井完整性/控制

土工聚合物作为修复作业处理液的开发——特性及与最先进材料的比较

本文介绍了一种基于偏高岭土的地质聚合物作为油气井修复作业候选处理方法与传统先进材料的表征和比较。

228407_图1.jpg
<b>图 1——S2-Geoseal 试验所用的 S2 试验样品的密封剂/套管界面处的水力孔径。
来源：论文 SPE 228407

油井泄漏给石油和天然气行业带来了重大的环境、经济和运营挑战。油气井的修复作业极具挑战性，尤其是在狭窄井眼的情况下，通常需要针对井下环境的特定挑战定制处理材料。土聚物是一种低碳环保的传统水泥替代品，可用于修复作业。

本文介绍了 Geoseal（一种偏高岭土基土聚物）的开发、表征和比较分析，该材料可作为修复作业的候选处理材料。本研究进行了实验室实验，以评估 Geoseal 在密封剂/套管界面的流变性、力学性能和密封性能。

通过在模拟井下条件下将处理液注入密封剂/套管界面处自然形成的微环隙中，评估微环隙的密封性能。研究了三种密封剂材料：热熔胶（S1）、花岗岩基土聚物（S2）（图1）和膨胀水泥（S3）。

此外，还比较了 Geoseal 与热固性树脂和硅酸盐溶液等传统修复材料在密封狭窄微环隙孔径方面的效果。对比评估主要关注注入性、密封完整性以及与微环隙界面现有密封剂的材料兼容性。

虽然每种处理液都展现出各自的优势和局限性，但结果凸显了Geoseal在有效修复微环隙方面的潜力。然而，在孔径小于6微米的环境中采用Geoseal存在明显的注入问题。

本文的研究结果为寻求提高油气井水泥密封剂补救措施有效性的行业从业者和研究人员提供了实用见解。

本文摘要摘自斯塔万格大学 Adijat Ayobami Ogienagbon 和 Mahmoud Khalifeh 的论文 SPE 228407。该论文已通过同行评审，并以开放获取的形式在 OnePetro 的 SPE 期刊上发布。

原文链接/JPT
Well integrity/control

Development of Geopolymer as Treatment Fluid for Remedial Operations—Characterization and Comparison With State-of-the-Art Materials

This paper presents the characterization and comparison of a metakaolin-based geopolymer as a candidate treatment for remedial operations in oil and gas wells versus conventional state-of-the-art materials.

228407_Fig1.jpg
<b>Fig. 1—</b>The hydraulic aperture at the sealant/casing interface of the S2 test sample used in the S2-Geoseal test.
Source: Paper SPE 228407

Oilwell leakage poses significant environmental, economic, and operational challenges to the oil and gas industry. Remedial operations in oil and gas wells are quite challenging, especially for narrow apertures, and often require treatment materials tailored to specific challenges encountered in downhole environments. Geopolymers represent a low-carbon and environmentally friendly alternative to conventional cement, which can be explored for remedial operations.

This paper presents the development, characterization, and comparative analysis of Geoseal, a metakaolin-based geopolymer, as a candidate treatment material for remedial operations. In this study, laboratory experiments were conducted to evaluate the rheological, mechanical, and sealing performance of Geoseal at the sealant/casing interface.

Microannuli sealing performance was evaluated by injecting the treatment fluids under simulated downhole conditions into naturally formed microannuli at the sealant/casing interface. Three sealant materials—neat G cement (S1), granite-based geopolymer (S2) (Fig. 1), and expansive cement (S3)—were considered.

The effectiveness of Geoseal in sealing narrow microannuli apertures was also compared with that of conventional remedial materials such as thermosetting resin and silicate solution. The comparative assessments focused on injectivity, sealing integrity, and material compatibility with the existing set sealants at the microannuli interface.

While each treatment fluid exhibited unique advantages and limitations, the results highlight the potential of Geoseal for effective microannuli remediation. However, its adoption in apertures narrower than 6 µm presented notable injectivity issues.

The findings of this paper provide practical insights for industry practitioners and researchers seeking to enhance the effectiveness of remedial interventions of cementitious sealants in oil and gas wells.

This abstract is taken from paper SPE 228407 by Adijat Ayobami Ogienagbon and Mahmoud Khalifeh, University of Stavanger. The paper has been peer reviewed and is available as Open Access in SPE Journal on OnePetro.