改进的贝叶斯迭代反演方法及其在白云岩致密储层识别的应用
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摘要
由于低孔隙度和低渗透率的白云岩致密油储集层的纵波阻抗与其围岩差异非常小,利用叠后反演技术难以有效预测储层,而可以提取丰富弹性信息的叠前反演是解决此问题的有效手段,但是由于噪声等问题,叠前反演方程有较强的不适定性,笔者在贝叶斯框架下引入了改进的多变量柯西分布和改进的低频约束因子,重新推导了反演方程,获得了新的目标函数,有效地减少了反演的不适定性,从而提高了反演的稳定性,并结合迭代的思想来不断更新反演求解过程中的背景纵横波速度比值,从而增加了反演结果的精度。模型数据测试和实际资料应用都证明了该方法的稳定性和适用性。统计表明,利用提出的反演方法,目的层段内优质储层厚度预测吻合率高达89.75%。因此,此方法对类似硅质致密储层的勘探有重要的借鉴意义。
It is difficult to accurately predict the dolomite tight oil reservoir which has the characteristics of low porosity and low permeability by using the post-stack inversion,due to the small difference in acoustic impedance between the reservoir and its surrounding rock.Therefore,more abundant elastic information is needed.AVO inversion is an effective means to extract elastic information from pre-stack data.However,due to the noise and other factors,the pre-stack inversion equation has a strong ill-posed problem.Bayesian theory allows the construction of a regularization term by introducing a priori information about the model parameters,thereby effectively reducing the ill-posed problem of the inversion.Therefore,the modified Trivariate Cauchy constraint and the modified low-frequency constraint factor is introduced into the objective function,which can improve the ill-posed problem of the inversion,thus upgrading the accuracy of the inversion results.The iterative idea is used to address the non-linear nature of the proposed inverse operator.The P and S-wave velocity is updated in the iterations,which leads to more reliable results when applied to real data.Both the model data tests and the field data applications prove the validity and stability of the proposed method.Statistics show that,by using the proposed inversion method,the prediction accuracy rate of the reservoir thickness is as high as 89.5%. Therefore,this method has important reference significance for the exploration of similar siliceous reservoirs.
It is difficult to accurately predict the dolomite tight oil reservoir which has the characteristics of low porosity and low permeability by using the post-stack inversion,due to the small difference in acoustic impedance between the reservoir and its surrounding rock.Therefore,more abundant elastic information is needed.AVO inversion is an effective means to extract elastic information from pre-stack data.However,due to the noise and other factors,the pre-stack inversion equation has a strong ill-posed problem.Bayesian theory allows the construction of a regularization term by introducing a priori information about the model parameters,thereby effectively reducing the ill-posed problem of the inversion.Therefore,the modified Trivariate Cauchy constraint and the modified low-frequency constraint factor is introduced into the objective function,which can improve the ill-posed problem of the inversion,thus upgrading the accuracy of the inversion results.The iterative idea is used to address the non-linear nature of the proposed inverse operator.The P and S-wave velocity is updated in the iterations,which leads to more reliable results when applied to real data.Both the model data tests and the field data applications prove the validity and stability of the proposed method.Statistics show that,by using the proposed inversion method,the prediction accuracy rate of the reservoir thickness is as high as 89.5%. Therefore,this method has important reference significance for the exploration of similar siliceous reservoirs.
引文
[1]贾承造,郑民,张永峰,等.中国非常规油气资源与勘探开发前景[J].石油勘探与开发,2012,39(2):129-136.Jia C Z,Zheng M,Zhang Y F,et al.Unconventional hydrocarbon resources in China and the prospect of exploration and development[J].Petroleum Exploration and Development,2012,39(2):129-136.
[2]邹才能,杨智,朱如凯,等.中国非常规油气勘探开发与理论技术发展[J].地质学报,2015,89(6):979-1007.Zou C N,Yang Z,Zhu R K,et al.Progress in China's unconventional oil and gas exploration and development and theoretical technologies[J].Acta Geologica sinica,2015,89(6):979-1007.
[3]田忠斌,申有义,王建青,等.非常规气地震勘探采集技术---以沁水煤田中东部煤系为例[J].物探与化探,2016,40(1):167-173.Tian Z B,Shen Y Y,Wang J Q,et al.Unconventional gas seismic exploration acquisition technology:A case study of the middle east Qinshui coalfield[J].Geophysical and Geochemical Exploration,2016,40(1):167-173.
[4]杜江民,张小莉,钟高润,等.致密油烃源岩有机碳含量测井评价方法优选及应用---以鄂尔多斯盆地延长组长7段烃源岩为例[J].地球物理学进展,2017,31(6):2526-2533.Du J M,Zhang X L,Zhong G R,et al.Analysis on the optimization and application of well logs indentification methods for organic carbon content in source rocks of the tight oil-illustrated by the example of the source rocks of Chang 7 member of Yanchang Formation in Ordos Basin[J].Progress in Geophysics,2017,31(6):2526-2533.
[5]王社教,蔚远江,郭秋麟,等.致密油资源评价新进展[J].石油学报,2014,35(6):1095-1105.Wang S J,Wei Y J,Guo Q L,et al.New advance in resources evaluation of tight oil[J].Acta Petrolei sinica,2014,35(6):1095-1105.
[6]章雄,张本健,梁虹,等.波形指示叠前地震反演方法在致密含油薄砂层预测中的应用[J].物探与化探,2018,42(3):545-554.Xiong Z,Zhang B J,Hong L,et al.The application of pre-stack inversion based on seismic waveform indicator to the prediction of compact and thin oil-bearing sand layer[J].Geophysical and Geochemical Exploration,2018,42(3):545-554.
[7]Zhou L,Li J,Chen X,et al.Pre-stack AVA inversion of exact Zoeppritz equations based on modified trivariate Cauchy distribution[J].Journal of Applied Geophysics,2017,138:80-90.
[8]Aki K,Richards P.Quantitative Seismology[M].New York:W.H.Freeman&Co,1980.
[9]Smith G C,Gidlow P M.Weighted stacking for rock property estimation and detection of gas[J].Geophysical Prospecting,1987,35:993-1014.
[10]Goodway B,Chen T W,Downton J.Improved AVO fluid detection and lithology discrimination using Lame petrophysical parameters:”λρ”,”μρ”,&”λ/μfluid stack,from P and S inversions[C]//Expanded Abstracts of the 67thAnnual SEG Meeting,Society of Exploration Geophysicists,1997,16:183-186.
[11]Russell B H,Gray D,Hampson D P.Linearized AVO inversion and poroelasticity[J].Geophysics,2011,76(3):19-29.
[12]宗兆云,印兴耀,张峰,等.杨氏模量和泊松比反射系数近似方程及叠前地震反演[J].地球物理学报,2012,55(11):3786-3794.Zong Z Y,Yin X Y,Zhang F,et al.Reflection coefficient equotion and pre-stack seismic inversion with Young's modulus and Possion ratio[J].Chinese Journal of Geophysics,2012,55(11):3786-3794.
[13]王彦飞,唐静,耿伟峰,等.带粒子滤波约束的PP-PS联合反演的稀疏解算法[J].地球物理学报,2018,61(3):1169-1177.Wang Y F,Tang J,Geng W F,et al.Sparse solution of PP-PSjoint inversion with constraint of particle filtering[J].Chinese Journal of Geophysics,2018,61(3):1169-1177.
[14]Buland A,Omre H.Bayesian linearised AVO inversion[J].Geophysics,2003,68:185-198.
[15]Alemie W,Sacchi M D.High-resolution three-term AVO inversion by means of a trivariate Cauchy probability distribution[J].Geophysics,2011,76:43-55.
[16]Zhang J H,Zhang B B,Zhang Z J,et al.Low-frequency data analysis and expansion[J].Applied Geophysics,2015,12(2):212-220.
[17]Fang Y,Zhang F Q,Wnag Y C.Generalized linear joint PP-PS inversion based on two constraints[J].Applied Geophysics,2016,13(1):103-115.
[18]贾凌霄,王彦春,菅笑飞,等.叠后地震反演面临的问题与进展[J].地球物理学进展,2016,31(5):2108-2115.Jia L X,Wang Y C,Jian X F,et al.Problems and progress in poststack seismic inversion[J].Progress in Geophysics,2016,31(5):2108-2115.
[19]Ma Q Q,SUN Z D.Fluid identification of secondary carbonate reservoir based on iterative AVO inversion[C]//Expanded Abstracts of the 86thAnnual SEG Meeting,Society of Exploration Geophysicists,2016:602-606.
[20]Bortfeld R.Approximation to the reflection and transmission coefficients of plane longitudinal and transverse waves[J].Geophysical Journal of the Royal Astronomical Society,1978,53:467-496.
[21]张丰麒,金之钧,盛秀杰,等.贝叶斯三参数低频软约束同步反演[J].石油地球物理勘探,2016,51(5):965-975.Zhang F Q,Jin Z J,Sheng X J,et al.Bayesian pre-stack three-term inversion with soft low-frequency constraint[J].Oil Geophysical Prospecting,2016,51(5):965-975.
[22]Backs G E,Gibert F.The resolving power of gross earth data[J].Geophysical Journal International,1968,16:169-205.
[23]黄捍东,汪佳蓓,郭飞.敏感参数分析在叠前反演流体识别中的应用[J].物探与化探,2012,36(6):941-946.Huang H D,Wang J B,Guo F.Thev application of sensitive parameters analysis to fluid identification based on pre-stack inversion[J].Geophysical and Geochemical Exploration,2012,36(6):941-946.
[2]邹才能,杨智,朱如凯,等.中国非常规油气勘探开发与理论技术发展[J].地质学报,2015,89(6):979-1007.Zou C N,Yang Z,Zhu R K,et al.Progress in China's unconventional oil and gas exploration and development and theoretical technologies[J].Acta Geologica sinica,2015,89(6):979-1007.
[3]田忠斌,申有义,王建青,等.非常规气地震勘探采集技术---以沁水煤田中东部煤系为例[J].物探与化探,2016,40(1):167-173.Tian Z B,Shen Y Y,Wang J Q,et al.Unconventional gas seismic exploration acquisition technology:A case study of the middle east Qinshui coalfield[J].Geophysical and Geochemical Exploration,2016,40(1):167-173.
[4]杜江民,张小莉,钟高润,等.致密油烃源岩有机碳含量测井评价方法优选及应用---以鄂尔多斯盆地延长组长7段烃源岩为例[J].地球物理学进展,2017,31(6):2526-2533.Du J M,Zhang X L,Zhong G R,et al.Analysis on the optimization and application of well logs indentification methods for organic carbon content in source rocks of the tight oil-illustrated by the example of the source rocks of Chang 7 member of Yanchang Formation in Ordos Basin[J].Progress in Geophysics,2017,31(6):2526-2533.
[5]王社教,蔚远江,郭秋麟,等.致密油资源评价新进展[J].石油学报,2014,35(6):1095-1105.Wang S J,Wei Y J,Guo Q L,et al.New advance in resources evaluation of tight oil[J].Acta Petrolei sinica,2014,35(6):1095-1105.
[6]章雄,张本健,梁虹,等.波形指示叠前地震反演方法在致密含油薄砂层预测中的应用[J].物探与化探,2018,42(3):545-554.Xiong Z,Zhang B J,Hong L,et al.The application of pre-stack inversion based on seismic waveform indicator to the prediction of compact and thin oil-bearing sand layer[J].Geophysical and Geochemical Exploration,2018,42(3):545-554.
[7]Zhou L,Li J,Chen X,et al.Pre-stack AVA inversion of exact Zoeppritz equations based on modified trivariate Cauchy distribution[J].Journal of Applied Geophysics,2017,138:80-90.
[8]Aki K,Richards P.Quantitative Seismology[M].New York:W.H.Freeman&Co,1980.
[9]Smith G C,Gidlow P M.Weighted stacking for rock property estimation and detection of gas[J].Geophysical Prospecting,1987,35:993-1014.
[10]Goodway B,Chen T W,Downton J.Improved AVO fluid detection and lithology discrimination using Lame petrophysical parameters:”λρ”,”μρ”,&”λ/μfluid stack,from P and S inversions[C]//Expanded Abstracts of the 67thAnnual SEG Meeting,Society of Exploration Geophysicists,1997,16:183-186.
[11]Russell B H,Gray D,Hampson D P.Linearized AVO inversion and poroelasticity[J].Geophysics,2011,76(3):19-29.
[12]宗兆云,印兴耀,张峰,等.杨氏模量和泊松比反射系数近似方程及叠前地震反演[J].地球物理学报,2012,55(11):3786-3794.Zong Z Y,Yin X Y,Zhang F,et al.Reflection coefficient equotion and pre-stack seismic inversion with Young's modulus and Possion ratio[J].Chinese Journal of Geophysics,2012,55(11):3786-3794.
[13]王彦飞,唐静,耿伟峰,等.带粒子滤波约束的PP-PS联合反演的稀疏解算法[J].地球物理学报,2018,61(3):1169-1177.Wang Y F,Tang J,Geng W F,et al.Sparse solution of PP-PSjoint inversion with constraint of particle filtering[J].Chinese Journal of Geophysics,2018,61(3):1169-1177.
[14]Buland A,Omre H.Bayesian linearised AVO inversion[J].Geophysics,2003,68:185-198.
[15]Alemie W,Sacchi M D.High-resolution three-term AVO inversion by means of a trivariate Cauchy probability distribution[J].Geophysics,2011,76:43-55.
[16]Zhang J H,Zhang B B,Zhang Z J,et al.Low-frequency data analysis and expansion[J].Applied Geophysics,2015,12(2):212-220.
[17]Fang Y,Zhang F Q,Wnag Y C.Generalized linear joint PP-PS inversion based on two constraints[J].Applied Geophysics,2016,13(1):103-115.
[18]贾凌霄,王彦春,菅笑飞,等.叠后地震反演面临的问题与进展[J].地球物理学进展,2016,31(5):2108-2115.Jia L X,Wang Y C,Jian X F,et al.Problems and progress in poststack seismic inversion[J].Progress in Geophysics,2016,31(5):2108-2115.
[19]Ma Q Q,SUN Z D.Fluid identification of secondary carbonate reservoir based on iterative AVO inversion[C]//Expanded Abstracts of the 86thAnnual SEG Meeting,Society of Exploration Geophysicists,2016:602-606.
[20]Bortfeld R.Approximation to the reflection and transmission coefficients of plane longitudinal and transverse waves[J].Geophysical Journal of the Royal Astronomical Society,1978,53:467-496.
[21]张丰麒,金之钧,盛秀杰,等.贝叶斯三参数低频软约束同步反演[J].石油地球物理勘探,2016,51(5):965-975.Zhang F Q,Jin Z J,Sheng X J,et al.Bayesian pre-stack three-term inversion with soft low-frequency constraint[J].Oil Geophysical Prospecting,2016,51(5):965-975.
[22]Backs G E,Gibert F.The resolving power of gross earth data[J].Geophysical Journal International,1968,16:169-205.
[23]黄捍东,汪佳蓓,郭飞.敏感参数分析在叠前反演流体识别中的应用[J].物探与化探,2012,36(6):941-946.Huang H D,Wang J B,Guo F.Thev application of sensitive parameters analysis to fluid identification based on pre-stack inversion[J].Geophysical and Geochemical Exploration,2012,36(6):941-946.