Abstract

The article discusses the mathematical modeling results on formation of concentration zones of failure stresses in annular space of a well during hydraulic fracturing of productive formations from vertical or nearly vertical boreholes. The rigid connection between the cement lining and rocks fails because of a thin clay layer in-between, which leads to unsealing of the annular space and to various troubles, including environmental implications. To prevent annular space unsealing during hydraulic fracturing, it is proposed to ream out borehole in the area of contact with the productive stratum roof, and to install a bow springs centralizer on this level then.

中文翻译：

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水力压裂环空开封机理

摘要

本文讨论了在垂直或接近垂直钻孔的生产地层水力压裂过程中，井环形空间破坏应力集中区形成的数学建模结果。水泥衬里和岩石之间的刚性连接由于中间的薄粘土层而失效，这导致环形空间的开封和各种问题，包括环境影响。为防止水力压裂时环空开裂，建议在与生产地层顶板接触的区域扩孔，然后在该层安装弓形弹簧扶正器。