Abstract: Among other things, techniques are described for determining precedence order at a multiway stop. In embodiments, identifications are assigned to tracks, and young tracks are compared to stale tracks. A young track matches a stale track based on one or more factors. An identification of the young track is reassigned to an identification of the stale track, wherein the young track is determined to match the stale track based on the one or more factors. An earliest time of appearance of agents is determined based on identifications and in view of perception obscured areas. A precedence order for navigating through the intersection is determined based on local rules, the identifications, and the earliest time of appearance of agents, and the vehicle proceeds through the multiway stop intersection in accordance with the precedence order.

Abstract: The present application provides constructs comprising a single-domain antibody (sdAb) moiety that specifically recognizes TIGIT. Also provided are methods of making and using these constructs.

Abstract: A technique facilitates fluid analysis in situ at a downhole location. According to an embodiment, a sample of fluid, e.g. oil, is obtained from a reservoir at the downhole location in a borehole. A downhole sampling system is used to determine contamination of the sample of fluid and to determine other selected characteristics of the sample. The data obtained is then processed to determine a true phase transition property of a native fluid in the sample of fluid. The sample analysis may be performed at selected stations along the borehole during, for example, a well cleanup operation. The immediate analysis of fluid samples downhole facilitates rapid development of an understanding of fluid characteristics in the reservoir, thus enabling an improved oil recovery strategy.

Abstract: Bayesian recursive estimation is used to analyze performance parameters of a membrane separation system based on historical operational data of a membrane system. Bayesian estimation considers historical data over prior time intervals to predict future membrane separation performance to avoid unexpected downtime and unanticipated maintenance. A set of state variables used for modeling performance is used with a degradation model of to anticipate performance changes and maintenance based on measured properties of permeate, non-permeate, and feed flows.

Abstract: Systems and methods presented herein generally relate to greenhouse gas emission management and, more particularly, to greenhouse gas emission management systems and methods for performing greenhouse gas detection sensor placement planning, leakage source tracing, and quantification of leakage source detections for oil and gas production facilities.

Abstract: Methods of operating membrane processes, such as seawater purification processes, are described herein. The methods generally include flowing seawater into a membrane purification process; recovering purified seawater and concentrated seawater from the membrane purification process; sensing operating parameters of the membrane purification process; determining a state of the membrane purification process from the operating parameters using a physical model; using a statistical model to resolve a time dependence of the state of the membrane purification process; using a recursive statistical process to update the statistical model; using the updated statistical model to predict a future state of the membrane purification process; comparing the predicted future state of the membrane purification process to a threshold state; and predicting a remaining time before the membrane purification process reaches the threshold state.

Abstract: A method includes placing a downhole acquisition tool in a wellbore in a geological formation containing a reservoir fluid. The method includes performing downhole fluid analysis using the downhole acquisition tool to determine at least one measurement of the reservoir fluid. The method includes using a processor to estimate at least one fluid component property by using an equation of state based at least in part on the at least one measurement of the reservoir fluid and to simulate a diffusion process using a diffusion model that takes into account the at least one estimated fluid property to generate a composition path. The method includes using a processor to estimate one or more phase envelopes based in part on the at least one fluid property and compare the one or more phase envelopes with the composition path. The method includes outputting a visualization identify potential areas of asphaltene instability.

Abstract: Membranes used in membrane separation technologies change over time due to changes in physical characteristics of the membrane. Predicting remaining useful lifetime of a membrane is performed by fitting an evolution model of the membrane to real-time performance characteristics recorded for the membrane and by comparing later performance characteristics of the membrane to the evolution model. Updating an evolution model during membrane operation improves estimates of remaining useful membrane lifetime and allows for accurate estimates of estimated membrane end-of-life.

Abstract: Bayesian recursive estimation is used to analyze performance parameters of a membrane separation system based on historical operational data of a membrane system. Bayesian estimation considers historical data over prior time intervals to predict future membrane separation performance to avoid unexpected downtime and unanticipated maintenance. A set of state variables used for modeling performance is used with a degradation model of to anticipate performance changes and maintenance based on measured properties of permeate, non-permeate, and feed flows.

Abstract: A technique facilitates fluid analysis in situ at a downhole location. According to an embodiment, a sample of fluid, e.g. oil, is obtained from a reservoir at the downhole location in a borehole. A downhole sampling system is used to determine contamination of the sample of fluid and to determine other selected characteristics of the sample. The data obtained is then processed to determine a true phase transition property of a native fluid in the sample of fluid. The sample analysis may be performed at selected stations along the borehole during, for example, a well cleanup operation. The immediate analysis of fluid samples downhole facilitates rapid development of an understanding of fluid characteristics in the reservoir, thus enabling an improved oil recovery strategy.

Abstract: A method includes receiving first fluid property data from a first location in a hydrocarbon reservoir and receiving second fluid property data from a second location in the hydrocarbon reservoir. The method includes performing a plurality of realizations of models of the hydrocarbon reservoir according to a respective plurality of one or more plausible dynamic processes to generate one or more respective modeled fluid properties. The method includes selecting the one or more plausible dynamic processes based at least in part on a relationship between the first fluid property data, the second fluid property data, and the modeled fluid properties obtained from the realizations to identify potential disequilibrium in the hydrocarbon reservoir.

Abstract: A method includes identifying linearly behaving data within obtained data associated with fluid obtained from a subterranean formation. Shrinkage factor is determined based on the linearly behaving data. A function relating GOR data of the obtained fluid with the determined shrinkage factor is determined. A first linear relationship between optical density (OD) data of the obtained fluid and the function is determined. A second linear relationship between density data of the obtained fluid and the function is determined. An oil-based mud (OBM) filtrate contamination property of OBM filtrate within the obtained fluid based on the first linear relationship is determined. A native formation property of native formation fluid within the obtained fluid based on the second linear relationship is determined. A volume fraction of OBM filtrate contamination within the obtained fluid based on the OBM filtrate contamination property and the native formation property is estimated.

Abstract: A method includes identifying linearly behaving data within obtained data associated with fluid obtained from a subterranean formation. Shrinkage factor is determined based on the linearly behaving data. A function relating GOR data of the obtained fluid with the determined shrinkage factor is determined. A first linear relationship between optical density (OD) data of the obtained fluid and the function is determined. A second linear relationship between density data of the obtained fluid and the function is determined. An oil-based mud (OBM) filtrate contamination property of OBM filtrate within the obtained fluid based on the first linear relationship is determined. A native formation property of native formation fluid within the obtained fluid based on the second linear relationship is determined. A volume fraction of OBM filtrate contamination within the obtained fluid based on the OBM filtrate contamination property and the native formation property is estimated.

Abstract: A downhole tool, surface equipment, and/or remote equipment are utilized to obtain data associated with a subterranean hydrocarbon reservoir, fluid contained therein, and/or fluid obtained therefrom. At least one condition indicating that a density inversion exists in the fluid contained in the reservoir is identified from the data. Molecular sizes of fluid components contained within the reservoir are estimated from the data. A model of the density inversion is generated based on the data and molecular sizes. The density inversion model is utilized to estimate the density inversion amount and depth and time elapsed since the density inversion began to form within the reservoir. A model of a gravity-induced current of the density inversion is generated based on the data and the density inversion amount, depth, and elapsed time.

Abstract: A method includes placing a downhole acquisition tool in a wellbore in a geological formation within a hydrocarbon reservoir that contains a reservoir fluid. The method also includes performing downhole fluid analysis using the downhole acquisition tool in the wellbore to determine a measurement associated with the reservoir fluid and using a processor to: estimate a fluid component property by using an equation of state based the measurement and simulate a diffusion process using a diffusive model that takes into account the estimated fluid property. The diffusive model accounts for gravitational diffusion of components in the reservoir fluid. The method also includes using the processor to estimate reservoir fluid geodynamic processes based on the fluid property; compare the estimated reservoir fluid geodynamic processes with the measurement associated with the reservoir fluid; and output reservoir fluid geodynamic processes corresponding to the measurement associated with the reservoir fluid.

Abstract: A method includes identifying linearly behaving data within obtained data associated with fluid obtained from a subterranean formation. Shrinkage factor is determined based on the linearly behaving data. A function relating GOR data of the obtained fluid with the determined shrinkage factor is determined. A first linear relationship between optical density (OD) data of the obtained fluid and the function is determined. A second linear relationship between density data of the obtained fluid and the function is determined. An oil-based mud (OBM) filtrate contamination property of OBM filtrate within the obtained fluid based on the first linear relationship is determined. A native formation property of native formation fluid within the obtained fluid based on the second linear relationship is determined. A volume fraction of OBM filtrate contamination within the obtained fluid based on the OBM filtrate contamination property and the native formation property is estimated.

Abstract: A method includes placing a downhole acquisition tool in a wellbore in a geological formation within a hydrocarbon reservoir. The wellbore or the geological formation, or both, contain a reservoir fluid. The method also includes performing downhole fluid analysis using the downhole acquisition tool in the wellbore to determine at least one measurement associated with the reservoir fluid and using a processor to: estimate at least one fluid component property by using an equation of state based at least in part on at least one measurement associated with the reservoir fluid and simulate a diffusion process using a diffusive model that takes into account the at least one estimated fluid property. The diffusive model accounts for gravitational diffusion of at least one or more components in the reservoir fluid.

Abstract: A method includes placing a downhole acquisition tool in a wellbore in a geological formation containing a reservoir fluid. The method includes performing downhole fluid analysis using the downhole acquisition tool to determine at least one measurement of the reservoir fluid. The method includes using a processor to estimate at least one fluid component property by using an equation of state based at least in part on the at least one measurement of the reservoir fluid and to simulate a diffusion process using a diffusion model that takes into account the at least one estimated fluid property to generate a composition path. The method includes using a processor to estimate one or more phase envelopes based in part on the at least one fluid property and compare the one or more phase envelopes with the composition path. The method includes outputting a visualization identify potential areas of asphaltene instability.

Abstract: A downhole tool, surface equipment, and/or remote equipment are utilized to obtain data associated with a subterranean hydrocarbon reservoir, fluid contained therein, and/or fluid obtained therefrom. At least one condition indicating that a density inversion exists in the fluid contained in the reservoir is identified from the data. Molecular sizes of fluid components contained within the reservoir are estimated from the data. A model of the density inversion is generated based on the data and molecular sizes. The density inversion model is utilized to estimate the density inversion amount and depth and time elapsed since the density inversion began to form within the reservoir. A model of a gravity-induced current of the density inversion is generated based on the data and the density inversion amount, depth, and elapsed time.

Abstract: A method and system that characterizes hydrogen sulfide in petroleum fluid employs a tool that includes a fluid analyzer for performing fluid analysis (including optical density (OD) for measuring carbon dioxide concentration) of a live oil sample, and a storage chamber for an analytical reagent fluidly coupled to a measurement chamber. An emulsion from fluid of the sample and the reagent is produced into the measurement chamber. The reagent changes color due to pH changes arising from chemical reactions between components of the sample and the reagent in the measurement chamber. The tool includes an optical sensor system that measures OD of a water phase of the emulsion at one or more determined wavelengths. The pH of the water phase is derived from such OD measurements. The pH of the water phase and the carbon dioxide concentration in the sample is used to calculate hydrogen sulfide concentration in the sample.