A novel method for quantitatively identifying driving forces and evaluating their contributions to oil and gas accumulation

Abstract

Different driving forces govern the formation of distinct types of oil and gas accumulation and yield diverse oil and gas distributions. Complex oil and gas reservoirs in basins are commonly formed by the combination of multiple forces. It is very difficult but essential to identify driving forces and evaluate their contributions in predicting the type and distribution of oil and gas reservoirs. In this study, a novel method is proposed to identify driving forces and evaluate their contribution based on the critical conditions of porosity and permeability corresponding to buoyancy-driven hydrocarbon accumulation depth (BHAD). The application of this method to the Nanpu Sag of the Bohai Bay Basin shows that all oil and gas accumulations in the reservoirs are jointly formed by four driving forces: buoyance (I), non-buoyance (II), tectonic stress (III₁) and geofluid activity (III₂). Their contributions to all proven reserves are approximately 63.8%, 16.2%, 2.9%, and 17.0%, respectively. The contribution of the driving forces is related to the depth, distance to faults and unconformity surfaces. Buoyancy dominates the formation of conventional reservoirs above BHAD, non-buoyant dominate the formation of unconventional reservoirs below BHAD, tectonic stress dominates the formation of fractured reservoirs within 300 m of a fault, and geofluids activity dominates the formation of vuggy reservoirs within 100 m of an unconformity surface.

Keywords

Driving forces / Dynamic mechanisms / Buoyancy-driven hydrocarbon accumulation depth / Unconventional oil and gas / Resources evaluation

References

F.L. Bagni, M.M. Erthal, S.N. Tonietto, R.P. Maia, F.H. Bezerra, F. Balsamo, C.V. Córdoba, F.G. Souza, J.A. Brod, C.P. Fernandes, J.P.T. Fonseca. Karstified layers and caves formed by superposed epigenic dissolution along subaerial unconformities in carbonate rocks –Impact on reservoir-scale permeability. Mar. Pet. Geol., 138 (2022), Article 105523

D.H. Cheng, X.R. Jiao, J.W. Wang, Z.D. Zhuang, Z.J. Wang, S. Jiang. Shale oil reservoir characteristics and significance of the first member of Paleogene Shahejie Formation in Nanpu Sag, Huanghua Depression. Lithol. Reserv., 34 (03) (2022), pp. 70-81

G.E. Claypool. Kerogen conversion in fractured shale petroleum systems. AAPG Bull., 82 (13 Suppl.) (1998), p. 5

J. Connan. Biodegradation of crude oils in reservoirs. J. Brooks, D.H. Welte (Eds.), Advances in Petroleum Geochemistry, Academic Press, London (1994), pp. 299-335

J.X. Dai, Y.Y. Ni, C.N. Zou, S.Z. Tao, G.Y. Hu, A.P. Hu, C. Yang, X.W. Tao. Stable carbon isotopes of alkane gases from the Xujiahe coal measures and implication for gas-source correlation in the Sichuan Basin, SW China. Org. Geochem., 40 (5) (2009), pp. 638-646

Y.X. Dong, X.Q. Pang, M.N. Huang, L.Y. Wu, J. Bai. Quantitative prediction and evaluation of favorable hydrocarbon accumulation zones in Nanpu Sag of Bohai Bay Basin. Acta Petrol. Sinica, 36 (S2) (2015), pp. 19-35

Gautier, D.L., Dolton, G.L., Takahashi, K.I., Varnes, K.L., 1996. 1995 National assessment of United States oil and gas resources: Results, methodology, and supporting data. U.S. Geological Survey, https://doi.org/10.3133/ds30.

Gies, R.M., 1984. Case history for a major Alberta deep basin gas trap: The Cadomin formation. In: Masters, J.A. (Ed.), Case study of a deep basin gas field. AAPG Memoir 38, 115-140.

A. Firoozabadi, H.J. Ramey Jr.. Surface tension of water-hydrocarbon systems at reservoir conditions. J. Can. Pet. Technol., 27 (03) (1988),

Y.C. Guo, X.Q. Pang, Z.X. Li, F.T. Guo, L.C. Song. The critical buoyancy threshold for tight sandstone gas entrapment: Physical simulation, interpretation, and implications to the Upper Paleozoic Ordos Basin. J. Petrol. Sci. Eng., 149 (2017), pp. 88-97

J.F. Han, Z. Su, L.X. Chen, D.S. Guo, Y.T. Zhang, Y.G. Ji, H.F. Zhang, J.Y. Yuan. Reservoir-controlling and accumulation-controlling of strike-slip faults and exploration potential in the platform of Tarim Basin. Acta Petrol. Sinica, 40 (11) (2019), pp. 1296-1310

S.J. Han, J.F. Zhao, C.Y. Liu, J.J. Lu, N. Jia. Restoration of the original sedimentary extent of Miaoxi Sag in Bohai Sea during the sedimentary period of the third member of Shahejie Formation in Paleogene. Geol. Rev., 60 (02) (2014), pp. 339-347

S. Holditch. Tight gas sands. J. Pet. Technol., 58 (06) (2006), pp. 86-93

C.Z. Jia, X.Q. Pang, S. Yan. The mechanism of unconventional hydrocarbon formation: Hydrocarbon self-sealing and intermolecular forces. Petrol. Explor. Devel., 48 (3) (2021), pp. 507-526

F.Z. Jiao. Significance and prospect of ultra-deep carbonate fault-karst reservoirs in Shunbei area, Tarin Basin. Oil Gas Geol., 39 (02) (2018), pp. 207-216

B.E. Law, J.B. Curtis. Introduction to unconventional petroleum systems. AAPG Bull., 86 (11) (2002), pp. 1851-1852

Y. Li, Z.H. Fan. Developmental pattern and distribution rule of the fracture-cavity system of Ordovician carbonate reservoirs in the Tahe Oilfield. Acta Petrol. Sinica, 32 (01) (2011), pp. 101-106

Magoon, L.B., Dow, W.G., 1994. The petroleum system. In: Magoon, L.B., Dow. W.G. (Eds.), The Petroleum System: From Source to Trap. AAPG Bull. 75, 3-24.

J.A. Masters. Deep basin gas trap, Western Canada. AAPG Bull., 63 (2) (1979), pp. 152-181

M.H. Nazari, V. Tavakoli, H.R. Bonab, M.S. Yazdi. Investigation of factors influencing geological heterogeneity in tight gas carbonates, Permian reservoir of the Persian Gulf. J. Petrol. Sci. Eng., 183 (2019), Article 106341

R.A. Nelson, E.P. Moldovanyi, C.C. Matcek, I. Azpiritxaga, E. Bueno. Production characteristics of the fractured reservoirs of the La Paz field, Maracaibo bain, Venezuela. AAPG Bull., 84 (11) (2000), pp. 1791-1809

B. Pang, Y.X. Dong, D. Chen, X.Q. Pang. Main controlling factors and basic model for hydrocarbon enrichment in the sandstone target layer of petroliferous basin: a case study of Neogene sandstone reservoirs in Nanpu Sag, Bohai Bay Basin. Acta Petrol. Sinica, 40 (05) (2019), pp. 519-531

X.Q. Pang, X.Y. Zhou, Z.X. Jiang, Z.M. Wang, S.M. Li, J. Tian, C.F. Xiang, H.J. Yang, D.X. Chen, W.J. Yang, H. Pang. Hydrocarbon reservoirs formation, evolution, prediction and evaluation in the superimposed basins. Acta Geol. Sinica, 86 (01) (2012), pp. 1-103

X.Q. Pang, Z.X. Jiang, H.D. Huang, D.X. Chen, F.J. Jiang. Formation mechanisms, distribution models, and prediction of superimposed, continuous hydrocarbon reservoirs. Acta Petrol. Sinica, 35 (05) (2014), pp. 795-828

X.Q. Pang, C.Z. Jia, H. Pang, H.J. Yang. Destruction of hydrocarbon reservoirs due to tectonic modifications: conceptual models and quantitative evaluation on the Tarim Basin, China. Mar. Petrol. Geol., 91 (2018), pp. 401-421

X.Q. Pang, T. Hu, S. Larter, Z.X. Jiang, M.W. Li, L.Y. Wu, K.Y. Liu, S. Jiang, W.Y. Wang, Q.H. Hu, K. Zhang, Z. Li, H. Bai. Hydrocarbon accumulation depth limit and implications for potential resources prediction. Gondwana Res., 103 (2022), pp. 389-400

Q.H. Peng, J.Y. Zhou, S.B. Jiang, Y.M. Wang, Y.Q. Ma. Unconformity types and erosion thickness restoration in Nanpu Sag, Huanghua Depression, Bohai Bay Basin. Xinjiang Petrol. Geol., 34 (06) (2013), pp. 657-660

S. Purewal, J. Etherington. . Introduction to SPE's Petroleum Resources Management System and Applications Guidelines Document, Academic Press (2013),

C.T. Rightmire, G.E. Eddy, J.N. Kirr. Coalbed Methane Resources of the United States. American Association of Petroleum Geologists, Tulsa, Oklahoma (1984), pp. 1-14

I. Rubinstein, O.P. Strausz, C. Spyckerelle, R.J. Crawford, D.W.S. Westlake. The origin of the oil sand bitumens of Alberta: a chemical and a microbiological simulation study. Geochim. Cosmochim. Acta., 41 (9) (1977), pp. 1341-1353

J. Schmoker. Continuous Hydrocarbon Reservoirs: Selected Issues in the USGS Energy Resource Surveys Program. U.S. Geological Survey (1995)

C.W. Spencer, R.F. Mast. Geology of Tight Gas Reservoirs. The American Association of Petroleum Geologists, Tulsa, Oklahoma, U.S.A (1986)

N.V. Trofimuk, V.P. Cherskiy, V.P. Tsarev. Accumulation of natural gases in zones of hydrate —formation in the hydrosphere. Doklady Akademii Nauk SSSR, 212 (4) (1973), pp. 931-934

E.Z. Wang, X.Q. Pang, X.D. Zhao, Z.J. Wang, Z.M. Wang, T. Hu, Z.Y. Wu, J.Q. Yang, Y. Feng, Z.H. Zhang. Characteristics, diagenetic evolution and controlling factors of the Es1 deep burial high-quality sandstone reservoirs in the PG2 oilfield, Nanpu Sag, Bohai Bay Basin, China. Geol. J., 55 (4) (2019), pp. 2403-2419

X.S. Wei, J.P. Chen, Q.Q. Lyu, X.H. Zhao, Y.N. Jia. Quality differences between dolomite and tight sandstone reservoirs. Oil Gas Geol., 40 (02) (2019), pp. 294-301

I.C. White. The geology of natural gas. Science, 5 (125) (1885), pp. 521-522

H.Y. Wu, X.D. Liang, C.F. Xiang, Y.W. Wang. Characteristics of synclinal oil reservoirs in Songliao Basin and their accumulation mechanism. Sci. Sinica Terrae, 37 (2) (2007), pp. 185-191

J.C. Zhang. Research progress of root margin gas (deep basin gas). Geoscience, 17 (2) (2003), p. 210

C.J. Zhang, C.Z. Jia, B.L. Li, X.Y. Luo, Y.X. Liu. Ancient karsts and hydrocarbon accumulation in the middle and western parts of the North Tarim uplift, NW China. Petrol. Explor. Devel., 37 (3) (2010), pp. 263-269