| dc.description.abstract | Cement is one of the most integral components of a wellbore, yet minimal experimental research has been done to understand the basic processes as to what ensures a cement sheaths’ success. Globally, minimizing greenhouse gas emissions has become one of the most influential factors in material selection for both households and industries, and it is common knowledge that the manufacturing of cement is one of the largest contributors to greenhouse gas emissions, specifically, carbon dioxide. Industries that rely on cement for structural purposes, including the petroleum industry, have begun to investigate cement alternatives or cement replacement materials to minimize the emissions associated with cement manufacturing. Pozzolanic materials such as fly ash, slag, and metakaolin are common wellbore cement additives that have proven to be advantageous in achieving the required downhole mechanical properties but many of these materials have also become less prevalent as emissions are reduced due to their cost and availability. During the drilling process, there is an abundance of a pozzolanic material that has not been utilized as a cement additive or replacement material: shale. In this work, an investigation on the poroelastic constant for class H wellbore cement is conducted. The poroelastic constant is a common input parameter for wellbore modelling and is regularly assumed to be the same as unconsolidated material. The poroelastic constant is a key parameter for determining effective stress and has an impact on cement design in wellbores. Consolidated isotropic drained (CID) testing on class H cement is also performed at three confining stress to obtain a Mohr-Coulomb failure envelope. During CID testing, the samples are sheared and an understanding of shear behavior is evaluated. This information can be used to generate more detailed failure criteria for wellbore cements and be applied to cement system designs and modeling programs. From the results of this work, it can be concluded that cement is indeed a poroelastic material. An investigation on curing time, particle size, and additive quantity is also conducted to determine the feasibility of using shale cuttings as a cement additive or replacement material. It has been determined that the samples containing micron particle sized shale tended to have superior results for all quantities when compared to the millimeter and micron samples, possibly due to these particles being similar to the size of the cement. While this work is preliminary, future validation of the findings could be instrumental in decreasing the amount of waste and emissions produced both from cement manufacturing as well as from the recycling of drill cuttings. | en_US |
