Foams for Effective Gas Blockage in the Presence of Crude Oil

Abstract

Foams for Effective Gas Blockage in the Presence of Crude Oil J.E. Hanssen; J.E. Hanssen Rogaland Research Inst. Search for other works by this author on: This Site Google Scholar M. Dalland M. Dalland Rogaland Research Inst. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1990. Paper Number: SPE-20193-MS https://doi.org/10.2118/20193-MS Published: April 22 1990 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Hanssen, J.E., and M. Dalland. "Foams for Effective Gas Blockage in the Presence of Crude Oil." Paper presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, Oklahoma, April 1990. doi: https://doi.org/10.2118/20193-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Improved Oil Recovery Conference Search Advanced Search SPE MembersAbstractA study of foams for possible application in a new process with a potential for improving production process with a potential for improving production from thin oil rims by formation of effective barriers against gas coning is reported. A total of 48 foaming agents for aqueous and non-aqueous systems have been evaluated using a gas-blockage test, as well as bulk foam stability tests and measurements of relevant surfactant properties. All experiments were performed in contact with sea water and crude oil at performed in contact with sea water and crude oil at elevated temperature. In the gas-blockage test, foam is generated in 2-m long, 8.5-40m bead packs by constant-pressure displacement of a surfactant solution by gas at residual oil saturation. Stabilized gas rates through the foam-filled glass-bead pack are subsequently measured as a function of step-wise increasing pressure gradients. Only 4 foams were found capable of reducing gas permeability to the order of 0.1 40m or lower, at pressure gradients of 1 to 5 bar/m. These four products were found to be effective also in long-term tests at a constant pressure gradient of 1.5 bar/m. A number of foams pressure gradient of 1.5 bar/m. A number of foams known to be efficient gas-blocking agents in oil-free media were non-blocking in presence of residual oil. Bulk stability could not predict the gas-blocking ability for the foams studied. Further, no correlation was found between foam gas-blocking ability and the interfacial tensions, spreading conditions, oil saturation, foam quality, surfactant oil solubilization, or relative wetting abilities of surfactants measured. The four successful products found are fluorinated surfactants, from three different manufacturers, and were effective at 0.5 to 1 wt% concentration. Several fluorinated surfactants failed the gas-blockage test. Possible relations between observed gas-blockage Possible relations between observed gas-blockage performance and other properties are discussed. performance and other properties are discussed. The phenomena involved appear to be complex and no clear relation between surfactant properties and foam performance has been found. Speculation is offered on what may be the controlling factors for foam gas-blockage efficiency.IntroductionA foam is a dispersion of gas in liquid, usually with a surface-active agent present. Foams are not thermodynamically stable and ultimately decay into their constituent phases, but can be mechanically stable. The properties of bulk, or unconfined, foams have been studied extensively.When a foam exists inside a confining medium, dimensions of this confining medium relative to the average bubble size determine the texture and properties of the foam. When the confining diameter properties of the foam. When the confining diameter is large relative to typical bubble size, such as in a pipe, the foam is similar to a bulk foam. its flow can pipe, the foam is similar to a bulk foam. its flow can then be treated as that of a non-Newtonian, compressible pseudofluid. Where the diameter of the confining body is comparable to, or smaller than, minimum bubble size, the foam exists as a network of lamellae rather than bubbles. This is the case in most reservoir pore systems, as shown by Figure 1. Such a lamellar-structure foam cannot be treated as a single fluid, because liquid and gas flows by different mechanisms. Holm found liquid to flow as a continuous phase, but gas flow to occur by a sometimes very slow process of continually breaking and re-forming the liquid films. This explains why gas flow may be essentially blocked by foam in pores, while the permeability to liquid is merely reduced in proportion to the liquid saturation. proportion to the liquid saturation. P. 209 Keywords: bulk foam, blockage, gas injection method, lamellae, pressure gradient, application, stability, experiment, permeability, surfactant Subjects: Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Flow in porous media, Gas-injection methods, Chemical flooding methods This content is only available via PDF. 1990. Society of Petroleum Engineers You can access this article if you purchase or spend a download.