The oil industry has been drilling wells since the last century using Portland cement as a cementing basic material. There are several environmental impacts associated with the Portland cement production from the raw materials extraction to the macro impact generated by clinkerization such as the emission of greenhouse gases, mainly carbon dioxide (CO₂), combined with huge energy consumption for its production. The study of cement slurries with other precursors types is extremely important in order to obtain a paste with the best properties which are aimed to reduce the negative effects on the environment. Calcium sulfate α-hemihydrate (α-HH) is a material that presents high ecological potential and can be considered a less aggressive agglomeration agent to the environment than Portland cement. The objective of the present work was to develop and analyze the behavior of slurry systems based on α-HH as a basic agglomeration agent for oil well cementing. For this study, slurries were prepared with different water/gypsum ratio (WGR) and submitted to different curing periods (24 hours, 7 and 28 days) and temperatures (27, 38 and 60°C). Then, the additives were added to the slurries using different concentrations of retarding admixture (sodium tetraborate), of superplasticizer (polycarboxylate) and antifoam agent (silicol), aiming to obtain the technological properties required by the oil industry. Such formulations were evaluated through rheology tests, compressive strength and thickening, and thermal characterization (TG/DTG), X-ray diffraction (XRD), X-ray fluorescence (XRF), Infrared region absorption spectroscopy (IR) and scanning electron microscopy (SEM) techniques were performed to characterize the α-HH and its additive formulations. The results showed that the α-HH system with 0.5 WGR showed the best results. The additives were used satisfactorily to enable optimizing the technological properties of the slurry. The α-HH slurry is applicable for cementing shallow oil wells (500 m) under mild temperature and pressure conditions.

自上个世纪以来，石油工业一直在使用波特兰水泥作为固井基础材料来钻井。从原材料提取到熟化产生的宏观影响，与波特兰水泥生产相关的若干环境影响，例如温室气体的排放，主要是二氧化碳（CO _2）的排放。），并为其生产消耗大量能源。为了获得具有最佳性能的糊状物，以减少对环境的负面影响，对其他前体类型的水泥浆进行研究非常重要。硫酸钙α-半水合物（α-HH）是具有高生态潜力的材料，与波特兰水泥相比，它被认为对环境的侵蚀性较小。本工作的目的是开发和分析基于α-HH作为油井固井基础凝集剂的泥浆体系的性能。对于本研究，制备具有不同水/石膏比（WGR）的浆料，并使其经受不同的固化时间（24小时，7和28天）和温度（27、38和60°C）。然后，使用不同浓度的缓凝剂（四硼酸钠），高效减水剂（聚羧酸盐）和消泡剂（硅树脂）将添加剂添加到浆料中，旨在获得石油工业所需的技术性能。通过流变学测试，抗压强度和增稠以及热特性（TG / DTG），X射线衍射（XRD），X射线荧光（XRF），红外区吸收光谱（IR）和扫描电子显微镜（进行了SEM）技术表征α-HH及其添加剂配方。结果表明，具有0.5 WGR的α-HH系统显示出最好的结果。令人满意地使用添加剂以使浆料的技术性能最优化。