多羟基高效页岩抑制剂的性能及机理研究

Research on performance and action mechanism of polyhydroxy high-efficiency shale inhibitor

摘要:

为解决深层页岩地层钻井井壁失稳难题，针对传统页岩抑制剂存在的抗温性能不足、防膨效果有限等问题，以三乙醇胺与二溴乙烷为原料，在温和条件下合成了一种多羟基高效页岩抑制剂，通过防膨率、抗温性、岩心线性膨胀及滚动回收测试等系统评价其性能，并借助红外光谱、扫描电镜、X射线光电子能谱表征其结构与作用机理。结果表明：该抑制剂合成产率达98.7%，水溶性好，工艺温和，具备良好的工业化潜力；23%抑制剂水溶液室温防膨率达96.7%，140 ℃老化后防膨率仍达92.3%，140 ℃下页岩岩心滚动回收率达92.5%，线性膨胀量大幅降低，各指标均显著优于传统抑制剂。机理分析表明，其分子中的多羟基基团与页岩矿物表面的羟基形成氢键，质子化后的氨基产生静电吸附，共同在页岩表面形成致密的吸附膜，阻隔钻井液滤液向页岩内部侵入；同时，分子中的羟基与页岩矿物表面的硅羟基发生缩合反应，形成化学键合，进一步提升吸附膜的致密性和稳定性，共同赋予抑制剂在页岩表面强吸附与长效成膜的效果。本研究为深层复杂页岩地层钻井用抑制剂的研发提供了新的技术思路，具有良好应用前景。

Abstract:

To address the challenge of wellbore instability in drilling deep shale formations and overcome the shortcomings of conventional shale inhibitors， such as insufficient temperature resistance and limited anti-swelling efficiency， a highly efficient polyhydroxy shale inhibitor was synthesized under mild conditions using triethanolamine and 1，2-dibromoethane as raw materials. Its performance was systematically evaluated through tests including anti-swelling rate， temperature resistance， core linear expansion， and hot-rolling recovery. The structure and action mechanism were characterized using Fourier transform infrared （FT-IR） spectroscopy， scanning electron microscopy （SEM）， and X-ray photoelectron spectroscopy （XPS）. The results indicate that the inhibitor achieves a synthesis yield of 98.7%， exhibits good water solubility， and features a mild synthesis process， demonstrating great potential for industrialization. A 23% aqueous solution of the inhibitor exhibits an anti-swelling rate of 96.7% at room temperature and maintains 92.3% after aging at 140 ℃. Furthermore， the hot-rolling recovery of shale cores reaches 92.5% at 140 ℃， with a significantly reduced linear expansion. All indicators are markedly superior to those of conventional inhibitors. Mechanism analysis reveals that the multiple hydroxyl groups in the molecule form hydrogen bonds with the hydroxyl groups on shale mineral surfaces， while the protonated amino groups generate electrostatic adsorption. Together， they form a dense adsorption film on the shale surface， blocking the invasion of drilling fluid filtrate. Simultaneously， the hydroxyl groups in the molecule undergo condensation reactions with the silanol groups on the shale surface to form chemical bonds， further enhancing the compactness and stability of the adsorption film. These synergistic effects endow the inhibitor with strong adsorption and long-lasting film-forming capabilities on the shale surface. This study provides a novel technical approach for the development of inhibitors used in drilling deep and complex shale formations， showing promising application prospects.