Abstract: A microfluidic device for evaluation of an organic/inorganic scale inhibitor is provided. The device comprises a substrate mountable to a disc for rotation about an axis. The device further comprises a proximal end and a distal end. The substrate defines a sample reservoir, a solvent reservoir, an inhibitor reservoir, and a precipitant reservoir at the proximal end and an analysis chamber at the distal end in fluid communication with the sample, solvent, inhibitor, and precipitant reservoirs. The substrate is constructed to direct one or more of fluids in the sample reservoir, solvent reservoir, inhibitor reservoir, and precipitant reservoir radially outwardly towards the analysis chamber under the influence of centrifugal force when the microfluidic device rotates.

Abstract: A technique facilitates detection and analysis of constituents, e.g. chemicals, which may be found in formation fluids and/or other types of fluids. The technique comprises intermittently introducing a first fluid and a second fluid into a channel in a manner which forms slugs of the first fluid separated by the second fluid. The intermittent fluids are flowed through the channel to create a mixing action which mixes the fluid in the slugs. The mixing increases the exchange, e.g. transfer, of the chemical constituent between the second fluid and the first fluid. The exchange aids in sensing an amount of the chemical or chemicals for analysis. In many applications, the intermittent introduction, mixing, and measuring can be performed in a subterranean environment.

Abstract: A system for performing a flash separation of a reservoir fluid includes a sample chamber configured to hold the reservoir fluid and a flash apparatus in fluid communication with the sample chamber. The flash apparatus includes a microfluidic device configured to flash the reservoir fluid in fluid communication with the sample chamber, and a separation chamber configured to separate the flashed reservoir fluid into a liquid phase and a gaseous phase in fluid communication with the microfluidic device. The system further includes a gas receptacle configured to store the gaseous phase, A method for performing a flash separation of a reservoir fluid includes providing a reservoir fluid to a microfluidic device, urging the reservoir fluid through the microfluidic device such that the reservoir fluid is lashed within the microfluidic device, and separating a liquid phase and a gaseous phase from the flashed reservoir fluid.

Abstract: A method of evaluating an asphaltene inhibitor includes providing a centrifugal microfluidic system including: a disc mounted to rotate about an axis; a microfluidic device mounted on the disc, the device having sample, solvent, inhibitor, and precipitant reservoirs and an analysis chamber in fluid communication with the sample, solvent, inhibitor, and precipitant reservoirs; and an optical detection system coupled to the analysis chamber and configured to measure the optical transmission of fluid in the analysis chamber. The method includes filling the sample, solvent, inhibitor, and precipitant reservoirs, respectively, with a sample, solvent, inhibitor, and precipitant; rotating the disc to generate centrifugal force to cause the sample, solvent, inhibitor, and precipitant to travel radially outward to the analysis chamber; and measuring the optical transmission of a mixture of the sample, solvent, inhibitor, and precipitant in the analysis chamber as a function of radial distance of the analysis chamber.

Abstract: A test method and apparatus employs a microfluidic device to characterize properties of a fluid. The microfluidic device has an inlet port, an outlet port, and a microchannel as part of a fluid path between the inlet port and the outlet port. While a fluid is introduced into the microchannel, the fluid temperature is maintained while the fluid pressure in the microchannel is varied to characterize the properties of the fluid in the microchannel. The properties of the fluid can relate to a scale onset condition of the fluid at the pressure of the flow through the microchannel. In one aspect, fluid pressure in the microchannel is maintained while the fluid temperature is varied to characterize the properties of the fluid. In another aspect, flow rate of the fluid through the microchannel is varied while the fluid temperature is maintained to characterize the properties of the fluid in the microchannel.

Abstract: A method and apparatus for analyzing solubility of asphaltenes of a hydrocarbon fluid sample involves a sequence of operations including: i) performing microfluidic mixing operations that form a mixture that includes the hydrocarbon fluid sample, a solvent that dissolves asphaltenes and a precipitant that precipitates asphaltenes; ii) using microfluidic processes that result in precipitation of asphaltenes from the mixture resulting from i); iii) performing microfluidic filtering operations that remove precipitated asphaltenes resulting from ii) and passes permeate; and iv) performing optical spectroscopy on the permeate resulting from iii). The operations of i)-iv) can be repeated over iterations that vary the amount of solvent relative to the precipitant in the mixture. These iterations can cause varying fractional precipitation of asphaltenes in each given iteration.

Abstract: A test method and test apparatus is provided that employs a microfluidic device to characterize properties of a fluid. The microfluidic device has a first inlet port, an outlet port, and a microchannel as part of a fluid path between the first inlet port and the outlet port. While generating a flow of the fluid through the microchannel of the microfluidic device, fluid pressure at the first inlet port of the microfluidic device is measured and recorded in conjunction with varying the controlled temperature of the microchannel of the microfluidic device to characterize the properties of the fluid that flows through the microchannel of the microfluidic device. The properties of the fluid can relate to the clathrate hydrate formation condition of the fluid at the pressure of the flow through the microchannel of the microfluidic device.

Abstract: A technique facilitates detection and analysis of constituents, e.g. chemicals, which may be found in formation fluids and/or other types of fluids. The technique comprises intermittently introducing a first fluid and a second fluid into a channel in a manner which forms slugs of the first fluid separated by the second fluid. The intermittent fluids are flowed through the channel to create a mixing action which mixes the fluid in the slugs. The mixing increases the exchange, e.g. transfer, of the chemical constituent between the second fluid and the first fluid. The exchange aids in sensing an amount of the chemical or chemicals for analysis. In many applications, the intermittent introduction, mixing, and measuring can be performed in a subterranean environment.

Abstract: A method of determining saturate, aromatic, resin, and asphaltene (SARA) fractions of a hydrocarbon fluid sample, including: i) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a solvent fluid that dissolves asphaltenes; ii) performing optical spectroscopy on the hydrocarbon fluid sample-solvent fluid mixture resulting from i); iii) microfluidic mixing that forms a mixture including the hydrocarbon fluid sample and a titrant fluid that precipitates asphaltenes; iv) microfluidically precipitating asphaltenes from the hydrocarbon fluid sample titrant fluid mixture resulting from iii); v) performing a microfluidic filtering operation that removes precipitated asphaltenes from the mixture resulting from iv) while outputting permeate; vi) performing optical spectroscopy on the permeate resulting from v); vii) determining an asphaltene fraction percentage of the hydrocarbon fluid sample based on the optical spectroscopy performed in ii) and vi); viii) sequentially separating satur

Abstract: A method for determining the asphaltene content of oil includes obtaining an oil sample, determining an optical spectrum of the oil sample and removing asphaltenes from the oil sample by precipitating asphaltenes using a first alkane precipitant. The method also includes determining an optical spectrum of maltenes of the oil sample and subtracting the optical spectrum of the maltenes of the oil sample from the optical spectrum of the oil sample to yield an optical spectrum of asphaltenes of the oil sample. The method further includes using the optical spectrum of asphaltenes of the oil sample to determine asphaltene content of the oil sample using a second alkane precipitant.

Abstract: An optical sensor includes a flow cell permitting flow of a hydrocarbon-based analyte therethrough. A metallic film is disposed adjacent or within the flow cell. At least one optical element directs polychromatic light for supply to an interface of the metallic film under conditions of surface plasmon resonance (SPR) and directs polychromatic light reflected at the interface of the metallic film (which is sensitive to SPR at such interface and thus provides an SPR sensing region within the flow cell) for output to at least one spectrometer that measures spectral data of such polychromatic light. A computer processing system is configured to process the measured spectral data over time as the hydrocarbon-based analyte flows through the flow cell to determine SPR peak wavelength over time and to process the SPR peak wavelength over time to determine at least one property related to phase transition of the analyte.

Abstract: An apparatus for measuring phase behavior of a reservoir fluid comprises a first sample container and a second sample container in fluid communication with a microfluidic device defining a microchannel. A first pump and a second pump are operably associated with the sample containers and the microfluidic device to fill the microchannel with a reservoir fluid and to maintain a predetermined pressure of reservoir fluid within the microchannel.

Abstract: A method of evaluating an asphaltene inhibitor includes providing a centrifugal microfluidic system including: a disc mounted to rotate about an axis; a microfluidic device mounted on the disc, the device having sample, solvent, inhibitor, and precipitant reservoirs and an analysis chamber in fluid communication with the sample, solvent, inhibitor, and precipitant reservoirs; and an optical detection system coupled to the analysis chamber and configured to measure the optical transmission of fluid in the analysis chamber. The method includes filling the sample, solvent, inhibitor, and precipitant reservoirs, respectively, with a sample, solvent, inhibitor, and precipitant; rotating the disc to generate centrifugal force to cause the sample, solvent, inhibitor, and precipitant to travel radially outward to the analysis chamber; and measuring the optical transmission of a mixture of the sample, solvent, inhibitor, and precipitant in the analysis chamber as a function of radial distance of the analysis chamber.

Abstract: A microfluidic apparatus has a microchannel that includes at least one vertically oriented segment with a top section having a relatively wide opening and a bottom section having a relatively narrow opening. The top section is larger in volume relative to the bottom sections, and the middle sections taper down in at least one dimension from the top section to the bottom section. One or tens or hundreds of vertically-oriented segments may be provided, and they are fluidly coupled to each other. Each segment acts as a pressure-volume-temperature (PVT) cell, and the microchannel apparatus may be used to determine a parameter of a fluid containing hydrocarbons such as the dew point of the fluid or the liquid drop-out as a function of pressure.

Abstract: A method for determining an asphaltene onset condition of a crude oil is provided. The method includes receiving a crude oil within a downhole tool inside a well and taking a first measurement of an optical property of the received crude oil. The method also includes lowering the pressure or temperature of the crude oil after taking the first measurement of the optical property to cause aggregation of asphaltenes in the crude oil, and then separating aggregated asphaltenes from the crude oil. Further, the method includes taking a second measurement of the optical property of the crude oil within the downhole tool after separating aggregated asphaltenes from the crude oil and determining an asphaltene onset condition of the crude oil through comparison of the first and second measurements of the optical property. Additional methods, systems, and devices are also disclosed.

Abstract: An optical sensor and corresponding method of operation can detect a phase transition and/or related property of a hydrocarbon-based analyte. The optical sensor includes an optical element with a metallic film coupled or integral thereto, with a sample chamber holds the hydrocarbon-based analyte such that the hydrocarbon-based analyte is disposed adjacent the metallic layer. The optical sensor further includes a light source configured to direct light through the optical element such that the light is reflected by the metallic layer under conditions of surface plasmon resonance. The optical sensor analyzes the reflected light to detect a phase transition and/or related property of a hydrocarbon-based analyte.

Abstract: A method for determining an asphaltene onset condition of a crude oil is provided. The method includes receiving a crude oil within a downhole tool inside a well and taking a first measurement of an optical property of the received crude oil. The method also includes lowering the pressure or temperature of the crude oil after taking the first measurement of the optical property to cause aggregation of asphaltenes in the crude oil, and then separating aggregated asphaltenes from the crude oil. Further, the method includes taking a second measurement of the optical property of the crude oil within the downhole tool after separating aggregated asphaltenes from the crude oil and determining an asphaltene onset condition of the crude oil through comparison of the first and second measurements of the optical property. Additional methods, systems, and devices are also disclosed.

Abstract: A method includes providing a water sample for analysis at a well site, or at a location proximate the well site, where the water sample is collected from at least one water source and the water sample comprises at least one analyte. The water sample and a reagent are introduced into a microfluidic mixing cell to produce a mixture of the reagent and water sample, and the mixture has a detectable characteristic indicative of concentration of the at least one analyate in the water sample. The detectable characteristic is measured by spectrophotometry to determine concentration of the at least one analyte. Then a subterranean formation treatment fluid is prepared using water from the at least one water source based on the concentration of the at least one analyte. The introducing into the microfluidic mixing cell and the measuring by spectrophotometry are conducted over an elapsed time period of about 5 minutes or less.

Abstract: A method for measuring saturate, aromatic, and resin fractions of a hydrocarbon fluid includes separating maltenes from the hydrocarbon fluid and separating saturate, aromatic, and resin fractions from the maltenes. The method further includes determining an optical density of each of the saturate, aromatic, and resin fractions at a predetermined wavelength and correlating the optical density of each of the saturate, aromatic, and resin fractions to predetermined data to determine each of the saturate, aromatic, and resin fractions.

Abstract: A test method and test apparatus is provided that employs a microfluidic device to characterize properties of a fluid. The microfluidic device has a first inlet port, an outlet port, and a microchannel as part of a fluid path between the first inlet port and the outlet port. While generating a flow of the fluid through the microchannel of the microfluidic device, fluid pressure at the first inlet port of the microfluidic device is measured and recorded in conjunction with varying the controlled temperature of the microchannel of the microfluidic device to characterize the properties of the fluid that flows through the microchannel of the microfluidic device. The properties of the fluid can relate to the clathrate hydrate formation condition of the fluid at the pressure of the flow through the microchannel of the microfluidic device.