高温深层非均质性碳酸盐岩水平井分段改造技术

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

碳酸盐岩非均质性强的特点决定了常规水平井分段改造优化设计方法不再适用,同时塔中地区高温、深层及缝洞发育等特点给储层改造液体和分段改造工艺带来挑战。从统计分析反映非均质性储层特征的资料出发,确定了基于改造设计为目的的压前储层描述模型,明确反映远井储层特征的地震资料对于指导改造设计具有重要作用,并基于该认识,建立了在缝洞精细雕刻基础上的非均质性碳酸盐岩水平井分段改造优化设计方法。通过稠化剂优选、交联剂研发形成耐温140℃地面交联酸体系,其低滤失、缓速好的特征为实现深穿透酸蚀缝提供基础;并根据碳酸盐岩缝洞发育特点,优选裸眼封隔器多级滑套水平井分段压裂工具,从而形成系统的水平井分段改造技术。现场应用表明,该技术适用性好,增产效果显著,在国内同类非均质性海相碳酸盐岩储层中具备较大的推广应用前景。

The conventional design method is no longer applicable to the segmented reconstruction and optimization of horizontal well due to the strong carbonate heterogeneity.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 lfuid 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 relfects the important guiding function of the seismic data about distant-well reservoir characteristics in the recon-struction design. On the basis of this recognition and the ifne seam/cave carving, the design method for segmented reconstruction and op-timization 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 R＆D 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 ifeld application indicates that this technique has a good applicability and increases the yield signiifcantly. Therefore, this technique has a great prospect of popularization and application in the similar heterogeneous marine carbonate reservoir at home.