基于实验方法的酸压裂缝分形研究  

Experimental study on fractal characteristics of fractures in acidizing fracturing process

作　　者：付应坤[1] 李治平[1] 韩宁 钟富萍 赖枫鹏[1] 杨森[1] 孟超[1] 

机构地区：[1]中国地质大学(北京)能源学院非常规天然气能源地质评价与开发工程北京市重点实验室,北京100083 [2]中国石油华北油田采油工艺研究院,河北任丘062552 [3]中国石油青海油田钻采工艺研究院,甘肃敦煌736202

出　　处：《西安石油大学学报（自然科学版）》2014年第2期55-59,3,共5页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：国家重大专项"新一代油藏数值模拟软件"(编号:2011ZX05009-006);国家自然科学基金项目"CO2驱油对储层的伤害机理研究"(编号:51174178)

摘　　要：酸压是提高碳酸盐岩储层渗透率的主要措施,酸压裂缝的形成和延伸直接影响到油气井产能。为此,采用分形方法研究酸压过程中裂缝的形成和延伸机理。首先推导出裂缝导流能力与裂缝分形维数之间的函数关系,然后采用造缝后的岩心进行一次酸压和重复酸压实验,测试酸压前后裂缝导流能力的变化,得到一次酸压和重复酸压前后裂缝的分形特征变化。研究表明:酸压裂缝的几何形态及分布具有明显的分形特征,其中一次酸压以酸蚀原始裂缝、促进原始裂缝延伸为主,酸压前后裂缝分形维数明显降低;重复酸压以造新裂缝为主,分形维数较一次酸压明显提高。Acidizing fracturing is one of the major measures of enhancing the permeability of carbonate reservoir. For this reason, the forming and growth mechanism of fractures in the acidizing fracturing process is studied using fractal method. Firstly,the relationship between the fracture flow capacity and fractal dimension is derived,and then,the fractal dimensions of fractures before and after the first acidizing fracturing and the second acidizing fracturing are obtained by testing fracture flow capacity. The fractal characteristics of fractures in the first acidizing fracturing and the second acidizing fracturing are studied according to the change of the fractal dimension of fractures before and after acidizing fracturing. It is shown that,the geometrical morphology and size distribution of acidizing fracturing fractures have obvious fractal feature; the fractal dimension of fractures decreases after the first acidizing fracturing,so the effect of the first acidizing fracturing is mainly the acid corrosion and growth of original fractures; the fractal dimension of fractures increases after the second acidizing fracturing,so the effect of the second acidizing fracturing is mainly generating new fractures.

关 键 词：裂缝分形 裂缝导流能力 重复酸压 

分 类 号：TE357[石油与天然气工程—油气田开发工程]