Abstract: An apparatus for determining the identity, location or level of one or more material phases or the location of an interface between two material phases, the apparatus comprising: an array of radio frequency (RF) transmitters and receivers for transmitting and receiving RF signals, the array being configured to be at least partially submerged within one or more material phases; and a Faraday cage in which the array of RF transmitters and receivers is disposed, the Faraday cage defining a measurement zone in which RF signals from the RF transmitters are contained and external RF signals are excluded, at least a portion of the one or more material phases being disposed within the measurement zone when the array is submerged within the one or more material phases; wherein the transmitters are arranged to transmit RF signals into the one or more material phases in the measurement zone when the array is submerged within the one or more material phases, and the receivers are arranged to receive RF signals passing th

Abstract: A tracer material for tracing fluid flows from a hydrocarbon reservoir. The tracer material is a particulate tracer material including a plurality of particles of a porous particulate solid material, the particles having pores containing a tracer composition characterised in that a retaining material overlies the tracer composition in at least some of the pores. The retaining material retards the release of the tracer material so that the tracer is released at a more constant rate over a longer period than in the absence of the retaining material.

Abstract: A method for determining residual oil saturation of an oil reservoir, the method comprising: introducing a partitioning tracer comprising a sulfone compound having a log Kow value in the range ?0.5 to 3 into the oil reservoir; and monitoring the production of the tracer from the oil reservoir over time to determine the residual oil saturation. Optionally the method comprises introducing both a conservative tracer and the partitioning tracer into the oil reservoir and monitoring the production of both the tracers from the oil reservoir over time to determine the residual oil saturation.

Abstract: A method of monitoring a fluid is described comprising: introducing a tracer into the fluid and analysing the fluid to determine if the tracer is present in the fluid; characterised in that the tracer comprises luminescent carbon-based nanoparticles exhibiting a peak luminescence intensity at an emission wavelength of at least 500 nm. The method is in particular a method of monitoring a parameter of a hydrocarbon well, pipeline or formation. A use of a tracer and a tracer composition comprising carbon-based nanoparticles exhibiting a peak luminescence intensity at an emission wavelength of at least 500 nm are also described.

Abstract: Provided are compositions containing a mixture of microcapsules and a bulk polymer, where the microcapsules have an oil field chemical contained within the microcapsules. The microcapsules can be present in a variety of configurations. The microcapsules contain a core or a micro-matrix containing the oil field chemicals. The core or micro-matrix can be surrounded by one or more polymeric shells, where each shell contains at least one polymer that affects the release of the oil field chemical from the composition. The compositions provide for the sustained release of an oil field chemical into fluid in an oil field reservoir over long periods of time. Also provided are methods of making the compositions and articles containing the compositions, along with methods are of tracing the movement of fluid in a hydrocarbon reservoir using the compositions, and methods of providing for the sustained release of oil field chemicals.

Abstract: Compositions containing a mixture of microcapsules (1, 10, 11, 13, 14, 15) and a bulk polymer, where the microcapsules have an oil field chemical contained within the microcapsules are described. The microcapsules can be present in a variety of configurations. The microcapsules contain a core (2, 12) or a micro-matrix (7) containing the oil field chemicals. The core or micro-matrix can be surrounded by one or more polymeric shells (3), where each shell contains at least one polymer that affects the release of the oil field chemical from the composition. The compositions provide for the sustained release of an oil field chemical into fluid in an oil field reservoir over long periods of time. Methods of making the compositions and articles containing the compositions are described. Methods of tracing the movement of fluid in a hydrocarbon reservoir using the compositions, and methods of providing for the sustained release of oil field chemicals are also described.

Abstract: Compositions containing a mixture of microcapsules and a bulk polymer, where the microcapsules have an oil field chemical contained within the microcapsules are provided. The microcapsules can be present in a variety of configurations. The microcapsules contain a core or a micro-matrix containing the oil field chemicals. The core or micro-matrix can be surrounded by one or more polymeric shells, where each shell contains at least one polymer that affects the release of the oil field chemical from the composition. The compositions provide for the sustained release of an oil field chemical into fluid in an oil field reservoir over long periods of time. Methods of making the compositions and articles containing the compositions are also provided. Further provided are methods of tracing the movement of fluid in a hydrocarbon reservoir using the compositions, and methods of providing for the sustained release of oil field chemicals.

Abstract: Use of a partitioning tracer for determining a property of a system is disclosed. The partitioning tracer comprises a sulfone compound having a log Kow value in the range ?0.5 to 3.

Abstract: Compositions containing a mixture of microcapsules and a bulk polymer, where the microcapsules have an oil field chemical contained within the microcapsules are described. The microcapsules can be present in a variety of configurations. The microcapsules contain a core or a micro-matrix containing the oil field chemicals. The core or micro-matrix can be surrounded by one or more polymeric shells, where each shell contains at least one polymer that affects the release of the oil field chemical from the composition. The compositions provide for the sustained release of an oil field chemical into fluid in an oil field reservoir over long periods of time. Methods of making the compositions and articles containing the compositions are described. Methods of tracing the movement of fluid in a hydrocarbon reservoir using the compositions, and methods of providing for the sustained release of oil field chemicals are also described.

Abstract: A method of monitoring a parameter of a hydrocarbon well, pipeline or formation is provided. The method comprises introducing a tracer into the hydrocarbon well, pipeline or formation; producing a fluid from the hydrocarbon well, pipeline or formation; and analysing the fluid to determine if the tracer is present in the fluid. The tracer comprises a halogenated thiophene carboxylic or sulfonic acid or a salt of a halogenated thiophene carboxylic or sulfonic acid.

Abstract: A tracer material for tracing fluid flows from a hydrocarbon reservoir. The tracer material is a particulate tracer material including a plurality of particles of a porous particulate solid material, the particles having pores containing a tracer composition characterised in that a retaining material overlies the tracer composition in at least some of the pores. The retaining material retards the release of the tracer material so that the tracer is released at a more constant rate over a longer period than in the absence of the retaining material.