浅层碳酸盐岩多级注入酸压技术研究与应用

Research and Application of Multistage Injection Acid Fracturing Technology for Shallow Carbonate Rock

临兴区块马家沟组储层岩性为碳酸盐岩,具有埋藏浅、温度低、渗透率低等特征。在对目标储层地质特征、物性条件进行分析的基础上,进行多级注入酸压工艺研究,采用的工作液体系中前置液体系黏度较高,酸液体系黏度较低,两种体系多级交替注入,通过多次指进,形成较长的酸蚀裂缝。通过实验研究及数值模拟的方法,分析多级注入工艺不同规模、级数等对酸压效果的影响,得出最优的多级注入酸压工艺。该工艺应用于临兴区块LX-Y井,取得良好效果。

The lithology of Majiagou Formation reservoir in Linxing block is carbonate rock,which is characterized by shallow burial,low temperature and low permeability.Based on the analysis of the geological characteristics and physical conditions of the target reservoir,the multistage injection acid fracturing technology is studied.In the working fluid system,the viscosity of the preflush fluid system is higher than that of the acid fluid system.The two systems are injected alternately in multiple stages,and long acid corrosion cracks are formed through multiple fingering.By means of experimental research and numerical simulation,the influences of injection scale and stage number of multi-stage injection technology on acid fracturing effect are analyzed,and the optimal multi-stage injection acid fracturing technology is obtained.The application of the technology in well LX-Y of Linxing block achieved a good result.