复杂缝网压裂二氧化碳悬浮支撑剂技术及悬砂性能

CO₂ Suspended Proppant Technology and Evaluation of Suspended Sand Performance for Complex Fracture Network Fracturing

黄 涛 钟 颖 牟秋杭 严耀辉 李建林 张 浩

HUANG Tao ZHONG Ying MOU Qiuhang YAN Yaohui LI Jianlin ZHANG Hao

滑溜水压裂液由于其自身黏度低、携砂能力弱，往往无法满足压后支撑剂对复杂缝网的高效充填。基于气泡悬砂理论，文章提出一种CO2悬浮支撑剂技术，并室内试验评价了常温常压、高温高压条件下滑溜水中CO2悬砂效果。研究结果表明，悬浮支撑剂表面改性涂层能起到稳定的气-固桥联作用，通过吸附CO2有效降低支撑剂密度，大幅减缓支撑剂在滑溜水中的沉降速度（0.15 cm/min），降低幅度为 99%，从而实现滑溜水“低伤害、高携砂”的效果；常温常压下CO2悬砂性能主要受滑溜水黏度影响，悬浮程度及稳定悬浮时长随滑溜水压裂液黏度增大而增加，基本不受砂比影响；高温高压下，二氧化碳为超临界状态（SC-CO2），但其依旧能吸附在悬浮石英砂表面起到一定的悬浮作用，使得大量的悬浮石英砂在搅拌过程中被悬浮起来。因此，CO2悬浮支撑剂技术能显著提高滑溜水压裂液的携砂能力，对降低复杂缝网压裂砂堵风险及提高油气井改造效果具有重要意义。

Due to its low viscosity and weak sand carrying capacity，the slickwater fracturing fluid is often unable to meet the efficient filling of proppant in complex fracture networks post-fracture. Based on the theory of bubble suspended sand，a CO2 suspension proppant technology was proposed and the CO2 suspension sand effect in slickwater fracturing fluid was evaluated under normal temperature and pressure，high temperature and high pressure，respectively. The results showed that the surface modified coating of suspended proppant could play a stable gas-solid bridging effect. For the surface modified suspended proppant，the adsorption of CO2 and the bridging effect of proppant could effectively reduce the specific gravity of proppant，significantly slow down the settling speed of the proppant in slickwater with a reduction of 99%，being of 0.15 cm/min，thus achieving the effect of “low formation damage and high sand carrying capacity”. The performance of CO2 suspended sand under the condition of normal temperature and pressure was mainly affected by the viscosity of slickwater. The degree of suspension and stable suspension duration increased with the increase of viscosity of slippery water fracturing fluid，but it is basically not affected by sand concentration. Under the condition of high temperature and pressure，carbon dioxide was in a supercritical state（SC-CO2），but it could still adsorb on the surface of suspended quartz sand and play a certain suspension role，causing a large amount of suspended quartz sand to be suspended during the stirring process. CO2 suspension proppant technology can significantly improve the sand carrying capacity of slickwater，and has important practical significance to reduce the risk of sand plugging in complex fracture networks and improve the efficiency of oil and gas well reconstruction by efficient proppant filling.

10.19346/j.cnki.1000-4092.2025.01.006