超高温屏蔽暂堵剂SMHHP的室内实验研究

Laboratory Study on Ultra-high Temperature Temporary Plugging Agent SMHHP

为满足超高温储层暂堵要求,开发了一种屏蔽暂堵剂SMHHP。该屏蔽暂堵剂由颗粒材料、纤维材料、弹性材料和纳米材料组成,通过利用理想充填理论确定粒径级配,优选了颗粒材料;引入高酸溶抗高温纤维,起到相互拉筋的作用,提高封堵层的稳定性;利用高温弹性材料,弥补由于材料加工工艺导致的颗粒不规则造成的级配不合适,提高粒径级配效果;利用纳米材料,对架桥填充后留下的小孔隙进行精细封堵,提高封堵层的致密性。将上述材料通过合理配比,开发出了适用于超高温储层的屏蔽暂堵剂SMHHP。该暂堵剂具有对钻井液流变性影响小、抗温性高、封堵性强、暂堵效果好、酸溶率高的特点,抗温可达200℃,0.2 mm裂缝承压大于7 MPa,砂粒为0.28~0.90 mm的砂床侵入深度小于3 cm,岩心渗透率恢复值达到93.9%以上,酸溶率大于82.1%,可在超高温储层段使用,起到保护油气层的作用。

A temporary plugging agent SMHHP has been developed to satisfy the needs of temporary plugging in ultra-high temperature reservoirs. SMHHP is composed of particle material, fiber material, elastic material and nanophase material which are in reasonable ratios. The sizing and selection of particles was based on ideal packing theory. A high temperature highly acid soluble fiber was introduced into SMHHP to improve the stability of the plugged formations. Considering the poor adaptability of particle sizes to the sizes of pores to be plugged because of the irregularity of particles during processing, a high temperature elastic material was added into SMHHP. Tiny pores formed in bridging can be further precisely packed with nanophase material, thereby improvingthe compactability of plugged formations. SMHHP only slightly affect mud rheology, and has high temperature resistance, strong sealing ability, goodtemporary plugging effect and high acid solubility. SMHHP functioned normally at 200 ℃. Test performed with SMHHP slurry on 0.2 mm fractures showed that pressure bearing capacity of more than 7 MPa can be achieved. Filtration depth of SMHHP slurry on sand bed with 0.28-0.90 mm sand particles was less than 3 cm. Percent permeability recovery of cores contaminated with SMHHP slurry was greater than 93.9%. Acid solubility of SMHHP was greater than 82.1%. SMHHP can be used in reservoirs of ultrahigh temperatures, protecting the reservoirs from being damaged.