Abstract: In order to determine the gas hydrate anti-agglomeration power of a system composed of an aqueous phase dispersed in a liquid hydrocarbon phase in the presence of a gas, at least two successive cycles of hydrate formation and dissociation is carried out by cooling and reheating a sample of said system placed in the cell of a calorimeter to record thermograms; the anti-agglomeration power of said system is determined by comparing the thermograms obtained during the various cycles.

Abstract: The present invention relates to a method for determining the kinetics of gas hydrate formation in a fluid comprising water, wherein the following stages are carried out: a sample of the fluid is provided in form of a water-in-oil stable emulsion, DSC measurements are performed on the sample to obtain at least one peak corresponding to the gas hydrate conversion energy in the water drops of said emulsion, kinetic characteristics of the formation of hydrates in said fluid are deduced from the peak.

Abstract: In order to determine the gas hydrate anti-agglomeration power of a system composed of an aqueous phase dispersed in a liquid hydrocarbon phase in the presence of a gas, at least two successive cycles of hydrate formation and dissociation is carried out by cooling and reheating a sample of said system placed in the cell of a calorimeter to record thermograms; the anti-agglomeration power of said system is determined by comparing the thermograms obtained during the various cycles.

Abstract: The present invention relates to a method and to a system for monitoring the evolution of the characteristics of a fluid circulating in a well (1) for example, wherein complex dynamic viscosity measurements are performed with a suitable detector (6) arranged on a line (5) through which said fluid circulates, so as to obtain a law of variation of the complex dynamic viscosity &eegr;* as a function of 2&pgr;f; a rheogram of the fluid, i.e. a law of variation of the viscosity &eegr; as a function of the shear ({dot over (&ggr;)}), is deduced therefrom; Va, Vp and YV are calculated from the rheogram; these stages are repeated after a predetermined time interval; the evolution of the characteristics of the fluid is deduced from these measurements.

Abstract: The present invention relates to a method and to a system for monitoring the evolution of the characteristics of a fluid circulating in a well (1) for example, wherein complex dynamic viscosity measurements are performed with a suitable detector (6) arranged on a line (5) through which said fluid circulates, so as to obtain a law of variation of the complex dynamic viscosity &eegr;* as a function of 2&pgr;f; a rheogram of the fluid, i.e. a law of variation of the viscosity &eegr; as a function of the shear ({dot over (&ggr;)}), is deduced therefrom; Va, Vp and YV are calculated from the rheogram; these stages are repeated after a predetermined time interval; the evolution of the characteristics of the fluid is deduced from these measurements.

Abstract: The invention concerns a water-based additive for well fluid, comprising an acrylamide and branched styrene sulphonate copolymer. It also concerns a water-based fluid comprising an acrylamide and branched styrene sulphonate copolymer. The additive is useful for controlling the filtering of a well fluid through the wall. The invention is advantageously applicable to drilling and/or completion of oil wells having a temperature higher than 120° C.