【作者】 常莉；

【导师】 张玉君；

【作者基本信息】 吉林大学 ， 声学， 2009， 硕士

【摘要】 本文着重进行实测(交叉)偶极声测井资料衰减的提取和各向异性渗透率反演的应用研究。根据各向同性和横向各向同性双相介质的理论公式,编制了计算实测声测井资料各向同性、各向异性衰减的提取和渗透率反演的MATLAB程序,利用信号频域加权相似法,提取并作出实测资料的全波波形、频散、频谱曲线,分析其图像,采用开窗方法提取弯曲波,再采用不同道幅度比作出衰减曲线,提取弯曲波的衰减作为实测数值,最后利用最小二乘法,反演渗透率。由于实际地层情况比较复杂,我们首先把地层先看成是各向同性地层,确定各向同性地层弹性模量,反演计算了某口井的一段渗透率,并与已有斯通利波渗透率的结果相对比;其次根据各向异性弹性模量确定的操作路线,地层可能为各向异性(TIV)地层,因此确定了各向异性(TIV)地层的弹性模量,反演了软,硬地层的纵、横向渗透率。最后,从交叉偶极阵列声测井数据提取的图像分析中,发现XX,YY方向的频散曲线有一定的分裂,我们尝试性的用各向同性近似的方法来研究TIH介质,分别反演XX、YY方向的渗透率,并反演了一段深度的渗透率值。本文从三种地层角度逐渐深入分析,对于各向同性地层弯曲波渗透率的反演,与斯通滤波渗透率相对比,发现在有一小段深度点趋势相同,孔隙度大的,渗透率大,但数值上相差10到100倍;对于各向异性(TIV)介质,横向渗透率比纵向渗透率反演的情况要好,软地层纵向渗透率反演具有可行性,而硬地层纵向渗透率反演并没有反演出结果,还有待于进一步研究;各向异性(TIH)介质,从作出的结果看XX—YY发生横(弯曲)波分裂的同时,衰减也发生分裂,这说明水平面内各向异性。更多还原

【Abstract】 Permeability is one of the most important parameter that estimates the reserves of formation. There are a lot of works to gained the permeability in long time. Biot established the two-phase medium elastic theory in 1956, indicate the parameters like permeability and porosity effects the acoustic character of hole medium. Rosenbaum use this theory on the side of acoustic well logging, found that permeability is closely related to Stoneley-wave. Kexie Wang had reviewed the permeability’s and porosity’s effect on the field of well acoustic in cylindrical model, established definitely that the attenuation of Stoneley-wave is the most sensitive to permeability. Jun Ma used the flexural wave to calculate the permeability of formation first, gained satisfactory result. In this paper, we use the dipole acoustic well logging data to calculate the permeability in the isotropy model and transverse isotropy model.Firstly, prove theory expressions the field of acoustic which is excitated by dipole source in isotropy and transverse isotropy hole model, and simulate in numerical value, draw the full wave picture which is excitated by dipole source. Analyse the mode wave in each model, research the guide wave which is toward the apices residua in apex wave number plane. Calculate the exact analytic formula from the dispersion formula of the guide wave, and make the program of it.Secondly, research the flexural wave’s dispersion, attenuation and the range ratio of two wave in fast and slow formation of the two models, found that in isotropy model, the dispersion of flexural wave is sensitive to different porosities, but not to different permeabilities; in contrary that its attenuation is sensitive to different permeabilities but not to different porosities, so we believe that we can use the attenuation to calculate the permeability of formation. In transverse isotropy model, the dispersion of flexural wave is sensitive different porosities, but the distinction become little when in high frequency field, it is sensitive to neither horizontal nor vertical permeability. In fast formation, the attenuation is very sensitive to different horizontal permeabilities, but it does nothing to vertical permeability, even its change by different porosities is more obviously. In slow formation, the condition is better than fast formation, the attenuation is more sensitive to both horizontal permeability and vertical permeability. So we conjecture that it is feasible to use the attenuation of flexural wave to calculate the permeability of transverse isotropy formation, especially in slow formation. In fast formation, the horizontal permeability can be calculated also.Third, in the isotropic formation model, the use of flexural wave inversion of permeability and Stoneley wave permeability known relative to a short stratigraphic penetration curve,Images observed from the results of inversion or less the same trend, but the gap between the larger values, we have the results are generally in less than 100mD, The information given by the Stoneley wave permeability 6000mD some even as high as above, in the numerical accuracy but also need to be further verify the error. In the anisotropy (TIH) formation model, the extraction with the same well depth point XX, YY direction of the field data, we try to approximate isotropy of the methods used to study the TIH medium inversion, respectively, XX, YY direction penetration. Inversion of the XX, YY different direction of penetration, within reasonable limits basic. Flexural wave in the soft strata permeability inversion XX, YY vary in both directions, and for the hard formation may be the reasons for data quality, good results can not extract the field data.Finally, using the measured isotropic dipole acoustic logging data, the extraction of anisotropic attenuation and the use of their inversion of stratigraphic penetration rate, To obtain more satisfactory results.we use the flexural wave which intercept from full wave as the sampling function and the flexural wave which is calculated by residua of pole formula as the theory model function, calculate the permeability by nonlinear ordinary least squares estimation. Confirmed the reliability of the inversion. From the inversion results, in the transversely isotropic medium, the result of soft strata than in the hard strata, have been relatively satisfied with the results.更多还原