【摘要】 在碳酸盐岩地层中,由于诸如溶蚀孔、晶簇孔等形状、大小和分布都不规则的次生孔隙的出现,使得由威利公式计算的基质孔隙度与地层的真实基质孔隙度不符。这种差异是由于威利公式只考虑了孔隙体积对声波传播的影响,忽略了孔隙几何形状等的影响而造成的。用描述声波传播属性的Kuster-Toksoz模型来表达双孔隙地层对声波响应的影响,并求解出基质孔隙度和次生孔隙度值。使用这种技术建立了用声波时差求解双孔隙度的迭代算法;用计算实例说明了该方法取得的良好效果。更多还原

【Abstract】 In carbonate formation, the presence of secondary porosity such as vugs and moldic pores which have utterly irregular forms, amount and distribution, makes the true sonic velocity faster than the one computed from the Wyllie formula and then leads to the block porosity got from it deviating from the true matrix porosity. This difference is caused by the Wyllie formula solely considering pore volume’s effect on acoustic transmission and ignoring pore geometry’s effect. This paper uses the Kuster -Toksoz model, which describes the acoustic transmitting attribute, to illustrate the double pores formation’s effect on acoustic log responses. Using this model we get the formation secondary porosity and matrix porosity. And then through this technology, we set up the iterative algorithm from sonic transit time to get secondary porosity and matrix porosity solution. Computation examples prove this algorithm is feasible.更多还原