多级交替注入酸压工艺优化研究——以磨溪龙女寺构造龙王庙组储层改造为例

摘要

为了提高磨溪—龙女寺构造龙王庙组储层多级交替注入酸压工艺设计的准确性,通过酸蚀裂缝导流能力实验,结合数值扫描技术,开展了不同注入级数、不同液体组合和不同排量下酸蚀裂缝导流能力保持率和裂缝壁面影响规律研究.结果表明,相比于一级和二级注入,三级交替注入可获得最高的酸蚀裂缝导流能力保持率,且能形成贯穿岩板的酸蚀沟槽;注入级数从一级增加到二级再增加到三级,导流能力保持率提高量逐渐变小;相同闭合压力和主体酸液条件下,以冻胶作为前置液的三级注入获得的导流能力保持率与自生酸为前置液的导流能力保持率差别不大;提高注入速率有利于提高酸蚀裂缝导流能力保持率.优化后的多级交替注入酸压工艺应用于磨溪龙女寺构造龙王庙组储层改造,单井施工曲线和后期拟合表明,该工艺可以实现沟通井周有利储集体的工程目标,为低渗储层改造提供了有效的技术手段.%In order to improve the accuracy of the acid fracturing by the multistage alternative injection in Longwangmiao Forma?tion of Moxi-Longnvsi area, we studied the conservation rate of the conductivity of the acid corrosion fractures and the fracture sur?face morphology influence of different injection rounds, fluid groups and injection rate by the experiment and the numerical scan?ning. The results showed that the 3rd injection round obtained higher conservation rate of the conductivity of the acid etched frac?tures, and formed the acid corrosion groove through rock plate. With the increasing of the injection round, the increment of the con?servation rate of the conductivity decreased gradually. With the same closing pressure and main acid, little different existed in the 3rd injection round when it took the gel and the authigenic acid as the preflush. With the increasing of the injection rate, the conser?vation rate of the conductivity of the acid etched fracture was more ideal. The optimized technology has been used in Longwangmiao Formation of Moxi-Longnvsi area. The acid-fracturing curves and fitting data indicate that the technology can realize the engineer?ing purpose. It also provides an effective technical mean for the transformation of the low permeability reservoir.