A method is provided for increasing the rate of injection of flooding fluids into injection wells. A slug of polar solvent or a mixture of polar solvent and non-aqueous flooding fluid is injected into the injection well to displace aqueous and hydrocarbon liquids in the rock surrounding the injection well. Thereafter, the solvent is removed from the vicinity of the injection well by flooding fluid. The process may be repeated following each time water is injected into the injection well.
Disclosed is a method for recovering and re-employing ionic surfactants from solutions, dispersions and emulsions of water and liquid hydrocarbons, by the addition of a second non-aqueous polar phase and an inorganic salt which changes the ionic strength of the surfactant and causes the surfactant to partition principally into the non-aqueous second polar phase. More specifically, the method applies to recovering hydrate growth inhibitor/modifying compounds, with cationic surfactants such as ammonium, phosphonium and sulphonium alkylated compounds from the effluent of hydrocarbon production wells; the effluent including water, hydrate inhibitor compound, at least one additional polar solvent and inorganic salt. Sufficient additional ions of inorganic salt, and if necessary, an alcohol/glycol are added to the effluent to form a second polar phase that is less polar than the aqueous phase, into which the hydrate inhibitor can then dissolve and be separated from the effluent.
The invention is a method for simulating one or more characteristics of a multi-component, hydrocarbon-bearing formation into which a displacement fluid having at least one component is injected to displace formation hydrocarbons. The first step of the method is to equate at least part of the formation to a multiplicity of gridcells. Each gridcell is then divided into two regions, a first region representing a portion of each gridcell swept by the displacement fluid and a second region representing a portion of each gridcell essentially unswept by the displacement fluid. The distribution of components in each region is assumed to be essentially uniform. A model is constructed that is representative of fluid properties within each region, fluid flow between gridcells using principles of percolation theory, and component transport between the regions. The model is then used in a simulator to simulate one or more characteristics of the formation.
The invention is a method for simulating one or more characteristics of a multi-component, hydrocarbon-bearing formation into which a displacement fluid having at least one component is injected to displace formation hydrocarbons. The first step of the method is to equate at least part of the formation to a multiplicity of gridcells. Each gridcell is then divided into two regions, a first region representing a portion of each gridcell swept by the displacement fluid and a second region representing a portion of each gridcell essentially unswept by the displacement fluid. The distribution of components in each region is assumed to be essentially uniform. A model is constructed that is representative of fluid properties within each region, fluid flow between gridcells using principles of percolation theory, and component transport between the regions. The model is then used in a simulator to simulate one or more characteristics of the formation.
Hydrocarbon solids are removed from an oil well by feeding into the oil well a composition comprising at least 40 vol. % dense phase carbon dioxide and at least 30 vol. % of a C.sub.1 C.sub.3 alkanol component and optionally one or more surfactants, under a pressure of 300 to 10,000 psia and a temperature of 90.degree. F. to 120.degree. F., holding the composition in the well to solubilize hydrocarbon solids, and then removing from the well a liquid composition comprising solubilized hydrocarbon solids and alkanol.
A flexible hose construction adapted for conveying fluids under relatively high internal pressures and capable of withstanding relatively high external pressures without collapsing. The construction includes a tubular first elastomeric layer having a first inner radial surface and a first outer radial surface, and a tubular second elastomeric layer having a second inner radial surface and a second outer radial surface. A helical reinforcement element is spiral wound over the first elastomeric layer as interposed between that layer and the second elastomeric layer. The element is wound at a predetermined pitch angle to define a series of turns each being spaced-apart from an adjacent turn to define an interstitial area therebetween. The first and second elastomeric members each extends into the interstitial area with the first outer radial surface of the first elastomeric member being bonded to the second inner radial surface of the second elastomeric member such that the spiral reinforcement member is encapsulated therebetween.
