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HCl/Formic In-Situ-Gelled Acids as Diverting Agents for Carbonate Acidizing
- Ahmed I. Rabie (Texas A&M University) | Ahmed M. Gomaa (Texas A&M University) | Hisham A. Nasr-El-Din (Texas A&M University)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- May 2012
- Document Type
- Journal Paper
- 170 - 184
- 2012. Society of Petroleum Engineers
- 1.6.9 Coring, Fishing, 5.4.10 Microbial Methods, 4.2.3 Materials and Corrosion, 3.2.4 Acidising, 5.8.7 Carbonate Reservoir, 5.5.2 Core Analysis, 1.10 Drilling Equipment, 2.5.2 Fracturing Materials (Fluids, Proppant)
- HCl/formic acids, formic acid, carbonates, diversion, acidizing
- 7 in the last 30 days
- 974 since 2007
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In highly heterogeneous carbonate reservoirs, several acid systems have been used to enhance acid diversion during matrix acidizing such as surfactant-based acids and in-situ-gelled acids. In-situ-gelled acids are also used to reduce leakoff rate in acid fracturing. The main acid used in this system is hydrochloric acid (HCl). However, high reaction rates and severity of corrosion problems, especially for wells completed with Cr-based tubulars, limit the use of HCl at high temperatures. On the other hand, mixing organic acids with HCl either increases the acid penetration or reduces the necessary strength of HCl and the necessary load of the corrosion inhibitors. A few studies addressed the systems that use both advantages.
The objective of this work is to investigate the behavior and the performance of different in-situ-gelled HCl/formic acid blends as diverting agents by conducting viscosity measurements and reaction-rate measurements using the rotating-disk apparatus, and through coreflood study.
Formic acid was blended with HCl, and four in-situ-gelled acids were examined. Formic acid concentration varied from 0 to 6.31 wt%, and HCl concentration ranged from 0 to 5 wt%. Pink Desert limestone was used for reaction-rate and coreflood experiments. The rotating-disk apparatus was used to measure the reaction rate at 250degF at disk rotational speeds of 100 and 1,000 rev/min. The effect of formic acid concentration and zirconium crosslinking on the reaction rate was examined. Coreflood experiments were conducted at 250°F using two different rates of injection (2 and 10 cm3/min), and the core samples were imaged using a computed-tomography (CT) scan technique after each coreflood experiment.
Increasing formic acid concentration decreased the reaction rate of in-situ-gelled HCl/formic acid with calcite at both low and high disk rotational speeds. This was confirmed by viscosity measurements, which showed that increasing formic acid concentration increased the viscosity of the live acids and decreased the viscosity of the spent acids. Coreflood results showed that increasing formic acid concentration in HCl/formic acid blends reduced acid ability for diversion. In the selected range of acid concentration and for the type of polymer and crosslinking agent used, the in-situ HCl/formic acid behaved more like gelled acid and reached a breakthrough in all coreflood experiments. The higher the formic acid concentration, the higher the pore volume of the acid required to break through.
The objective of this work is to investigate the behavior and the performance of different in-situ gelled HCl-formic acid blends as diverting agents by conducting viscosity measurements, reaction rate measurements using the rotating disk apparatus, and through core flood study.
Formic acid was blended with HCl and four in-situ gelled acids were examined. Formic acid concentration varied from 0 to 6.31 wt% and HCl concentration ranged from 0 to 5 wt%. Pink Desert limestone was utilized for reaction rate and core flood experiments. The rotating disk apparatus was used to measure the reaction rate at 250°F at disk rotational speeds of 100 and 1000 rpm. The effect of formic acid concentration and zirconium crosslinking on the reaction rate was examined. Core flood experiments were conducted at 250°F using two different rates of injection (2 and 10 cm3/min) and the core samples were imaged using a CT scan technique after each core flood experiment.
Boles, J.L., Metcalf, A.S., and Dawson, J.C. 1996. Coated breaker forcross-linked acid. US Patent No. 5,497,830.
Bryant, S.L., Rabaioli, M.R., and Lockhart, T.P. 1996. Influence ofSyneresis on Permeability Reduction by Polymer Gels. SPE Prod & Fac 11 (4): 209-215. SPE-35446-PA. http://dx.doi.org/10.2118/35446-PA.
Buijse, M., de Boer, P., Breukel, B., and Burgos, G. 2004. Organic Acids inCarbonate Acidizing. SPE Prod & Fac 19 (3): 128-134.SPE-82211-PA. http://dx.doi.org/10.2118/82211-PA.
Chang, F., Qu, Q., and Frenier, W. 2001. A Novel Self-Diverting AcidDeveloped for Matrix Stimulation of Carbonate Reservoirs. Paper SPE 65033presented at the SPE International Symposium on Oilfield Chemistry, Houston,13-16 February. http://dx.doi.org/10.2118/65033-MS.
Chang, F.F., Nasr-El-Din, H.A., Lindvig, T., and Qiu, X.W. 2008. MatrixAcidizing of Carbonate Reservoir Using Organic Acids and Mixture of HCl andOrganic Acids. Paper SPE 116601 presented at the SPE Annual TechnicalConference and Exhibition, Denver, 21-24 December. http://dx.doi.org/10.2118/116601-MS.
Dill, R.W. and Keeney, B.R. 1978. Optimizing HCl-Formic Acid Mixtures forHigh Temperature Stimulation. Paper SPE 7567 presented at the SPE Annual FallTechnical Conference and Exhibition, Houston, 1-3 October. http://dx.doi.org/10.2118/7567-MS.
Fredd, C.N. and Fogler, H.S. 1998a. The influence of chelating agents on thekinetics of calcite dissolution. J. Colloid Interface Sci. 204 (1): 187-197. http://dx.doi.org/10.1006/jcis.1998.5535.
Fredd, C.N. and Fogler, H.S. 1998b. The Influence of Transport and Reactionon Wormhole Formation in Porous Media. AIChE J. 44 (9):1933-1949. http://dx.doi.org/10.1002/aic.690440902.
Gomaa, A.M. and Nasr-El-Din, H. 2010a. New Insights into WormholePropagation in Carbonate Rocks Using Regular, Gelled and In-Situ Gelled Acids.Paper SPE 133303 presented at the SPE Production and Operations Conference andExhibition, Tunis, Tunisia, 8-10 June. http://dx.doi.org/10.2118/133303-MS.
Gomaa, A.M. and Nasr-El-Din, H.A. 2010b. New Insights Into the Viscosity ofPolymer-Based In-Situ Gelled Acids. SPE Prod & Oper 25(3): 367-375. SPE-121728-PA. http://dx.doi.org/10.2118/121728-PA.
Gomaa, A.M., Mahmoud, M.A., and Nasr-El-Din, H.A. 2011. Effect of Shear Rateon the Propagation of Polymer-Based In-Situ-Gelled Acids Inside CarbonateCores. SPE Prod & Oper 26 (1): 41-54. SPE-142927-PA. http://dx.doi.org/10.2118/142927-PA.
Hill, D.G. 2005. Gelled Acid. US Patent No. 20050065041.
Kalfayan, L.I. and Martin, A.N. 2009. The Art and Practice of Acid Placementand Diversion: History, Present State and Future. Paper SPE 124141 presented atthe SPE Annual Technical Conference and Exhibition, New Orleans, 4-7 October.http://dx.doi.org/10.2118/124141-MS.
MaGee, J., Buijse, M.A., and Pongratz, R. 1997. Method for Effective FluidDiversion When Performing a Matrix Acid Stimulation in Carbonate Formations.Paper SPE 37736 presented at the Middle East Oil Show, Bahrain, 17-20 March. http://dx.doi.org/10.2118/37736-MS.
Nasr-El-Din, H.A., Chesson, J.B., Cawiezel, K., and Devine, C.S. 2006.Lessons Learned and Guidelines for Matrix Acidizing With ViscoelasticSurfactant Diversion in Carbonate Formations. Paper SPE 102468 presented at theSPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA, 24-27September. http://dx.doi.org/10.2118/102468-MS.
Nasr-El-Din, H.A., Driweesh, S.M., and Muntasheri, G.A. 2003. FieldApplication of HCl-Formic Acid System to Acid Fracture Deep Gas Wells Completedwith Super Cr-13 Tubing in Saudi Arabia. Paper SPE 84925 presented at the SPEInternational Improved Oil Recovery Conference in Asia Pacific, Kuala Lumpur,20-21 October. http://dx.doi.org/10.2118/84925-MS.
Smith, C.L., Anderson, J.L., and Roberts, P.G. 1969. New DivertingTechniques for Acidizing and Fracturing. Paper SPE 2751 presented at the SPECalifornia Regional Meeting, San Francisco, 6-7 November. http://dx.doi.org/10.2118/2751-MS.
Taylor, K.C. and Nasr-El-Din, H.A. 2002. Coreflood Evaluation of In-SituGelled Acids. Paper SPE 73707 presented at the International Symposium andExhibition on Formation Damage Control, Lafayette, Louisiana, USA, 20-21February. http://dx.doi.org/10.2118/73707-MS.
van Domelen, M.S. and Jennings Jr., A.R. 1995. Alternate Acid Blends forHTHP Applications. Paper SPE 30419 presented at the SPE Offshore Europe,Aberdeen, 5-8 September. http://dx.doi.org/10.2118/30419-MS.
Welton, T.D. and van Domelen, M.S. 2008. High-Viscosity-Yield Acid Systemsfor High-Temperature Stimulation. SPE Prod & Oper 23(2): 177-183. SPE-98237-PA. http://dx.doi.org/10.2118/98237-PA.
Woo, G.T., Lopez, H., Metcalf, A.S., and Boles, J. 1999. A New GellingSystem for Acid Fracturing. Paper SPE 52169 presented at the SPE Mid-ContinentOperations Symposium, Oklahoma City, Oklahoma, USA, 28-31 March. http://dx.doi.org/10.2118/52169-MS.
Yeager, V. and Shuchart, C. 1997. In-Situ Gels Improve Formation Acidizing.Oil Gas J. 95 (3): 70-72.
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