Studies on seepage law considering stratigraphic dips

Abstract

Currently, water injection is widely used for oil field developments. For reservoirs with complex geological structures, large stratigraphic dip angles, low porosities and extra-low permeabilities, the effect of water injection is not satisfying. This paper establishes a modified radial flow formula on the dip angle, and uses the plane radial seepage theory to get formation pressure distributions and a production formula in tilted strata. For injectors with their threshold pressures greater than their formation in-situ pressures, the effective radius for waterflooding is derived for a given injection pressure and then it is used to evaluate waterflooding effect and well pattern suitability, and guide the oilfield production. This method can also be applied to other waterflooding oilfields with similar geological conditions.

Keywords

Plane radial flow / Stratigraphic dip / Flow rate / Effective radius / Threshold pressure

References

[1] J. Bear, Dynamics of Fluids in Porous Media, Dover Publications, 1988, pp. 65-102.

[2] D.S. Dai, K.L. Liu, J. Xiong, Water absorption capability studies in low permeable waterflooding reservoir, Gasf. Surf. Eng. 29 (7) (2013) 14e16 (in Chinese).

[3] A. Noaman,Waterflooding performance in inclined communicating stratified reservoirs, in:Paper SPE 113144 Presented at North Africa Technical Conference and Exhibition in Cairo, Egypt, February 14-17, 2010.

[4] H. Pu, L.L. Cao, P.T. Qiu, Study of overlying strata creep affected by seepage in backfill mining process, in: Paper ISRM182 Presented at the International Symposium-8th Asian Rock Mechanics Symposium, Sapporo, Japan, October 14-16, 2014.

[5] A. Vervoort, B. Madden, C. Lear, Inclined shafts in coal strata: the role of the rock mechanics engineer,in:Paper ISRM242 Presented at the 7th ISRM Congress, Aachen, Germany, September 16-20, 2011.

[6] Y.S. Zhao, Y.Q. Hu, D. Yang, An experimental research on the seepage law of two-phase fluid of gas-liquid in rock fracture, in: Paper ISRM164 Presented at 9th ISRM Congress, Paris, France, August 25-28, 1999.

[7] KERZNER, Obtaining structural and stratigraphic dip information using segmentation trees and optimization, SPEFE 3 (1) (1988) 47-54.

[8] A.B. Salim, N.H. Desmond, Prediction of sand body trend based on stratigraphic dip pattern from microresistivity images in permian sandstone reservoir, in: Paper ISRM242 Presented at the SPE Saudi Arabia Section Technical Symposium, Al-Khobar, Saudi Arabia, May 9-11, 2014.

[9] M.S. Chen, S.F. Zhan, Y. Zhan, et al., Generating high-precision seismic stratigraphic cubes by dip-spreading, SEG Tech. Program 15 (3) (2015) 1949-4645.

[10] K. Parvaneh, F. Sergey,Stratigraphic coordinate system, in:Paper SEG 0960 Presented at SEG Annual Meeting, San Antonio, Texas, September 18-23, 2016.

[11] E.L. Bigelow, Making more intelligent use of log derived dip information, Soc. Petrophys. Well-log Anal. 26 (5) (1985) 382-391.

[12] R. Charles, C. Andrew,Newson, Geosteering using true stratigraphic thickness, in:Paper SPE 168866 Presented at Unconventional Resources Technology Conference, Colorado, USA August 12-14, 2013.

[13] L. Qun, X. Wei, J. Yuan, et al., Behavior of flow through low-permeability reservoirs,in:Paper SPE 113144 Presented at EAGE Conference and Exhibition held in Rome, Italy, June 9-12, 2012.

[14] B. Zeng, L.S. Cheng, F. Hao,Experiment and mechanism analysis on threshold pressure gradient with different fluids, in:Paper SPE 140678 Presented at SPE Annual Technical Conference and Exhibition held in Tinapa-Calabar, Nigeria, July 31-August 7, 2015.

[15] H.B. Han, L.S. Cheng, M.L. Zhang, Extra low permeability reservoirs consider threshold pressure gradient of physical simulation and numerical simulation method, J. Univ. Petrol. 28 (6) (2014) 49e53 (in Chinese).

[16] Q. Kaibin, G. Yousef, S. Mohamed, et al., Application of shared geomechanical model on a matured field in Libya,in:Paper SPE 114633 Presented at SPE Asia Pacific Drilling Technology Conference and Exhibition held in Jakarta, Indonesia, August 25-27, 2008.

[17] T. Evgeny, A.S.A. Statoil, O. Pierre, et al., A new approach to thin oil zone modeling in high-dipping multilayered reservoirs,in:Paper SPE 140678 Presented at SPE Annual Technical Conference and Exhibition in Barcelona, Spain, June14-17, 2016.

[18] S. Liu, F.R. Han, K. Zhang, et al., Well test interpretation model on powerlaw non-linear percolation pattern in low-permeability reservoirs,in:Paper SPE 132271 Presented at International Oil and Gas Conference and Exhibition in Beijing, China, June 8-10, 2015.

[19] A. Mijinyawa, P. Alamina, A. Orekoya,An integrated approach to well test analysis-use of numerical simulation for complex reservoir systems, in:Paper SPE 140617 Presented at SPE Annual Technical Conference and Exhibition held in Tinapa-Calabar, Nigeria, July 31-August 7, 2014.

[20] A.O. Ajab, Y.S. Wu,An alternative approach to modeling Non-Darcy flow for pressure transient analysis in porous and fractured reservoirs, in:Paper SPE 149123 Presented at SPE Saudi Arabia Section Technical Symposium and Exhibition held in Al-Khobar, Saudi Arabia, May 15-18, 2011.