塔河油田一井多靶可酸溶堵漏技术

塔河油田碳酸盐岩油藏欠发育区储层缝洞规模小,单井难以实现经济开发,通过采用“一井多靶”钻井穿过多个缝洞储集体,可有效提高单井产能,而钻遇的复杂缝洞漏失问题制约了钻井工程提速提效。针对碳酸盐岩储层堵漏技术难点,分析储层漏失特征及堵漏需求,研制了一种可酸溶凝胶颗粒,酸溶率大于86%,膨胀倍数为3～5倍,膨胀后具有良好的韧性和变形性。基于凝胶颗粒堵漏机理,采用正交实验方法,形成了与可酸溶凝胶颗粒协同复配可酸溶的矿物柔性纤维、片状等材料的可酸溶凝胶复合堵漏剂,抗温150℃,酸溶率大于85%,适应0.1～3.0 mm裂缝和4～10目的孔隙,正向承压强度大于9 MPa,反向承压强度大于5 MPa,现场应用效果表明,该堵漏技术可解决碳酸盐岩储层复杂的缝洞漏失问题,应用前景广。

Study on an Acid Soluble LCM Used for Multi-Target Well in Tahe Oilfield

The underdeveloped carbonate reservoirs in the Tahe Oilfield have fractures and vugs that are small scaled and production through a single well generally cannot realize its expected economy. Use multi-target well to penetrate multiple fractured reservoirs or reservoirs with vugs through one well, the production potential of a single well can be economically increased. The problem with the multi-target well drilling is mud losses in the complex fracture structures, which restrict the realization of fast and high efficiency drilling. By analyzing the characteristics of the mud losses taking place in fractured reservoirs and the difficulties encountered during drilling, an acid-soluble gel particle lost circulation material (LCM) was developed to solve the mud losses in reservoir drilling. Percent acid solubility of this LCM is 86%. After swelling, the volume of the LCM can be 3-5 times of its original volume, and the swollen LCM has good toughness and deformability. The acid soluble gel particle LCM, through orthogonal test, was mixed with an acid soluble flexible fiber and a flaky material to form a compound acid soluble LCM based on the mechanisms of mud loss control with gel particles. The compound LCM can be used at temperatures up to 150 ℃ and has percent acid solubility of 85%. It can used to stop mud losses through fractures of 0.1-3.0 mm in width and pores of 4-10 mesh. The pressure bearing capacity of the LCM layer is 9 MPa on the front side and 5 MPa on the opposite. Field application has shown that this compound acid soluble LCM can be used to solve mud losses into the complex fractures developed in carbonate rock reservoirs and should have broad application prospects.