The idea of injecting low salinity water into a petroleum reservoir is not novel and was often used in the 70s prior to the injection of surfactant. Recently it was shown that simply injecting sufficiently low salinity water improves oil recovery. Many possible mechanisms concerning low-salinity waterflood have been proposed in the literature. This paper describes an experimental investigation into some of the factors controlling the increased oil recovery observed when low salinity brine is injected into oil saturated reservoir core samples. Extensive chemical analyses were performed on the effluent showing the extent of interaction between the injected brine, the oil and the rock matrix.

Low salinity oil recovery - an experimental investigation

Publisher Summary It is noted that colloidal particles can be effectively transported through subsurface porous media under certain hydrogeochemical conditions. If present in large concentrations, mobile colloids can act as carriers for strongly sorbing contaminants and thereby provide an unretarded transport pathway for contaminants that are otherwise strongly retarded. This potential transport pathway can be considered in risk assessments of sites heavily contaminated with toxic chemicals, such as certain radionuclides, heavy metals, and hydrophobic organic compounds. The chapter reviews the current state of knowledge about the behavior of colloids in porous media and their role in contaminant transport. The chapter also identifies some important future research needs. Colloids are commonly defined as small particles or other entities with dimensions roughly between 1 nm and 1 μm. These size limits to dissolved molecules on one side and to larger suspended particles on the other side. Colloidal particles remain stable in suspension over long time periods, unless they coagulate to form larger aggregates or deposit onto surfaces of larger grains.

Mobile Subsurface Colloids and Their Role in Contaminant Transport

Critical review of low-salinity waterflooding

A method for improving hydrocarbon flow from a consolidated, tight reservoir rock having authigenic clay cementation includes thermally heating the reservoir rock in-situ surrounding a production well to change the mode of occurrence of clay cements within the rock so as to enhance reservoir permeability and carrying out rapid flowback into the production well.

Method of thermal stimulation for recovery of hydrocarbons

A method has been invented for recovering hydrocarbons from an earth formation containing hydrocarbons, the method including injecting a recovery injectant into the earth formation at a plurality of injection points spaced apart by about 14 to about 208 feet, and producing hydrocarbons from the formation with at least one producer well. In one aspect the method includes injecting steam into an earth formation which contains oil bearing diatomite at a plurality of injection points spaced apart by about 14 to about 208 feet, and producing hydrocarbons from the formation with a one or more producer wells extending into the oil bearing diatomite formation, with a plurality of producer wells spaced apart by a distance ranging between about 14 to about 149 feet, injecting steam into the oil bearing diatomite at an injection rate of between about 10 to about 149 barrels of steam per day per hundred feet thickness of diatomite, and injecting the steam at a pressure between about 10 p.s.i. to about 260 p.s.i. The present invention also discloses a method for treating a hydrocarbon-bearing diatomite formation including applying an artificial overburden over at least a portion of the formation and applying a variable well spacing as needed. A field on an earth formation has been invented for recovering hydrocarbons, the earth formation having an earth surface above it, the field including a plurality of injector well and a plurality of producing wells, the field including at least one injector well per acre of earth surface above the earth formation and at least one producing well per acre. Certain parts of the wells may be in below-grade chambers.

Systems and methods for hydrocarbon recovery

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Water sensitivity of sandstones containing swelling and non-swelling clays

The disclosure provides a novel catalyst support, a method of making said support by treatment of prior art crystalline catalyst supports with hydroxy-aluminum solution and hydrocarbon conversion processes wherein the catalyst used therein includes said support.

Hydrocarbon hydroconversion process employing hydroxy-aluminum stabilized catalysts supports

The effect of salt composition of fluid injected into clay-bearing Berea sandstones on the water-sensitivity phenomenon has been studied. Experiments were carried out with solutions of sodium and/or calcium ions, which are the ions commonly found in the formation. Freshwater flooding of sandstones previously exposed to sodium salt solutions results in the release of clay particles and a drastic reduction in permeability. The permeability reduction is lessened, however, when calcium ions are also present in the salt solution. Formation damage is virtually eliminated when the solution composition is adjusted to give calcium surface coverages greater than a critical value of 75%. The effect of the fluid composition on the damage process is explained by the double-layer interactions between the surface of the clay particles and the pore walls.

Effect of salt composition on clay release in Berea sandstones

Formation damage in smectitic sandstones by high ionic strength brines

The disclosure provides an aqueous hydroxy-aluminum drilling fluid having a ratio of hydroxy groups to aluminum atoms in the range of from 1.0 to 2.7 and a concentration of at least 0.5 molar and including an effective amount of a polymer selected from the group consisting of polyvinylpyrrolidone and polyvinyl alcohol and a corrosion inhibitor.

Marion G. Reed

Papers

Water sensitivity of sandstones containing swelling and non-swelling clays

Hydrocarbon hydroconversion process employing hydroxy-aluminum stabilized catalysts supports

Effect of salt composition on clay release in Berea sandstones

Formation damage in smectitic sandstones by high ionic strength brines

Hydroxy-aluminum based drilling fluid