塔中地区碳酸盐岩缝洞型储层叠前流体识别
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摘要
塔中地区奥陶系碳酸盐岩的储集空间是由裂缝和次生溶蚀孔洞组成的,其地震响应为"串珠状"反射。由于受到地表沙丘覆盖和埋藏深度较大的影响,导致地震资料信噪比较低、储层成像精度差。同时该储层油水关系复杂,利用叠后地震方法进行油气检测时,无法有效识别储层中的油水特征。以上难题严重制约了塔中地区碳酸盐岩勘探开发的进程。针对上述问题,基于塔中地区高密度地震资料开展了研究,由于高密度数据信噪比、储层成像精度相对较高,因此有利于进行缝洞体储层叠前烃类检测方法研究。首先,利用岩石物理建模得到了准确度较高的纵、横波速度;其次,对油气、水井进行AVO正演,正演结果表明不同类型井的AVO响应特征是有差异的,可以用AVO属性分析技术对碳酸岩储层流体识别;最后,利用叠前同时反演技术对研究区储层进行定量的流体预测,预测结果与该区试油成果对比分析,流体预测精度达到83. 3%,该方法为研究区内提升钻井成功率,降低油气勘探风险提供了有效的技术支持。
The reservoir space of the Ordovician carbonates in Tazhong area,Tarim Basin,is mainly composed of fractures and secondary dissolved pores and cavities,and its seismic responses are bead-like reflections. The fact that the reservoir is covered by surface dunes and buried in depth leads to a relatively low signal-to-noise ratio of seismic data and the poor imaging precision for the reservoir. The oil-water contact is complex in the reservoir,making it hard to effectively identify its features by using post-stack hydrocarbon detection method. These problems have seriously restricted the progress of exploration and development of carbonate reservoirs in this area. In order to address these problems,we conducted research based on high-density seismic data in Tazhong area. As the high-density seismic data have higher signal-to-noise ratio and reservoir imaging precision,they are beneficial to study pre-stack hydrocarbon detection method for fractured-vuggy reservoirs. Firstly,more accurate P and S wave velocity can be worked out by Rock Physics Model. Secondly,AVO forward modeling of oil/gas and water wells is conducted,showing discrepant responses from different wells as a result. Therefore,the AVO attributive analysis technique can be used to identify liquids in carbonate reservoirs. Finally,pre-stack simultaneous inversion technique is used to quantitatively identify fluid types in reservoirs in the research area; The predictions are in turn compared with the results of formation testing,revealing an accuracy of liquid predictionsof 83. 3%,which manifests that this method provides effective technical support for improving the success rate of drilling and reducing risks of hydrocarbon exploration.
The reservoir space of the Ordovician carbonates in Tazhong area,Tarim Basin,is mainly composed of fractures and secondary dissolved pores and cavities,and its seismic responses are bead-like reflections. The fact that the reservoir is covered by surface dunes and buried in depth leads to a relatively low signal-to-noise ratio of seismic data and the poor imaging precision for the reservoir. The oil-water contact is complex in the reservoir,making it hard to effectively identify its features by using post-stack hydrocarbon detection method. These problems have seriously restricted the progress of exploration and development of carbonate reservoirs in this area. In order to address these problems,we conducted research based on high-density seismic data in Tazhong area. As the high-density seismic data have higher signal-to-noise ratio and reservoir imaging precision,they are beneficial to study pre-stack hydrocarbon detection method for fractured-vuggy reservoirs. Firstly,more accurate P and S wave velocity can be worked out by Rock Physics Model. Secondly,AVO forward modeling of oil/gas and water wells is conducted,showing discrepant responses from different wells as a result. Therefore,the AVO attributive analysis technique can be used to identify liquids in carbonate reservoirs. Finally,pre-stack simultaneous inversion technique is used to quantitatively identify fluid types in reservoirs in the research area; The predictions are in turn compared with the results of formation testing,revealing an accuracy of liquid predictionsof 83. 3%,which manifests that this method provides effective technical support for improving the success rate of drilling and reducing risks of hydrocarbon exploration.
引文
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[15] Pickett G R. Acoustic character logs and their applications in formation evaluation[J]. Journal of Petroleum Technology,1963,15(6):650-667.
[16] Castagna J P. Shear-wave time-average equation for sand-stones[C]∥SEG. SEG Technical program expanded abstract. Washington D. C.:SEG,1985:447-448.
[17] Hill R. A self-consistent mechanics of composite materials[J]. Journal of the Mechanics&Physics of Solids,1965,13(4):213-222.
[18] Wood A W. A textbook of sound[M]. New York:The Mac Millan Co,1995:360-363.
[19] Gassmann F. Elastic waves through a packing of spheres[J]. Geophysics,1951,96:1-23.
[20]张广智,刘洪,印兴耀.井旁道精细地震子波提取方法[J].石油地球物理勘探,2005,40(2); 158-162.Zhang Guangzhi,Liu Hong,Yin Xingyao. Method for fine picking up seismic wavelet at up-hole trace[J]. Oil Geophysical Prospecting,2005,40(2):158~162.
[21]张恒,蔡忠贤,漆立新,等.塔中地区西北部鹰山组成岩早期岩溶作用类型及其特征[J].石油与天然气地质,2016,37(2):291-303.Zhang Heng,Cai Zhongxian,Qi Lixin,et al. Types and characteristics of eogenetic karst in the Yingshan Formation in northwestern Tazhong area,Tarim Basin[J]. Oil&Gas Geology,2016,37(2):291-303.
[22]韩长城,林承焰,鲁新便,等.塔河油田奥陶系碳酸盐岩岩溶斜坡断控岩溶储层特征及形成机制[J].石油与天然气地质,2016,37(5):644-652.Han Changcheng,Lin Chengyan,Lu Xinbian,et al. Characterization and genesis of fault-controlled karst reservoirs in Ordovician carbonate karst slope of Tahe oilfield,Tarim Basin[J]. Oil&Gas Geology,2016,37(5):644-652.
[23]张艳萍,吕修祥,于红枫,等.塔中隆起两组走滑断裂对岩溶储层发育的控制机制[J].石油与天然气地质,2016,37(5):663-673.Zhang Yanping,Lyu Xiuxiang,Yu Hongfeng,et al. Controlling mechanism of two strike-slip fault groups on the development of the Ordovician karst reservoirs in the Tazhong Uplift,Tarim Basin[J]. Oil&Gas Geology,2016,37(5):663-673.
[2]张广智,李呈呈,印兴耀,等.基于修正Xu-White模型的碳酸盐岩横波速度估算方法[J].石油地球物理勘探,2012,47(5):717-722.Zhang Guangzhi,Li Chengcheng,Yin Xingyao,et al. A shear velocity estimation method for carbonate rocks based on the improved XuWhite model[J]. Oil Geophysical Prospecting,2012,47(5):717-722.
[3] Xu S,White R E. A new velocity model for clay-sand mixtures[J].Geophysical Prospecting,1995,43(1):91-118.
[4]杨敏,李明,李艳东,等.优化岩石物理模型以提高横波速度预测精度[J].石油天然气学报,2013,35(7):74-77.Yang Min,Li Ming,Li Yandong,et al. Prediction of shear wave velocity by using optimized rock physical models[J]. Journal of Oil and Gas Technology,2013,35(7):74-77.
[5] Mavko G,Mukerje T,Dvorkin J. The rock physics handbook:tools for seismic analysis in porous media[M]. Cambridge:Cam-bridge University Press,1998:106-132.
[6] Berryman J G. Mixture theories for rock properties,in a handbook of physical constants[M]. Washington:American Geophysical Union,1995,205-228.
[7]镇晶晶,刘洋.裂缝介质岩石物理模型研究综述[J].地球物理学进展,2011,26(5):1708-1716.Zhen Jingjing,Liu Yang. Review over physical model of fractured rock medium[J]. Progress in Geophysics,2011,26(5):1708-1716.
[8] Shuey R T. A Simplification of the Zoeppritz equation[J]. Geophysics,1985,(5):609-614.
[9] Connolly P. Elastic impedance[J]. The Leading Edge,1999,18(4):438-452.
[10] Whitecombe D N,Connolly P A,Reagan R L,et al. Extended elastic impedance for fluid and lithology prediction[J]. Geophysics,2002,67(1):63-67.
[11] Li Yongyi,Jonathan D. The application of amplitude versus offset in carbonate reservoirs:re-examining the potential[C]∥SEG. SEG Technical Program Expanded Abstracts. Calgary:SEG,1949:166-169.
[12]李宗杰.正演模拟验证叠前弹性阻抗反演在碳酸盐岩储层预测中的应用[J].石油物探,2013,52(3):323-328.Li Zongjie. Application of pre-stack elastic impedance inversion in carbonate reservoirs prediction based on forward modeling[J]. Geophysical Prospecting for Petroleum,2013,52(3):323-328.
[13]唐金良,周单,王世星.基于叠前反演的缝洞型碳酸盐岩流体检测及评价技术研究[J].石油物探,2013,52(3):313-323.Tang Jinliang,Zhou Dan,Wang Shixing. Hydrocarbon prediction and evaluation of fracture-vuggy carbonate based on prestackinversion[J]. Geophysical Prospecting for Petroleum,2013,52(3):313-323.
[14]张远银,孙赞东,唐志远,等.基于AVO反演的溶蚀孔洞型碳酸盐岩储层预测[J].石油地球物理勘探,2013,48(1):109-113,120.Zhang Yuanyin,Sun Zandong,Tang Zhiyuan,et al. Caved carbonate reservoir prediction based on AVO inversion[J]. Oil Geophysical Prospecting,2013,48(1):109-113,120.
[15] Pickett G R. Acoustic character logs and their applications in formation evaluation[J]. Journal of Petroleum Technology,1963,15(6):650-667.
[16] Castagna J P. Shear-wave time-average equation for sand-stones[C]∥SEG. SEG Technical program expanded abstract. Washington D. C.:SEG,1985:447-448.
[17] Hill R. A self-consistent mechanics of composite materials[J]. Journal of the Mechanics&Physics of Solids,1965,13(4):213-222.
[18] Wood A W. A textbook of sound[M]. New York:The Mac Millan Co,1995:360-363.
[19] Gassmann F. Elastic waves through a packing of spheres[J]. Geophysics,1951,96:1-23.
[20]张广智,刘洪,印兴耀.井旁道精细地震子波提取方法[J].石油地球物理勘探,2005,40(2); 158-162.Zhang Guangzhi,Liu Hong,Yin Xingyao. Method for fine picking up seismic wavelet at up-hole trace[J]. Oil Geophysical Prospecting,2005,40(2):158~162.
[21]张恒,蔡忠贤,漆立新,等.塔中地区西北部鹰山组成岩早期岩溶作用类型及其特征[J].石油与天然气地质,2016,37(2):291-303.Zhang Heng,Cai Zhongxian,Qi Lixin,et al. Types and characteristics of eogenetic karst in the Yingshan Formation in northwestern Tazhong area,Tarim Basin[J]. Oil&Gas Geology,2016,37(2):291-303.
[22]韩长城,林承焰,鲁新便,等.塔河油田奥陶系碳酸盐岩岩溶斜坡断控岩溶储层特征及形成机制[J].石油与天然气地质,2016,37(5):644-652.Han Changcheng,Lin Chengyan,Lu Xinbian,et al. Characterization and genesis of fault-controlled karst reservoirs in Ordovician carbonate karst slope of Tahe oilfield,Tarim Basin[J]. Oil&Gas Geology,2016,37(5):644-652.
[23]张艳萍,吕修祥,于红枫,等.塔中隆起两组走滑断裂对岩溶储层发育的控制机制[J].石油与天然气地质,2016,37(5):663-673.Zhang Yanping,Lyu Xiuxiang,Yu Hongfeng,et al. Controlling mechanism of two strike-slip fault groups on the development of the Ordovician karst reservoirs in the Tazhong Uplift,Tarim Basin[J]. Oil&Gas Geology,2016,37(5):663-673.