Evaluation of Hydraulic Fracturing Fluids
As explained by Keelan and Koepf (1977) fracturing fluids cause formation damage by water-block, solids invasion associated with fluid leak-off, and clay hydration in the near-fracture formation. Therefore, it is important to use compatible fluids and fluid-loss additives. Hence, they recommend performing tests on core samples extracted from the reservoir formation, in which fractures will be created. In these tests, the spurt loss, fluid-loss coefficient, effect of additives, acid solubility of formation, fines release with the acid reaction, are typically determined (Keelan and Koepf, 1977).
Evaluation of Workover and Injection Fluids
These tests indicate the incompatibility of clays with the extraneously introduced water, including filtered formation brine and filtered mud filtrate (Keelan and Koepf, 1977). Such tests can also be used to evaluate the effectiveness of clay stabilizers added to workover and injection fluids (Keelan and Koepf, 1977). Keelan and Koepf (1977) state that "Use of filtered workover fluids removes plugging solids and results in evaluation of damage resulting from clay swelling and/or clay-particle movement." The rock-water system is considered compatible when the formation permeability does not decrease by fluid injection. Keelan and Koepf (1977) state that
The clays damage productivity either by swelling in place or by release from their anchor point and subsequent movement to block pore channels. The inclusion of certain ions in workover and injection fluids often offers a relatively inexpensive and effective stabilization of the clays and prevention of productivity impairment.
Keelan and Koepf (1977) presents the test sequence and the equations necessary for determining formation damage for evaluation of the compatibility of the injection and workover fluids with the formation clays. Keelan and Koepf (1977) shows the results of injecting brines with and without KC1 and CaCl2 added. Injecting a brine, rather than the formation brine, into a core sample A reduced the permeability to 50% of its formation brine permeability. Injecting a brine containing 100 ppm KC1 into a core sample B doubled
its formation brine permeability. However, injecting a brine containing 100 ppm CaCl2 reduced the permeability to 50% of its formation brine permeability.
Keelan and Koepf (1977) shows that consecutively decreasing concentrations of KCI and CaCl2 in the injected brines yields permeabilities above the initial formation brine permeability. Keelan and Koepf (1977) concluded that KCI treatment is favorable even though the data appear unusual.
Keelan and Koepf (1977) recommend the water-oil relative permeability measurements as a practical approach to damage assessment in core plugs. Keelan and Koepf (1977) express that the fluids compatible with the core material should typically yield the relative permeability curves similar to those shown between the AA' and BB' lines.
Keelan and Koepf (1977) explain that, when a filtered injection brine is injected into a core containing irreducible oil, a specific value of the water relative permeability, denoted by Point E in this article, is obtained. This particular value represents the water relative permeability at the injection-wellbore formation face. Whereas, the water relative permeability at a sufficiently long distance from the well bore is represented by Point B.
References
Amaefule, J. O., Ajufo, A., Peterson, E., & Durst, K., "Understanding Formation Damage Processes," SPE 16232 paper, SPE Production Operations Symposium, Oklahoma City, Oklahoma, 1987.
Amaefule, J. O., Kersey, D. G., Norman, D. L., & Shannon, P. M., "Advances in Formation Damage Assessment and Control Strategies," CIM 88-39-65 paper, 39th Annual Technical Meeting of Petroleum Society of CIM and Canadian Gas Processors Association, June 12- 16, 1988, Calgary, Alberta, 16 p.
Amyx, J. W., Bass Jr., D. M., & Whiting, R. L., Petroleum Reservoir Engineering, Physical Properties, R.L. McGraw-Hill, 1960, New York, 610 p.
Bennion, D. B., & Thomas, F. B., "Underbalanced Drilling of Horizontal Wells: Does it Really Eliminate Formation Damage?," SPE 27352 paper, SPE Formation Damage Control Symposium, February 1994, Lafayette, LA.
Cernansky, A., & Siroky, R., "Deep-bed Filtration on Filament Layers on Particle polydispersed in Liquids," Int. Chem. Eng., Vol. 25, No. 2, 1985, pp. 364-375.
Civan, F., "A Generalized Model for Formation Damage by Rock-Fluid Interactions and Particulate Processes," SPE 21183 paper, SPE 1990 Latin American Petroleum Engineering Conference, October 14-19, 1990, Rio de Janeiro, Brazil, l i p .
Civan, F, "Evaluation and Comparison of the Formation Damage Models," SPE 23787 paper, SPE International Symposium on Formation Damage Control, February 26-27, 1992, Lafayette, Louisiana, pp. 219-236.
Civan, F, Predictability of Formation Damage: An Assessment Study and Generalized Models, Final Report, U.S. DOE Contract No. DE-AC22- 90-BC14658, April 1994.
Civan, F., "A Multi-Phase Mud Filtrate Invasion and Well Bore Filter Cake Formation Model," SPE 28709 paper, SPE International Petroleum Conference & Exhibition of Mexico, October 10-13, 1994, Veracruz, Mexico, pp. 399-412.
Civan, F., "A Multi-Purpose Formation Damage Model," SPE 31101 paper, SPE Formation Damage Symposium, Lafayette, Louisiana, February 14-15, 1996, pp. 311-326.
Delclaud, J., "Laboratory Measurement of the Residual Gas Saturation," in Worthington, P. F. & Longeron, D. (Eds.), Advances in Core Evaluation //, Proceedings of the Second Society of Core Analysts, European Core Analysis Symposium, London, UK, pp. 431-451, 1991.
Demir, I., "Formation Water Chemistry and Modeling Fluid-Rock Interaction for Improved Oil Recovery in Aux Vases and Cypress Formations," Illinois Basin, Illinois Petroleum Series 148, Department of Natural Resources, Illinois State Geological Survey, 1995, 60 p.
Deo, M., Tariq, S., & Halleck, P. J., "Linear and Radial Flow Targets for Characterizing Downhole Flow in Perforations," SPE 16896 paper, 62nd Annual Technical Conference and Exhibition of the Society of Petroleum Engineers, September 27-30, 1987, Dallas, Texas, pp. 181-188.
Doane, R. D., Bennion, D. B., Thomas, F. W., "Special Core Analysis Designed to Minimize Formation Damage Associated with Vertical/Horizontal Drilling Applications, " J. Canadian Petroleum Technology, Vol. 38, No. 5, May 1999, pp. 35-45.
Egbogah, E. O., "An Effective Mechanism for Fines Movement Control in Petroleum Reservoirs, "CIM 84-35-16 paper, 35th annual Technical Meeting of the Petroleum Society of CIM, June 10-13, 1984, Calgary, Canada.
Eickmeier, J. R., & Raimey Jr., H. J., "Wellbore Temperature and Heat Losses During Production or Injection Operations, " 7016 paper, Proceedings of the 21st Annual Technical Meeting, Calgary, Canada, may 1970, Canadian Institute of Mining.
Fambrough, J. D., & Newhouse, D. P., "A Comparison of Short-Core and Long-Core Acid Flow Testing for Matrix Acidizing Design, " SPE 26186 paper, SPE Gas Technology Symposium, June 28-30, 1993, Calgary, Canada, pp. 491-502.
Forchheimer, P., Hydraulik, L. Ed. Teubner, Leipzing and Berlin, Ch. 15, 1914, pp. 116-118.
Gabriel, G. A., & Inamdar, G. R., "An Experimental Investigation of Fines Migration in Porous Media, " SPE 12168 paper, SPE Annual Technical Conference and Exhibition, September 5-8, 1983, San Francisco, California.
Gadiyar, B., & Civan, F., "Acidization Induced Formation Damage-Experimental and Modeling Studies, " SPE 27400 paper, SPE Formation Damage Control Symposium, February 9-10, 1994, Lafayette, Louisiana, pp. 549-460.
Gruesbeck, C., & collins, R. E., "Entrainment and Deposition of Fine Particles in Porous Media, " SPEJ, December 1982, pp. 847-856.
Haggerty, D. J., & Seyler, B., "Investigation of Formation Damage from Mud Cleanout Acids and Injection Waters in Aux Vases Sandstone Reservoirs, " Illionois Petroleum Series 152, Department of Natural Resources, Illionois State Geological Survey, 1997, 40 p.
ISGS Oil and Gas Section, "Improved and Enhanced Oil Recovery Through Reservoir Characterization: Standard Operating and QA/QC Procedures," Illionois State Geological Survey, Open File Series 1993-13, 184 p.
Keelan, D., & Amaefule, J. O., "Rock-Water Reaction: Formation Damage,: Laboratory Methods, Part 5, pp. @49-257, in Development Geology Reference Manual, Methods 10, 1993, edited by D. Morton-Thompson and A. M. Woods. 548 p. AAPG Publication, Tulsa, Oklahoma.
Keelan, D. K., & Koepf, E. H., "The Role of Cores and Core Analysis in Evaluation of Formation Damage," JPT, May 1977, pp. 482-490.
Kersey, D. G., "The Role of Petrographic Analysis in the Design of Nondamaging Drilling, Completion, and Stimulation Programs," SPE 14089 paper, SPE International Meeting on Petroleum Engineering, Beijing, March 17-20, 1986.
Khilar, K. C, & Fogler, H. S., "Water Sensitivity of Sandstones," SPEJ, February 1983, pp. 55-64.
Kia, S. F., Fogler, H. S., & Reed, M. G., "Effect of Salt Composition on Clay Release in Berea Sandstones," SPE 16254, February 1987.
Kyte, J. R., & Rapoport, L. A., "Linear Waterflood Behavior and End Effects in Water-Wet Porous Media," Transactions of the American Institute of Mining, Metallurgy and Petroleum Engineers, Vol. 213, 1958, pp. 423-426.
Levorsen, A. I., Geology of Petroleum (2nd ed.), W.H. Freeman & Company, 1967, San Francisco, California, 409 p.
Marshall, D. S., Gray, R., & Byrne, M., "Development of a Recommended Practice for Formation Damage Testing," SPE 38154 paper, SPE European Formation Damage Conference, June 2-3, 1997, The Hague, The Netherlands, pp. 103-113.
Masikevich, J., & Bennion, D. B., "Fluid Design to Meet Reservoir Issues —A Process," /. Canadian Petroleum Technology, Vol. 38, No. 5, May 1999, pp. 61-71.
Miranda, R. M., & Underdown, D. R., "Laboratory Measurement of Critical Rate: A Novel Approach for Quantifying Fines Migration Problems," SPE 25432 paper, SPE Production Operations Symposium, March 21-23, 1993, Oklahoma City, Oklahoma, pp. 271-286.
Mungan, N., "Discussion of An Overview of Formation Damage," JPT, Vol. 41, No. 11, November 1989, p. 1224.
Piot, B. M., & Perthuis, H. G., "Matrix Acidizing of Sandstones," in M. J. Economides & K. G. Nolle (eds.), Reservoir Stimulation (2nd ed.), Prentice-Hall, Englewood Cliffs, New Jersey, 1989, pp. 14.1-6.
Porter, K. E., "An Overview of Formation Damage," JPT, Vol. 41, No. 88,1989, pp. 780-786.
Prada, A., Civan, F., & Dalrymple, E. D., "Evaluation of Gelation Systems for Conformance Control," Paper SPE 59322, SPE Permian Basin Oil & Gas Recovery Conference held in Midland, TX, March 21-23, 2000, 15 p.
Saleh, S. T., Rustam, R., El-Rabaa, W., & Islam, M. R., "Formation Damage Study with a Horizontal Wellbore Model," /. of Petroleum Science and Engineering, Vol. 17, No. 1/2, 1997, pp. 87-99.
Selby, R. J., "Flow of Fines and Sand Production in Unconsolidated Porous Media," Masters thesis, The University of Alberta, 1987, 212 p.
Seyler, B., "Geologic and Engineering Controls on Aux Vases Sandstone Reservoirs i« "^ ' Field, Illinois—A Comprehensive Study of a Well-Managed Oil Field," Illinois Petro eum Series 153, 1998, Department of Natural Resources, Illinois State Geological Survey, 79 p.
Sharma, M. M., & Yortsos, Y. C., "Fines Migration in Porous Media," AIChE J., Vol. 33, No. 10, 1987, pp. 1654-1662.
Thomas, R. L., Saxon, A., & Milne, A. W., "The Use of Coiled Tubing During Matrix Acidizing of Carbonate Reservoirs Completed in Horizontal Deviated, and Vertical Wells," \SPE Production & Facilities, August 1998, pp. 147-162.
Wojtanowicz, A. K., Krilov, Z., & Larglinais, J. P., "Experimental Determination of Formation Damage Trans, of the ASME, Journal of Energy Resources Technology, Vol. 110, 1988, pp. 34-42.
Wojtanowicz, A. K., Krilov, Z., & Langlirjais, J. P., "Study on the Effect of Pore Blocking Mechanisms on Formation Damage," SPE 16233 paper, Society of Petroleum Engineers 5 Oklahoma City, Oklahoma, pp. 449-463.
