储层岩石T_2-G实验采集参数自动匹配技术研究
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摘要
针对改良式CPMG(Car-Purcel-Meiboom-Gill)序列测量储层岩石内部磁场梯度分布时难以确定第一个窗口持续时间t0及回波个数NE1的问题,在总结T2-G实验采集参数人工调节规律的基础上提出t0、NE1的一项自动匹配技术:构造待测岩石的T2-G近似分布模型,基于该模型变化t0、NE1进行T2-G回波串正演数值模拟,结合T2-G最优化采集参数的约束条件确定t0、NE1。该技术在保证实验精度的前提下显著提高了实验效率,不同区块8块砂岩的T2-G实验结果也验证了该技术的可行性和实用性。
In order to solve the difficulties in determining the acquisition parameters such as t0 and NE1when using the modified CPMG( Car-Purcel-Meiboom-Gill) sequence to measure the internal magnetic field gradient of formation rock,an automatic matching technology for determining t0 and NE1was proposed after summarizing the empirical rules applied in the field:the T2-G approximated distribution model of tested rocks is first constructed; then with the approximated model the response of T2-G experiment is calculated by tuning t0 and NE1using numerical simulation methods,and lastly the suitable t0 and NE1are determined by using constraints from the optimal model. The accuracy and efficiency of the method is further verified in the T2-G experiment using eight sandstone samples from different regions.
In order to solve the difficulties in determining the acquisition parameters such as t0 and NE1when using the modified CPMG( Car-Purcel-Meiboom-Gill) sequence to measure the internal magnetic field gradient of formation rock,an automatic matching technology for determining t0 and NE1was proposed after summarizing the empirical rules applied in the field:the T2-G approximated distribution model of tested rocks is first constructed; then with the approximated model the response of T2-G experiment is calculated by tuning t0 and NE1using numerical simulation methods,and lastly the suitable t0 and NE1are determined by using constraints from the optimal model. The accuracy and efficiency of the method is further verified in the T2-G experiment using eight sandstone samples from different regions.
引文
[1]KLEINBERG R L,VINEGAR H J.NMR properties of reservoir fluids[J].Log Analyst,1996,37(6):20-32.
[2]DUNN K J.Enhanced transverse relaxation in porous media due to internal field gradients[J].Journal of Magnetic Resonance,2002,156(2):171-180.
[3]ZHANG G Q,HIRASAKI G J,HOUSE W V.Effect of internal field gradients on NMR measurements[J].Petrophysics,2001,42(1):37-47.
[4]HURLIMANN M D.Effective gradients in porous media due to susceptibility differences[J].Journal of Magnetic Resonance,1998,131(2):232-240.
[5]ZHANG G Q,HIRASAKI G J,HOUSE W V.Internal field gradients in porous media:proceedings of SPWLA41st Annual Logging Symposium,Dallas,TX[C].Houston:The Society of Petrophysicists and Well Log Analysts,2000,paper AA.
[6]QUAN C,ANDREW E M,BRUCE G C,et al.The internal magnetic field distribution and single exponential magnetic resonance free induction decay in rocks[J].Journal of Magnetic Resonance,2005,175(2):300-308.
[7]APPEL M,FREEMAN J J,PERKINS R B,et al.Restricted diffusion and internal field gradient:proceedings of SPWLA 40th Annual Logging Symposium,Oslo,Norway[C].Houston:The Society of Petrophysicists and Well Log Analysts,1999,paper FF.
[8]BENDEL P.Spin-echo attenuation by diffusion in nonuniform field gradients[J].Journal of Magnetic Resonance,1990,86(3):509-515.
[9]ZHANG G Q,HIRASAKI G J,HOUSE W V.Diffusion in internal field gradients:proceedings of International Symposium of the Society of Core Analysts[C].The Hague,Canada:Society of Core Analysts,1998,paper23.
[10]SHAFER L S,MARDON D,GARDNER J.Diffusion effects on NMR response of oil&water in rock:impact of internal gradients:proceedings of International Symposium of the Society of Core Analysts,Golden[C].Colorado,Canada:Society of Core Analysts,1999,paper 16.
[11]DUNN K J,APPEL M,FREEMAN J J,et al.Interpretation of restricted diffusion and internal field gradients in rock data:proceedings of SPWLA 42nd Annual Logging Symposium,Houston,TX[C].Houston:The Society of Petrophysicists and Well Log Analysts,2001,paper AAA.
[12]SUN B Q,DUNN K J.Probing the internal field gradients of porous media[J].Phys Rev E,2002,65(5):051309.
[13]谢然红,肖立志.核磁共振测井探测岩石内部磁场梯度的方法[J].地球物理学报,2009,52(5):1341-1347.XIE Ranhong,XIAO Lizhi.NMR logging probing the internal magnetic field gradients of rocks[J].Chinese Journal of Geophysics(in Chinese),2009,52(5):1341-1347.
[14]邓克俊.核磁共振测井理论及应用[M].东营:中国石油大学出版社,2010.
[15]SUN B Q,DUNN K J.A global inversion method of multi-dimensional NMR logging[J].Journal of Magnetic Resonance,2005,172(1):152-160.
[16]VENKATARAMANNAN L,SONG Y Q,HURLIMANN M D.Solving fredholm integrals of the first kind with tensor product structure in 2 and 2.5 dimensions[J].IEEE Trans Signal Processing,2002,50(5):1017-1026.
[17]ARNS C H,WASHBUEN K E,CALLAGHAN P T.Multidimensional inverse Laplace NMR spectroscopy in petrophysics:proceedings of SPWLA 47th Annual Logging Symposium,Veracruz,Mexico[C].Houston:The Society of Petrophysicists and Well Log Analysts,2006,paper X.
[18]SUN B Q,DUNN K J.Core analysis with two dimensional NMR:proceedings of International Symposium of the Society of Core Analysts,Monterey,USA[C].Houston:The Society of Petrophysicists and Well Log Analysts,2002,paper 38.
[2]DUNN K J.Enhanced transverse relaxation in porous media due to internal field gradients[J].Journal of Magnetic Resonance,2002,156(2):171-180.
[3]ZHANG G Q,HIRASAKI G J,HOUSE W V.Effect of internal field gradients on NMR measurements[J].Petrophysics,2001,42(1):37-47.
[4]HURLIMANN M D.Effective gradients in porous media due to susceptibility differences[J].Journal of Magnetic Resonance,1998,131(2):232-240.
[5]ZHANG G Q,HIRASAKI G J,HOUSE W V.Internal field gradients in porous media:proceedings of SPWLA41st Annual Logging Symposium,Dallas,TX[C].Houston:The Society of Petrophysicists and Well Log Analysts,2000,paper AA.
[6]QUAN C,ANDREW E M,BRUCE G C,et al.The internal magnetic field distribution and single exponential magnetic resonance free induction decay in rocks[J].Journal of Magnetic Resonance,2005,175(2):300-308.
[7]APPEL M,FREEMAN J J,PERKINS R B,et al.Restricted diffusion and internal field gradient:proceedings of SPWLA 40th Annual Logging Symposium,Oslo,Norway[C].Houston:The Society of Petrophysicists and Well Log Analysts,1999,paper FF.
[8]BENDEL P.Spin-echo attenuation by diffusion in nonuniform field gradients[J].Journal of Magnetic Resonance,1990,86(3):509-515.
[9]ZHANG G Q,HIRASAKI G J,HOUSE W V.Diffusion in internal field gradients:proceedings of International Symposium of the Society of Core Analysts[C].The Hague,Canada:Society of Core Analysts,1998,paper23.
[10]SHAFER L S,MARDON D,GARDNER J.Diffusion effects on NMR response of oil&water in rock:impact of internal gradients:proceedings of International Symposium of the Society of Core Analysts,Golden[C].Colorado,Canada:Society of Core Analysts,1999,paper 16.
[11]DUNN K J,APPEL M,FREEMAN J J,et al.Interpretation of restricted diffusion and internal field gradients in rock data:proceedings of SPWLA 42nd Annual Logging Symposium,Houston,TX[C].Houston:The Society of Petrophysicists and Well Log Analysts,2001,paper AAA.
[12]SUN B Q,DUNN K J.Probing the internal field gradients of porous media[J].Phys Rev E,2002,65(5):051309.
[13]谢然红,肖立志.核磁共振测井探测岩石内部磁场梯度的方法[J].地球物理学报,2009,52(5):1341-1347.XIE Ranhong,XIAO Lizhi.NMR logging probing the internal magnetic field gradients of rocks[J].Chinese Journal of Geophysics(in Chinese),2009,52(5):1341-1347.
[14]邓克俊.核磁共振测井理论及应用[M].东营:中国石油大学出版社,2010.
[15]SUN B Q,DUNN K J.A global inversion method of multi-dimensional NMR logging[J].Journal of Magnetic Resonance,2005,172(1):152-160.
[16]VENKATARAMANNAN L,SONG Y Q,HURLIMANN M D.Solving fredholm integrals of the first kind with tensor product structure in 2 and 2.5 dimensions[J].IEEE Trans Signal Processing,2002,50(5):1017-1026.
[17]ARNS C H,WASHBUEN K E,CALLAGHAN P T.Multidimensional inverse Laplace NMR spectroscopy in petrophysics:proceedings of SPWLA 47th Annual Logging Symposium,Veracruz,Mexico[C].Houston:The Society of Petrophysicists and Well Log Analysts,2006,paper X.
[18]SUN B Q,DUNN K J.Core analysis with two dimensional NMR:proceedings of International Symposium of the Society of Core Analysts,Monterey,USA[C].Houston:The Society of Petrophysicists and Well Log Analysts,2002,paper 38.