冀东油田水平井钻井液技术

针对水平井钻井要求和冀东油田的地层特点,采用强包被、强抑制、强封堵的技术措施,定向井段和水平井段采用聚磺硅氟乳化原油钻井液.该钻井液中PMHA与JGYJ配合使用进一步提高抑制泥页岩水化分散的能力;GT-98、KJ-1与NPAN复配使用可以降低高温高压滤失量,改善泥饼质量;QSAM-K、YL-1与JGWJ复配使用可以提高钻井液的封堵能力;MMH可改善悬浮携带能力,添加了不同粒径的超细碳酸钙和软化点与油层温度相匹配的沥青类材料,对油层孔隙进行快速封堵,避免液相和固相对油层的损害.现场应用表明,该钻井液具有较强的防塌能力、清洁井眼能力和润滑防卡能力,解决了上部地层和水平井段砂岩储层的井塌以及大斜度井段、水平井段的携砂、润滑问题和疏松砂层油层保护问题,完全满足了冀东地区垂深小于3000 m水平井的钻井需要.

Drilling fluid technology for horizontal wells in Jidong oilfield

Based on requirements of drilling horizontal wells and formation characteristics, polysulfonate silicofluoric drilling fluid was used in directional section and horizontal section in Jidong oilfield, and technical measures such as strong encapsulating, strong inhibiting and strong sealing were taken. In this fluid, PMHA and JGYJ were used together to improve the fluid ability to inhibit mud-shale hydrating and dispersing; GT-98, KJ-1 and NPAN were employed together to reduce the HPHT filtration and improve the mud cake quality; QSAM-K, YL-1 and JGWJ were combined to increase the fluid sealing ability; MMH was used to improve cuttings transportation capacity. In addition, ultra-fine calcium carbonate of different size and asphalt materials with soft points matching with oil formation were used to seal pores in oil layer, trying to avoid damage caused by liquids and solids. In-situ application showed that this drilling fluid provided strong collapse prevention, hole cleaning and lubrication and pipe stuck prevention. Problems of hole caving in upper formation and horizontal section (sand reservoir ), cuttings transportation and lubrication in large angle section and horizontal section, and reservoir protection in unconsolidated sand, were addressed., which qualifies the fluid to drill wells of true vertical depth less than 3000 m in Jidong oilfield.