考虑启动压力梯度与裂缝时变性的特低渗油藏数值模拟

目前成熟的油藏数值模拟软件难以精确表征特低渗油藏的压裂裂缝时变性和非线性渗流状况,而矿场开发和实验研究表明特低渗储层开发中存在启动压力梯度且裂缝形态与属性呈动态变化。基于室内启动压力梯度实验、压裂支撑剂导流能力实验以及压裂矿场裂缝监测数据和生产数据,利用一种新的数值模拟软件tNavigator,等效表征了特低渗油藏中压裂裂缝的时变性和非线性启动压力梯度渗流状况。延长油田实际油藏模型应用表明,与常规软件数值模拟结果相比,新软件可精确模拟裂缝变化和储层启动情况。本文认识对运用数值模拟商业软件精准开展特低渗油藏开发方案优化与预测研究具有指导意义。

关于砌体结构变形裂缝的成因分析及控制措施的研究

砌体结构裂缝不仅种类繁多,而且较为普遍,轻微者影响建筑物美观,造成渗漏,严重者降低建筑结构的承载力、刚度、稳定和整体性、耐久性,甚至还会导致整体倒塌的重大质量事故。因此,正确分析其成因、切实加以防治十分必要。本文详细阐述了砌体结构变形裂缝的原因,并提出了选举由针对性的裂缝预防与控制措施,相关的研究结论,可为以后相类的工程施工提供参考依据。

Abnormality diagnosis of cracks in the concrete dam based on dynamical structure mutation

A method of the fuzzy cross-correlation factor exponent in dynamics is researched and proposed to diagnose abnormality of cracks in the concrete dam. Moreover, the Logistic time series changing from period-doubling bifurcation to chaos is tested first using this method. Results indicate that it can distinguish inherent dynamics of time series and can detect mutations. Considering that cracks in the concrete dam constitute an open, dissipative and complex nonlinear dynamical system, a typical crack on the downstream face of a concrete gravity arch dam is analyzed with the proposed method. Two distinct mutations are discovered to indicate that the abnormality diagnosis of cracks in the concrete dam is achieved dynamically through this method. Furthermore, because it can be directly utilized in the measured crack opening displacement series to complete abnormality diagnosis, it has a good prospect for practical applications.