边界追踪算法在地质储量计算中的应用

单井控制面积计算是油田开发中原始和剩余地质储量研究的基础。针对注采井网形成的平面变密度离散点集的边界搜索问题，本文提出以角度为判别标准，基于变搜索步长的滚边新算法进行井网边界的追踪。首先通过合理的搜索步长确定当前边界点的邻域，然后对邻域内的离散点按角度进行排序并确定下个合理边界点，最后在井网边界追踪的基础上，进一步给出储量边界外扩和单井控制面积计算方法。该算法简单、高效，可有效识别变密度平面点集的凸边界和凹边界特征，并在大庆油田的原始地质储量复算和剩余潜力评价中得到应用，提高工效5倍以上，表内地质储量复算精度2.7%，取得了很好的应用效果。

Geological Reserve Calculation Based on Boundary Searching Algorithm

The calculation of well-controlled area is the foundation of geological and remaining reserve evaluation in the oilfield development and adjustment. As in the case of discrete points with variable well spaces, a new kind of edge pivoting boundary searching algorithm with angle identification and variable searching step is promoted. The neighborhood of the current boundary point is firstly determined based on a proper searching step. The corresponding angles of those points in the neighborhood are calculated and sorted, and the next proper boundary point is determined. Based on the identified boundary wells, the general boundary enlarging method is presented. And finally the well-controlled area calculation method is given. The algorithm has the advantages of easy-to-use and high efficiency. It could be effectively used to identify the convex and concave characteristic in a discrete point set with variable point spaces. The method has been applied in the geological reserve recalculation and remaining reserve evaluation in SZ oilfield, which improves the working efficiency more than 5 times, obtains an accuracy of 2.7% in the recalculation of geological reserve and shows a good result of application.