碳酸盐岩储层水平井靶向酸化研究及应用

水平井极大增加了油层泄油面积，具有直井无法比拟的优势。但是，油藏强非均质性给有效布酸带来了巨大挑战。结合中东地区碳酸盐岩油藏的开发现状，系统梳理了水平井酸化所面临的关键技术难点。针对油田不同开发阶段，提出了水平井的靶向酸化技术思路，推导了水平井三维径向酸化数学模型，模拟分析了不同布酸方法对水平新、老井酸化效果的影响。研究表明，针对水平（新）井酸化，基于钻井伤害特征的靶向布酸效果优于均匀布酸、物性布酸和锥台布酸；当达到相同酸化效果下，靶向布酸至少能够节约10%酸量；5口新井采液指数分析表明，靶向布酸能够提高新井酸化投产效果。针对水平（老）井酸化，采用局部酸化能够有效实现均衡水平井产液剖面目的；对于局部低渗层段改造，采用1.5 in.（1 in.=2.54 cm）连续油管进行定点喷射酸化，能够形成深穿透酸蚀蚓孔；7口老井酸化前后对比分析表明，靶向布酸能够大幅提高水平井重复酸化效果。

Research and Application of Targeted Acidizing Tech in Horizontal Well of Carbonate Reservoir

The horizontal well greatly increase the flow area of oil. It's advantages are much higher than that of vertical well. However, the serious heterogeneity of the reservoir brings great challenges to the effective acid placement in horizontal well. Based on the development situation of carbonate reservoirs in the Middle East, this paper systematically analyzes the main technical difficulties faced by acidization of horizontal well. According to the different development stages of the oilfield, the targeted acidizing technology for horizontal wells are proposed. The three-dimensional radial acidizing simulation model for horizontal wells is also deduced. According to the simulation, the influence of acid placement patterns on the acidizing effect are analyzed for both new and old horizontal wells. The research shows that the targeted acid placement pattern based on the drilling damage is better than the uniformed, physical-based and cone-shaped acid placement pattern for new horizontal well; under the same acidizing effect, the targeted acidizing can save at least 10% acid use; the production index analysis of 5 acidized new wells shows that the targeted acidizing can improve the production performance of those wells well. For the acidizing of old horizontal wells, partial acidizing can effectively balance the production profile of horizontal wells; for the partial low-permeability interval with reconstruction, 1.5 in. coiled tubing can be used for jet acidizing, which can penetrate deep into the reservoir through acid wormhole; the analysis of acidization in 7 old wells conducted by re-acidizing shows that targeted acidizing can greatly improve the production capacity for old horizontal wells.