Analysis of Critical Operational and Reservoir Parameters in Carbonate Acidizing Design
- R. Safari (Weatherford International Ltd.) | F. Fragachan (Weatherford International Ltd.) | C. S. Smith (Weatherford International Ltd., Newpark Drilling Fluids)
- Document ID
- Society of Petroleum Engineers
- SPE Western Regional Meeting, 22-26 April, Garden Grove, California, USA
- Publication Date
- Document Type
- Conference Paper
- 2018. Society of Petroleum Engineers
- 4.1 Processing Systems and Design, 5.8 Unconventional and Complex Reservoirs, 2 Well completion, 4.1.2 Separation and Treating, 4 Facilities Design, Construction and Operation, 5 Reservoir Desciption & Dynamics, 2.1 Completion Selection and Design, 2.1 Completion Selection and Design, 3 Production and Well Operations, 2.6 Acidizing, 3 Production and Well Operations, 5.8.7 Carbonate Reservoir
- Coupled Model, Carbonate Acidizing, Sensitivity Analysis
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- 84 since 2007
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This work employs an integrated analysis method to quantify the impact of operational parameters and subsurface conditions on the acid stimulation efficiency of a carbonate reservoir. Examined parameters include reservoir type, completion design (initial skin), reservoir thickness, reservoir liquid properties (viscosity and compressibility), reservoir temperature, reservoir heterogeneity, acid type, acid volume, injection rate, and diversion technique.
In general, a combination of operational parameters and local geological conditions control the efficiency of carbonate acidizing. The operational parameters include acid type, injection volume, injection rate, and diversion technique. Optimizing these parameters maximizes stimulation efficiency and consequently hydrocarbon recovery. However, optimization needs to be evaluated within the context of local geology and subsurface conditions. For instance, the presence of natural fracture swarms or a high permeability zone along a limited length of the wellbore can present acid placement challenges that only advanced analysis can carefully address.
In our study, an integrated wellbore and reservoir model is used to simulate carbonate reservoir acidizing. The model first simulates the movement of stimulation fluid in a wellbore and couples it with transient reservoir flow. This analysis provides the distribution of reactive fluid along the well and calculates dynamics of skin evolution of a wellbore during stimulation. The model simulates the local change of injectivity and the interactions of different reservoir zones along the completed length of the well during stimulation time.
The analyzed results show that the interactions between wellbore flow and reservoir flow along the completed length of the wellbore is a dominant governing factor for stimulation efficiencies. It shows that at a limited volume of acid or low injection rate, most of the acid stimulates the upper sections of the reservoir while inadequate amounts of acid reach the bottom of the reservoir. The results show that the reservoir porosity system (i.e. porosity and permeability), pay-zone height, initial skin (i.e. completion design), reservoir temperature, and heterogeneity have governing effects on the optimum acid volume and injection rate. The reservoir condition might impose a wasteful acid volume and injection rate for a bullheaded treatment that can be optimized further with diversion technology. The latter situation being important in optimizing the volume of acid needed to efficiently stimulate the reservoir to obtain higher production.
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Buijse, M.A. and Glasbergen, G. 2005. A Semi-Empirical Model to Calculate Wormhole Growth in Carbonate Acidizing. Paper presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas. Society of Petroleum Engineers. DOI: 10.2118/96892-MS.
Dormieux, L., Jeannin, L., Bemer, E., Le, T.H., and Sanahuja, J. 2010. Micromechanical Models of the Strength of a Sandstone. International Journal for Numerical and Analytical Methods in Geomechanics 34 (3): 249–271. DOI: 10.1002/nag.804
Fredd, C.N. and Fogler, H.S. 1999. Optimum Conditions for Wormhole Formation in Carbonate Porous Media: Influence of Transport and Reaction. DOI: 10.2118/56995-PA
Fredd, C.N., Tjia, R., and Fogler, H.S. 1997. The Existence of an Optimum Damkohler Number for Matrix Stimulation of Carbonate Formations. Paper presented at the SPE European Formation Damage Conference, The Hague, Netherlands. Society of Petroleum Engineers. DOI: 10.2118/38167-MS.
Hill, A.D. and Rossen, W.R. 1994. Fluid Placement and Diversion in Matrix Acidizing. Paper presented at the University of Tulsa Centennial Petroleum Engineering Symposium, Tulsa, Oklahoma. Society of Petroleum Engineers. DOI: 10.2118/27982-MS.
Kalfayan, L.J. and Martin, A.N. 2009. The Art and Practice of Acid Placement and Diversion: History, Present State, and Future. Paper presented at the SPE Annual Technical Conference and Exhibition, New Orleans, Louisiana. Society of Petroleum Engineers. DOI: 10.2118/124141-MS.
Kalia, N. and Balakotaiah, V. 2007. Modeling and Analysis of Wormhole Formation in Reactive Dissolution of Carbonate Rocks. Chemical Engineering Science 62 (4): 919–928. DOI: http://dx.doi.org/10.1016/j.ces.2006.10.021
Li, X., Gomaa, A., Nino-Penaloza, A., and Chaudhary, S. 2015. Integrated Carbonate Matrix Acidizing Model for Optimal Treatment Design and Distribution in Long Horizontal Wells. Paper presented at the SPE Production and Operations Symposium, Oklahoma City, Oklahoma, USA. Society of Petroleum Engineers. DOI: 10.2118/173607-MS.
Maheshwari, P., Ratnakar, R.R., Kalia, N., and Balakotaiah, V. 2013. 3-D Simulation and Analysis of Reactive Dissolution and Wormhole Formation in Carbonate Rocks. Chemical Engineering Science 90: 258–274. DOI: http://dx.doi.org/10.1016/j.ces.2012.12.032
McDuff, D., Shuchart, C.E., Jackson, S., Postl, D., and Brown, J.S. 2010. Understanding Wormholes in Carbonates: Unprecedented Experimental Scale and 3-D Visualization. Paper presented at the SPE Annual Technical Conference and Exhibition, Florence, Italy. Society of Petroleum Engineers. DOI: 10.2118/134379-MS.
Mishra, V., Zhu, D., Hill, A.D., and Furui, K. 2007. An Acid Placement Model for Long Horizontal Wells in Carbonate Reservoirs. Paper presented at the European Formation Damage Conference, Scheveningen, The Netherlands. Society of Petroleum Engineers. DOI: 10.2118/107780-MS.
Nasr-El-Din, H.A., Hill, A.D., Chang, F.F., and Sultan, A.S. 2007. Chemical Diversion Techniques Used for Carbonate Matrix Acidizing: An Overview and Case Histories. Paper presented at the International Symposium on Oilfield Chemistry, Houston, Texas, U.S.A. Society of Petroleum Engineers. DOI: 10.2118/106444-MS.
Paccaloni, G. 1995. A New, Effective Matrix Stimulation Diversion Technique. DOI: 10.2118/24781-PA
Paccaloni, G. and Tambini, M. 1993. Advances in Matrix Stimulation Technology. DOI: 10.2118/20623-PA
Panga, M.K.R., Ziauddin, M., and Balakotaiah, V. 2005. Two-Scale Continuum Model for Simulation of Wormholes in Carbonate Acidization. AIChE Journal 51 (12): 3231–3248. DOI: 10.1002/aic.10574
Safari, R., Smith, C.L., and Fragachan, F. 2017. Improved Recovery of Carbonate Reservoir by Optimizing Acidizing Strategy; Coupled Wellbore, Reservoir, and Geomechanical Analysis. Paper presented at the SPE Abu Dhabi International Petroleum Exhibition & Conference, Abu Dhabi, UAE. Society of Petroleum Engineers. DOI: 10.2118/188683-MS.
Santos, E.S.R. and Ferreira, F.H. 2015a. Wellbore Stability Model for Standalone Liner Completed Wells in Carbonate Reservoirs Subjected to Acidizing Jobs - I. Dissolution-Induced Mechanical Weakening Model. Paper presented at the Offshore Technology Conference, Rio de Janeiro, Brazil. Offshore Technology Conference. DOI: 10.4043/26290-MS.
Santos, E.S.R. and Ferreira, F.H. 2015b. Wellbore Stability Model for Standalone Liner Completed Wells in Carbonate Reservoirs Subjected to Acidizing Jobs – Ii. Wellbore Stability Simulator. Paper presented at the Offshore Technology Conference, Rio de Janeiro, Brazil. Offshore Technology Conference. DOI: 10.4043/26280-MS.
Shuchart, C.E., Jackson, S., Mendez-Santiago, J., Choi, N.H., Montgomery, J.K., Khemakhem, A.S.D., Sieben, C.J., Clancey, B.M., Chintaluri S, R., Farah, A.M., and Wang, Z. 2009. Effective Stimulation of Very Thick, Layered Carbonate Reservoirs without the Use of Mechanical Isolation. Paper presented at the International Petroleum Technology Conference, Doha, Qatar. International Petroleum Technology Conference. DOI: 10.2523/IPTC-13621-MS.
Wang, Y., Hill, A.D., and Schechter, R.S. 1993. The Optimum Injection Rate for Matrix Acidizing of Carbonate Formations. Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas. Society of Petroleum Engineers. DOI: 10.2118/26578-MS.