William R Foster

Bio: William R Foster is an academic researcher from Mobil. The author has contributed to research in topics: Aqueous solution & Pulmonary surfactant. The author has an hindex of 9, co-authored 12 publications receiving 282 citations.

Lattice Expansion and Rheological Behavior Relationships in Water-Montmorillonite Systems

Abstract: Some divergent experimental data have been reported on the swelling behavior of sodium montmorillonite. At water contents above 50 percent (based on the weight of dry clay) the basal reflection of sodium montmorillonite at 19.2 A becomes weak and very diffuse; some workers have stated that it disappears altogether while others report a persistent weak line even at very high water content. The pronounced differences in physical properties of sodium and calcium montmorillonite suggest that their lattice expansions should also be dissimilar. This paper describes some X-ray diffraction experiments using purified lithium, sodium, and potassium montmorillonites dispersed in water and in salt solutions which were conducted for the purpose of resolving some of these disputed points. The X-ray diffraction instrument employed was a General Electric geiger counter spectrometer unit with a copper tube and nickel filters. The knowledge thus gained has provided some insight into other properties of these clays, such as their rheological behavior. A recording Couette-type viscometer designed to provide a wide spectrum of shear rates and shearing stresses has been used to examine the rheological transformations which occur in passing from states of maximum dispersion to states of varying degrees of agglomeration as a result of interactions between LiCl, NaCl, KCl, and CaCl2, and the Li, Na, K, and Ca salts of montmorillonite in terms of certain ideal rheological models. Filtration characteristics of these systems have also been explored using a standard technique.

Method of minimizing adsorption of surfactant from flooding water

Abstract: A method for minimizing surfactant adsorption employs a preflush of sacrificial inorganic compounds. The sacrificial materials are sodium carbonate and inorganic polyphosphate wetting agents, such as sodium tripolyphosphate, tetrasodium pyrophosphate, and borax. Preferably, the sacrificial inorganic additive is also contained in the surfactant and in the floodwater behind the surfactant. The preferred surfactant is a petroleum sulfonate sodium salt having a median molecular weight from about 400 to about 430. The additives may be used in the presence of brines or of high concentrations of divalent cations if certain precautions are taken. Laboratory tests on core samples from the Loma Novia sand, Duval County, Texas, showed substantial decreases in surfactant adsorption when the sacrificial additives were injected.

Alkaline waterflooding process

Abstract: A process for the recovery of oil from a subterranean oil reservoir involving the injection of an aqueous alkaline solution to neutralize organic acids in the reservoir oil to form surfactants in situ. This solution contains sufficient alkaline agent to impart a pH within the range of 11.5 to 13 and a monovalent salt within the range of 0.5 to 2.0 weight percent. The initial aqueous alkaline slug may be followed by a second alkaline slug containing a thickening agent.

Multistep method of waterflooding

Abstract: Surfactant adsorption can be minimized using the following injection procedure: (1) an aqueous solution of sacrificial inorganic additives (e.g. sodium carbonate and sodium tripolyphosphate) to cover the adsorption sites of the formation, (2) an optional buffer liquid containing a lower concentration of sacrificial inorganic additive to provide an environment chemically compatible with the surfactant solution to follow, (3) an aqueous, saline solution having a salinity of from about one to two percent by weight, the surfactant having a high molecular weight component (e.g. Alconate 80, median molecular weight 418) and a low molecular weight component (e.g. Pyronate 50, median molecular weight 346), (4) an aqueous, less-saline solution of the low molecular weight component to desorb from the formation high molecular weight component adsorbed from the aqueous, saline solution of surfactant and to create a second bank of surfactant, (5) an optional thickening agent (e.g. Kelzan biopolymer) having decreasing concentrations of thickening agents to form a zone of graded viscosity between the viscosity of the oil and that of the flood water to be injected, and (6) flood water.

Hydraulic conductivity and swelling of nonprehydrated gcls permeated with single-species salt solutions

Abstract: The influence of single-species salt solutions of various concentration, cation valence, and pH on swelling and hydraulic conductivity of nonprehydrated GCLs was examined. At similar concentration, swell was largest with NaCl, KCl, and LiCl solutions (monovalent cations Na+, K+, and Li+) and smallest with LaCl3 solutions (trivalent cation La3+). Intermediate swell volumes were obtained with divalent solutions (CaCl2, MgCl2, ZnCl2, and CuCl2). Analogous results were obtained from hydraulic conductivity tests. GCL specimens permeated with solutions containing divalent or trivalent cations had higher hydraulic conductivity than GCLs permeated with monovalent solutions or deionized water, unless the divalent or trivalent solutions were very dilute (≤0.01 M). Hydraulic conductivity increased as the concentration increased, and at high concentration (1 M) only small differences existed between hydraulic conductivities measured with all solutions. Swelling and hydraulic conductivity were related to size of the h...

In situ chemical stimulation of diatomite formations

Abstract: An improved method of recovering oil from diatomite is described. A solvent is injected into the diatomite followed by an aqueous surface active solution. The aqueous surface active solution contains a diatomite/oil water wettability improving agent and an oil/water surface tension lowering agent. The method may be supplemented by injection of water and/or steam into the diatomite.