阵列侧向测井仪器的正演响应分析

Forward response analysis of array lateral logging tool

为了进一步了解阵列侧向测井仪器在实际地层中的响应特性,在设计实现阵列侧向测井响应有限元数值计算基础上,考察了不同二维地层模型下目的层厚度和侵入深度变化对测井响应的影响.结果表明,阵列侧向测井的不同探测深度曲线分辨率匹配、层厚和测量模式不同,读数不同.侵入半径变化影响明显,除浅探测深度曲线外,其余曲线的侵入影响特性接近.高侵时,测量读数会乱序.不同的井眼、围岩、侵入和地层参数时侧向测井的仪器常数不同,将影响测井响应读数.

Being similar to array induction logging,array lateral logging(ALL) can provide the several logging response curves of different detecting depth.The characteristics of the ALL response of ideal logging model indicate that the lateral logging tool has advantages of high vertical resolution and great radical detecting range.In order to find out the response characteristics of the tool in actual logging stratum,the effects of the thickness and the invasion radius of target zone on the logging responses of different 2D stratum models are studied based on the simulation data obtained by finite element method(FEM).It is shown that the responses of ALL will vary with the parameters of the different stratum models,the thickness of the target zone and the resolution matching of the response curves of different detecting depth.The effect of the invasion radius on the responses of ALL is obvious.Except the response curve of shallowest radial depth,the effects of the invasion radius on the response curves of other radial depth are near to the same.When the invasion radius is greater,the response curves of different detecting depth will cross each other.The tool constant(K) will influence the response curves of ALL,which is determined by the parameters(resistivity of invasion zone,resistivity of original formation,resistivity of target zone) of the stratum model.