井筒高含水型微乳液冲洗液研究

随着油气资源开采的不断发展，油基钻井液因其优异的性能而广泛使用，这使得钻井后井筒井壁的润湿性转变为油润湿，影响固井水泥浆的胶结质量。通过冲洗液对井筒井壁上黏附的油基钻井液进行清洗，并转变其润湿性为水润湿是提高水泥胶结质量的有效措施之一。以EAB-40、SDBS、正丁醇、煤油、水为原料，制备了高水量（≥80%）型微乳液冲洗液，研究了微乳液的气泡率、清洗能力以及对岩心的润湿性转变能力，将微乳液制备成隔离液，通过隔离液清洗实验探究了隔离液的清洗性能以及与水泥浆、油基钻井液的相容性。结果表明，微乳液冲洗液的起泡率为17.07%，清洗率为可达99%以上，且对岩心具有优异的润湿性转变能力；同时所配制的隔离液对油基钻井液的清洗效率仍可达99%以上，且与油基钻井液和水泥浆混合后仍具有良好的相容性。此研究获得了一种清洗效率高、气泡率低、相容性好的清洗井筒用高含水量型微乳液冲洗液。

Study on High Water Content Microemulsion Flushing Fluid Used in Borehole Flushing

Oil based drilling fluids are now more and more used in the continuous development of oil and gas resources because of their excellent performance. Wells drilled with oil based drilling fluids have their borehole wall oil wetted, and this inevitably affects the cementing quality of the cement slurries. One way of dealing with this problem is to use flushing fluid to clean the oil based drilling fluids adhered on the borehole walls, hence turning the borehole wall to water wet. A high water content (≥ 80%) microemulsion flushing fluid was developed with raw materials such as EAB-40, SDBS, n-butanol, kerosene and water. The microemulsion flushing fluid was evaluated of its bubble rate, flushing capacity and ability to reverse the wettability of the borehole walls. The microemulsion was then made into a spacer, and flushing with the spacer fluid was done to investigate the flushing performance of the spacer and the compatibility of the spacer with cement slurries and oil based drilling fluids. The experimental results show that the microemulsion flushing fluid has a bubble rate of 17.07%, a flushing efficiency of at least 99%, and has excellent wettability reversal ability. The spacer made from the microemulsion flushing fluid has a flushing efficiency of at least 99%, and has good compatibility with cement slurries and oil based drilling fluids. As a result, this study has produced a high efficiency, low bubble rate, high water content microemulsion flushing fluid with good compatibility.