FOAM AS A MOBILITY CONTROL AGENT IN STEAM INJECTION PROCESSES

Abstract

Foam as a Mobility Control Agent in Steam Injection Processes Jin C. Chiang; Jin C. Chiang Stanford Univ. Search for other works by this author on: This Site Google Scholar Subir K. Sawyal; Subir K. Sawyal Stanford Univ. Search for other works by this author on: This Site Google Scholar Louis M. Castanier; Louis M. Castanier Stanford Univ. Search for other works by this author on: This Site Google Scholar William E. Brigham; William E. Brigham Stanford Univ. Search for other works by this author on: This Site Google Scholar Arshad Sufi Arshad Sufi Stanford Univ. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE California Regional Meeting, Los Angeles, California, April 1980. Paper Number: SPE-8912-MS https://doi.org/10.2118/8912-MS Published: April 09 1980 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Chiang, Jin C., Sawyal, Subir K., Castanier, Louis M., Brigham, William E., and Arshad Sufi. "Foam as a Mobility Control Agent in Steam Injection Processes." Paper presented at the SPE California Regional Meeting, Los Angeles, California, April 1980. doi: https://doi.org/10.2118/8912-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Western Regional Meeting Search Advanced Search AbstractAlthough our primary interest in studying the technique of mobility control by foaming agents was for steam injection processes, this method seems to offer excellent prospects of improving oil recovery efficiency in any type of gas drive process. Laboratory studies showed that gravity override of injected gases in gas drive processes can be strikingly reduced and hence recovery increased by in-situ generation of foam. A two-dimensional, vertical plexiglas model holding a 4' × 1' × 0.25" sandpack was used to investigate this phenomenon. Saturation of the sandpack by a surfactant solution instead of pure water sharply increased liquid recover and breakthrough time in nitrogen flooding process. The improvement in production was shown to be due to a reduction of gravity override caused by in-situ generation of foam at the gas-liquid interface. A large range of surfactant solutions of various concentrations with different amounts of monovalent and bivalent salts and alcohols has been studied as to their effectiveness as foamers. Surface tension rate of drainage, bubble size and shape of the foams were measured in each case. In-situ foaming in the model increased generally with surfactant concentration until the critical micelle concentration (CMC) was reached; above CMC additional amounts of surfactant had very little effect on the phenomenon. Similar increase of recovery and delay in breakthrough time was observed in oil flooding processes. A slug of surfactant solution was injected into the pack saturated with oil, and water at irreducible pack saturated with oil, and water at irreducible water saturation, and then nitrogen was injected. Gravity override was much less than in the case when no surfactant was present.IntroductionA significant fraction of the oil-in-place is left in the ground after primary or secondary recovery due to various reasons. Gas injection is one method used to extract these oils. There are basically four types of gases used in gas injection: natural hydrocarbon gas, inert gas, carbon dioxide, and steam; but in all cases there is the problem of gravity override, meaning the preferential movement of the injected gas through the upper part of the reservoir due to the lighter density of gas compared with oil. Gravity override causes early gas breakthrough in production wells and hence, reduced oil recovery. One of the research projects at the Stanford University Petroleum Research Institute is aimed at improving the efficiency of steam injection as a method of recovering heavy oil. The steam is injected into the ground to reduce the viscosity of the oil and to make the oil more mobile. Unfortunately, due to gravity override, the steam heats the oil in the top portion of the reservoir to a greater extent than the portion of the reservoir to a greater extent than the oil in the lower part of the reservoir. Because of this, recovery is not improved to the degree desired. The most practical method of correcting this problem is to selectively block the flow of gas into the problem is to selectively block the flow of gas into the higher elevation zone. The injection of a permeability blacking agent would do this. Elson, et al reviewed the literature on the selective blockage of fluids in thermal recovery projects and concluded that foam is best suited for this purpose. Foam has been used successfully in the past purpose. Foam has been used successfully in the past as an aerated drilling fluid, a way of preventing gas leakage from storage reservoirs, to remove liquids and solids from wells and to overcome the problem of produced liquid intrusion during air drilling. Foam produced liquid intrusion during air drilling. Foam should also provide good displacement efficiency due to the high apparent viscosity of foam (Ref. 2, 3) which improves the mobility ratio of the displacement process, and the high gas saturation which can exist process, and the high gas saturation which can exist without the creation of a high gas-oil relative permeability ratio. permeability ratio. The U.S. Bureau of Mines investigated the effectiveness of surfactants as foaming agents. Various laboratory studies on the properties of foam in porous media have been reported in the literature. porous media have been reported in the literature. The permeability blocking by foam during gas flow in porous media have been reported in Refs. 11 and 12. porous media have been reported in Refs. 11 and 12. Keywords: flow in porous media, Fluid Dynamics, concentration, enhanced recovery, Upstream Oil & Gas, mineral oil, SAGD, breakthrough, sandpack, thermal method Subjects: Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Flow in porous media, Thermal methods This content is only available via PDF. 1980. Society of Petroleum Engineers You can access this article if you purchase or spend a download.