Abstract: Aqueous liquid which has been in contact with a subterranean geological formation, especially a hydrocarbon reservoir, is examined in order to detect or measure viscosifying polymer therein, by flowing a sample of the liquid through a constriction thereby causing extensional flow and alignment of any polymer molecules with the flow, and examining the solution for birefringence of aligned polymer molecules. The amount of birefringence is determined from intensity of light which has passed through the solution relative to intensity of the light source.

Abstract: Aqueous liquid which has been in contact with a subterranean geological formation, especially a hydrocarbon reservoir, is examined in order to detect or measure viscosifying polymer therein, by flowing a sample of the liquid through a constriction thereby causing extensional flow and alignment of any polymer molecules with the flow, and examining the solution for birefringence of aligned polymer molecules. The amount of birefringence is determined from intensity of light which has passed through the solution relative to intensity of the light source.

Abstract: A system and method for measuring physical properties of non-Newtonian fluids, such as fluids containing dispersed solid particulate material and having a yield stress. A fluid resistance member is moved through the non-Newtonian fluid sufficiently slowly that viscous drag on the member is negligible and fluid resistance is essentially due to the yield stress of the fluid. The torque required to maintain the movement of the member through the fluid is measured, and at least one physical property, other than apparent viscosity of the fluid, is determined by employing a known relationship between the measured torque and the physical property of interest.

Abstract: A system and method for measuring physical properties of non-Newtonian fluids, such as fluids containing dispersed solid particulate material and having a yield stress. A fluid resistance member is moved through the non-Newtonian fluid sufficiently slowly that viscous drag on the member is negligible and fluid resistance is essentially due to the yield stress of the fluid. The torque required to maintain the movement of the member through the fluid is measured, and at least one physical property, other than apparent viscosity of the fluid, is determined by employing a known relationship between the measured torque and the physical property of interest.

Abstract: Systems and methods for analysis of drilling cuttings are described. Complex permittivity is measured of rock cutting samples obtained during drilling operations. The origin of the cuttings is known by flow rate analysis in the drilling system. Various means can be used for rock cutting dielectric measurement. For example, the dielectric measurement can be made by matching the unknown permittivity of the medium to be analyzed to the permittivity of known liquid mixtures by successive saturation and looking for a “zero-contrast” measurement.

Abstract: Systems and methods for analysis of drilling cuttings are described. Complex permittivity is measured of rock cutting samples obtained during drilling operations. The origin of the cuttings is known by flow rate analysis in the drilling system. Various means can be used for rock cutting dielectric measurement. For example, the dielectric measurement can be made by matching the unknown permittivity of the medium to be analyzed to the permittivity of known liquid mixtures by successive saturation and looking for a “zero-contrast” measurement.

Abstract: A rheometer is provided for measuring rheological properties of a filtercake. The rheometer comprises a cell for containing a pressurised fluid supporting a particulate suspension. The cell has two outlets for removing the fluid from the cell. The cell further has a respective foraminous body at each outlet, such that the particulate suspension forms a filtercake on a surface of each foraminous body as pressurised fluid filters through the body when the fluid passes from the cell to the respective outlet. The foraminous bodies are translatable relative to each other, such that the filtercakes formed on said surfaces can be approached to form a unified filtercake. The foraminous bodies are also rotatable relative to each other. The rheometer further comprises a torque sensor for measuring a torque required to rotate the foraminous bodies relative to each other. The measured torque is indicative of one or more rheological properties of the unified filtercake.

Abstract: A method of removing particulate solids from an oil based drilling or completion fluid (1) is disclosed. The method involves exposing the fluid to an electric field to electrically migrate particulate solids suspended therein, and collecting the migrated particulate solids to remove them from the fluid.

Abstract: A method of removing particulate solids from an oil based drilling or completion fluid is disclosed. The method involves exposing the fluid to an electric field to electrically migrate particulate solids suspended therein, and collecting the migrated particulate solids to remove them from the fluid.

Abstract: A rheometer is provided for measuring rheological properties of a filtercake. The rheometer comprises a cell for containing a pressurised fluid supporting a particulate suspension. The cell has two outlets for removing the fluid from the cell. The cell further has a respective foraminous body at each outlet, such that the particulate suspension forms a filtercake on a surface of each foraminous body as pressurised fluid filters through the body when the fluid passes from the cell to the respective outlet. The foraminous bodies are translatable relative to each other, such that the filtercakes formed on said surfaces can be approached to form a unified filtercake. The foraminous bodies are also rotatable relative to each other. The rheometer further comprises a torque sensor for measuring a torque required to rotate the foraminous bodies relative to each other. The measured torque is indicative of one or more rheological properties of the unified filtercake.

Abstract: A seismic data acquisition assembly includes a cable; seismic sensors that are disposed along the cable; and a filler material inside the cable. The filler includes a hydrocarbon-based liquid and an agent to cause the filler material to have a rheological property that is substantially different than a corresponding rheological property of the hydrocarbon-based liquid.

Abstract: A method and apparatus is disclosed for determining the flow rates of fluid phases in a pipe containing multiple fluid phases. A Venturi is provided to measure total volumetric flow rate measurement and a holdup measurement is taken approximately 3-10 pipe diameters downstream of the Venturi. The holdup measurement is made at a downstream location where a substantial amount of mixing occurs and the differences between the velocities of the fluid phases can effectively be ignored. The flow rates of the phases can thus be determined directly from the holdup measurements.

Abstract: An additive for a water-based fluid which is to be used when the likelihood of differential sticking is high and which reduces the sticking tendency of the fluid and mud cake. An additive according to the invention comprises a well dispersed-particulate phase such as an emulsion, a fine emulsion, a microemulsion, a micellar phase or a polymeric phase having a particle size comparable with the pore throat size of a mud cake and comprising a material which forms easily deformable particles and which reduces the sticking propensity of the mud. One embodiment of the invention comprises a microemulsion of an oil which is well dispersed, substantially stable and has a substantial portion of the particle size distribution in the range 5-500 nm. An alternative embodiment comprises a micellar phase comprising one or more surfactants. The additive is typically used at a level of about 5% by volume in the drilling fluid.