岩石的酸化敏感性微观机理研究

Study on Micro Mechanism of Rock Acidizing Sensitivity

酸化地层是一种改善低产井近井地带孔隙度的有效增产措施,其作用原理是利用酸液的腐蚀作用腐蚀地层中的岩石,增大孔隙,有效沟通地层增大产量。酸化效果的影响因素多种多样,与岩石性质、酸液种类、浓度、温度有关。目前常见的文献对于酸蚀效率的研究皆注重酸液配方对不同岩石的反应效率的研究,利用聚四氟酸液容器,以15%质量分数的盐酸溶液分别对不同的岩石粉末在不同的温度、反应时间下观察岩石的溶蚀效率。结果表明:盐酸腐蚀时砾岩与盐酸的反应效果最好,其次是页岩,最后是砂岩;各种岩石与酸反应都会生成极细小的不溶于水的岩石碎屑,它们很可能是堵塞孔道的主要物质。本研究对酸化地层的微观反应机理做出研究,对地层酸化的敏感性研究提供新的研究方向。

Acidizing formation is an effective stimulation measure to improve the porosity near the well zone of low production wells. Its principle is to use the corrosion of acid to corrode the rocks in the formation, increase the porosity, effectively communicate with the formation and increase the production. There are many factors affecting the acidizing effect, which are related to rock properties, acid type, concentration and temperature. At present, the common literature on the research of acid etching efficiency focuses on the reaction efficiency of acid formula on different rocks. In this paper, PTFE acid container was used to observe the dissolution efficiency of rocks with different rock powders at different temperatures and reaction times with 15% hydrochloric acid solution. The results showed that the reaction effect of conglomerate with hydrochloric acid was the best, followed by shale and finally sandstone;All kinds of rocks could react with acid to produce very fine rock debris insoluble in water, which was the main material to block the pores. The micro reaction mechanism of acidified formation was studied, which could provide a new research direction for the sensitivity of formation acidification.