Segmented reconstruction technique of high-temperature deep heterogeneous carbonate horizontal well

The conventional design method is no longer applicable to the segmented reconstruction and optimization of horizontal well due to the strong carbonate heterogeneity. The characteristics of Tazhong area such as high temperature, deep layer and seam/cave development bring more challenges for reservoir fluid reconstruction and segmented reconstruction process. This article is based on the analysis of the data about heterogeneous reservoir characteristics, determines the pre-fracturing reservoir description model designed for reconstruction and reflects the important guiding function of the seismic data about distant-well reservoir characteristics in the reconstruction design. On the basis of this recognition and the fine seam/cave carving, the design method for segmented reconstruction and optimization of heterogeneous carbonate horizontal well is developed. And a cross-linked acid system with the heat resistance of 140 ℃ is established through thickener optimization and RD of cross-linking agent, and its characteristics of low leak-off and excellent reducing rate of acid-rock reaction provide the basis for deep penetration of acid corrosion seam. On the basis of development characteristics of carbonate seam/cave, the open hole packer, a horizontal-well segmented fracturing tool with multi-stage sliding sleeve, is recommended, so as to form a systematic horizontal-well segmented reconstruction technique. The field application indicates that this technique has a good applicability and increases the yield significantly. Therefore, this technique has a great prospect of popularization and application in the similar heterogeneous marine carbonate reservoir at home.