“多级孔隙最优充填”暂堵方法与现场试验

Temporary Plugging and Field Testing with"Optimum Filling for Multi-stage Pores"Method

为了提高对渗透率贡献较大孔隙孔径分布不集中储层的暂堵效率,提出了"多级孔隙最优充填"暂堵方法。该方法基于"隔层堆积"理论,将储层孔隙与暂堵微粒的连续分布进行离散处理及匹配,对储层多级孔隙进行"最优充填",即可得到架桥颗粒的标准粒度分布曲线。对岐口凹陷某区块储层岩心进行连续分布孔隙离散后,对其进行"多级孔隙最优充填",依据得到的标准粒度分布曲线对现有的暂堵剂颗粒分布进行了优选,1 000目碳酸钙的粒度分布最接近标准粒度分布曲线。储层保护试验结果表明,加入利用"多级孔隙最优充填"方法优选暂堵剂颗粒的钻井液具有良好的暂堵效果,其污染深度<0.9cm,污染端切去后其渗透率恢复率达97.29%。现场应用结果表明,加入优化暂堵剂颗粒的钻井液能形成封堵层,阻止钻井液滤液侵入地层。这表明"多级孔隙最优充填"方法可用于孔隙孔径分布不集中储层暂堵颗粒的优选,暂堵效果优良。

To improve temporary plugging efficiency of reservoir rock with divergent distribution of larger pores,the temporary plugging method called＂optimum filling for multi-stage pores＂are presented in this paper.Based on the＂interlayer packing＂theory,continuous distribution of pore and bridging particles were discretely processed and matched to let reservoir pores be best filled,getting standard particle size distribution curve.The discrete process of continuous pore distribution was used to Qikou depression for selecting bridging particles in terms of distribution curve of particle sizes to get the best filling of multi-stage pores.The results showed that size distribution of calcium carbonate particles larger than 100-mesh was the best match of the standard size distribution curves.Reservoir protection experimental results indicated that drilling and completion fluid developed based on＂best filling of multi-level pores＂temporary plugging methods had good sealing performance,the pollution depth was less than 0.9 cm,and the rock permeability recovery rate was 97.29% after the polluting end being cut down.Field application results showed that the optimized particles can form a seal to prevent drilling and completion fluid from entering into formation,it can be concluded that temporary plugging method of＂best filling of multi-stage pores＂is suitable and effective for optimization of bridging particles for those pay zones with dispersed pores.