Please wait a minute...
Shopping Cart Email List Chinese
Advanced Search Fig/Tab
Frontiers of Earth Science

ISSN 2095-0195

ISSN 2095-0209(Online)

CN 11-5982/P

Postal Subscription Code 80-963

2018 Impact Factor: 1.205

Featured Articles  |  Most Downloaded  |  Most Reading
Online Submission Subscribe to Our RSS Content Feed
Front. Earth Sci.    2021, Vol. 15 Issue (4) : 719-736    https://doi.org/10.1007/s11707-020-0860-y
RESEARCH ARTICLE
Pressure transient analysis for a fractured well in a stress-sensitive tight multi-medium oil reservoir
Wancai NIE1,2(), Tingshan ZHANG1, Xiaopeng ZHENG3, Jun LIU2
1. School of Geosciences and Technology, Southwest Petroleum University, Chengdu 610500, China
2. Yihuang Natural Gas Project Department, PetroChina Changqing Oilfield Company, Xi’an 710018, China
3. Research Institute of Exploration and Development , PetroChina Changqing Oilfield Company, Xi’an 710018, China
 Download: PDF(1898 KB)   HTML
 Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks
Abstract

Tight multi-medium oil reservoirs are the main source of hydrocarbon resources around the world. Acid fracturing is the most effective technology to improve productivity in such reservoirs. As carbonates are primarily composed of dolomite and calcite, which are easily dissolved by hydrochloric acid, high-permeability region will be formed near the well along with the main artificial fracture when acid fracturing is implemented in tight multi-medium oil reservoirs. In this study, a comprehensive composite linear flow model was developed to simulate the transient pressure behavior of an acid fracturing vertical well in a naturally fractured vuggy carbonate reservoir. By utilizing Pedrosa’s substitution, perturbation, Laplace transformation and Stehfest numerical inversion technology, the pressure behavior results were obtained in real time domain. Furthermore, the result of this model was validated by comparing with those of previous literature. Additionally, the influences of some prevailing parameters on the type curves were analyzed. Moreover, the proposed model was applied to an acid fracturing well to evaluate the effectiveness of acid fracturing measures, to demonstrate the practicability of the proposed model.
Keywords tight multi-medium oil reservoir      acid fracturing      stress-sensitive permeability      composite linear flow     
Corresponding Author(s): Wancai NIE   
Online First Date: 13 July 2021    Issue Date: 20 January 2022
 Cite this article:   
Wancai NIE,Tingshan ZHANG,Xiaopeng ZHENG, et al. Pressure transient analysis for a fractured well in a stress-sensitive tight multi-medium oil reservoir[J]. Front. Earth Sci., 2021, 15(4): 719-736.
 URL:  
https://academic.hep.com.cn/fesci/EN/10.1007/s11707-020-0860-y
https://academic.hep.com.cn/fesci/EN/Y2021/V15/I4/719
Fig.1  Schematic of an acid fracturing well in a fractured-vuggy carbonate reservoir.
Fig.2  Physical modelling sketch map of tight multi-medium.
Fig.3  Physical modeling sketch map of tight multi-medium.
Parameters Value
Dimensionlessacidized main fracturehalf-length, x1D 1
Dimensionlessacidized main fracturehalf- width, wD 0.000001
Dimensionlessacidized main fracture conductivity, FCD 1.2
Dimensionlessacidized regionhalf-width, y1D 10
Dimensionlessacidized regionhalf-height, z1D 10
Dimensionless reservoir half-length, x2D 8
Dimensionless reservoir half-width, y2D 10
Dimensionless reservoir half-height, z2D 10
Dimensionless wellbore storage coefficient, CD 0.1
Tab.1  Basic dimensionless parameters for model validation
Fig.4  Comparison of the results between this model and trilinear-flow method.
Parameters Value
Dimensionlessacidized main fracturehalf-length, x1D 1
Dimensionlessacidized main fracturehalf- width, wD 0.000001
Dimensionlessacidized main fracture conductivity, FCD 0.8
Dimensionlessacidized regionhalf-width, y1D 1
Dimensionlessacidized regionhalf-height, z1D 8
Dimensionless reservoir half-length, x2D 8
Dimensionless reservoir half-width, y2D 10
Dimensionless reservoir half-height, z2D 10
Dimensionless wellbore storage coefficient, CD 0.1
Tab.2  Basic dimensionless parameters for flow regimes recognition
Fig.5  Pressure type curves of an acid fracturing well in a tight multi-medium oil reservoir.
Fig.6  The effect of fracture conductivity on transient pressure behavior.
Fig.7  The effect of permeability modulus on transient pressure behavior.
Fig.8  The effect of interporosity flow coefficient on transient pressure behavior.
Fig.9  The effect of storativity ratio on transient pressure behavior.
Fig.10  The effect of acidized region width on transient pressure behavior.
Fig.11  The effect of reservoir size on transient pressure behavior.
Fig.12  The effect of reservoir size on transient pressure behavior.
Parameters Interpretation Results
Half artificial fracture length, x1 (m) 31
Artificialfracture permeability, kF (10-3μm2) 2928
Natural fracture permeability in acidized region, kf1 (10-3μm2) 325
Matrix permeability in acidized region, km1 (10-3μm2) 7.3
Natural fracture permeability in un-acidized region,
kf2= kf3= kf4= kf5= kf6 (10-3μm2)		 86
Matrix permeability in un-acidized region,
Km2= km3= km4= km5= km6 (10-3μm2)		 7.3
Interporosity flow coefficient between vugand fracture in acidized region,λfv1 0.1
Interporosity flow coefficient between matrix and fracture in acidized region, λfm1 0.001
Interporosity flow coefficient between vug and matrix in acidized region, λmv1 0.001
Storativity ratio of natural fracture, ωf1 0.001
Storativity ratio of matrix, ωm1 0.994
Storativity ratio of vugs, ωv1 0.005
Dimensionless wellbore storage coefficient,CD 0.0013
Skin factor, Sc 0
Tab.3  The interpretation results of pressure-curve fitting
1 H H Abass , A A Al-Mulhem , M H Alqam , M R Khan (2006). Acid fracturing or proppant fracturing in carbonate formation? A rock mechanics view. In: SPE Annual Technical Conference and Exhibition, San Antonio, USA
2 D Abdassah , I Ershaghi (1986). Triple-porosity system for representing naturally fractured reservoirs. SPE Form Eval, 1(02): 113–127
https://doi.org/10.2118/13409-PA
3 M Brown , E Ozkan , R Raghavan , H Kazemi (2011). Practical solutions for pressure transient responses of fractured horizontal wells in unconventional reservoirs. SPE Reservoir Eval Eng, 14(06): 663–676
https://doi.org/10.2118/125043-PA
4 R Camacho-Velázquez , M Vasquez-Cruz , R Castrejon-Aivar , V Arana-Ortiz (2002). Pressure transient and decline curve behaviors in naturally fractured vuggy carbonate reservoirs. In: SPE Annual Technical Conference and Exhibition, San Antonio, USA
5 P R Dora (2008). Pressure behavior of a system containing multiple vertical fractures, Dissertation for the Doctoral Degree. Norman: University of Oklahoma
6 C N Fredd (2000). Dynamic model of wormhole formation demonstrates conditions for effective skin reduction during carbonate matrix acidizing. In: SPE Permian Basin Oil and Gas Recovery Conference, Midland, USA
7 G Fuentes-Cruz , R Camacho-Velazquez , M Vasquez-Cruz (2004). Pressure transient and decline curve behaviors for partially penetrating wells completed in naturally fractured-vuggy reservoirs. In: SPE International Petroleum Conference in Mexico, Puebla Pue., Mexico
8 J Guo , R Nie , Y Jia (2012). Dual permeability fow behavior for modeling horizontal well production in fractured vuggy carbonate reservoirs. J Hydrol (Amst), 464-465: 281–293
https://doi.org/10.1016/j.jhydrol.2012.07.021
9 A O Igbokoyi , D Tiab (2008). Pressure transient analysis in partially penetrating infinite conductivity hydraulic fractures in naturally fractured reservoirs. In: SPE Annual Technical Conference and Exhibition, Denver, USA
10 C A Kossack , O A Gurpinar (2001). Methodology for simulation of vuggy and fractured reservoirs. In: SPE Reservoir Simulation Symposium, Houston, USA.
11 Z Kang , Y S Wu , J Li , Y Wu , J Zhang , G Wang (2006). Modeling multiphase flow in naturally fractured vuggy petroleum reservoirs. In: SPE Annual Technical Conference and Exhibition, San Antonio, USA
12 J Liu , G S Bodvarsson , Y S Wu (2003). Analysis of flow behavior in fractured lithophysal reservoirs. J ContamHydrol, 62–63(1): 189–211
https://doi.org/10.1016/S0169-7722(02)00169-9 pmid: 12714291
13 M Liu , S Zhang , J Mou , F Zhou (2013). Wormhole propagation behavior under reservoir condition in carbonate acidizing. Transp Porous Media, 96(1): 203–220
https://doi.org/10.1007/s11242-012-0084-z
14 G Lei , Q Liao , D A Zhang (2018). New analytical model for flow in acidized fractured-vuggy porous media. Scientifc Reports, 9(1): 8293
15 O A Pedrosa (1986) Pressure transient response in stress-sensitive formations. In: SPE California Regional Meeting, Oakland, USA
16 R Raghavan , A Uraiet , G W Tomas (1978).Vertical fracture height: effect on transient flow behavior. Soc Petrol Eng J, 18(4): 265–277
17 F Rodriguez , R N Horne , H Cinco-Ley (1984). Partially penetrating fractures: pressure transient analysis of an infinite conductivity fracture. In: SPE Annual Technical Conference and Exhibition, Houston, USA
18 E Stalgorova , L Mattar (2012).Practical analytical model to simulate production of horizontal wells with branch fractures. In: SPE Canadian Unconventional Resource Conference, Calgary, Canada
19 H Stehfest (1970). Numerical inversion of Laplace transforms. Commun ACM, 13(1): 47–49
https://doi.org/10.1145/361953.361969
20 H Tao, L Zhang, Q Liu, Q Deng, M Luo, Y Zhao (2018). An analytical flow model for heterogeneous multi-fractured systems in shale gas reservoirs. Energies, 3422(12):
https://doi.org/10.3390/en11123422
21 Y S Wu , G Qin , R E Ewing , Y Efendiev , Z Kang , Y Ren (2006). A multiple-continuum approach for modeling multiphase flow in naturally fractured vuggy petroleum reservoirs. In: International Oil & Gas Conference and Exhibition in China, Beijing, China
22 Y S Wu , C A Ehlig-Economides , G Qin , Z Kang , W Zhang , B T Ajayi , Q Tao (2007). A triple-continuum pressure-transient model for a naturally fractured vuggy reservoir. In: SPE Annual Technical Conference and Exhibition, Anaheim, USA
23 L Wang , X Wang , E Luo , J Wang (2014). Analytical modeling of fow behavior for wormholes in naturally fractured-vuggy porous media. Transp Porous Media, 105(3): 539–558
https://doi.org/10.1007/s11242-014-0383-7
24 L Wang , X Chen , Z Xia (2018a). A novel semi-analytical model for multi-branched fractures in naturally fractured-vuggy reservoirs. Sci Rep, 8(1): 11586
https://doi.org/10.1038/s41598-018-30097-2 pmid: 30072702
25 M X Wang, Z F Fan, X Y Dong, H Song, W Zhao, G Xu (2018b). Analysis of flow behavior for acid fracturing wells in fractured-vuggy carbonate reservoirs. Mathematical Problems in Engineering, 2018(PT.3): 6431910.1–6431910.20
26 Y Wang , X Yi (2017). Transient pressure behavior of a fractured vertical well with a finite-conductivity fracture in triple media carbonate reservoir. J Porous Media, 20(8): 707–722
https://doi.org/10.1615/JPorMedia.v20.i8.30
27 Y Wu, L Cheng , S Huang , S Fang , P Jia , S Wang (2019). A semianalytical model for simulating fluid flow in naturally fractured reservoirs with nonhomogeneous vugs and fractures. SPE J, 24(01): 334–348
https://doi.org/10.2118/194023-PA
28 S Wang , L Cheng , Y Xue , S Huang , Y Wu , P Jia , Z Sun (2018). A semi-analytical method for simulating two-phase flow performance of horizontal volatile oil wells in fractured carbonate reservoirs. Energies, 11(10): 2700
https://doi.org/10.3390/en11102700
29 C Xing , H Yin , K Liu , X Li , J Fu (2018). Well test analysis for fractured and vuggy carbonate reservoirs of well drilling in large scale cave. Energies, 11(1): 80
https://doi.org/10.3390/en11010080
30 Y Xu , P Li , X Du , Z Lu , D Li , D Lu (2019). A novel analytical well test model for fractured vuggy carbonate reservoirs considering the coupling between oil flow and wave propagation. J Petrol Sci Eng, 173: 447–461
https://doi.org/10.1016/j.petrol.2018.09.077
31 Y Yang , Z Liu , Z Sun , S An , W Zhang , P Liu , J Yao , J Ma (2017). Research on Stress Sensitivity of Fractured Carbonate Reservoirs Based on CT Technology. Energies, 10(11): 1833
https://doi.org/10.3390/en10111833
32 J Yuan , R Jiang , W Zhang (2018). The workflow to analyze hydraulic fracture effect on hydraulic fractured horizontal well production in composite formation system. Advances in Geo-Energy Research, 2(3): 319–342
https://doi.org/10.26804/ager.2018.03.09
33 J Yao , Z Huang , Y Li , C Wang , X ( Lv 2010). Discrete fracture-vug network model for modeling fluid flow in fractured vuggy porous media. In: International Oil and Gas Conference and Exhibition in China, Beijing, China
34 F Zhang , M An , B Yan , Y Wang (2017). Modeling the depletion of fractured vuggy carbonate reservoir by coupling geomechanics with reservoir flow. In: SPE Reservoir Characterisation and Simulation Conference and Exhibition
https://doi.org/10.2118/186050-MS
35 H, Zhang X, Wang L Wang (2015). An analytical solution of partially penetrating hydraulic fractures in a box-shaped reservoir. Math Probl in Eng, 2015:11 (in Chinese)
36 Y Zeng , Q Wang , Z Ning , H Sun (2018). A mathematical pressure transient analysis model for multiple fractured horizontal wells in shale gas reservoirs. Geofluids, 2018: 8065949
https://doi.org/10.1155/2018/8065949
37 J Zeng , X Wang , J Guo , F Zeng (2017). Composite linear flow model for multi-fractured horizontal wells in heterogeneous shale reservoir. J Nat Gas Sci Eng, 38: 527–548
https://doi.org/10.1016/j.jngse.2017.01.005
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed