The aim of this paper is to solve the problems that the existing method of critical production of gas cap reservoir is only suitable for single-phase flow, and the method of critical production of gas cap reservoir un...The aim of this paper is to solve the problems that the existing method of critical production of gas cap reservoir is only suitable for single-phase flow, and the method of critical production of gas cap reservoir under water-flooding is still blank. In this paper, the relationships between dynamic and static equilibrium, plane radial flow theory, oil-water infiltration method and three-dimensional seepage field decomposition theory, were applied to study a calculation method for critical production of directional wells and horizontal wells. Furthermore, the effects of different factors on critical output were studied, such as horizontal permeability, ratio of horizontal permeability to vertical permeability, length of horizontal section, effective thickness, viscosity of crude oil and water content etc. Results show that the critical production increases with the increment of the horizontal permeability, the ratio of the vertical permeability to the horizontal permeability, the reservoir thickness and the horizontal well length;when the viscosity of crude oil is small, the critical production decreases first and then increases with the increase of water content;when the viscosity of crude oil is high, the critical production increases continuously with the increase of water content. This study could provide theoretical and technical guidance for changing of the working system of oil wells. It can avoid gas channeling and improve the development effect.展开更多
CFSFDP算法(Clustering by Fast Search and Find of Density Peaks)具有简单高效且需要较少参数的优点,但存在需要人为确定截断距离参数和聚类中心的不足。为克服以上不足,提出了自适应快速搜索密度峰值聚类算法。该算法针对截断距离...CFSFDP算法(Clustering by Fast Search and Find of Density Peaks)具有简单高效且需要较少参数的优点,但存在需要人为确定截断距离参数和聚类中心的不足。为克服以上不足,提出了自适应快速搜索密度峰值聚类算法。该算法针对截断距离参数的确定问题,构造关于截断距离参数的局部密度信息熵,通过最小化信息熵自适应地确定截断距离参数;针对聚类中心的确定问题,利用从非聚类中心到聚类中心数据点局部密度和距离的乘积,存在明显跳跃这一特征确定阈值,从而能自动确定聚类中心。实验结果表明该算法能够取得较好的聚类性能,且无需人为确定截断距离参数和聚类中心。展开更多
文摘The aim of this paper is to solve the problems that the existing method of critical production of gas cap reservoir is only suitable for single-phase flow, and the method of critical production of gas cap reservoir under water-flooding is still blank. In this paper, the relationships between dynamic and static equilibrium, plane radial flow theory, oil-water infiltration method and three-dimensional seepage field decomposition theory, were applied to study a calculation method for critical production of directional wells and horizontal wells. Furthermore, the effects of different factors on critical output were studied, such as horizontal permeability, ratio of horizontal permeability to vertical permeability, length of horizontal section, effective thickness, viscosity of crude oil and water content etc. Results show that the critical production increases with the increment of the horizontal permeability, the ratio of the vertical permeability to the horizontal permeability, the reservoir thickness and the horizontal well length;when the viscosity of crude oil is small, the critical production decreases first and then increases with the increase of water content;when the viscosity of crude oil is high, the critical production increases continuously with the increase of water content. This study could provide theoretical and technical guidance for changing of the working system of oil wells. It can avoid gas channeling and improve the development effect.
文摘CFSFDP算法(Clustering by Fast Search and Find of Density Peaks)具有简单高效且需要较少参数的优点,但存在需要人为确定截断距离参数和聚类中心的不足。为克服以上不足,提出了自适应快速搜索密度峰值聚类算法。该算法针对截断距离参数的确定问题,构造关于截断距离参数的局部密度信息熵,通过最小化信息熵自适应地确定截断距离参数;针对聚类中心的确定问题,利用从非聚类中心到聚类中心数据点局部密度和距离的乘积,存在明显跳跃这一特征确定阈值,从而能自动确定聚类中心。实验结果表明该算法能够取得较好的聚类性能,且无需人为确定截断距离参数和聚类中心。
