You must log in to edit PetroWiki. Help with editing

Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. More information


Foams as mobility control agents: Difference between revisions

PetroWiki
Jump to navigation Jump to search
No edit summary
 
No edit summary
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
Foams, as a conformance improvement technology for use during gas flooding (e.g., steam, CO<sub>2</sub>, and miscible gas flooding), have historically been most widely studied and applied when the foams are to be used in the form of a “viscosity-enhancing” mobility-control agent that is injected from the injection-well side. Because relatively large volumes of foam are required and because the foam must be propagated significant distances in the reservoir, applying foams for mobility control has proven technically and economically challenging. This article discusses applications and challenges associated with foams as mobility control agents.
Foams, as a conformance improvement technology for use during gas flooding (e.g., steam, CO<sub>2</sub>, and miscible gas flooding), have historically been most widely studied and applied when the foams are to be used in the form of a “viscosity-enhancing” mobility-control agent that is injected from the injection-well side. Because relatively large volumes of foam are required and because the foam must be propagated significant distances in the reservoir, applying foams for mobility control has proven technically and economically challenging. This article discusses applications and challenges associated with foams as mobility control agents.


==Reducing gas channeling and override==  
== Reducing gas channeling and override ==
As discussed in [[Foam properties]], the low effective density of most mobility-control foams, which are used during a gas flood such as a steam or CO<sub>2</sub> flood, provides a driving force for the foam to flow and be desirably placed in the upper reservoir vertical interval where the offending gas override is occurring and where the foam will be most effective at countering the negative impact of the gas override. Shi and Rossen<ref name="r1" /> describes an “improved” surfactant-alternating-gas foam injection process to control gravity override during gas flooding projects.


==Applications==
As discussed in [[Foam_properties|Foam properties]], the low effective density of most mobility-control foams, which are used during a gas flood such as a steam or CO<sub>2</sub> flood, provides a driving force for the foam to flow and be desirably placed in the upper reservoir vertical interval where the offending gas override is occurring and where the foam will be most effective at countering the negative impact of the gas override. Shi and Rossen<ref name="r1">Shi, J.-X. and Rossen, W.R. 1998. Improved Surfactant-Alternating-Gas Foam Process to Control Gravity Override. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39653-MS. http://dx.doi.org/10.2118/39653-MS</ref> describes an “improved” surfactant-alternating-gas foam injection process to control gravity override during gas flooding projects.
===CO<sub>2</sub> Flooding===
CO<sub>2</sub> foams are considered to be an effective mobility-control agent candidate for use during CO<sub>2</sub> flooding to improve CO<sub>2</sub> sweep efficiency.<ref name="r2"/><ref name="r3"/><ref name="r4"/><ref name="r5"/><ref name="r6"/><ref name="r7"/><ref name="r8"/> This includes the use of “foams” formulated with supercritical and dense CO<sub>2</sub>. Surfactant selection and surfactant adsorption/retention losses are particularly critical parameters to the successful economic application of CO<sub>2</sub> foams during CO<sub>2</sub> flooding operations. The exploitation of relatively low-cost CO<sub>2</sub> foams formulated with surfactant concentrations below the critical micelle concentration has been suggested.<ref name="r8"/> The sequential or water alternating gas (WAG) injection of the CO<sub>2</sub> and the foaming solution is often preferred for the injection of mobility-control CO<sub>2</sub> foam. (see [[Foam properties]])


===Steam flooding===
== Applications ==
Use of steam foams has been studied extensively and has been reduced to field practice as a technique to improve vertical and areal sweep efficiency and to reduce steam channeling and override during [[Thermal recovery by steam injection|steam flooding]] that is being applied to shallow heavy-oil reservoirs. The steam foam process consists of adding surfactant, with and without the addition of a noncondensable gas, to the injected steam.<ref name="r9" /><ref name="r10" /> Based on the combined findings of theory, laboratory studies, and field performance, it has been determined that steam foams are normally more effective when a small amount of a noncondensable gas, such as nitrogen, is incorporated into a steam-foam formula. Steam foams have been used in conjunction with both continuous and cyclic steam injection.


As with foams for CO<sub>2</sub> flooding, the effectiveness and the economics of the steam-foam process are critically dependent on surfactant adsorption and retention. Unlike CO<sub>2</sub> foams, surfactant thermal stability is also a critical issue. Alpha-olefin sulfonates, along with petroleum sulfonates, are the surfactants that have been favored for use in conformance improvement steam foams.<ref name="r11" /> Borchardt and Strycker<ref name="r12" /> have studied commercial olefin sulfonate surfactants to determine what the optimum chemistry should be in terms of favorable surfactant performance in foams for steam flooding applications.
=== CO<sub>2</sub> Flooding ===


To mitigate the destabilizing effect of oil on steam foam, one proposed strategy is to inject a prefoam surfactant slug to mobilize the residual oil ahead of the steam foam.<ref name="r10" /> Steam foams have been extensively applied in conjunction with the heavy oil production operations in Kern County, California, US. The application of steam foam in Kern County has been considered a technical success, but its economic success is suspect.<ref name="r10" />
CO<sub>2</sub> foams are considered to be an effective mobility-control agent candidate for use during CO<sub>2</sub> flooding to improve CO<sub>2</sub> sweep efficiency.<ref name="r2">Casteel, J.F. and Djabbarah, N.F. 1988. Sweep Improvement in CO2 Flooding by Use of Foaming Agents. SPE Res Eng 3 (4): 1186–1192. SPE-14392-PA. http://dx.doi.org/10.2118/14392-PA</ref><ref name="r3">Tsau, J.-S., Yaghoobi, H., and Grigg, R.B. 1998. Smart Foam to Improve Oil Recovery in Heterogeneous Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39677-MS. http://dx.doi.org/10.2118/39677-MS</ref><ref name="r4">Heller John, P. 1994. CO2 Foams in Enhanced Oil Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 5, 201-234. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch005.doi:10.1021/ba-1994-0242.ch005</ref><ref name="r5">Di Julio, S.S. and Emanuel, A.S. 1989. Laboratory Study of Foaming Surfactant for CO2 Mobility Control. SPE Res Eng 4 (2): 136-142. SPE-16373-PA. http://dx.doi.org/10.2118/16373-PA</ref><ref name="r6">Stevens, J.E. 1995. CO2 Foam Field Verification Pilot Test at EVGSAU: Phase IIIB--Project Operations and Performance Review. SPE Res Eng 10 (4): 266-272. SPE-27786-PA. http://dx.doi.org/10.2118/27786-PA</ref><ref name="r7">Prieditis, J. and Paulett, G.S. 1992. CO2-Foam Mobility Tests at Reservoir Conditions in San Andres Cores. Presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, 22-24 April 1992. SPE-24178-MS. http://dx.doi.org/10.2118/24178-MS</ref><ref name="r8">Kuhlman, M.I., Falls, A.M., Hara, S.K. et al. 1992. CO2 Foam With Surfactants Used Below Their Critical Micelle Concentrations. SPE Res Eng 7 (4): 445-452. SPE-20192-PA. http://dx.doi.org/10.2118/20192-PA</ref> This includes the use of “foams” formulated with supercritical and dense CO<sub>2</sub>. Surfactant selection and surfactant adsorption/retention losses are particularly critical parameters to the successful economic application of CO<sub>2</sub> foams during CO<sub>2</sub> flooding operations. The exploitation of relatively low-cost CO<sub>2</sub> foams formulated with surfactant concentrations below the critical micelle concentration has been suggested.<ref name="r8">Kuhlman, M.I., Falls, A.M., Hara, S.K. et al. 1992. CO2 Foam With Surfactants Used Below Their Critical Micelle Concentrations. SPE Res Eng 7 (4): 445-452. SPE-20192-PA. http://dx.doi.org/10.2118/20192-PA</ref> The sequential or water alternating gas (WAG) injection of the CO<sub>2</sub> and the foaming solution is often preferred for the injection of mobility-control CO<sub>2</sub> foam. (see [[Foam_properties|Foam properties]])


===Miscible gas flooding===
=== Steam flooding ===
Although it would appear that foams would be well suited to impart mobility control and to improve sweep efficiency during miscible gas flooding (in a similar manner as during CO<sub>2</sub> and steam flooding), relatively few papers have appeared in the literature about this application of conformance improvement foams, especially the actual field application of foams for use in conjunction with miscible gas flooding. Mannhardt and Novosad<ref name="r13" /> studied the adsorption of foaming surfactants to be used with hydrocarbon-miscible flooding in reservoirs with high salinities. Two sources<ref name="r14" /><ref name="r15" /> discuss the application of foams for use during hydrocarbon miscible flooding in Canada.


==Sizing volume injected==
Use of steam foams has been studied extensively and has been reduced to field practice as a technique to improve vertical and areal sweep efficiency and to reduce steam channeling and override during [[Thermal_recovery_by_steam_injection|steam flooding]] that is being applied to shallow heavy-oil reservoirs. The steam foam process consists of adding surfactant, with and without the addition of a noncondensable gas, to the injected steam.<ref name="r9">Hirasaki, G.J. 1989. The Steam-Foam Process. J Pet Technol 41 (5): 449–456. SPE-19505-PA. http://dx.doi.org/10.2118/19505-PA</ref><ref name="r10">Isaacs, E.E., Ivory, J., and Green, M.K. 1994. Steam-Foams for Heavy Oil and Bitumen Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 6, 235-258. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch006.doi:10.1021/ba-1994-0242.ch006</ref> Based on the combined findings of theory, laboratory studies, and field performance, it has been determined that steam foams are normally more effective when a small amount of a noncondensable gas, such as nitrogen, is incorporated into a steam-foam formula. Steam foams have been used in conjunction with both continuous and cyclic steam injection.
The volume of foam that should be injected during application, as a mobility control agent in conjunction with gas flooding, is a subject that lacks good and sound engineering guidelines. Thus, the sizing of such foam applications must be custom design based on previous experience with similar applications, and/or be based on empirical guidelines. It does not make sense to design the depth of foam placement to be greater than the distance the foam can propagate through the reservoir.  


==Polymer enhanced foams==
As with foams for CO<sub>2</sub> flooding, the effectiveness and the economics of the steam-foam process are critically dependent on surfactant adsorption and retention. Unlike CO<sub>2</sub> foams, surfactant thermal stability is also a critical issue. Alpha-olefin sulfonates, along with petroleum sulfonates, are the surfactants that have been favored for use in conformance improvement steam foams.<ref name="r11">Hamida, F.M. et al. 1992. Further Characterization of Surfactants as Steamflood Additives. In Situ 16 (2): 137.</ref> Borchardt and Strycker<ref name="r12">Borchardt, J.K. and Strycker, A.R. 1997. Olefin Sulfonates for High Temperature Steam Mobility Control: Structure - Property Correlations. Presented at the International Symposium on Oilfield Chemistry, Houston, Texas, 18-21 February 1997. SPE-37219-MS. http://dx.doi.org/10.2118/37219-MS</ref> have studied commercial olefin sulfonate surfactants to determine what the optimum chemistry should be in terms of favorable surfactant performance in foams for steam flooding applications.
The addition of a water-soluble [[Polymers|polymer]] to the foaming solution has been suggested as a means to increase stability of the foam, increase the effective viscosity and structure of foams, and improve the oil tolerance of foams.<ref name="r16" /><ref name="r17" /><ref name="r18" /><ref name="r19" /><ref name="r20" /><ref name="r21" /> The possible use of polymer-enhanced foams to treat fracture conformance problems has been suggested.<ref name="r18" /> Polymer enhanced foams formulated with high-molecular weight (MW) acrylamide polymers have been noted to be rheologically [[Glossary:Shear thinning|shear-thinning]] fluids that substantially aid in the injectivity of preformed polymer enhanced foams.  


Potential disadvantages of the use of polymer enhanced foams are
To mitigate the destabilizing effect of oil on steam foam, one proposed strategy is to inject a prefoam surfactant slug to mobilize the residual oil ahead of the steam foam.<ref name="r10">Isaacs, E.E., Ivory, J., and Green, M.K. 1994. Steam-Foams for Heavy Oil and Bitumen Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 6, 235-258. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch006.doi:10.1021/ba-1994-0242.ch006</ref> Steam foams have been extensively applied in conjunction with the heavy oil production operations in Kern County, California, US. The application of steam foam in Kern County has been considered a technical success, but its economic success is suspect.<ref name="r10">Isaacs, E.E., Ivory, J., and Green, M.K. 1994. Steam-Foams for Heavy Oil and Bitumen Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 6, 235-258. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch006.doi:10.1021/ba-1994-0242.ch006</ref>
*Reduced injectivity of preformed polymer enhanced foams as compared with conventional foams
*Possible increased difficulty in propagating the polymer enhanced foam through matrix reservoir rock
*Somewhat increased operational and chemical complexity in applying polymer-enhanced foams as compared with conventional foams.  


==Outlook==
=== Miscible gas flooding ===
The original interest in foams as mobility control agents has faded somewhat and interest in the use of conventional foams as fluid-flow blocking agents has also faded because foam fluid-flow blocking treatments are operationally and chemically relatively complex and polymer gels are considered by many petroleum engineers to be more effective, durable, and stronger.


==References==
Although it would appear that foams would be well suited to impart mobility control and to improve sweep efficiency during miscible gas flooding (in a similar manner as during CO<sub>2</sub> and steam flooding), relatively few papers have appeared in the literature about this application of conformance improvement foams, especially the actual field application of foams for use in conjunction with miscible gas flooding. Mannhardt and Novosad<ref name="r13">Karin, M. and Jerry, J.N. 1994. Adsorption of Foam-Forming Surfactants for Hydrocarbon-Miscible Flooding at High Salinities. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 7, 259-316. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch007.doi:10.1021/ba-1994-0242.ch007</ref> studied the adsorption of foaming surfactants to be used with hydrocarbon-miscible flooding in reservoirs with high salinities. Two sources<ref name="r14">Chad, J., Malsalla, P., and Novosad, J.J. 1988. Foam Forming Surfactants In Pembina/Ostracod 'G' Pool. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 12 - 16, 1988 1988. PETSOC-88-39-40. http://dx.doi.org/10.2118/88-39-40</ref><ref name="r15">Liu, P.C. and Besserer, G.J. 1988. Application of Foam Injection in Triassic Pool, Canada: Laboratory and Field Test Results. Presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 2-5 October 1988. SPE-18080-MS. http://dx.doi.org/10.2118/18080-MS</ref> discuss the application of foams for use during hydrocarbon miscible flooding in Canada.
<references>
<ref name="r1">Shi, J.-X. and Rossen, W.R. 1998. Improved Surfactant-Alternating-Gas Foam Process to Control Gravity Override. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39653-MS. http://dx.doi.org/10.2118/39653-MS </ref>


<ref name="r2">Casteel, J.F. and Djabbarah, N.F. 1988. Sweep Improvement in CO2 Flooding by Use of Foaming Agents. ''SPE Res Eng'' '''3''' (4): 1186–1192. SPE-14392-PA. http://dx.doi.org/10.2118/14392-PA</ref>
== Sizing volume injected ==


<ref name="r3">Tsau, J.-S., Yaghoobi, H., and Grigg, R.B. 1998. Smart Foam to Improve Oil Recovery in Heterogeneous Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39677-MS. http://dx.doi.org/10.2118/39677-MS </ref>
The volume of foam that should be injected during application, as a mobility control agent in conjunction with gas flooding, is a subject that lacks good and sound engineering guidelines. Thus, the sizing of such foam applications must be custom design based on previous experience with similar applications, and/or be based on empirical guidelines. It does not make sense to design the depth of foam placement to be greater than the distance the foam can propagate through the reservoir.


<ref name="r4">Heller John, P. 1994. CO<sub>2</sub> Foams in Enhanced Oil Recovery. In ''Foams: Fundamentals and Applications in the Petroleum Industry'', 242, 5, 201-234. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch005.doi:10.1021/ba-1994-0242.ch005</ref>
== Polymer enhanced foams ==


<ref name="r5">Di Julio, S.S. and Emanuel, A.S. 1989. Laboratory Study of Foaming Surfactant for CO2 Mobility Control. ''SPE Res Eng'' '''4''' (2): 136-142. SPE-16373-PA. http://dx.doi.org/10.2118/16373-PA</ref>
The addition of a water-soluble [[Polymers|polymer]] to the foaming solution has been suggested as a means to increase stability of the foam, increase the effective viscosity and structure of foams, and improve the oil tolerance of foams.<ref name="r16">Kabir, A.H. 2001. Chemical Water and Gas Shutoff Technology—An Overview. Presented at the SPE Asia Pacific Improved Oil Recovery Conference, Kuala Lumpur, 8–9 October. SPE-72119-MS. http://dx.doi.org/10.2118/72119-MS</ref><ref name="r17">Minssieux, L. 1974. Oil Displacement by Foams in Relation to Their Physical Properties in Porous Media. J Pet Technol 26 (1): 100–108. SPE-3991-PA. http://dx.doi.org/10.2118/3991-PA</ref><ref name="r18">Sydansk, R.D. 1994. Polymer-Enhanced Foams Part 1: Laboratory Development and Evaluation. SPE Advanced Technology Series 2 (2): 150–159.</ref><ref name="r19">Zhu, T., Strycker, A., Raible, C.J. et al. 1998. Foams for Mobility Control and Improved Sweep Efficiency in Gas Flooding. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39680-MS. http://dx.doi.org/10.2118/39680-MS</ref><ref name="r20">Ye, Z., Pu, W., Zhang, S. et al. 1997. Laboratory Study On Profile Modification By Using Foamed Polymer Solution. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 8 - 11, 1997 1997. PETSOC-97-128. http://dx.doi.org/10.2118/97-128</ref><ref name="r21">Romero, C., Alvarez, J.M., and Müller, A.J. 2002. Micromodel Studies of Polymer-Enhanced Foam Flow Through Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 13-17 April 2002. SPE-75179-MS. http://dx.doi.org/10.2118/75179-MS</ref> The possible use of polymer-enhanced foams to treat fracture conformance problems has been suggested.<ref name="r18">Sydansk, R.D. 1994. Polymer-Enhanced Foams Part 1: Laboratory Development and Evaluation. SPE Advanced Technology Series 2 (2): 150–159.</ref> Polymer enhanced foams formulated with high-molecular weight (MW) acrylamide polymers have been noted to be rheologically [[Glossary:Shear_thinning|shear-thinning]] fluids that substantially aid in the injectivity of preformed polymer enhanced foams.


<ref name="r6">Stevens, J.E. 1995. CO2 Foam Field Verification Pilot Test at EVGSAU: Phase IIIB--Project Operations and Performance Review. ''SPE Res Eng'' '''10''' (4): 266-272. SPE-27786-PA. http://dx.doi.org/10.2118/27786-PA</ref>
Potential disadvantages of the use of polymer enhanced foams are


<ref name="r7">Prieditis, J. and Paulett, G.S. 1992. CO2-Foam Mobility Tests at Reservoir Conditions in San Andres Cores. Presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, 22-24 April 1992. SPE-24178-MS. http://dx.doi.org/10.2118/24178-MS </ref>
*Reduced injectivity of preformed polymer enhanced foams as compared with conventional foams
*Possible increased difficulty in propagating the polymer enhanced foam through matrix reservoir rock
*Somewhat increased operational and chemical complexity in applying polymer-enhanced foams as compared with conventional foams.


<ref name="r8">Kuhlman, M.I., Falls, A.M., Hara, S.K. et al. 1992. CO2 Foam With Surfactants Used Below Their Critical Micelle Concentrations. ''SPE Res Eng'' '''7''' (4): 445-452. SPE-20192-PA. http://dx.doi.org/10.2118/20192-PA</ref>
== Outlook ==


<ref name="r9">Hirasaki, G.J. 1989. The Steam-Foam Process. ''J Pet Technol'' '''41''' (5): 449–456. SPE-19505-PA. http://dx.doi.org/10.2118/19505-PA</ref>
The original interest in foams as mobility control agents has faded somewhat and interest in the use of conventional foams as fluid-flow blocking agents has also faded because foam fluid-flow blocking treatments are operationally and chemically relatively complex and polymer gels are considered by many petroleum engineers to be more effective, durable, and stronger.


<ref name="r10">Isaacs, E.E., Ivory, J., and  Green, M.K. 1994. Steam-Foams for Heavy Oil and Bitumen Recovery. In ''Foams: Fundamentals and Applications in the Petroleum Industry'', 242, 6, 235-258. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch006.doi:10.1021/ba-1994-0242.ch006</ref>
== References ==


<ref name="r11">Hamida, F.M. et al. 1992. Further Characterization of Surfactants as Steamflood Additives. ''In Situ'' '''16''' (2): 137.</ref>
<references />


<ref name="r12">Borchardt, J.K. and Strycker, A.R. 1997. Olefin Sulfonates for High Temperature Steam Mobility Control: Structure - Property Correlations. Presented at the International Symposium on Oilfield Chemistry, Houston, Texas, 18-21 February 1997. SPE-37219-MS. http://dx.doi.org/10.2118/37219-MS </ref>
== Noteworthy papers in OnePetro ==


<ref name="r13">Karin, M. and Jerry, J.N. 1994. Adsorption of Foam-Forming Surfactants for Hydrocarbon-Miscible Flooding at High Salinities. In ''Foams: Fundamentals and Applications in the Petroleum Industry'', 242, 7, 259-316. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch007.doi:10.1021/ba-1994-0242.ch007</ref>
Use this section to list papers in OnePetro that a reader who wants to learn more should definitely read


<ref name="r14">Chad, J., Malsalla, P., and  Novosad, J.J. 1988. Foam Forming Surfactants In Pembina/Ostracod 'G' Pool. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 12 - 16, 1988 1988. PETSOC-88-39-40. http://dx.doi.org/10.2118/88-39-40 </ref>
== External links ==


<ref name="r15">Liu, P.C. and Besserer, G.J. 1988. Application of Foam Injection in Triassic Pool, Canada: Laboratory and Field Test Results. Presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 2-5 October 1988. SPE-18080-MS. http://dx.doi.org/10.2118/18080-MS </ref>
Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro


<ref name="r16">Kabir, A.H. 2001. Chemical Water and Gas Shutoff Technology—An Overview. Presented at the SPE Asia Pacific Improved Oil Recovery Conference, Kuala Lumpur, 8–9 October. SPE-72119-MS. http://dx.doi.org/10.2118/72119-MS </ref>
== See also ==


<ref name="r17">Minssieux, L. 1974. Oil Displacement by Foams in Relation to Their Physical Properties in Porous Media. ''J Pet Technol'' '''26''' (1): 100–108. SPE-3991-PA. http://dx.doi.org/10.2118/3991-PA</ref>
[[Foams|Foams]]


<ref name="r18">Sydansk, R.D. 1994. Polymer-Enhanced Foams Part 1: Laboratory Development and Evaluation. ''SPE Advanced Technology Series'' '''2''' (2): 150–159.</ref>
[[Foams_as_blocking_agents|Foams as blocking agents]]
 
<ref name="r19">Zhu, T., Strycker, A., Raible, C.J. et al. 1998. Foams for Mobility Control and Improved Sweep Efficiency in Gas Flooding. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39680-MS. http://dx.doi.org/10.2118/39680-MS </ref>
 
<ref name="r20">Ye, Z., Pu, W., Zhang, S. et al. 1997. Laboratory Study On Profile Modification By Using Foamed Polymer Solution. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 8 - 11, 1997 1997. PETSOC-97-128. http://dx.doi.org/10.2118/97-128 </ref>
 
<ref name="r21">Romero, C., Alvarez, J.M., and  Müller, A.J. 2002. Micromodel Studies of Polymer-Enhanced Foam Flow Through Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 13-17 April 2002. SPE-75179-MS. http://dx.doi.org/10.2118/75179-MS </ref>
</references>
 
==Noteworthy papers in OnePetro==
Use this section to list papers in OnePetro that a reader who wants to learn more should definitely read
 
==External links==
Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro


==See also==
[[Foam_behavior_in_porous_media|Foam behavior in porous media]]
[[Foams]]


[[Foams as blocking agents]]
[[Foam_properties|Foam properties]]


[[Foam behavior in porous media]]
[[Field_applications_of_conformance_improvement_foams|Field applications of conformance improvement foams]]


[[Foam properties]]
[[PEH:Polymers,_Gels,_Foams,_and_Resins]]


[[Field applications of conformance improvement foams]]
== Category ==


[[PEH:Polymers, Gels, Foams, and Resins]]
[[Category:5.4.5 Conformance improvement]]

Latest revision as of 12:14, 7 January 2016

Foams, as a conformance improvement technology for use during gas flooding (e.g., steam, CO2, and miscible gas flooding), have historically been most widely studied and applied when the foams are to be used in the form of a “viscosity-enhancing” mobility-control agent that is injected from the injection-well side. Because relatively large volumes of foam are required and because the foam must be propagated significant distances in the reservoir, applying foams for mobility control has proven technically and economically challenging. This article discusses applications and challenges associated with foams as mobility control agents.

Reducing gas channeling and override

As discussed in Foam properties, the low effective density of most mobility-control foams, which are used during a gas flood such as a steam or CO2 flood, provides a driving force for the foam to flow and be desirably placed in the upper reservoir vertical interval where the offending gas override is occurring and where the foam will be most effective at countering the negative impact of the gas override. Shi and Rossen[1] describes an “improved” surfactant-alternating-gas foam injection process to control gravity override during gas flooding projects.

Applications

CO2 Flooding

CO2 foams are considered to be an effective mobility-control agent candidate for use during CO2 flooding to improve CO2 sweep efficiency.[2][3][4][5][6][7][8] This includes the use of “foams” formulated with supercritical and dense CO2. Surfactant selection and surfactant adsorption/retention losses are particularly critical parameters to the successful economic application of CO2 foams during CO2 flooding operations. The exploitation of relatively low-cost CO2 foams formulated with surfactant concentrations below the critical micelle concentration has been suggested.[8] The sequential or water alternating gas (WAG) injection of the CO2 and the foaming solution is often preferred for the injection of mobility-control CO2 foam. (see Foam properties)

Steam flooding

Use of steam foams has been studied extensively and has been reduced to field practice as a technique to improve vertical and areal sweep efficiency and to reduce steam channeling and override during steam flooding that is being applied to shallow heavy-oil reservoirs. The steam foam process consists of adding surfactant, with and without the addition of a noncondensable gas, to the injected steam.[9][10] Based on the combined findings of theory, laboratory studies, and field performance, it has been determined that steam foams are normally more effective when a small amount of a noncondensable gas, such as nitrogen, is incorporated into a steam-foam formula. Steam foams have been used in conjunction with both continuous and cyclic steam injection.

As with foams for CO2 flooding, the effectiveness and the economics of the steam-foam process are critically dependent on surfactant adsorption and retention. Unlike CO2 foams, surfactant thermal stability is also a critical issue. Alpha-olefin sulfonates, along with petroleum sulfonates, are the surfactants that have been favored for use in conformance improvement steam foams.[11] Borchardt and Strycker[12] have studied commercial olefin sulfonate surfactants to determine what the optimum chemistry should be in terms of favorable surfactant performance in foams for steam flooding applications.

To mitigate the destabilizing effect of oil on steam foam, one proposed strategy is to inject a prefoam surfactant slug to mobilize the residual oil ahead of the steam foam.[10] Steam foams have been extensively applied in conjunction with the heavy oil production operations in Kern County, California, US. The application of steam foam in Kern County has been considered a technical success, but its economic success is suspect.[10]

Miscible gas flooding

Although it would appear that foams would be well suited to impart mobility control and to improve sweep efficiency during miscible gas flooding (in a similar manner as during CO2 and steam flooding), relatively few papers have appeared in the literature about this application of conformance improvement foams, especially the actual field application of foams for use in conjunction with miscible gas flooding. Mannhardt and Novosad[13] studied the adsorption of foaming surfactants to be used with hydrocarbon-miscible flooding in reservoirs with high salinities. Two sources[14][15] discuss the application of foams for use during hydrocarbon miscible flooding in Canada.

Sizing volume injected

The volume of foam that should be injected during application, as a mobility control agent in conjunction with gas flooding, is a subject that lacks good and sound engineering guidelines. Thus, the sizing of such foam applications must be custom design based on previous experience with similar applications, and/or be based on empirical guidelines. It does not make sense to design the depth of foam placement to be greater than the distance the foam can propagate through the reservoir.

Polymer enhanced foams

The addition of a water-soluble polymer to the foaming solution has been suggested as a means to increase stability of the foam, increase the effective viscosity and structure of foams, and improve the oil tolerance of foams.[16][17][18][19][20][21] The possible use of polymer-enhanced foams to treat fracture conformance problems has been suggested.[18] Polymer enhanced foams formulated with high-molecular weight (MW) acrylamide polymers have been noted to be rheologically shear-thinning fluids that substantially aid in the injectivity of preformed polymer enhanced foams.

Potential disadvantages of the use of polymer enhanced foams are

  • Reduced injectivity of preformed polymer enhanced foams as compared with conventional foams
  • Possible increased difficulty in propagating the polymer enhanced foam through matrix reservoir rock
  • Somewhat increased operational and chemical complexity in applying polymer-enhanced foams as compared with conventional foams.

Outlook

The original interest in foams as mobility control agents has faded somewhat and interest in the use of conventional foams as fluid-flow blocking agents has also faded because foam fluid-flow blocking treatments are operationally and chemically relatively complex and polymer gels are considered by many petroleum engineers to be more effective, durable, and stronger.

References

  1. Shi, J.-X. and Rossen, W.R. 1998. Improved Surfactant-Alternating-Gas Foam Process to Control Gravity Override. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39653-MS. http://dx.doi.org/10.2118/39653-MS
  2. Casteel, J.F. and Djabbarah, N.F. 1988. Sweep Improvement in CO2 Flooding by Use of Foaming Agents. SPE Res Eng 3 (4): 1186–1192. SPE-14392-PA. http://dx.doi.org/10.2118/14392-PA
  3. Tsau, J.-S., Yaghoobi, H., and Grigg, R.B. 1998. Smart Foam to Improve Oil Recovery in Heterogeneous Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39677-MS. http://dx.doi.org/10.2118/39677-MS
  4. Heller John, P. 1994. CO2 Foams in Enhanced Oil Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 5, 201-234. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch005.doi:10.1021/ba-1994-0242.ch005
  5. Di Julio, S.S. and Emanuel, A.S. 1989. Laboratory Study of Foaming Surfactant for CO2 Mobility Control. SPE Res Eng 4 (2): 136-142. SPE-16373-PA. http://dx.doi.org/10.2118/16373-PA
  6. Stevens, J.E. 1995. CO2 Foam Field Verification Pilot Test at EVGSAU: Phase IIIB--Project Operations and Performance Review. SPE Res Eng 10 (4): 266-272. SPE-27786-PA. http://dx.doi.org/10.2118/27786-PA
  7. Prieditis, J. and Paulett, G.S. 1992. CO2-Foam Mobility Tests at Reservoir Conditions in San Andres Cores. Presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, 22-24 April 1992. SPE-24178-MS. http://dx.doi.org/10.2118/24178-MS
  8. 8.0 8.1 Kuhlman, M.I., Falls, A.M., Hara, S.K. et al. 1992. CO2 Foam With Surfactants Used Below Their Critical Micelle Concentrations. SPE Res Eng 7 (4): 445-452. SPE-20192-PA. http://dx.doi.org/10.2118/20192-PA
  9. Hirasaki, G.J. 1989. The Steam-Foam Process. J Pet Technol 41 (5): 449–456. SPE-19505-PA. http://dx.doi.org/10.2118/19505-PA
  10. 10.0 10.1 10.2 Isaacs, E.E., Ivory, J., and Green, M.K. 1994. Steam-Foams for Heavy Oil and Bitumen Recovery. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 6, 235-258. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch006.doi:10.1021/ba-1994-0242.ch006
  11. Hamida, F.M. et al. 1992. Further Characterization of Surfactants as Steamflood Additives. In Situ 16 (2): 137.
  12. Borchardt, J.K. and Strycker, A.R. 1997. Olefin Sulfonates for High Temperature Steam Mobility Control: Structure - Property Correlations. Presented at the International Symposium on Oilfield Chemistry, Houston, Texas, 18-21 February 1997. SPE-37219-MS. http://dx.doi.org/10.2118/37219-MS
  13. Karin, M. and Jerry, J.N. 1994. Adsorption of Foam-Forming Surfactants for Hydrocarbon-Miscible Flooding at High Salinities. In Foams: Fundamentals and Applications in the Petroleum Industry, 242, 7, 259-316. Advances in Chemistry, American Chemical Society. http://dx.doi.org/10.1021/ba-1994-0242.ch007.doi:10.1021/ba-1994-0242.ch007
  14. Chad, J., Malsalla, P., and Novosad, J.J. 1988. Foam Forming Surfactants In Pembina/Ostracod 'G' Pool. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 12 - 16, 1988 1988. PETSOC-88-39-40. http://dx.doi.org/10.2118/88-39-40
  15. Liu, P.C. and Besserer, G.J. 1988. Application of Foam Injection in Triassic Pool, Canada: Laboratory and Field Test Results. Presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, 2-5 October 1988. SPE-18080-MS. http://dx.doi.org/10.2118/18080-MS
  16. Kabir, A.H. 2001. Chemical Water and Gas Shutoff Technology—An Overview. Presented at the SPE Asia Pacific Improved Oil Recovery Conference, Kuala Lumpur, 8–9 October. SPE-72119-MS. http://dx.doi.org/10.2118/72119-MS
  17. Minssieux, L. 1974. Oil Displacement by Foams in Relation to Their Physical Properties in Porous Media. J Pet Technol 26 (1): 100–108. SPE-3991-PA. http://dx.doi.org/10.2118/3991-PA
  18. 18.0 18.1 Sydansk, R.D. 1994. Polymer-Enhanced Foams Part 1: Laboratory Development and Evaluation. SPE Advanced Technology Series 2 (2): 150–159.
  19. Zhu, T., Strycker, A., Raible, C.J. et al. 1998. Foams for Mobility Control and Improved Sweep Efficiency in Gas Flooding. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 19-22 April 1998. SPE-39680-MS. http://dx.doi.org/10.2118/39680-MS
  20. Ye, Z., Pu, W., Zhang, S. et al. 1997. Laboratory Study On Profile Modification By Using Foamed Polymer Solution. Presented at the Annual Technical Meeting, Calgary, Alberta, Jun 8 - 11, 1997 1997. PETSOC-97-128. http://dx.doi.org/10.2118/97-128
  21. Romero, C., Alvarez, J.M., and Müller, A.J. 2002. Micromodel Studies of Polymer-Enhanced Foam Flow Through Porous Media. Presented at the SPE/DOE Improved Oil Recovery Symposium, Tulsa, Oklahoma, 13-17 April 2002. SPE-75179-MS. http://dx.doi.org/10.2118/75179-MS

Noteworthy papers in OnePetro

Use this section to list papers in OnePetro that a reader who wants to learn more should definitely read

External links

Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro

See also

Foams

Foams as blocking agents

Foam behavior in porous media

Foam properties

Field applications of conformance improvement foams

PEH:Polymers,_Gels,_Foams,_and_Resins

Category