裂缝非均质碳酸盐岩酸蚀蚓孔发育规律

发布时间：2018-07-03 09:01

本文选题：碳酸盐岩储层 + 基质酸化　；参考：《油气地质与采收率》2016年06期

【摘要】：碳酸盐岩储层非均质性强,天然裂缝发育,常采用酸化措施消除近井污染。天然裂缝的存在加剧了碳酸盐岩储层的非均质性,在酸化措施中必然会对酸蚀蚓孔发育产生影响。目前的研究聚焦于基质酸蚀蚓孔的发育规律,而对存在天然裂缝的碳酸盐岩酸蚀蚓孔发育规律研究较少。采用径向双尺度连续模型,结合等效渗流理论,分析天然裂缝的长度、数量与方向对酸蚀蚓孔形态特征与酸液注入的影响。研究结果表明:平行于酸液流动方向的天然裂缝越长,则注入端无天然裂缝区域的蚓孔发育越少,蚓孔突破时酸液用量越少;天然裂缝数量越多,则注入端其他方向蚓孔发育越少,初始注入压力越小,蚓孔突破时酸液用量由天然裂缝前的非均质储层物性决定;垂直于酸液流动方向的天然裂缝只能改变其附近的局部蚓孔形态,需要注入更多酸液,蚓孔才能从裂缝方向突破。
[Abstract]:Carbonate reservoir has strong heterogeneity and natural fractures, so acidizing measures are often used to eliminate near-well pollution. The existence of natural fractures intensifies the heterogeneity of carbonate reservoir, which will inevitably affect the development of acid wormhole in acidizing measures. At present, the research focuses on the development of the acid wormhole in the matrix, but there is little research on the development of the acid-wormhole in the carbonate rock with natural cracks. The radial two-scale continuous model and the equivalent seepage theory are used to analyze the effects of the length, quantity and direction of the natural cracks on the morphology of the wormhole and the injection of acid solution. The results show that the longer the natural crack is parallel to the flowing direction of the acid solution, the less the wormhole develops in the region without natural fissure at the injection end, the less the acid consumption is when the wormhole breaks through, and the more the number of natural cracks is. The less the other direction of the injection is, the smaller the initial injection pressure is, and the amount of acid solution is determined by the physical properties of the heterogeneous reservoir before the natural fractures when the wormhole breaks through. Natural cracks perpendicular to the direction of acid flow can only change the morphology of the local wormhole nearby, and more acid solution is needed to break through the wormhole from the crack direction.
【作者单位】：西南石油大学油气藏地质及开发工程国家重点实验室;
【基金】：国家自然科学基金项目“页岩地层动态随机裂缝控制机理与无水压裂理论”(51490653)
【分类号】：TE357.2

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