摘要
裂缝型碳酸盐岩储层天然裂缝和孔洞十分发育,导致酸液滤失非常严重,为现场酸压施工带来很多困扰。国内酸液滤失实验一直采用的是压裂液的计算方法 ,酸液滤失一直处于数学模型阶段,并未应用于实际施工。以玉北某井的裂缝型灰岩储层为研究对象,选取微裂缝为70-80μm的人工劈裂岩心作为实验对象,以胶凝酸在裂缝型灰岩岩心的动滤失实验结果为基础,利用数字化方法 ,得到酸蚀蚓孔的裂缝间距等值线图和三维图。考虑到酸液与压裂液的不同滤失特性,引入酸液突破时间的概念,提出新的酸液动滤失实验方法。利用胶凝酸动滤失实验数据并结合前人经验,提出酸液滤失量计算方法;利用酸液滤失量计算方法并结合研究区域的地质特征和泵注情况,计算出胶凝酸的滤失量,根据计算滤失量的方法来选取合适的酸液浓度与泵注排量,优化施工设计。该研究为今后现场施工提供了方便可行的滤失量计算方法,并为控制酸液滤失措施提供了依据。
Natural fractures and cavity developed well in the fractured carbonate reservoir,which results in serious filtration loss of the acid fluid and difficulties in field acid fracturing.Calculation method of fracturing flu-id was always applied in domestic filtration loss experiment of the acid fluid.The filtration loss of acid fluid is calculated by mathematical model and not applied in the actual operation.The fractured limestone reservoir of certain well in Yubei was taken as research object.Artificial split cores with micro-crack of 70-80 μm were selected as experimental objects.Based on dynamic filtration loss test result of the gelled acids in the fractured limestone cores,isograms and 3D graphs of crack spacing of acid wormhole were gained by digital algorithm.Considering different characteristics of the filtration loss between the acid fluid and the fracturing fluid,a concept of breakthrough time of the acid fluid was introduced and new dynamic filtration loss test method of the acid fluid was proposed.Through experimental data of the dynamic filtration loss experiments of the gelled acid and the previous experiences,the calculation method of filtration loss of the acid fluid was proposed.Combined with geologic features and pumping situation in research area,the filtration loss of the gelled acid was calculated,suitable acid concentration and discharge may be selected and operation design was optimized.This study provides a convenient and feasible method of filtration loss calculation for the future field operation and a basis for the measure of acid loss controlling.
出处
《中外能源》
CAS
2016年第3期58-61,共4页
Sino-Global Energy
基金
国家自然科学基金"高黏度酸液酸岩反应动力学机理研究"(编号:51274050)资助
关键词
碳酸盐岩
裂缝型储层
胶凝酸
滤失量
计算方法
carbonate rock
fractured reservoir
gelled acid
filtration loss
calculation method
