An apparatus for detecting one or more properties of a downhole fluid includes a housing. The apparatus also includes a location-sensitive optical detector, arranged within a chamber formed by the housing. The apparatus further includes a light source, arranged within the chamber. The apparatus also includes a lens, positioned at an end of the housing, the lens preferably having a flat side and a curved side, the flat side positioned proximate the chamber to position the flat side closer to the light source than the curved side. The apparatus further includes a mirror, arranged outside the housing.

A method and a system for predicting a molecular weight of a hydrocarbon fluid are provided. An exemplary method includes measuring a density of the hydrocarbon fluid, obtaining an alternative measurement of a physical property of the hydrocarbon fluid, calculating an index value for the hydrocarbon fluid from the alternative measurement, and calculating a predicted molecular weight using an equation that combines the density with the index value. The predicted molecular weight is provided as an output.

Systems and methods are provided for analyzing isotopes of a gas from a wellbore to determine geological information associated with the wellbore. A drill device can be used to drill rocks or particles in a wellbore, which can cause a gas to be released within the wellbore. Fluid can be pumped into the wellbore as the drill bit drills the rocks or particles and the fluid, along with the gas released, can flow through the wellbore and to a surface of the wellbore. A gas detector can be positioned near the wellbore for detecting an amount of gas and a type of gas in the fluid and gas mixture and transmitting data about the amount and type of the gas to a computing device. The computing device can output data based on the amount and type of gas in the mixture for determining geological information about the wellbore.

An apparatus to test a drilling fluid in a laboratory includes a test cell configured to test the fluid to determine a Sag Factor of the fluid. The test cell may be heated with a heating jacket to a predefined temperature. A plurality of densitometers are configured to continuously measure a density of the fluid circulating in the test cell. A computing device processes the density measurements to determine a Sag Factor of the drilling fluid.

An automated batch sampling drilling mud management system includes a portable mud measurement system and a communications system. The portable mud measurement system has or more measurement devices arranged to measure at least one property and/or characteristic of drilling mud; and a pumping system arranged to pump a batch sample of drilling mud from a supply of drilling mud to the one or more measurement devices. The pumping system is also able to subsequently flush the batch sample of drilling mud from the one or more measurement devices. The communications system enables bidirectional communications between the mud management system and a remote location to enable transfer of data therebetween and the exertion of control from the remote location to the mud management system.

A method of determining an API gravity of a crude oil is provided. The method includes obtaining a reservoir sample containing the crude oil and heating the sample to a first temperature using an oxidative testing apparatus. The sample is then heated to a second temperature, which is greater than the first temperature, over a period using a fixed heating rate. The rate of carbon dioxide emission from the sample is detected during the period of heating to the second temperature. The peak rate of carbon dioxide emission from the sample is then determined and the peak carbon dioxide emission temperature associated with the peak rate of carbon dioxide emission is also determined. The API gravity of the crude oil in the reservoir sample is determined using an empirical correlation between API gravity and the peak carbon dioxide emission temperature associated with the fixed heating rate.

A system for measuring fluid flow in a wellbore is provided. A probe includes at least a heater. A fiber optic cable is connected to the probe. The system is programmed to perform operations including: changing an output of the heater to thereby change a temperature of drilling fluid moving over a fiber optic cable; measuring a strain on the fiber optic cable caused by changing the temperature of the drilling fluid; preliminarily determining a velocity of the drilling fluid from the measured strain; measuring at least a second parameter of the drilling fluid; adjusting the preliminary determined velocity based on the measured at least a second parameter to yield an adjusted velocity; and determining a flow rate of the drilling fluid based on the adjusted velocity.

A method may comprise forming a data matrix, extracting chromatographs of a mud filtrate and a formation fluid, extracting concentration profiles of the mud filtrate and the formation fluid, and decomposing a data set on an information handling machine using a bilinear model. A system may comprise a downhole fluid sampling tool and an information handling tool. The downhole fluid sampling tool may comprise one or more multi-chamber sections, one or more fluid module sections, one or more gas chromatographers, wherein the one or more gas chromatographers are disposed in the one or more fluid module sections, and an information handling system.

An x-ray-based borehole fluid evaluation tool for evaluating the characteristics of a fluid located external to said tool in a borehole using x-ray backscatter imaging is disclosed, the tool including at least an x-ray source; a radiation shield to define the output faun of the produced x-rays into the borehole fluid outside of the tool housing; at least one collimated imaging detector to record x-ray backscatter images; sonde-dependent electronics; and a plurality of tool logic electronics and power supply units. A method of using an x-ray-based borehole fluid evaluation tool to evaluate the characteristics of a fluid through x-ray backscatter imaging is also disclosed, the method including at least producing x-rays in a shaped output; measuring the intensity of backscatter x-rays returning from the fluid to each pixel of one or more array imaging detectors; and converting intensity data from said pixels into characteristics of the wellbore fluids.

Asphaltene onset pressure of a formation fluid is determined by subjecting the fluid to a plurality of tests where depressurization is conducted at a different depressurization rate for each test while optically monitoring the fluid for asphaltene flocculation. The pressures at which asphaltene flocculation are detected in each test are fit to a curve as a function of depressurization rate, and the curve is extrapolated to a pressure (e.g., 0 psi) to provide the asphaltene onset pressure.