裂缝预测主曲率法的新探索

构造面主曲率在一定程度上控制了裂缝发育的密度、方向、宽度和深度；因而油层厚度及与之有关的裂缝孔隙体积和渗透率也在一定程度上受到构造面主曲率的影响。由微分几何学原理得到计算主曲率的一般公式，克服了由薄板小扰度弯曲理论得到的主曲率计算公式的局限性。使用趋势面分析与差分法相结合的方法，处理离散的构造层面数据，计算构造面主曲率，选取各点主方向上两个主曲率值中绝对值较大者作为裂缝发育区预测的依据。在江汉盆地王场地区用该方法预测的裂缝发育区与实际基本一致。图5参12

A new approach for predicting fractures using principal curvature

The density, direction, width, and depth of fracture development are controlled by the principal curvatures of structural surfaces. To certain extent, therefore, the thickness of the oil-bearing interval as well as the volume and permeability of the fracture porosity are also influenced by principal curvatures. The general equations of principal curvature derived from differential geometry overcame the limitations of previous equations derived from the theory of elastic thin plate with small deflection. By combining the analyses of trend surface and difference method, the scattered structural surface data are dealt with and the principal curvatures are calculated. The spatial distribution of fractures predicted using this method has been shown to have a generally good match with the field observations in the Wangchang area of the Jianghan Basin.