延长气田强抑制强封堵胺基钻井液技术

Amine-based Drilling Fluid Having High Inhibitive and Sealing Capacities Used in Yanchang gasfield

针对延长气田地层特性、井壁失稳原因、储层特性等特点,开展了强抑制强封堵胺基钻井液研究。实验室采用抑制膨润土造浆实验,优选出抑制效果与聚醚胺相同、成本较低的胺基抑制剂AI-1。采用延长气田刘家沟组泥岩进行的页岩滚动分散实验和膨胀率实验表明,AI-1的抑制性好,对钻井液性能影响小。采用AI-1作抑制剂,改性淀粉、SPNH及PAC-LV作降滤失剂,ZHFD和FT-1作封堵剂,优选出强抑制强封堵胺基钻井液。该钻井液的流变性能较好,滤失量低,具有良好的泥饼质量、强的抑制性与封堵性能,对气层的损害程度低,对延长气田石盒子组、山西组、本溪组等气层岩心的渗透率恢复值在90%以上。该钻井液在延长气田3口井的使用,防止了井塌、井漏的发生,井径规则,提高了钻井速度,减少了对气层的损害。

Amine-based drilling fluid having high inhibitive and sealing capacities is studied for use in Yanchang Gasfield. In laboratory studies, an amine inhibitor, AI-1, of low cost, is developed. AI-1 has inhibitive capacity similar to that of PEA, and inhibits the yield of bentonite. Hot rolling test and swelling test with shale samples from Liujiagou Formation of Yanchang show that AI-1 has very good inhibitive capacity and minor effect on mud rheology. An amine drilling fluid formulated with AI-1 as inhibitor, modified starch, SPNH and PAC-LV as filter loss reducers, and ZHFD and FT-1 as sealing and plugging agents, has excellent inhibitive capacity, good rheology, low filtration rate and tough mud cake. It has low impairment to reservoir's flow capacity, greater than 90% permeability recovery is obtained with core samples from Shihezi Formation, Shanxi Formation and Benxi Formation of Yanchang. This aminebased fluid has been used in three wells in Yanchang, wiping out borehole instability and mud losses. Gauge hole was obtained and ROP was increased.