Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

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Ever increasing energy needs have encouraged the operators to explore newer areas in deepwater. One of the high potential areas under exploration is the Caribbean basin, which includes Trinidad and Tobago, Suriname, Guyana and French Guiana. Due to the extreme environmental impact that can result from incidents occurring offshore, well integrity is a critical element in offshore development.. Cementing plays a major role in ensuring well integrity and this paper will cover various cementing challenges that were faced in Caribbean deepwater zones. The water depth of wells in Caribbean can be as much as 2300m with seabed temperature of about 4 ºC causing complex heat transfer and requiring fluid modeling software to accurately predict the bottom hole circulating temperature (BHCT) profile. Deepwater wells in the Caribbean can also be affected by the formation of gas hydrates. Cementing in hydrates requires cement slurries with low heat of hydration (HOH). The results from several field studies were used to select an optimum slurry design to successfully cement in hydrates. The wells in this area are also characterized by low fracture gradients with a narrow window between fracture and pore pressures. The cement jobs are designed with advanced computer aided design (CAD) to accurately simulate equivalent circulating density and assist in designing fluid placement within this narrow window. Engineered lost circulation material (LCM) can be used in fluids to achieve successful cement placement. Fluid modeling software also helps in optimizing mud removal by simulating the impact of centralizer distribution, optimizing spacer properties and more. To evaluate cement placement a combination of advanced acoustic logging-while-drilling (LWD) tools and pressure analysis can be used for deeper sections while for riserless sections, visual feedback from remote operating vehicle (ROV) can be used. A case study from Trinidad and Tobago and Southern Caribbean highlights some specific solutions and lessons learned.

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