Abstract: An apparatus and method for determining the minimum miscibility pressure of a system comprising a gas and a liquid. A liquid-filled tube is equilibrated at a predetermined temperature and initial pressure, and pressure changes are determined as a single gas bubble is launched, rises through the tube, and stabilizes in the liquid. The measurements are repeated with fresh liquid at a series of different predetermined pressures. The minimum miscibility pressure is obtained either by finding the final pressure at which the time between launch and stabilization is constant or by evaluating the derivative of an empirically derived relationship between initial pressure and final pressure.

Abstract: A process for recovering hydrocarbons from a subterranean formation having low permeability matrix blocks separated by a well-connected fracture network. Hot light gas is injected into the formation to heat the matrix blocks and create or enlarge a gas cap in the fracture network. The flowing pressure in one or more production wells is maintained at a value slightly less than the free gas pressure at the gas liquid interface, causing gas coning near the production well or wells. Both liquid and gas are recovered from below the gas/liquid interface in the fractures.

Abstract: A process employing a foamed gel in a wellbore as a drilling fluid, lost circulation fluid, or combined drilling/lost circulation fluid during the wellbore drilling operation. The foamed gel is formed from a crosslinkable carboxylate-containing polymer, a crosslinking agent containing a reactive transition metal cation, a surfactant, an aqueous solvent, and an added gas.

Abstract: A downhole burner that economically generates hot inert gas and injects this gas into a subterranean formation. The burner has a nipple attached to a first tubing string that carries an oxidizer to the burner. The first tubing string also contains a coil tubing string that carries fuel to a movable nozzle inside the nipple. A small orifice in the nozzle increases the velocity of the fuel, and the nozzle extends out through a small orifice in a burner shroud that increases the velocity of the oxidizer flowing around the nozzle. The high velocity of the fuel and oxidizer keeps the flame front below the shroud and nozzle. A second tubing string supplies coolant gas around the burner shroud. Injection of an oxygen containing coolant gas provides a method for enhancing in situ combustion reactions through superheating the oxygen containing mix of coolant and exhaust gas.

Abstract: A process is provided for selectively placing a permeability-reducing material in an interval of a subterranean hydrocarbon-bearing formation penetrated by a well bore to inhibit the vertical flow of fluid between the well bore and an aquifer underlying the interval. The process is performed by simultaneously injecting a pair of fluids into the well bore, wherein one fluid has a density substantially less than the density of the other, and displacing the fluids out into the interval. The two fluids directly contact one another as they are displaced, however, the density difference between the fluids causes the first fluid to preferentially enter an upper portion of the interval and the second fluid to preferentially enter a lower portion of the interval under the force of gravity stratification or gravity segregation.

Abstract: An integrated oilfield tubing string is provided with two continuous fluid-isolated interior passageways extending longitudinally therethrough, wherein the first interior passageway serves as a production or injection tube and the smaller second interior passageway serves as a service line. The second passageway has a crescentic cross section and is formed by affixing the longitudinal edges of an elongated arcuate band to the inside or outside of the tube while maintaining a space between the band and the tube wall. The internally and externally exposed surfaces of the tube and band define relatively smooth convex outside and concave inside surfaces of the integrated tubing string. The present invention further provides a method of constructing the integrated tubing string.

Abstract: A process for recovering oil from a multiple-layered heterogeneous reservoir with a higher oil saturation in the lower permeability layers than in the higher permeability layers. An aqueous surfactant solution is injected into the formation, where it imbibes into the lower permeability layers and displaces a first quantity of oil into the higher permeability layers. Next, a first aqueous fluid is injected to sweep the displaced oil from the higher permeability layers into at least one production well. A gas is injected into the formation to displace a second quantity of oil from the lower permeability layers. The second aqueous fluid is injected to sweep the displaced oil into at least one production well. The process may be repeated one or more times.

Abstract: A soil treatment process is provided utilizing a foamed gel to block the flow of a migratory fluid in a soil. Placement of the foamed gel in a desired treatment region of the soil produces a seal that substantially eliminates the permeability of the treatment region to the migratory fluid and prevents migration of fluid across the region. In each of its numerous embodiments, the process can be employed as either a remedial or a preventative treatment.

Abstract: A process for drilling and completing multiple subterranean wells from a common well bore and an assembly for guiding a drill string during drilling and casing during completion of such multiple wells. The assembly comprises a wellhead located at or near the surface of the earth and positioned over the common well bore, at least two tubulars positioned within the common well bore, and means positioned at said wellhead for segregating and supporting the tubulars. In accordance with the process, at least one subterranean well bore is drilled through one of the tubulars and into a subterranean formation and hydrocarbons can be produced from the subterranean formation to the surface via production casing and/or production tubing positioned within the subterranean well bore. Other subterranean well bores can be drilled in a similar manner through other tubulars of the assembly.

Abstract: A wellbore operation in which a downhole tool is given rotary motion without rotating the tubing string to which it is attached. A "Yankee screwdriver" type of connecting element is used to connect a downhole tool to a tubing string so that compressive forces acting on the connector as a result of relative linear movement between the connector and the tool cause the tool to rotate. A number of various types of downhole operations are possible, such as rotating a tool away from an obstruction and retrieving the upper section of a lost tubing string.

Abstract: An apparatus and process for separating and producing gas and liquid from a subterranean production zone via a well in fluid communication with the zone. After separation in the well, the gas is produced to the surface, compressed, and injected into an injection zone which is also in fluid communication with the well. The liquid is pumped to a production facility at the surface.

Abstract: A process and composition are provided for permeability reduction in a hydrocarbon-bearing formation to improve hydrocarbon recovery therefrom. The process includes placement of a crosslinked polymer gel in the treatment region preceded by surface preparation of a gelation solution from which the gel is formed. The gelation solution contains a crosslinkable polymer, a transition metal/poly-carboxylate precursor complex and an aqueous solvent. The gel is placed in the treatment region by injecting the gelation solution into a well bore in fluid communication with the formation, activating the gelation solution in situ, displacing the gelation solution into the desired treatment region and gelling the solution to completion forming the permeability-reducing gel in situ. The gelation rate is retarded in a controlled manner by adjusting the molar ratio of the polycarboxylate to transition metal in the precursor complex of the gelation solution.

Abstract: A process and composition are provided for permeability reduction in a hydrocarbon-bearing formation to improve hydrocarbon recovery therefrom. The process includes placement of a crosslinked polymer gel in the treatment region preceded by surface preparation of a gelation solution which is the gel precursor. The gelation solution contains a crosslinkable polymer, a chromium(III)/carboxylate complex crosslinking agent, a carboxylate salt delaying agent and an aqueous solvent. The gel is placed in the treatment region by injecting the gelation solution into a well bore in fluid communication with the formation, displacing it into the desired treatment region and gelling the solution to completion forming the permeability-reducing gel in situ. The gelation rate is retarded in a controlled manner by adjusting the composition or concentration of the delaying agent in the gelation solution.

Abstract: A process and composition are provided for permeability reduction in a hydrocarbon-bearing formation to improve hydrocarbon recovery therefrom. The process includes placement of a crosslinked polymer gel in the treatment region preceded by surface preparation of a gelation solution which is the gel precursor. The gelation solution containing a crosslinkable polymer and chromium(III)/carboxylate complex crosslinking agent is prepared by preforming the crosslinking agent in isolation from the polymer and thereafter combining the crosslinking agent and polymer in solution. The starting materials for the complex crosslinking agent are an organic chromium(III) salt and a selected polycarboxylate or alpha-hydroxy carboxylate anion. The gel is placed in the treatment region by injecting the gelation solution into the formation, displacing it into the desired treatment region and gelling the solution to completion forming the permeability-reducing gel in situ.

Abstract: A system for measuring the physical characteristics of a hydrocarbon places a reference hydrocarbon cell in thermal contact with a sample cell containing an unknown hydrocarbon. A near infrared spectrum measurement is taken of both the cells. Measurement data from the sample cell is adjusted by the measurement data from the reference cell, and the adjusted measurement data is evaluated by a model to predict the characteristics of the sample. The model is built from a teaching set of hydrocarbons having known physical characteristics and the reference hydrocarbon. Each of the teaching set hydrocarbons is measured and then adjusted by a measurement of the same reference hydrocarbon, and the adjusted measurements are used to build the model.

Abstract: A method determining the concentrations of fluids in a two-part fluid system. The heat loss in a test apparatus for measuring the temperatures and flow rate of a flowing fluid mixture is determined and the specific heat of the fluid mixture is calculated. Knowing the relationship between the specific heat of the fluid and its composition allows the fluid composition to be directly calculated, and hence the ratio of the two constituent fluids to be determined. A preferred heater is comprised of an electrically conductive conduit through which the fluid mixture flows which when energized efficiently heats the fluid mixture.

Abstract: A soil treatment process is provided utilizing a polymer enhanced foam to block the flow of a migratory fluid in a soil. Placement of the polymer enhanced foam in a desired treatment region of the soil produces a seal that substantially eliminates the permeability of the treatment region to the migratory fluid and prevents migration of fluid across the region. In each of its numerous embodiments, the process can be employed as either a remedial or a preventative treatment.

Abstract: A method of maintaining a constant predetermined hydrostatic pressure in a wellbore being drilled by a rotary drilling process utilizing aerated drilling fluid. The aerating gas, such as compressed air, is maintained at a constant pressure while its flow is changed in response to changes in the flow of the drilling fluid. This maintains a constant ratio of compressed air to drilling fluid, resulting in the hydrostatic pressure remaining constant.

Abstract: A method for rapidly and accurately determining the threshold and critical capillary pressures of a porous rock sample. A fluid saturating the sample, preferably oil, is withdrawn from the downstream end of the sample at an extremely low rate as a result of the introduction of another fluid, preferably gas, at the upstream end. The other fluid displaces the saturating fluid due to a differential pressure between the upstream and downstream ends of the sample. The differential pressure is created by means which does not require use of back pressure valves, thereby avoiding pressure surges and allowing constant slow withdrawal of the saturating fluid. The threshold and critical capillary pressures may be determined from a trace of the differential pressure.

Abstract: A process is provided for recovering liquid hydrocarbons from a subterranean hydrocarbon-bearing formation by sequential injection of a pair of immiscible gases of differing composition which displace the liquid hydrocarbons from the formation. The compositions of the displacement gases are selected such that one gas is characterized as a swelling gas and the other is characterized as a non-swelling gas with respect to the liquid hydrocarbons in place.