基于成像矿物谱的页岩气储层脆性指数计算方法——以四川盆地南部下志留统龙马溪组为例
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摘要
页岩气储层脆性指数是页岩气藏压裂方案设计所需的核心参数之一,但目前获取该指数的方法成本较高、耗时耗力且过分依赖于取心资料。为了解决上述问题,以四川盆地南部下志留统龙马溪组页岩气储层为研究对象,首先对该区的成像测井数据进行分析和校正、进行图像的直方图加强,将成像测井图像刻度为成像矿物谱;然后基于正态分布理论,并结合实验分析数据,通过解析成像矿物谱,获得了页岩气储层矿物含量;进而结合裂缝特征等建立了脆性指数的计算模型,形成了矿物含量及脆性指数的计算方法(以下简称新方法),并在该区的多口页岩气井进行了验证。研究结果表明:①新方法具有成本较低、适用性强、计算精度和实用价值较高等优点;②较之于目前常用的方法,新方法数据资料具有普遍性、脆性指数计算结果具有连续性;③新方法能够精确地反映层理、薄层及局部岩性变化等对脆性指数的影响,对于页岩气储层脆性及可压裂性评价有着重要的参考作用;④现场应用效果表明,新方法计算结果与实钻结果吻合程度高,该区多口井测试均获得了页岩气工业产能。结论认为,新方法为海相页岩气储层压裂优选评价提供了技术支撑。
The brittleness index of shale gas reservoirs is one of the key parameters for the fracturing scheme design. At present, however, the current method to calculate the brittleness index is expensive, time and labor consuming, and overly dependent on coring data.In view of this, the Lower Silurian Longmaxi shale gas reservoir in the southern Sichuan Basin was taken as the research object in this paper. Firstly, the imaging log data of this area was analyzed and corrected, the images were enhanced in the form of histogram and the imaging log image was calibrated as the imaging spectroscopy mineral map. Then, based on the theory of normal distribution, combined with experimental analysis data, the mineral content of shale gas reservoirs was estimated by analyzing the mineral map. Finally, based on fracture characteristics, the calculation model for brittleness index was established. In this way, a new method for calculating mineral content and brittleness index was developed and has been verified in many shale gas wells in this area. And the following research results were obtained. First, this new method has the advantages of low cost, strong applicability, high calculation accuracy and practical value. Second, compared with the brittleness index calculation methods that are currently used, the data obtained by the new method are universal and its brittleness index calculation results are continuous. Third, this new method can accurately reflect the effects of bedding,thin layer and local lithology change on the brittleness index, playing an important role in evaluating the brittleness and fracturing performance of shale gas reservoirs. Fourth, field application reveals that the calculation results of this new method are in a better accordance with the actual drilling results. Industrial productivity of shale gas is achieved in many wells of this area during the testing. In conclusion,this new method provides a technical support for fracturing optimization and evaluation of marine shale gas reservoirs.
The brittleness index of shale gas reservoirs is one of the key parameters for the fracturing scheme design. At present, however, the current method to calculate the brittleness index is expensive, time and labor consuming, and overly dependent on coring data.In view of this, the Lower Silurian Longmaxi shale gas reservoir in the southern Sichuan Basin was taken as the research object in this paper. Firstly, the imaging log data of this area was analyzed and corrected, the images were enhanced in the form of histogram and the imaging log image was calibrated as the imaging spectroscopy mineral map. Then, based on the theory of normal distribution, combined with experimental analysis data, the mineral content of shale gas reservoirs was estimated by analyzing the mineral map. Finally, based on fracture characteristics, the calculation model for brittleness index was established. In this way, a new method for calculating mineral content and brittleness index was developed and has been verified in many shale gas wells in this area. And the following research results were obtained. First, this new method has the advantages of low cost, strong applicability, high calculation accuracy and practical value. Second, compared with the brittleness index calculation methods that are currently used, the data obtained by the new method are universal and its brittleness index calculation results are continuous. Third, this new method can accurately reflect the effects of bedding,thin layer and local lithology change on the brittleness index, playing an important role in evaluating the brittleness and fracturing performance of shale gas reservoirs. Fourth, field application reveals that the calculation results of this new method are in a better accordance with the actual drilling results. Industrial productivity of shale gas is achieved in many wells of this area during the testing. In conclusion,this new method provides a technical support for fracturing optimization and evaluation of marine shale gas reservoirs.
引文
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[8]孙建孟,韩志磊,秦瑞宝,张晋言.致密气储层可压裂性测井评价方法[J].石油学报,2015,36(1):74-80.Sun Jianmeng,Han Zhilei,Qin Ruibao&Zhang Jinyan.Log evaluation method of fracturing performance in tight gas reservoir[J].Acta Petrolei Sinica,2015,36(1):74-80.
[9]袁俊亮,邓金根,张定宇,李大华,闫伟,陈朝刚,等.页岩气储层可压裂性评价技术[J].石油学报,2013,34(3):523-527.Yuan Junliang,Deng Jingen,Zhang Dingyu,Li Dahua,Yan Wei,Chen Chaogang,et al.Fracability evaluation of shale-gas reservoirs[J].Acta Petrolei Sinica,2013,34(3):523-527.
[10]Rickman R,Mullen MJ,Petre JE,Grieser WV&Kundert D.Apractical use of shale petrophysics for stimulation design optimization:All shale plays are not clones of the Barnett Shale[C]//Paper 115258-MS Presented at the SPE Annual Technical Conference and Exhibition,21-24 September 2008,Denver,Colorado,USA.
[11]Sondergeld CH,Newsham KE,Comisky JT,Rice MC&Rai CS.Petrophysical considerations in evaluating and producing shale gas resources[C]//Paper 131768-MS presented at the SPE Unconventional Gas Conference,23-25 February 2010,Pittsburgh,Pennsylvania,USA.
[12]赖锦,王贵文,范卓颖,陈晶,王抒忱,周正龙,等.非常规油气储层脆性指数测井评价方法研究进展[J].石油科学通报,2016,1(3):330-341.Lai Jin,Wang Guiwen,Fan Zhuoying,Chen Jing,Wang Shuchen,Zhou Zhenglong,et al.Research progress in brittleness index evaluation methods with logging data in unconventional oil and gas reservoirs[J].Petroleum Science Bulletin,2016,1(3):330-341.
[13]徐赣川,钟光海,谢冰,黄天俊.基于岩石物理实验的页岩脆性测井评价方法[J].天然气工业,2014,34(12):38-45.Xu Ganchuan,Zhong Guanghai,Xie Bing&Huang Tianjun.Petrophysical experiment-based logging evaluation method of shale brittleness[J].Natural Gas Industry,2014,34(12):38-45.
[14]Zhang D,Ranjith PG&Perera MS.The brittleness indices used in rock mechanics and their application in shale hydraulic fracturing:A review[J].Journal of Petroleum Science and Engineering,2016,143:158-170.
[15]张矿生,刘顺,蒋建方,刘光普,蒋睿.长7致密油藏脆性指数计算方法及现场应用[J].油气井测试,2014,23(5):29-33.Zhang Kuangsheng,Liu Shun,Jiang Jianfang,Liu Guangpu&Jiang Rui.Calculation method about brittleness index in Chang7 dense reservoir and its field application[J].Well Testing,2014,23(5):29-33.
[16]Feng X,Liu C,Li XY,Guo Z&Shen Y.A shale rock physics model for analysis of brittleness index,mineralogy and porosity in the Barnett Shale[J].Journal of Geophysics and Engineering,2013,10(2):1-10.
[17]韩超,吴明昊,吝文,孔祥鑫,姜在兴,高丽华,等.川南地区五峰组-龙马溪组黑色页岩储层特征[J].中国石油大学学报(自然科学版),2017,41(3):14-22.Han Chao,Wu Minghao,Lin Wen,Kong Xiangxin,Jiang Zaixing,Gao Lihua,et al.Characteristics of black shale reservoir of Wufeng-Longmaxi formation in the southern Sichuan Basin[J].Journal of China University of Petroleum(Edition of Natural Science),2017,41(3):14-22.
[18]张晨晨,王玉满,董大忠,管全中.川南长宁地区五峰组-龙马溪组页岩脆性特征[J].天然气地球科学,2016,27(9):1629-1639.Zhang Chenchen,Wang Yuman,Dong Dazhong&Guan Quanzhong.Brittleness characteristics of Wufeng-Longmaxi shale in Changning region,Southern Sichuan,China[J].Natural Gas Geoscience,2016,27(9):1629-1639.
[19]赖锦,王贵文,孙思勉,蒋晨,周磊,郑新华,等.致密砂岩储层裂缝测井识别评价方法研究进展[J].地球物理学进展,2015,30(4):1712-1724.Lai Jin,Wang Guiwen,Sun Simian,Jiang Chen,Zhou Lei,Zheng Xinhua,et al.Research advance in logging recognition and evaluation method of fractures in tight sandstone reservoirs[J].Progress in Geophysics,2015,30(4):1712-1724.
[20]吴鹏程,陈一健,杨琳,戢俊文.成像测井技术研究现状及应用[J].天然气勘探与开发,2007,30(2):36-40.Wu Pengcheng,Chen Yijian,Yang Lin&Ji Junwen.Review of imaging logging[J].Natural Gas Exploration and Development,2007,30(2):36-40.
[21]李启翠,楼一珊,史文专,杨鹏,孔嫦娥,郭昊.FMI成像测井在四川盆地页岩气地层中的应用[J].石油地质与工程,2013,27(6):58-60.Li Qicui,Lou Yishan,Shi Wenzhuan,Yang Peng,Kong Chang'e&Guo Hao.Application of FMI imaging logging in shale gas formation of Sichuan Basin[J].Petroleum Geology and Engineering,2013,27(6):58-60.
[22]耿会聚,王贵文,李军,洪琪,秦民君.成像测井图像解释模式及典型解释图版研究[J].江汉石油学院学报,2002,24(1):26-29.Geng Huiju,Wang Guiwen,Li Jun,Hong Qi&Qin Minjun.Image interpretation modes and the typical interpretation chart for imaging well logging[J].Journal of Jianghan Petroleum Institute,2002,24(1):26-29.
[2]乔辉,贾爱林,贾成业,位云生,袁贺.长宁地区优质页岩储层非均质性及主控因素[J].西南石油大学学报(自然科学版),2018,40(3):23-33.Qiao Hui,Jia Ailin,Jia Chengye,Wei Yunsheng&Yuan He.Factors controlling heterogeneity in the high-quality shale reservoirs of the Changning Region[J].Journal of Southwest Petroleum University(Science&Technology Edition),2018,40(3):23-33.
[3]宋岩,姜林,马行陟.非常规油气藏的形成及其分布特征[J].古地理报,2013,15(5):605-614.Song Yan,Jiang Lin&Ma Xingzhi.Formation and distribution characteristics of unconventional oil and gas reservoirs[J].Journal of Palaeogeography,2013,15(5):605-614.
[4]夏宏泉,王瀚玮,赵昊.测井多参数两向量法识别页岩气地质“甜点”[J].天然气工业,2017,37(11):36-42.Xia Hongquan,Wang Hanwei&Zhao Hao.Logging multi-parameter two-vector method used for identifying geological"sweet spots"of shale gas[J].Natural Gas Industry,2017,37(11):36-42.
[5]李金磊,李文成.涪陵页岩气田焦石坝区块页岩脆性指数地震定量预测[J].天然气工业,2017,37(7):13-19.Li Jinlei&Li Wencheng.A quantitative seismic prediction technique for the brittleness index of shale in the Jiaoshiba Block,Fuling shale gas field in the Sichuan Basin[J].Natural Gas Industry,2017,37(7):13-19.
[6]蒋裕强,董大忠,漆麟,沈妍斐,蒋婵,何溥为.页岩气储层的基本特征及其评价[J].天然气工业,2010,30(10):7-12.Jiang Yuqiang,Dong Dazhong,Qi Lin,Shen Yanfei,Jiang Chan&He Fuwei.Basic features and evaluation of shale gas reservoirs[J].Natural Gas Industry,2010,30(10):7-12.
[7]付永强,马发明,曾立新,佘朝毅,陈艳.页岩气藏储层压裂实验评价关键技术[J].天然气工业,2011,31(4):51-54.Fu Yongqiang,Ma Faming,Zeng Lixin,She Chaoyi&Chen Yan.Key techniques of experimental evaluation in the fracturing treatment for shale gas reservoir[J].Natural Gas Industry,2011,31(4):51-54.
[8]孙建孟,韩志磊,秦瑞宝,张晋言.致密气储层可压裂性测井评价方法[J].石油学报,2015,36(1):74-80.Sun Jianmeng,Han Zhilei,Qin Ruibao&Zhang Jinyan.Log evaluation method of fracturing performance in tight gas reservoir[J].Acta Petrolei Sinica,2015,36(1):74-80.
[9]袁俊亮,邓金根,张定宇,李大华,闫伟,陈朝刚,等.页岩气储层可压裂性评价技术[J].石油学报,2013,34(3):523-527.Yuan Junliang,Deng Jingen,Zhang Dingyu,Li Dahua,Yan Wei,Chen Chaogang,et al.Fracability evaluation of shale-gas reservoirs[J].Acta Petrolei Sinica,2013,34(3):523-527.
[10]Rickman R,Mullen MJ,Petre JE,Grieser WV&Kundert D.Apractical use of shale petrophysics for stimulation design optimization:All shale plays are not clones of the Barnett Shale[C]//Paper 115258-MS Presented at the SPE Annual Technical Conference and Exhibition,21-24 September 2008,Denver,Colorado,USA.
[11]Sondergeld CH,Newsham KE,Comisky JT,Rice MC&Rai CS.Petrophysical considerations in evaluating and producing shale gas resources[C]//Paper 131768-MS presented at the SPE Unconventional Gas Conference,23-25 February 2010,Pittsburgh,Pennsylvania,USA.
[12]赖锦,王贵文,范卓颖,陈晶,王抒忱,周正龙,等.非常规油气储层脆性指数测井评价方法研究进展[J].石油科学通报,2016,1(3):330-341.Lai Jin,Wang Guiwen,Fan Zhuoying,Chen Jing,Wang Shuchen,Zhou Zhenglong,et al.Research progress in brittleness index evaluation methods with logging data in unconventional oil and gas reservoirs[J].Petroleum Science Bulletin,2016,1(3):330-341.
[13]徐赣川,钟光海,谢冰,黄天俊.基于岩石物理实验的页岩脆性测井评价方法[J].天然气工业,2014,34(12):38-45.Xu Ganchuan,Zhong Guanghai,Xie Bing&Huang Tianjun.Petrophysical experiment-based logging evaluation method of shale brittleness[J].Natural Gas Industry,2014,34(12):38-45.
[14]Zhang D,Ranjith PG&Perera MS.The brittleness indices used in rock mechanics and their application in shale hydraulic fracturing:A review[J].Journal of Petroleum Science and Engineering,2016,143:158-170.
[15]张矿生,刘顺,蒋建方,刘光普,蒋睿.长7致密油藏脆性指数计算方法及现场应用[J].油气井测试,2014,23(5):29-33.Zhang Kuangsheng,Liu Shun,Jiang Jianfang,Liu Guangpu&Jiang Rui.Calculation method about brittleness index in Chang7 dense reservoir and its field application[J].Well Testing,2014,23(5):29-33.
[16]Feng X,Liu C,Li XY,Guo Z&Shen Y.A shale rock physics model for analysis of brittleness index,mineralogy and porosity in the Barnett Shale[J].Journal of Geophysics and Engineering,2013,10(2):1-10.
[17]韩超,吴明昊,吝文,孔祥鑫,姜在兴,高丽华,等.川南地区五峰组-龙马溪组黑色页岩储层特征[J].中国石油大学学报(自然科学版),2017,41(3):14-22.Han Chao,Wu Minghao,Lin Wen,Kong Xiangxin,Jiang Zaixing,Gao Lihua,et al.Characteristics of black shale reservoir of Wufeng-Longmaxi formation in the southern Sichuan Basin[J].Journal of China University of Petroleum(Edition of Natural Science),2017,41(3):14-22.
[18]张晨晨,王玉满,董大忠,管全中.川南长宁地区五峰组-龙马溪组页岩脆性特征[J].天然气地球科学,2016,27(9):1629-1639.Zhang Chenchen,Wang Yuman,Dong Dazhong&Guan Quanzhong.Brittleness characteristics of Wufeng-Longmaxi shale in Changning region,Southern Sichuan,China[J].Natural Gas Geoscience,2016,27(9):1629-1639.
[19]赖锦,王贵文,孙思勉,蒋晨,周磊,郑新华,等.致密砂岩储层裂缝测井识别评价方法研究进展[J].地球物理学进展,2015,30(4):1712-1724.Lai Jin,Wang Guiwen,Sun Simian,Jiang Chen,Zhou Lei,Zheng Xinhua,et al.Research advance in logging recognition and evaluation method of fractures in tight sandstone reservoirs[J].Progress in Geophysics,2015,30(4):1712-1724.
[20]吴鹏程,陈一健,杨琳,戢俊文.成像测井技术研究现状及应用[J].天然气勘探与开发,2007,30(2):36-40.Wu Pengcheng,Chen Yijian,Yang Lin&Ji Junwen.Review of imaging logging[J].Natural Gas Exploration and Development,2007,30(2):36-40.
[21]李启翠,楼一珊,史文专,杨鹏,孔嫦娥,郭昊.FMI成像测井在四川盆地页岩气地层中的应用[J].石油地质与工程,2013,27(6):58-60.Li Qicui,Lou Yishan,Shi Wenzhuan,Yang Peng,Kong Chang'e&Guo Hao.Application of FMI imaging logging in shale gas formation of Sichuan Basin[J].Petroleum Geology and Engineering,2013,27(6):58-60.
[22]耿会聚,王贵文,李军,洪琪,秦民君.成像测井图像解释模式及典型解释图版研究[J].江汉石油学院学报,2002,24(1):26-29.Geng Huiju,Wang Guiwen,Li Jun,Hong Qi&Qin Minjun.Image interpretation modes and the typical interpretation chart for imaging well logging[J].Journal of Jianghan Petroleum Institute,2002,24(1):26-29.