Optimization of Acid Fracturing with Unified Fracture Design
- Arjun Ravikumar (University of Houston) | Matteo Marongiu-Porcu (Schlumberger) | Adrian Morales (Schlumberger)
- Document ID
- Society of Petroleum Engineers
- Abu Dhabi International Petroleum Exhibition and Conference, 9-12 November, Abu Dhabi, UAE
- Publication Date
- Document Type
- Conference Paper
- 2015. Society of Petroleum Engineers
- 4 Facilities Design, Construction and Operation, 2.5.2 Fracturing Materials (Fluids, Proppant), 3 Production and Well Operations, 2.5.1 Fracture design and containment, 2.5 Hydraulic Fracturing, 4.1 Processing Systems and Design, 4.1.2 Separation and Treating, 2 Well completion
- Acid fracturing, Unified Fracture Design
- 3 in the last 30 days
- 513 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 9.50|
|SPE Non-Member Price:||USD 28.00|
Acid fracturing is the most recognized and successful reservoir stimulation technique for conventional carbonate formations. Resulting fracture conductivity is the key parameter that controls final well productivity, while the competing diffusion and reaction phenomena control the "vital" acid coverage along the full areal extension of the fracture. However, not all reservoirs lend themselves to the same fracture geometry and conductivity, and this is where the "Unified Fracture Design" (UFD) approach is irreplaceable.
Classic fracture design optimization with the UFD approach involves the maximization of well productivity. For any mass of proppant to be injected as part of the treatment, the algorithm determines the unique fracture length and width (with height as a parasitic variable) that will provide the maximum productivity index.
In this paper we recast the UFD approach for specific acid fracturing applications, where the maximum productivity index is now determined as a function of the optimum fracture geometry determined for any volume of injected acid. The optimum fracture width profile is then obtained by solving the convection-diffusion equation for acid propagation, and subsequently used to study the required acid coverage through the fracture as a function of such optimum fracture width profile.
Acid reaction retardation plays a crucial role in ensuring proper acid coverage throughout the optimum fracture length, and this paper focuses on the two major reaction retardation fluid systems: Acid-Internal Emulsions (AIE) and gelled acids.
The workflow presented in this paper provides the basis for designing optimum acid fracturing treatments as a function of the volume of acid injected, the acid injection rate and the selected acid retardation method.
|File Size||1 MB||Number of Pages||17|
Al-Mutairi, S.H., Nasr-El-Din, H.A., Hill, A.D., and Al-Aamri, Aamri. 2009. Effect of Droplet Size on the Reaction Kinetics of Emulsified Acid with Calcite. SPEJ 14 (Vol. 14), No. 4 (December), pp 606–616. SPE-112454-PA. http://dx.doi.org/10.2118/112454-PA.
Ben-Naceur, K., and Economides, M.J. 1988. The Effectiveness of Acid Fractures and Their Production Behavior. Presented at the SPE Eastern Regional Meeting, Charleston, West Virginia, 1-4 November. SPE-18536-MS. http://dx.doi.org/10.2118/18536-MS.
Berman, A.S. 1953. Journal of Applied Physics (Vol.24), No. 9 (September), pp. 1232. http://dx.doi.org/10.1063/1.1721476.
Bustos, O.A., Sievert, C.J., Rodriguez, V.O., Galt, A.D., Temple, H.L., Stief, D.D., and Zaeff, G. 2007. Recent Acid-Fracturing Practices on Strawn Formation in Terrell County, Texas. Presented at the SPE Annual Technical Conference and Exhibition, Anaheim, California, 11-14 November. SPE-107978-MS. http://dx.doi.org/10.2118/107978-MS.
Cinco-Ley, H., and Samaniego, F. 1981. Transient Pressure Analysis for Fractured Wells. Journal of Petroleum Technology, (Vol. 33), No. 9 (September), pp. 1749–1766. SPE-7490-PA. http://dx.doi.org/10.2118/7490-PA.
Conway, M.W., Asadi, M., Penny, G.S., and Chang, F. 1999. A Comparative Study of Straight/Gelled/Emulsified Hydrochloric Acid Diffusivity Coefficient Using Diaphragm Cell and Rotating Disk. Presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 3-6 October. SPE-56532-MS. http://dx.doi.org/10.2118/56532-MS.
Daal, J.A., and Economides, M.J. 2006. Optimization of Hydraulically Fractured Wells in Irregularly Shaped Drainage Areas. Presented at the SPE International Symposium and Exhibition on Formation Damage Control, Lafayette, Louisiana 15-17 February. SPE-98047-MS. http://dx.doi.org/10.2118/98047-MS.
Demarchos, A.S., Chomatas, A.S., Economides, M.J., Mach, J.M., and Wolcott, D.S. 2004. Pushing the Limits in Hydraulic Fracture Design. Presented at the SPE International Symposium and Exhibition on Formation Damage Control, Lafayette, Louisiana, 18-20 February. SPE-86483-MS. http://dx.doi.org/10.2118/86483-MS.
De Rozieres, J. 1994. Measuring Diffusion Coefficients in Acid Fracturing Fluids and Their Application to Gelled and Emulsified Acids. Presented at the SPE Annual Technical Conference and Exhibition, New Orleans, Louisiana, 25-28 September. SPE-28552-MS. http://dx.doi.org/10.2118/28552-MS.
Economides, M.J., Marongiu-Porcu, M., Yang, M., and Martin, A.N. 2010. Fracturing Horizontal Transverse, Horizontal Longitudinal and Vertical Wells: Criteria for Decision. Presented at the Canadian Unconventional Resources and International Petroleum Conference, Calgary, Alberta, Canada, 19-21 October. SPE-137328-MS. http://dx.doi.org/10.2118/137328-MS.
Hoefner, M.L., and Fogler, H.S. 1989. Fluid-Velocity and Reaction-Rate Effects During Carbonate Acidizing: Application of Network Model. SPE Production Engineering (Vol. 4), No. 1 (February), pp. 56–62. SPE-15573-PA. http://dx.doi.org/10.2118/15573-PA.
Lund, K., Fogler, H., McCune, C., and Ault, J. 1973. Kinetic Rate Expressions for Reactions of Selected Minerals with HCl and HF Mixtures. Presented at the SPE Oilfield Chemistry Symposium, Denver, Colorado, 24-25 May. SPE-4348-MS. http://dx.doi.org/10.2118/4348-MS.
Marongiu-Porcu, M., Economides, M.J., and Holditch, S.A. 2013. Economic and Physical Optimization of Hydraulic Fracturing. Journal of Natural Gas Science & Engineering - JNGSE (Vol. 14), pp. 91–107. http://dx.doi.org/10.1016/j.jngse.2013.06.001.
Marongiu-Porcu, M., Ehlig-Economides, C.A., and Economides, M.J. 2011. Global Model for Fracture Falloff Analysis. Presented at the SPE North American Unconventional Gas Conference and Exhibition, The Woodlands, Texas, 14-16 June. SPE-144028-MS. http://dx.doi.org/10.2118/144028-MS.
Marongiu-Porcu, M., Retnanto, A., Economides, M.J., and Ehlig-Economides, C.A. 2014. Comprehensive Fracture Calibration Test Design. Presented at the SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, 4-6 February. SPE-168634-MS. http://dx.doi.org/10.2118/168634-MS.
Nasr-El-Din, H.A., Al-Mohammed, A.M., Al-Aamri, Aamri., and Al-Fuwaires, O.A. 2008. Reaction of Gelled Acids With Calcite. SPE Production & Operations (Vol. 23), No. 3 (August), pp. 353–361. SPE-103979-PA. http://dx.doi.org/10.2118/103979-PA.
Nierode, D.E., and Kruk, K.F. 1973. An Evaluation of Acid Fluid Loss Additives, Retarded Acids and Acidized Fracture Conductivity. Presented at the Fall Meeting of the Society of Petroleum Engineers of AIME, Las Vegas, Nevada, 30 September – 3 October. SPE-4549-MS. http://dx.doi.org/10.2118/4549-MS.
Rabie, A.I., Gomaa, A.M., and Nasr-El-Din, H.A. 2011. Reaction of In-Situ-Gelled Acids With Calcite: Reaction-Rate Study. SPE Journal (Vol. 16), No. 4 (December), pp. 981–992. SPE-133501-PA. http://dx.doi.org/10.2118/133501-PA.
Roberts, L.D., and Guin, J.A. 1975. A New Method for Predicting Acid Penetration Distance. SPE J (Vol. 15), No. 4 (August), pp. 277–286. SPE-5155-PA. http://dx.doi.org/10.2118/5155-PA.