Abstract: A method of detecting a tracer compound dissolved in a liquid composition via surface-enhanced spectroscopy includes the steps of: a. optionally, diluting the liquid composition or the separated liquid by mixing with a diluent liquid; b. bringing a sample of the separated liquid into contact with, a spectroscopy-enhancing surface including gold, silver or copper; c. obtaining a Raman spectrum from the sample; and d. calculating, from the spectrum, the concentration of the tracer in the sample relative to the concentration of a second component of the composition.

Abstract: This invention concerns a spectroscopic method, apparatus for determining whether a component is present in a sample. In one aspect, the method includes resolving a model of the spectral data separately for candidates from a set of predetermined component reference spectra, and determining whether a component is present in the sample based upon a figure of merit quantifying an effect of including the candidate reference spectrum corresponding to that component in the model.

Abstract: A method of detecting a tracer compound dissolved in a liquid composition via surface-enhanced spectroscopy includes the steps of: a. optionally, diluting the liquid composition or the separated liquid by mixing with a diluent liquid; b. bringing a sample of the separated liquid into contact with, a spectroscopy-enhancing surface including gold, silver or copper; c. obtaining a Raman spectrum from the sample; and d. calculating, from the spectrum, the concentration of the tracer in the sample relative to the concentration of a second component of the composition.

Abstract: A kit for use in a multiplex assay, the kit including a dye set consisting essentially of a plurality of dyes and an association of each dye to a reference concentration. The dye set has been selected such that, using surface enhanced resonant Raman spectroscopy, each dye of the set is identifiable at better than 90% sensitivity and 90% specificity in the presence of any other dye of the set throughout a range of concentrations of each of the two dyes from 0.6 to 1.5 of the respective dye's reference concentration. In one embodiment, the dye set consists of 10 of the following dyes: JOE, Rhodamine Green, ATTO520, BODIPY FL, BODIPY TMR-X, FAM, HEX, Cy3, Cy3.5, TAMRA and TYE563. The invention also concerns a multiplex assay including the set of dyes, apparatus for carrying out the multiplex assay and a method of selecting the set of dyes.

Abstract: A downhole transport assembly (100, 101) having first and second members (10, 20) having a common longitudinal axis, at least one of the members (10, 20) being rotatable about the longitudinal axis and movable along the longitudinal axis relative to the other member, the rotatable member having at least one engaging member (60), the or each engaging member (60) being configured and/or disposed on the rotatable member so that rotation of the rotatable member about the longitudinal axis causes the first and second members (10, 20) to move with respect to each other in opposite directions along the longitudinal axis.

Abstract: A transport assembly comprising: an attachment member attachable to a downhole tool; normally two rotatable members, connected to the attachment member, the rotatable members being arranged to rotate around their main longitudinal axis; a plurality of engaging members attached to each rotatable member and extending radially outwards therefrom with respect to the main longitudinal axis; the engaging members being helically arranged around the rotatable members. The transport assembly can thus be driven into a well in a ‘corkscrew’ type manner. Embodiments include a jarring mechanism which may be reset downhole and can jar attached tools in either direction.

Abstract: A transport assembly configured to be attached to downhole apparatus has a support assembly configured to be attached to the downhole apparatus and a ground engaging assembly, which may be a roller wheel configured to contact with and move in relation to a surface of a wellbore. The roller wheel may engage with the support assembly so as to provide for their relative rotation. The transport assembly also includes a retaining member disposed between the roller wheel and the support assembly, and the retaining member is operable to resist separation of the roller wheel from the support assembly. The transport assembly is further configured such that, when the transport assembly is in use moving along a wellbore, the roller wheel bears against the retaining member, which in turn bears against the support assembly. The retaining member is a ball-bearing.

Abstract: A transport assembly configured to be attached to downhole apparatus has a support assembly configured to be attached to the downhole apparatus and a ground engaging assembly, which in one embodiment is a roller wheel configured to contact with and move in relation to a surface of a wellbore. The roller wheel may engage with the support assembly so as to provide for their relative rotation. In this embodiment, the transport assembly also includes a retaining member disposed between the roller wheel and the support assembly, and the retaining member is operable to resist separation of the roller wheel from the support assembly. The transport assembly is further configured such that, when the transport assembly is in use moving along a wellbore, the roller wheel bears against the retaining member, which in turn bears against the support assembly. In specific embodiments, the retaining member is a ball-bearing.