Abstract: A method for evaluating a multiphase oilfield fluid includes blending a first sample of the fluid with a viscosity modifying agent to transform the sample into a paste; making a first XRF measurement of the paste to estimate an elemental composition of the fluid; making a calcimetry measurement of a second sample of the fluid to estimate a total carbonate concentration of the fluid and to obtain an acidified second sample; separating the acidified second sample to obtain an acidified brine; making a second XRF measurement of the acidified brine to estimate an elemental composition of the acidified brine; and determining an elemental composition of a solid phase of the multiphase oilfield fluid from the elemental composition of the acidified brine and the elemental composition of the multiphase oilfield fluid.

Abstract: A method for estimating an elemental composition of a multiphase oilfield fluid includes obtaining a sample of a multiphase oilfield fluid; blending the sample with a viscosity modifying agent to transform the sample into a high viscosity paste; introducing the high viscosity paste into a chamber of an XRF apparatus; using the XRF apparatus to make an XRF measurement of the high viscosity paste; and evaluating the XRF measurement to estimate an elemental composition of the obtained multiphase oilfield fluid.

Abstract: A method for evaluating a multiphase drilling fluid includes receiving a sample of the multiphase drilling fluid and modifying the sample to enhance a separation of a first NMR peak corresponding to a first fluid phase component and a second NMR peak corresponding to a second fluid phase component. A nuclear magnetic resonance (NMR) measurement is made of the modified sample and evaluated to compute a property of the drilling fluid.

Abstract: A method for estimating a differential lag time while drilling includes introducing a multiphase tracer into drilling fluid circulating in a wellbore while drilling. The multiphase tracer includes a solid tracer and a fluid tracer in which the fluid tracer includes at least one of a liquid tracer or a gaseous tracer. A first arrival time of the solid tracer and a second arrival time of the fluid tracer are measured at a surface location and evaluated to estimate the differential lag time. The differential lag time includes at least one of a difference between a cuttings lag time and a gaseous lag time or a difference between the cuttings lag time and a liquid lag time.

Abstract: A method of imaging an earth formation comprises identifying engagement data from an engagement sensor. The engagement data corresponds to an engagement of the instrumented engagement element with a borehole in the earth formation. The method includes identifying rotation data from a rotation sensor. The rotation data corresponds to a rotational orientation of the engagement data with respect to the borehole. The method includes mapping the engagement data to the rotation data to generate oriented engagement data.

Abstract: A method for evaluating solid drilling fluid additives such as lost cuttings materials (LCM) includes acquiring a calibrated digital image of solid particles separated from drilling fluid circulating in a wellbore. The calibrated digital image is processed to identify individual ones of the solid particles depicted in the image. Color features and/or texture features are extracted from the identified solid particles depicted in the image. The extracted color and/or texture features are processed to identify LCM particles among the identified solid particles and to classify each of the identified LCM particles into one of a plurality of LCM classes and thereby obtain an LCM particle classification.

Abstract: Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier has at least 5 repeating units. Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier includes at least 3 repeating units selected from allylamine, polyaminopolyamide, N-alkyl acrylamides, (meth)acrylic acid, alkyleneamine reacted with a dicarboxylic acid, alpha-olefin-alt-maleic anhydride, styrene maleic anhydride, alkylene oxide, wherein one or more amine or acid group on the repeating unit is amidized.

Abstract: Wellbore fluid compositions may include an oleaginous base fluid; and a polymeric rheology modifier incorporating a polar comonomer at a percent by weight (wt %) in the range of 1 wt % to 20 wt %; wherein the low shear rate viscosity (LSRV) of the wellbore fluid measured by FANN 35 rheometer at 3 rpm and 150° F. is in the range of 8 to 12. Methods may include emplacing a wellbore fluid in a wellbore, wherein the wellbore fluid comprises an oleaginous base fluid and a polymeric rheology modifier incorporating a polar comonomer at a percent by weight (wt %) in the range of 1 wt % to 50 wt %; wherein the low shear rate viscosity (LSRV) of the wellbore fluid is in the range of 8 to 12.

Abstract: Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier has at least 5 repeating units. Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier includes at least 3 repeating units selected from allylamine, polyaminopolyamide, N-alkyl acrylamides, (meth)acrylic acid, alkyleneamine reacted with a dicarboxylic acid, alpha-olefin-alt-maleic anhydride, styrene maleic anhydride, alkylene oxide, wherein one or more amine or acid group on the repeating unit is amidized.

Abstract: Apparatus and methods for degassing and analyzing drilling fluid discharged from a wellbore at an oil and gas wellsite. The apparatus may be a drilling fluid analysis system having a gas analyzer, a fluid analyzer, and a degasser operable to release and separate mud gas entrained in the drilling fluid. The degasser may include a gas-liquid separator having a separator inlet configured to receive the drilling fluid containing the entrained mud gas, a first separator outlet for discharging the mud gas fluidly connected with the gas analyzer, and a second separator outlet for discharging degassed drilling fluid fluidly connected with the fluid analyzer.

Abstract: An NMR sensor is configured to make NMR measurements of a fluid and includes a housing defining a chamber. A nonmagnetic cap is deployed in the chamber and divides the chamber into first and second regions. The cap is sized and shaped to define a fluid collector in the first region. A magnet assembly is deployed in the second region and is configured to generate a static magnetic field in the fluid collector. A radio frequency (RF) coil is interposed between the magnet assembly and the cap and is configured to generate an RF magnetic field in the fluid collector. Methods include using the sensor to make NMR measurements of multi-phase fluids such as drilling fluid.

Abstract: An additive composition includes a rheology modifier selected from alcohol ethoxylates, amine ethoxylates, or ethylene oxide/propylene oxide copolymers, wherein the rheology modifier has an HLB ranging from about 4 to 10; and a winterizing agent that is at least one aliphatic non-ionic surfactant that has a branched structure and/or includes at least one unsaturation, wherein the winterizing agent has an HLB value between about 8 and 10.5.

Abstract: Systems and methods measure one or more rheological properties and/or parameters of a fluid and establish at least one correlation between the measured one or more rheological properties and/or parameters. The systems and methods may correlate the measured one or more rheological properties and/or parameters to static aging results to establish the at least one correlation between the one or more rheological properties and/or parameters of the fluid. The systems and methods may predict at least one sagging tendency of the fluid based on the established at least one correlation and may measure and/or monitor static sagging of the fluid based on the predicted at least one sagging tendency of the fluid. The systems and methods may guide fluid treatment of the fluid or produce a mud system based on the predicted at least one sagging tendency of the fluid.

Abstract: An additive composition includes a rheology modifier selected from alcohol ethoxylates, amine ethoxylates, or ethylene oxide/propylene oxide copolymers, wherein the rheology modifier has an HLB ranging from about 4 to 10; and a winterizing agent that is at least one aliphatic non-ionic surfactant that has a branched structure and/or includes at least one unsaturation, wherein the winterizing agent has an HLB value between about 8 and 10.5.

Abstract: A method for evaluating drilling fluid includes making an NMR measurement of a sample of the drilling fluid and inverting the measurements to compute a corresponding T1T2 plot. The T1T2 plot is in turn evaluated to characterize the drilling fluid. In one embodiment, a stability index of the fluid may be computed from multiple NMR measurements made while aging the sample.

Abstract: An additive composition includes a rheology modifier selected from alcohol ethoxylates, amine ethoxylates, or ethylene oxide/propylene oxide copolymers, wherein the rheology modifier has an HLB ranging from about 4 to 10; and a winterizing agent that is at least one aliphatic non-ionic surfactant that has a branched structure and/or includes at least one unsaturation, wherein the winterizing agent has an HLB value between about 8 and 10.5.

Abstract: Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier has at least 5 repeating units. Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and a polymeric amidoamine emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the polymeric amidoamine emulsifier includes at least 3 repeating units selected from allylamine, polyaminopolyamide, N-alkyl acrylamides, (meth)acrylic acid, alkyleneamine reacted with a dicarboxylic acid, alpha-olefin-alt-maleic anhydride, styrene maleic anhydride, alkylene oxide, wherein one or more amine or acid group on the repeating unit is amidized.

Abstract: Wellbore fluids may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; and an emulsifier stabilizing the non-oleaginous discontinuous phase in the oleaginous continuous phase, wherein the emulsifier is the product of a reaction between an alkyl cyclic anhydride and a polar reactant, wherein the polar reactant is one or more selected from a group containing alkyl amine, alkanolamine, and polyamine. Methods may include drilling a wellbore with an oil-based mud, wherein the oil-based mud is an invert emulsion containing an emulsifier stabilizing the invert emulsion, wherein the emulsifier is the product of a reaction between an alkyl cyclic anhydride and a polar reactant, wherein the polar reactant is one or more selected from the group of alkyl amine, alkanolamine, and polyamine.

Abstract: An NMR sensor is configured to make NMR measurements of a fluid and includes a housing defining a chamber. A nonmagnetic cap is deployed in the chamber and divides the chamber into first and second regions. The cap is sized and shaped to define a fluid collector in the first region. A magnet assembly is deployed in the second region and is configured to generate a static magnetic field in the fluid collector. A radio frequency (RF) coil is interposed between the magnet assembly and the cap and is configured to generate an RF magnetic field in the fluid collector. Methods include using the sensor to make NMR measurements of multi-phase fluids such as drilling fluid.

Abstract: A method for evaluating drilling fluid includes making an NMR measurement of a sample of the drilling fluid and inverting the measurements to compute a corresponding T1T2 plot. The T1T2 plot is in turn evaluated to characterize the drilling fluid. In one embodiment, a stability index of the fluid may be computed from multiple NMR measurements made while aging the sample.