Research on Segmentation Methods of Horizontal Wells

Abstract

To equalize the inflow profile of horizontal well and reduce the influence of water breakthrough, the horizontal well should be divided into several sections. The problem of horizontal well segmentation can be classified into two types. The first one is how to segment with sufficient data, and the second one is how to segment with insufficient data. For the former, three segmentation methods have been proposed, named uniform segmentation method, ordered clustering segmentation method, and optimization segmentation method. In this study, for further indicate the application scope and condition of these three methods, the advantages and disadvantages of each method are fully studied. For the latter, the influence of reservoir parameter uncertainty should be considered. In this study, the segmentation method based on robust optimization is proposed to solve this problem. Assume that the horizontal well could be divided into 5 segmentations. For horizontal wells with sufficient data, three segmentation methods are discussed and compared through reservoir simulation. Results show that, in terms of cumulative oil production, the optimization segmentation method is the highest, followed by the ordered clustering segmentation method, and the uniform segmentation method is the lowest. In terms of simulation time, the optimization segmentation method is the longest because the optimal segmentation scheme will be found after iterative simulation. The ordered clustering segmentation method and the uniform segmentation method do not need iterations, so the segmentation scheme could be determined quickly. Therefore, if the computational cost is available, the optimization segmentation method is recommended; if not, the ordered clustering segmentation method is recommended. For horizontal wells with insufficient data, the segmentation method based on robust optimization proposed in this study has been proven to be effective, because the cumulative oil production of this method is greater than that of the uniform segmentation method. In conclusion, the segmentation strategies for horizontal wells with sufficient or insufficient data are presented and discussed. It will contribute to the completion design of horizontal well. Meanwhile, it will also help to delay water breakthrough and enhance oil production.