改进的孔隙模型评价流体性质与裂缝孔隙度

随着勘探开发的不断深入,渤海油田面临越来越多的疑难储层,这类储层流体性质识别与裂缝孔隙度评价成为测井评价的难点。本文依据Biot理论,描述了存在裂隙条件下的含裂隙Biot理论,形成改进的孔隙介质模型。根据该模型利用阵列声波测井数据进行反演得到裂缝孔隙度,同时通过流体置换,得到不同流体对应的岩石体积模量,对其进行交会判别流体性质,实现了阵列声波测井裂缝孔隙度定量评价与流体性质识别综合应用。利用该模型对渤海油田十几口井进行计算,结果表明该方法对于常规砂泥岩和复杂岩性储层均能取得较好效果,本文提出的储层流体性质识别与裂缝孔隙度评价方法,有助于扩展阵列声声波测井的应用范围。

Improved porosity model for fluid nature and fracture porosity evaluation

With the expanding of exploration and development, Bohai oilfield is facing more and more difficult reservoirs, fluid properties identification and fracture porosity evaluation become difficulties in these reservoirs. Based on the Biot theory, the paper describes an improved porosity media model, which adds cracks to the Biot theory forming a crack-pore theory. According to this model, the fracture porosity is obtained by the inversion from array acoustic logging data, and the bulk modulus of rock is computed from the fluid displacement, through crossplots to identify fluid nature. The improved model achieved comprehensive application for quantitative evaluation of fracture porosity and fluid property identification by array acoustic logging. The method is used for more than ten wells in Bohai oilfields, and the results show good effect in conventional sand-shale formation and complex lithology formation. The method enriches fluid identification and fracture porosity evaluation, and expands the application of acoustic logging.