变参数酸蚀裂缝导流能力实验

FLOW CONDUCTIVITY EXPERIMENTS ON VARIABLE-PARAMETER ACID ETCHED FRACTURES

酸蚀裂缝导流能力是评价酸压效果的决定性因素，测试是在固定的实验条件下主要采用鲜酸进行的，实验结果仅能表征近井筒区域的裂缝导流能力，影响了酸压效果的准确判断。采用变参数导流能力实验方法研究了沿缝长方向不同酸液质量分数、温度、流速、裂缝宽度下的裂缝导流能力。结果表明，酸蚀裂缝导流能力最高的区域出现在距井筒一段距离的区域，沿缝长方向酸液质量分数的变化是引起裂缝导流能力变化的主要原因，而裂缝宽度以及酸液流速的变化可能导致酸蚀裂缝的有效作用距离大幅度缩短。实验证明，酸液质量分数、裂缝宽度、注入速率等因素的综合变化对酸蚀裂缝导流能力沿缝长的分布影响很大。

The flow conductivity of an acid etched fracture is a crucial factor to evaluate the effects of acidizing and fracturing. The tests are conducted by fresh acid on the fixed experimental conditions. The results can only charac- terize the flow conductivity of the fractures near the borehole, so the accurate judgement of the stimulation effects is influenced. With the help of the experimental method of variable-parameter flow conductivity, the conductivities of the fractures along the direction of fracture lengths are researched under the conditions of the mass fractions, tem- peratures, flow rates, fracture widths of different acid liquids. The experimental results show that the highest con- ductivity appears in a certain domain away from the borehole. The changes of the mass fractions of the acid liquids along the directions are the main reason of resulting in the changes of the flow conductivity of the fractures, but the changes of the fracture widths and flow rates maybe cause the seriously reduction of the effective distance of acid- etched fractures. The tests prove that the comprehensive variation of the mass fraction, fracture width, injection rate and so on possess a great influence on the distribution of the acid-etched fracture conductivity along the fracture length.