Abstract: Liners may be cemented in a well bore contaminated with an oil-based or synthetic fluid by injecting an aqueous cleaning fluid into the well, energizing the cleaning fluid to displace fluids present in an annulus between the liner and the bore and to create turbulent flow of the cleaning fluid in the annulus, and injecting a cementitious slurry into the annulus after the cleaning fluid. The cleaning fluid comprises a weighting agent, a suspending agent, a surfactant, and nut shell particulates. The turbulent flow of the cleaning fluid through the annulus is effective to remove oily residues left by the oil-based or synthetic fluid.

Abstract: Novel coatings are disclosed prepared from electropolymerization of electropolymerizable monomers-analyte complexes onto a conducting layer or non-conducting of a substrate, where the analyte is removed by electrochemically mediated washing permitting linear molecular sensing of the analyte over a wide concentration range. The coating may also include templating particles deposited on the electrode substrate prior to electropolymerization, where the particles can be removed to form a submicron structured coating. Methods for making and using the coatings are also disclosed.

Abstract: Liners may be cemented in a well bore contaminated with an oil-based or synthetic fluid by injecting an aqueous cleaning fluid into the well, energizing the cleaning fluid to displace fluids present in an annulus between the liner and the bore and to create turbulent flow of the cleaning fluid in the annulus, and injecting a cementitious slurry into the annulus after the cleaning fluid. The cleaning fluid comprises a weighting agent, a suspending agent, a surfactant, and nut shell particulates. The turbulent flow of the cleaning fluid through the annulus is effective to remove oily residues left by the oil-based or synthetic fluid.

Abstract: Spacer fluids are provided for use in cementing liners in oil and gas wells. The fluids comprise pumice and a suspending agent. Pumice is the first-in weighting agent and is added in amounts sufficient to stabilize the rheology of the fluid over time and temperature.

Abstract: Cement slurries are provided for use in cementing oil and gas wells. The cement slurry comprises API Class C or Class H Portland cement and a pozzolan selected from the group consisting of pumice and mixtures of pumice and fly ash. Pumice is present in the mixtures in amounts at least about 40 wt % of the pozzolan. The weight ratio of the pozzolan to the cement is from about 35:65 to about 70:30. The novel cement slurries preferably will not comprise any additional lime, including hydrated lime, or other activators.

Abstract: Cement slurries are provided for use in cementing oil and gas wells. The cement slurry comprises API Class C or Class H Portland cement and a pozzolan selected from the group consisting of pumice and mixtures of pumice and fly ash. Pumice is present in the mixtures in amounts at least about 40 wt % of the pozzolan. The weight ratio of the pozzolan to the cement is from about 35:65 to about 70:30. The novel cement slurries preferably will not comprise any additional lime, including hydrated lime, or other activators.

Abstract: Spacer fluids are provided for use in cementing liners in oil and gas wells. The fluids comprise pumice and a suspending agent. Pumice is the first-in weighting agent and is added in amounts sufficient to stabilize the rheology of the fluid over time and temperature.

Abstract: Novel coatings are disclosed prepared by electropolymerization of non-fluorinated conducting pre-grafted hydrophobic electropolymerizable monomers onto a conducting layer of a substrate, where the electropolymerized coating exhibit both unique reversible wettability and electro-optical properties. The coating may also include one or more layers of polymer particles upon which the non-fluorinated conducting pre-grafted hydrophobic electropolymerizable monomers are polymerized imparting a submicron structure to the coating. Methods for making and using the coatings are also disclosed.

Abstract: Novel coatings are disclosed prepared from electropolymerization of electropolymerizable monomers-analyte complexes onto a conducting layer or non-conducting of a substrate, where the analyte is removed by electrochemically mediated washing permitting linear molecular sensing of the analyte over a wide concentration range. The coating may also include templating particles deposited on the electrode substrate prior to electropolymerization, where the particles can be removed to form a submicron structured coating. Methods for making and using the coatings are also disclosed.