川东沙罐坪飞仙关组构造裂缝分布与评价

Evaluation on Distribution of Structural Fractures of Feixianguan Formation in Shaguanping Gas Field of Eastern Sichuan

根据沙罐坪飞仙关组岩心、常规测井等资料,对研究区井剖面中裂缝的发育情况及面上裂缝的可能分布情况进行了识别,并对地层中裂缝的参数进行了计算和评价。结果表明,地层中主要有构造成因的垂直裂缝、斜交裂缝及成岩期的泥质充填缝,垂直裂缝是主要的有效裂缝,裂缝发育程度不均。由于有效垂直裂缝主要为构造裂缝,同时曲率法研究的是地层中构造裂缝的发育情况,因此采用构造变形的主曲率法对研究区构造裂缝分布进行了预测评价。曲率法研究结果:构造轴线、高点、构造鼻凸等部位因变形大,曲率值高,裂缝应该相对越发育。

According to core and conventional log data from Feixianguan formation in Shaguanping gas field, the fractural development and possible distribution on well profile in studied area are identified, the parameters about fractures are estimated and evaluated. The results show that there exist vertical and oblique fractures of tectonic origin as well as shale-packed fractures of diagenetic stage. The vertical fractures are as effective and structural ones with uneven development degrees. Hence, the structural fracture distribution in studied area has been predicted and evaluated by applying the principal curvature for structural deformation. Study shows that developed fractures should be found in locations of big deformation and high curvature such as structural axes, structural high and structural nose, etc.