理想充填暂堵型钻井完井液的设计及室内评价

传统的暂堵方法主要是依据储层的平均孔喉直径优选暂堵剂的颗粒尺寸，对具有较大尺寸的孔喉封堵效果较差。对根据储层孔喉尺寸分布确定暂堵剂颗粒粒度分布的理想充填暂堵新方法进行了阐述，并依据该方法设计出理想充填暂堵型钻井完井液，在室内对其进行了性能评价。实验结果表明，理想充填暂堵型钻井完井液可有效地封堵同一储层中不同粒径的孔喉，尤其是较大尺寸的孔喉。与传统方法相比，该方法设计的钻井完井液对储层岩样的侵入深度较浅，可获得更高的岩心渗透率恢复值及更低的突破压力梯度，具有显著的储层保护效果。

Design and lab evaluation of ideal packing bridging drilling and completion fluids

Because the particle size of conventional bridging agents is optimized based on the mean pore size of target formation, it is difficult tO seal the pore throats with large size effectively by conventional temporary bridging methods. A novel ideal packing bridging method was presented, in which the grain-size distribution of bridging agents was determined according to the pores size in reservoir. The ideal packing bridging drilling and completion fluid was designed according to this method, and the performances of the drilling and completion fluid were evaluated in lab. The pore throats with different size in the same formation can be sealed effectively by the ideal packing method, especially for those with considerably large size. Compared with the conventional temporary bridging methods, a minimal invading radius due to a compacted mudcake formed on the face of borehole in a short time, higher return permeability, a lower breakthrough pressure gradient and preferable effectiveness of reservoir damage control can be obtained by applying this new method.