套管/固井/区域隔离

用于低温固井应用的水填充低密度花岗岩基地质聚合物：前驱体选择和粒度分布的影响

本文介绍了一种可持续的低密度地质聚合物替代波特兰水泥用于低温井固井的应用研究和应用。

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扫描电子显微镜图像显示了高炉矿渣前体的结果。
来源：SPE 219760

由于寒冷的气候和较弱的地层等因素，在靠近海床的地区固井仍是一项挑战，这会导致水泥硬化延迟、钻井作业延长以及井完整性问题。考虑到波特兰水泥在寒冷地区的局限性以及其制造过程中产生的大量二氧化碳排放，人们迫切需要更可持续的替代品。

基于之前对低温应用的研究，通过水扩展方法开发了一种低密度地质聚合物。本研究使用花岗岩基材料，通过细化前体颗粒大小、使用高钙高炉矿渣 (BFS) 和加入无定形硅酸钾活化剂来优化混合设计。研究方法包括一系列固井评估，例如粘度测量、泵送性测试和机械强度评估。此外，还使用了粒度分布分析、扫描电子显微镜、X 射线衍射、热重分析和等温量热法等表征技术。这些测试对于了解材料在特定应用条件下的行为至关重要。

研究结果表明，所提出的土聚物混合物在较低温度下表现出可接受的硬化时间和机械强度发展，使其适合冷浅层水泥灌浆的挑战性条件。该研究证明了使用高含水量土聚物具有可接受性能的可行性，以及其在优化前体颗粒尺寸和添加高钙 BFS 方面的方法的新颖性。即使在高水/固比下，土聚物的性能也凸显了其作为波特兰水泥的潜在可持续高效替代品的多功能性。

本摘要摘自斯塔万格大学 M. Nur Agista、FD Gomado 和 M. Khalifeh 撰写的论文 SPE 219760。该论文已通过同行评审，可在 OnePetro 上的 SPE 期刊上以开放获取形式获取。

原文链接/JPT
Casing/cementing/zonal isolation

Water-Extended Low-Density Granite-Based Geopolymer for Low-Temperature Well-Cementing Applications: The Impact of Precursor Selection and Particle-Size Distribution

his paper presents research and application of a sustainable, low-density geopolymer alternative to Portland cement for cementing applications in low-temperature wells.

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A scanning electron microscope image shows the result of blast furnace slag precursor.
Source: SPE 219760

Well cementing in areas close to the seabed remains a challenge because of conditions such as cold temperatures and weaker formations, leading to delayed cement hardening, extended drilling operations, and well-integrity issues. Considering Portland cement’s limitations in cold areas and significant CO2 emissions through its manufacturing process, the need for more sustainable alternatives is highlighted.

A low-density geopolymer was developed through the water-extended approach based on a previous study on low-temperature applications. Using granite-based materials, this study optimizes the mix design by refining precursor particle sizes, using high-calcium blast furnace slag (BFS), and incorporating an amorphous potassium silicate activator. The research methodology includes sets of well-cementing evaluations such as viscosity measurements, pumpability tests, and mechanical strength assessments. In addition, characterization techniques such as particle-size distribution analysis, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and isothermal calorimetry were used. These tests were crucial in understanding the material’s behavior under the specified application conditions.

The findings reveal that the proposed geopolymer mix exhibits acceptable hardening time and mechanical strength development at lower temperatures, making it suitable for the challenging conditions of cold shallow-depth cementing. The study proves the feasibility of using high water content for geopolymers with acceptable properties and the novelty of its approach in the optimization of precursor particle sizes and the addition of higher-calcium BFS. The geopolymer’s performance, even with a high water/solids ratio, highlights its versatility as a potential sustainable and efficient alternative to Portland cement.

This abstract is taken from paper SPE 219760 by M. Nur Agista, F. D. Gomado, and M. Khalifeh, University of Stavanger. The paper has been peer reviewed and is available as Open Access in SPE Journal on OnePetro.