基于分型理论和神经网络的页岩气可钻性研究
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摘要
随着页岩气的大力开发,页岩气钻井过程中的机械钻速低、钻井周期长以及钻头磨损严重等问题日益突出,因此,预测地层岩石可钻性和建立地层岩石可钻性剖面有着十分重要的意义。文章结合分形理论对分形维数进行推导与分析,确定出上返岩屑的分形维数与岩屑质量和岩屑尺寸之间的联系。并以岩屑分形维数和测井数据作为输入参数,可钻性极值作为输出参数,利用BP神经网络建立涪陵页岩气区块输入参数与输出参数之间的映射关系。最后,进行了实例验证,结果与现场实际吻合,表明该方法具有现场实用性,对实际生产开发有一定指导意义。
With the shale gas development,it is becoming important to predict formation drillability and set up the rock drillability profile. In this article the fractal theory is briefly introduced,and the fractal dimensions D is derived and analyzed,the relationship between the cuttings dimensions and quality,and sizes is determined. The fractal dimension and log data are used as input parameters and the drillability extreme values are the output parameters. The mapping relationship between input parameters and output parameters of Fuling shale gas block is established using BP neural network. The model has been proved with high fitting degree by cases,which will be a guide for actual development.
With the shale gas development,it is becoming important to predict formation drillability and set up the rock drillability profile. In this article the fractal theory is briefly introduced,and the fractal dimensions D is derived and analyzed,the relationship between the cuttings dimensions and quality,and sizes is determined. The fractal dimension and log data are used as input parameters and the drillability extreme values are the output parameters. The mapping relationship between input parameters and output parameters of Fuling shale gas block is established using BP neural network. The model has been proved with high fitting degree by cases,which will be a guide for actual development.
引文
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[3]闫铁,张杨,杜树明.基于岩屑分形破碎特征的钻井工程能效评价模型[J].岩石力学与工程学报,2014,33(增):3158-3163.
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[5]杨明合,翟应虎,夏宏南.区域地层可钻性场数值模拟计算方法研究[J].石油地质与工程,2008,22(3):82-84.
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[7] Botsis J,Kunin B. On self-similarity of crack layer[J].Int. J Fracturing,1987,35:51-56.
[8]闫铁,李玮,李士斌.牙轮钻头的岩屑破碎机理及可钻性的分形法[J].石油钻采工艺,2007,29(2):27-30.
[9]马海,王延江,魏茂安,等.地层可钻性极值预测新方法[J].石油学报,2008,29(5):761-765.
[10]张辉,高德利.钻头下部未钻井地层的可钻性预测新方法[J].石油学报,2006,27(1):97-100.
[2]李士斌,李玮,由洪利.基于分形理论的岩石可钻性分级方法[J].天然气工业,2007,27(10):63-66.
[3]闫铁,张杨,杜树明.基于岩屑分形破碎特征的钻井工程能效评价模型[J].岩石力学与工程学报,2014,33(增):3158-3163.
[4]王谦源,张清.不等概率分形破碎及有限尺度破碎体分形[J].岩石力学与工程学报,1994,13(2):109-117.
[5]杨明合,翟应虎,夏宏南.区域地层可钻性场数值模拟计算方法研究[J].石油地质与工程,2008,22(3):82-84.
[6]谢和平.分形-岩石力学导论[M].北京:科学出版社,1997:240-246.
[7] Botsis J,Kunin B. On self-similarity of crack layer[J].Int. J Fracturing,1987,35:51-56.
[8]闫铁,李玮,李士斌.牙轮钻头的岩屑破碎机理及可钻性的分形法[J].石油钻采工艺,2007,29(2):27-30.
[9]马海,王延江,魏茂安,等.地层可钻性极值预测新方法[J].石油学报,2008,29(5):761-765.
[10]张辉,高德利.钻头下部未钻井地层的可钻性预测新方法[J].石油学报,2006,27(1):97-100.