic. 8 (2) (2001) 9e13 (in Chinese).

[10] R.C. Zheng, H.D. Chen, W.J. Liu, et al., Deep hydrothermal dissolution of Da’anzhai; reservoirs in north Sichuan, Oil Gas Geol. 17 (24) (1996) 293e301 (in Chinese).

[11] S. Liu, H.M. Xu, Research on predicted hydrocarbon enrichment zone of thin limestone of Da’anzhai member of Sichuan, China Pet. Explor. 6 (2) (2001) 44e50 (in Chinese).

[12] D.Q. Wang, Cognition on the sedimentary environment of Da’anzhai Member, north Sichuan, and it's significance in oil exploration, Exp. Pet. Geol. 5 (3) (1983) 170e176 (in Chinese).

[13] K.L. Shi, F.W. Chen, Z. Duan, et al., Lacustrine carbonate rock types and sedimentary environments of the lower Jurassic Da’anzhai member of Heping reservoir section in Beibei area, Chongqing, J. Paleaogeogr. 17 (2) (2015) 198e212 (in Chinese).

[14] Q. Zhang, J. Peng, An analysis of reservoir characteristics and controlling factors of Jurassic Da’anzhai section in Langzhong-Nanbu area (Science & Technology Edition), J. Southwest Pet. Univ. 38 (2) (2016) 29e38 (in Chinese).

[15] R.C. Zheng, W.J. Liu, A.R. Ji, Fluid inclusion study of unconventional reservoirs in limestone of the Da’anzhai member of lower Jurassic Ziliujing formation in northern Sichuan, Geol. Rev. 43 (5) (1997) 515e523 (in Chinese).

[16] Z.Z. Feng,The Editorial Committee of Sedimentology of China, second ed.ed., Petroleum Industry Press, Bei Jing, 2013, pp. 793e795 (in Chinese).

[17] Z.Q. Hu, R.C. Zhen, Y.M. Xiong, Sequence analysis of Da’anzhai formation of lower Jurassic in Sichuan basin, Nat. Gas Ind. 20 (3) (2000) 34e37 (in Chinese).

[18] R.L. Chen, X.X. Li, Study of claastic-coquina diagenesis and fluid enclosure in Da’anzhai member of Jurassic, northern Sichuan, Exp. Pet. Geol. 13 (2) (1991) 158e163 (in Chinese).

[19] D.H. Zhou, F.Z. Jiao, X.S. Guo, et al., Geological features of the Lower Jurassic shale gas play in Fuling area, the southeastern Sichuan basin, Oil Gas Geol. 34 (4) (2013) 450e454 (in Chinese).

[20] Z.Y. Tian, Q.C. Zhang, Lithofacies Paleogeographic and Hydrocarbon in Petroliferous Basins of China, Petroleum Industry Press, Bei Jing, 1997, pp. 189e191 (in Chinese).

[21] Y.J. Li, Y.Y. Feng, H. Liu, et al., Geological characteristics and resource potential of lacustrine shale gas in the Sichuan Basin, SW China, Pet. Explor. Dev. 40 (4) (2013) 423e428 (in Chinese).

[22] R.H. Ma, Predicting the distribution of biofragmental beaches in Da’anzhai member in northeast Sichuan by sequence stratigraphic method, Nat. Gas. Ind. 25 (2) (2005) 58e60 (in Chinese).

[23] J. Li, S.Z. Tao, Z.C. Wang, et al., Characteristics of Jurassic petroleum geology and main factors of hydrocarbon accumulation in NE Sichuan basin, Nat. Gas. Geosci. 21 (5) (2010) 732e741 (in Chinese).

[24] T.P. Liao, M. Hu, Geological Investigation Guide of Chongqing Area, Petroleum Industry Press, Bei Jing, 2008, pp. 3e6 (in Chinese).

[25] J.S. Chen, Z. Li, Z.Y. Wang, et al., Paleokarstification and reservoir distribution of ordovician carbonates in Tarim basin, Acta Sedimentol. Sin. 25 (6) (2008) 858e868 (in Chinese).

[26] Z.Y. Wang, L. Li, X.C. Tan, et al. Types and recognizable indicators of ordovician carbonate rock okarstification in Tarim basin (Science& Technology Edition), J. Southwest , Pet. Univ. 30 (5) (2008) 11e17 (in Chinese).

[27] X.C. Tan, D. Xiao, J.S. Chen, et al., New advance and enlightenment of eogenetic karstification, J. Paleaogeogr. 17 (4) (2015) 441e456 (in Chinese).

[28] D. Xiao, X.C. Tan, A.H. Xi, et al., An inland facies-controlled eogenetic karst of the carbonate reservoir in the Middle Permian Maokou Formation, southern Sichuan basin, SW China, Mar. Pet. Geol. 72 (2016) 218-233.

[29] C.P. Su, X.C. Tan, H. Liu, et al., Characteristics and diagenesis of platform margin reef-shoal reservoirs of Upper Permian Changxing Formation around Kaijiang-Liangping trough, eastern Sichuan basin, Geol. China 43 (6) (2016) 2046-2058 (in Chinese).

[30] C.H. Moore, Carbonate Reservoirs: Porosity Evolution and Diaf Color Guide to the Petrography of Carbonate Rocks:Grains, Texturenesis in a Sequence Stratigraphic Framework, Petroleum Industry Press, Bei Jing, 2010, pp. 56-61, 180-182 (in Chinese).

[31] P.A. Scholl, D.S. Ulmer Scholl, A Color Guide to the Petrography of Carbonate Rocks: Grains, Textures, Porosity, Diagenesis, Petroleum Industry Press, Bei Jing, 2010, pp. 169e178 (in Chinese).

[32] L.J. Florea, H.L. Vacher, Morphologic features of conduits and aquifer response in the unconfined Floridan Aquifer System, west central Florida,in: The 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions, 2006, pp. 32-44.

[33] H.L. Vacher, J.E. Mylroie, Eogenetic karst from the perspective of an equivalent porous medium, Carbonates Evaporites 7 (2) (2002) 182-196.

[34] Z.D. Bao, Y.C. Qi, Z.J. Jin, et al., Karst development respondence to sea-level fluctuationdda case from the Tarim area in the early Paleozoic, Acta Geol. Sin. 81 (2) (2007) 205e211 (in Chinese).

[35] X.F. Ni, L.J. Zhang, A.J. Shen, et al., Paleo-karstification types, karstification periods and superimposition relationship of Ordovician carbonates in northern Tarim Basin, Geol. China 36 (6) (2009) 1312e1321 (in Chinese).

[36] J.G. Zhang, Variation of mechanical property of marlite in process of karstification and weathering in Three Gorges region, Chin. J. Rock Mech. Eng. 23 (7) (2004) 1073e1077 (in Chinese).