胶结型强封堵防塌剂的研制与性能评价

Development and Performance Evaluation of Strong Plugging and Anti-collapse Agent with Cementation Type

余加水 尤志良 付超胜 敖 天 蒋官澄 谢春林 孔德昌

YU Jiashui YOU Zhiliang FU Chaosheng AO Tian JIANG Guancheng XIE Chunlin KONG Dechang

为改善准噶尔盆地南缘地区破碎性地层引起的钻井过程中井壁失稳及井漏问题，结合仿生强封堵理论，通过模仿贝壳的多层复合结构，研制了一种油基钻井液胶结型强封堵防塌剂XZ-OSD。通过扫描电镜和红外光谱表征了XZ-OSD的结构，评价了其热稳定性、降滤失效果和封堵性，并分析了封堵机理。结果表明，XZ-OSD的球状颗粒尺寸为50~200 nm。XZ-OSD的热稳定性较好，分解温度为250℃。XZ-OSD的降滤失效果显著，在基浆中仅加入1% XZ-OSD，油基钻井液API滤失量降低72.22%，150℃ 高温高压滤失量降低81.43%。XZ-OSD保护油气层效果显著，在堵漏浆中加入 1% XZ-OSD 后，岩心的正向封堵率和反向封堵率分别提高 2.89 倍和 0.4 倍。XZ-OSD高温封堵效果良好，在堵漏浆中加入6% XZ-OSD，180℃热滚16 h后的滤失量仅为2 mL。XZ-OSD在进入地层后，能进入不同尺寸孔隙、裂缝，通过桥塞和架桥作用封堵孔隙、裂缝，同时遇油膨胀，通过膨胀性能和XZ-OSD的胶结能力保证漏层承压能力，进而提高井筒稳定性，避免井漏等井下复杂事故发生。

In order to improve the problems of wellbore instability and lost circulation caused by fractured strata in the southern margin of Junggar Basin，a cementing strong plugging and anti-collapse agent XZ-OSD was developed by imitating the multilayer composite structure of shell and combining the bionic strong plugging theory. The structure of XZ-OSD was characterized by SEM and IR，its thermal stability，fluid loss reduction effect and plugging property were evaluated，and the plugging mechanism was analyzed. The results showed that the spherical particle size of XZ-OSD was 50—200 nm. XZ-OSD had good thermal stability，and the decomposition temperature was 250℃. XZ-OSD had a significant fluid loss reduction effect. When only 1% XZ-OSD was added to the base slurry，the API fluid loss of oil-based drilling fluid was reduced by 72.22%，and the fluid loss at 150℃ high temperature and high pressure was reduced by 81.43%. XZ-OSD had a significant effect in protecting oil and gas formation. After 1% XZ-OSD was added to the plugging slurry，the forward plugging rate and reverse plugging rate of the core were increased by 2.89 times and 0.4 times，respectively. XZ-OSD had a good plugging effect at hightemperature. When 6% XZ-OSD was added to the plugging slurry，the fluid loss after heating at 180℃ for 16 h was only 2 mL. After entering the formation，XZ-OSD could enter pores and cracks of different sizes，plug the pores and cracks through the bridge plug and bridging. Furthermore，XZ-OSD expanded in contact with oil，the pressure-bearing capacity of leakage layer was enhanced through the expansion property and the cementing ability，thereby improving the stability of wellbore，and avoiding the occurrence of complicated down-hole accidents such as lost circulation.