The Xu-2 Member of the Upper Triassic Xujiahe Formation (Hechuan area, southwestern China) is an important potential sedimentary sequence for gas exploration in the central Sichuan Basin. Thus, we performed a comprehensive study of drilling parameters, sedimentary cores, well logging, and core test data and combined our results with previous research and the geological background of the basin. We found that the Hechuan area was a delta front that included underwater distributary channels, interchannels, and mouth and distal bars during deposition of the Xu-2 Member. The sand body genetic types were divided into three categories based on where they developed: an underwater distributary channel, a mouth bar, or a distal bar. The lithology of the Xu-2 reservoirs is mainly feldspathic litharenite, lithic arkose, subarkose, litharenite, and sublitharenite. Residual intergranular pores and intergranular dissolution pores are the major pore types in the reservoirs. Reservoirs with porosities of 0.18–15.84% and permeabilities of 0.001–8.72 × 10−3 μm2 showed a correlation coefficient of 0.7592. The reservoir throats are mainly tubular and constricted. Overall, the sedimentary environment and diagenesis are the major controlling factors for reservoir formation in the study area. The reservoir zones with relatively high porosity and permeability mainly developed in a delta front with underwater distributary channels and mouth bars. Chlorite growth preserved the primary pores during early diagenesis stage B, and intergranular dissolution pores resulted from contact with organic acids derived from source rocks during middle diagenesis stage A1. Compaction and cementation significantly decreased porosity during middle diagenesis stage A2. These important factors influenced reservoir quality.
This is a preview of subscription content, log in to check access.
We thank Kara Bogus, PhD, from Liwen Bianji, Edanz Editing China (www.liwenbianji.cn/ac), for editing the English text of a draft of this manuscript.
This work was initially carried out with the support by the China Scholarship Council Foundation (201708515155), Open Fund (PLN201613) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), and PetroChina Innovation Foundation (2015D-5006-0107).
Ajesh J, Ankit A, Manoj G, Kothari V (2016) Challenges and opportunities of wireline formation testing in tight reservoirs: a case study from Barmer basin, India. J Pet Explor Prod Technol 7(1):33–42Google Scholar
Anna P, Jarosław S (2016) A tight-gas reservoir in the basinal facies of the Upper Permian Ca1 in the southwestern Zechstein Basin, Poland. Facies 62:3–15CrossRefGoogle Scholar
Benayad S, Park Y-S, Chaouchi R, Kherfi N (2014) Parameters controlling the quality of the Hamra Quartzite reservoir, southern Hassi Messaoud, Algeria: insights from a petrographic, geochemical, and provenance study. Arab J Geosci 7:1541–1557CrossRefGoogle Scholar
Bjørlykke K (2014) Relationships between depositional environments, burial history and rock properties. Some principal aspects of diagenetic process in sedimentary basins. Sediment Geol 301:1–14CrossRefGoogle Scholar
Chen SF, Wilson CJ, Luo ZL, Deng QD (1994) The evolution of the western Sichuan foreland basin, southwestern China. J SE Asian Earth Sci 10:159–168CrossRefGoogle Scholar
Ding X, Tan XC, Li L, Huang L, Luo B, Tang QS, Ma HL (2014) Differences between the platform-margin shoal reservoirs and the platform-interior shoal reservoirs of the Middle Triassic Leikoupo Formation, Sichuan Basin, China [J]. Carbonates Evaporites 29:349–361CrossRefGoogle Scholar
Gong L, Zeng LB, Gao ZY, Zhu RK, Zhang BJ (2016) Reservoir characterization and origin of tight gas sandstones in the Upper Triassic Xujiahe Formation, western Sichuan Basin, China. J Pet Explor Prod Technol 6(3):319–329CrossRefGoogle Scholar
Hammer E, Mørk MBE, Næss A (2010) Facies controls on the distribution of diagenesis and compaction in fluvial-deltaic deposits. Mar Pet Geol 27:1737–1751CrossRefGoogle Scholar
Kelvin A, John YW, Mku TI (2013) Parametric study of fracture treatment parameters for ultra-tight gas reservoirs. Pet Explor Prod Technol 3(3):159–168CrossRefGoogle Scholar
Kima JC, Leea YI, Hisadab K (2007) Depositional and compositional controls on sandstone diagenesis, the Tetori Group (Middle Jurassic-Early Cretaceous), central Japan. Sediment Geol 195:183–202CrossRefGoogle Scholar
Li W, Zou CN, Yang JL, Wang K, Yang JJ, Wu YD, Gao XH (2010) Types and controlling factors of accumulation and high productivity in the Upper Triassic Xujiahe Formation gas reservoirs, Sichuan Basin. Acta Sedimentol Sin 28:1037–1045Google Scholar
Liu CH, Liu JZ, Zhang X (2001) The sequence stratigraphic research on middle dyas series in Wucaiwan-Shishugou region in the eastern Junggar Basin. J Chengdu Univ Technol 28:371–375 (in Chinese with English abstract)Google Scholar
Lü ZX, Ye SJ, Yang X, Li R, Qing YH (2015) Quantification and timing of porosity evolution in tight sand gas reservoirs: an example from the Middle Jurassic Shaximiao Formation, western Sichuan, China. Pet Sci 12(2):207–217CrossRefGoogle Scholar
Ma YS, Cai XY, Zhao PR, Luo Y, Zhang XF (2010) Distribution and further exploration of the large-medium sized gas fields in Sichuan Basin. Acta Petrol Sin 31:347–354CrossRefGoogle Scholar
Nelson PH (2009) Pore-throat sizes in sandstones, tight sandstones, and shales. AAPG Bull 93:329–430CrossRefGoogle Scholar
Ozkan E, Brown ML, Raghavan R, Kazemi H (2011) Comparison of fractured-horizontal-well performance in tight sand and shale reservoirs. SPE Reserv Eval Eng 14:248–259CrossRefGoogle Scholar
Shahid G, Perveiz K, Tahir A, Zulqarnain S, Tanzila H (2016) Petrophysical analysis of a clastic reservoir rock: a case study of the Early Cambrian Khewra Sandstone, Potwar Basin, Pakistan. Geosci J 20(1):27–40CrossRefGoogle Scholar
Sur KH, Lee YI, Hisada K (2002) Diagenesis of the Lower Cretaceous Kanmon Group, SW Japan. J Asian Earth Sci 20:921–935CrossRefGoogle Scholar
Tan XC, Xia QS, Chen JS, Li L, Liu H, Luo B, Xia JW, Yang JJ (2013) Basin-scale sand deposition in the Upper Triassic Xujiahe formation of the Sichuan Basin, Southwest China: sedimentary framework and conceptual model. J Earth Sci 24(1):89–103CrossRefGoogle Scholar
Tao S, Zou C, Mi J, Gao X, Yang C, Zhang X, Fan J (2014) Geochemical comparison between gas in fluid inclusions and gas produced from the Upper Triassic Xujiahe Formation, Sichuan Basin, SW China. Org Geochem 74:59–65CrossRefGoogle Scholar
Taylor TR, Giles MR, Hathon LA, Diggs TN, Braunsdorf NR, Birbiglia GV, Kittridge MG, Macaulay CI, Espejo IS (2010) Sandstone diagenesis and reservoir quality prediction: models, myths, and reality. AAPG Bull 94:1093–1132CrossRefGoogle Scholar
Wang ML, Zhang SA, Zhang FD, Liu YT, Guan H, Li J, Shao LY, Yang S, She YQ (2015) Quantitative research on tight oil microscopic state of Chang 7 Member of Triassic Yanchang Formation in Ordos Basin, NW China. Pet Explor Dev 42:827–832CrossRefGoogle Scholar
Yu Y, Lin LB, Gao J (2016) Formation mechanisms and sequence response of authigenic grain-coating chlorite: evidence from the Upper Triassic Xujiahe Formation in the southern Sichuan Basin, China. Pet Sci 13(4):657–668CrossRefGoogle Scholar
Zhang SN (2008) Tight sandstone gas reservoirs: their origin and discussion. Oil Gas Geol 29:1–10 (in Chinese with English abstract)Google Scholar
Zhang L, Guo X, Hao F, Zou H, Li P (2016) Lithologic characteristics and diagenesis of the Upper Triassic Xujiahe Formation, Yuanba area, northeastern Sichuan Basin. J Nat Gas Sci Eng 35:1320–1335CrossRefGoogle Scholar
Zhu R, Zhao X, Liu L, Wang XS, Zhang N, Guo HL, Song LH (2009) Depositional system and favorable reservoir distribution of Xujiahe Formation in Sichuan Basin. Pet Explor Dev 36:46–55CrossRefGoogle Scholar
Zou CN, Zhu RK, Wu ST, Yang Z, Tao SZ, Yuan XJ, Bai B (2012) Types, characteristics, genesis and prospects of conventional and unconventional hydrocarbon accumulations: taking tight oil and tight gas in China as an instance. Acta Petrol Sin 33:173–187CrossRefGoogle Scholar
Zou CN, Gong YJ, Tao SZ, Liu SB (2013) Geological characteristics and accumulation mechanisms of the “continuous” tight gas reservoirs of the Xu 2 Member in the middle-south transition region, Sichuan Basin, China. Pet Sci 10(2):171–182CrossRefGoogle Scholar