致密砂岩裂缝测井评价方法及其在迪那2气田的应用

Method for Logging Evaluation in Tight Sandstone Fractures and Its Application in Dina 2 Gas Field

裂缝发育对致密低孔低渗砂岩储层具有重要意义。在岩心刻度基础上,综合利用井壁成像测井和双侧向测井资料,采用图像处理和数值模拟计算技术可以得到砂岩裂缝宽度和裂缝孔隙度等参数,进而估算裂缝渗透率。库车地区迪那2气田为典型的低孔低渗砂岩储层,且储层中裂缝发育,这些裂缝构造大大改善了储层品质,提高了油气产能,利用测井资料能够定量地对裂缝进行评价。研究结果表明:砂岩裂缝的发育降低了有效储层下限,使下限孔隙度从原先的6%降低到3%,从而大大增加了有效储层厚度,研究区增幅达到20%～30%,同时裂缝定量参数的引入,也使得利用测井方法预测该类储层产能成为现实,加深了对这类储层的认识。

Growth of fractures is of great significance of low porosity and low permeability tight reservoirs.On the basis of rock core calibration,by comprehensively using the wellbore imaging logging and dual laterolog data,the techniques of image process and numerical simulation calculation are deployed to obtain the width of sandstone fractures and fracture permeability,consequently the permeability of the fractures are estimated.Dina2 Gas Field in Kuche Area is a typical low porosity and low permeability sandstone reservoir,fractures are grown in the reservoir,by which the reservoir quality is greatly improved,the hydrocarbon productivity is raised.Logging data can be employed for quantitatively evaluating the fractures.The result of study shows that the effective low limitation of the reservoir is reduced by the growth of sandstone fractures,its porosity is reduced to 3% from 6%,the effective reservoir thickness is substantially raised,the increment is 20%~20% in the study area.The quantitative parameters of the fractures are used for predicting the productivity of the reservoirs with well logging method,thus the recognition of the reservoir is deepened.