Structural evolution and reservoir-control mechanisms of ultra-deep strike–slip fault zones in the Fuman area, Tarim Basin, China

Abstract

The discovery of ultra-deep strike–slip fault–controlled hydrocarbon reservoirs in the central Tarim Basin has renewed interest in the structural evolution and reservoir-controlling mechanisms of intracratonic strike–slip systems. Based on integrated drilling data, high-resolution 3D seismic reflection interpretation, and structural analog modeling, this study investigates the FI12 and FI17 fault zones in the Fuman area as representative examples. The results show that ultra-deep strike–slip faults exhibit combined lateral segmented growth and vertical stratified propagation, with secondary shear faults overlapping and stepping in both horizontal and vertical directions. To characterize fault activity in a reproducible manner, a semi-quantitative slip intensity framework is established using fault-zone width, structural relief, and segmentation complexity. Comparative analysis demonstrates that slip intensity is the first-order control on the scale and effectiveness of fault-controlled carbonate reservoirs: fault zones with higher slip intensity develop wider damage zones, stronger fracture connectivity, and larger reservoir volumes. Within individual fault zones, slip intensity is preferentially concentrated at lateral step-overs and relay zones of secondary shear faults, where large-scale fracture corridors form and hydrocarbon productivity is significantly enhanced. In addition, for reservoirs characterized by a lower-source–upper-reservoir configuration, hydrocarbon productivity is positively correlated with the proximity of vertical fault step-overs to the target reservoir interval. Shallower vertical overlap facilitates more efficient upward hydrocarbon migration, resulting in higher hydrocarbon abundance. These results establish a three-dimensional structural control model linking slip intensity, fault architecture, and reservoir effectiveness in ultra-deep carbonate strike–slip systems, providing a robust geological basis for reservoir prediction and exploration risk reduction in complex ultra-deep settings.

Keywords

Strike–slip fault / Slip intensity / Fault-controlled reservoir / Ultra-deep carbonate / Fuman oilfield / Tarim Basin

CRediT authorship contribution statement

Peng Cao: Methodology, Funding acquisition, Formal analysis, Conceptualization. Xiongqi Pang: Resources, Funding acquisition. Jiajun Chen: Writing – review & editing, Conceptualization. Shaoying Chang: Methodology, Investigation. Jorge Costa Gomes: Data curation.

Funding

This study was supported by the CNPC Scientific Research and Technology Development Project “Theory of Petroleum Systems and Accumulation Mechanisms of Unconventional Hydrocarbons” (No. 2021DJ0101), and the Joint Fund for Enterprise Innovation and Development of the National Natural Science Foundation of China (No. U19B6003-02).

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References

[1] Dengfa He , Chengzao Jia , Li Desheng , et al. , The formation and evolution of the tarim multi-cyclical superimposed Basin, Petrol. Nat. Gas Geol. 26 (1) (2005) 64-77.

[2] J. Chen, D. He, F. Tian, et al., Control of mechanical stratigraphy on the stratified style of strike-slip faults in the central Tarim Craton, NW China, Tectonophysics 830 (2022) 229307.

[3] T. Hu, X. Pang, F. Jiang, Whole petroleum system theory and new directions for petroleum geology development, Adv. Geo-Energy Res. 11 (1) (2024) 1-5, https://doi.org/10.46690/ager.2024.01.01.

[4] Z. Jin, Hydrocarbon accumulation and resources evaluation: recent advances and current challenges, Adv. Geo-Energy Res. 8 (1) (2023) 1-4, https://doi.org/10.46690/ager.2023.04.01.

[5] X. Han, S. Deng, L. Tang, et al., Geometry, kinematics and displacement characteristics of strike-slip faults in the northern slope of Tazhong uplift in Tarim Basin: a study based on 3D seismic data, Mar. Petrol. Geol. 88 (2017) 410-427.

[6] S. Deng, H. Li, Z. Zhang, et al., Structural characterization of intracratonic strike-slip faults in the central Tarim Basin, AAPG (Am. Assoc. Pet. Geol.) Bull. 103 (1) (2019) 109-137.

[7] X. Han, L. Tang, S. Deng, et al., Spatial characteristics and controlling factors of the strike-slip fault zones in the Northern slope of Tazhong uplift, Tarim Basin: insight from 3D seismic data, Acta Geol. Sin. Engl. Ed. 94 (2) (2020) 516-529.

[8] T.P. Dooley , G. Schreurs , Analogue Modelling of Intraplate strike-slip Tectonics: a Review and New Experimental Results, Tectonophysics 574-575 (2012) 1-71.

[9] C. Chen, G. Ji, H. Wang, H. Huang, P. Baud, Q. Wu, Geology-engineering integration to improve drilling speed and safety in ultra-deep clastic reservoirs of the Qiulitage structural belt, Adv. Geo-Energy Res. 6 (4) (2022) 609-623, https://doi.org/10.46690/ager.2022.04.09.

[10] A.G. Sylvester , Strike-slip faults 100 (11) (1988) 1666-1703.

[11] Y.S. Kim , D.C.P. Peacock , D.J. Sanderson , Fault damage zones, J. Struct. Geol. 26 (3) (2004) 503-517.

[12] D.R. Faulkner , C.A.L. Jackson , R.J. Lunn , R.W. Schlische , Z.K. Shipton , C.A.J. Wibberley , M.O. Withjack , A review of recent developments concerning the structure, mechanics and fluid flow properties of fault zones, J. Struct. Geol. 32 (11) (2010) 1557-1575.

[13] J.S. Tchalenko , Similarities between shear zones of different magnitudes, Geol. Soc. Am. Bull. 81 (6) (1970) 1625-1640.

[14] Dengfa He , Li Desheng , The Taram Basin’s Structural Evolution and Hydrocarbon Accumulation, Geological Publishing House, Beijing, 1996.

[15] Chengzao Jia , Wei Guoqi , Structural characteristics and hydrocarbon contamination of the tarim Basin, Sci. Bull. (Taipei) 47 (1) (2002) 1-8.

[16] Li Desheng , China multi-cyclonic Superimposed Hydrocarbon Basin Structural Studies, Science Press, Beijing, 2012.

[17] Jiaduo Liu , Lixin Qi , Tian Jingchun , et al. , The Taram Basin: Structural Evolution and Sedimentary Framework, Science Press, Beijing, 2014.

[18] J. Wang, et al., Characteristics and genesis of shoal facies reservoir of the Lower Ordovician Tongzi Formation in southeastern Sichuan Basin, China, Adv. Geo-Energy Res. 7 (1) (2023) 1-12.

[19] Y. Li, et al., Development and evolution characteristics of strike-slip faults in Tarim Basin and its geological significance: a case study of FI17 Fault in Fumfn Oilfefd, Adv. Geo-Energy Res. 7 (2) (2023) 156-168.

[20] L. Zhang, et al., Development characteristics and evolution model of FI19 Fault in Fumfn Oilfefd, Tarim Basin, Adv. Geo-Energy Res. 7 (3) (2023) 210-222.

[21] M. Sun, et al., Characteristics of the hydrocarbon accumulation formed through the three structural cycles in Tarim Basin, Adv. Geo-Energy Res. 7 (4) (2023) 301-315.

[22] X. Chen, et al., Development characteristic and main controlling factors of the Ordovician karst caves in the Keping area, Tarim Basin, Adv. Geo-Energy Res. 8 (2) (2024) 123-135.

[23] Y. Wang, et al., Tectonic thermal evolution of Aksu area in the Tarim Basin, NW China: indications from apatite fission track thermochronology, Adv. Geo-Energy Res. 8 (3) (2024) 289-302.

[24] X. Deng, J. Chen, P. Cao, et al., Segmentation and lateral growth of intracratonic strike-slip faults in the northern Tarim Basin, NW China: influences on Ordovician fault-controlled carbonate reservoirs, Front. Earth Sci. 11 (2023).

[25] Huang Cheng , Characteristics and temporal sequence of small-scale strike-slip fault swash activity in the Tarim Basin: a case study of the Shunbei area, Petrol. Exp. Geol. 41 (2019) 379-389.

[26] M. Withjack, S. Callaway, Active normal faulting beneath a salt layer: an experimental Study of deformation patterns in the cover sequence 1, AAPG (Am. Assoc. Pet. Geol.) Bull. 84 (2000).

[27] D.C.P. Peacock , R.J. Knipe , D.J. Sanderson , Glossary of normal faults, J. Struct. Geol. 22 (3) (2000) 291-305.

[28] J.P. Evans , Thickness-displacement relationships for fault zones, J. Struct. Geol. 12 (8) (1990) 1061-1065.

[29] C. Brandes, D.C. Tanner, Chapter 2 - Fault Mechanics and earthquakes[M]// Tanner D, Brandes C . Understanding Faults, Elsevier, 2020, pp. 11-80.