古巴油气井钻井过程中常见问题及处理方案

Common problems in drilling of oil and gas wells in Cuba and their solutions

李成有

LI Chengyou

中国石油长城钻井公司，北京　100101

Great Wall Drilling Company, Beijing 100101, China

由于古巴地层复杂，井型基本都是大位移水平井，油气井开发钻进过程难度较大。受地质条件影响，古巴大位移水平井的开发在井壁稳定、井眼清洁、管柱受力和钻井液的处理方面都存在其特殊性。以开发GUA-101井为例，针对这些问题进行逐一分析，并提出了解决方案。该井断层裂隙多，漏失严重，井壁容易掉块坍塌，岩屑在自重作用下下沉到下井壁，形成严重的堆积，堵塞井眼，造成恶性卡钻。管柱的摩阻扭矩大，重晶石沉淀严重。在施工过程中，通过及时检查并调整钻井液性能；使用短起下钻，控制速度；增大钻头水眼，进一步提高钻井液排量；合理地使用钻具，采取旋转井内钻具等措施圆满解决了以上问题，为以后开发相同类型的油井提供了实践基础和技术参考。

Due to the complicated formation, most wells in Cuba are extended reach ones, which results in difficult oil and gas development and drilling. Affected by the geological conditions, the development of extended reach wells in Cuba has unique features in borehole stabilization, hole cleaning, drill string force, and treatment of drilling fluids. Taking the successful drilling of GUA-101 well as an example, the problems in development are analyzed one by one, and corresponding solutions are developed. The well has many fault fissures and severe leakage, the borehole is easily to collapse, cuttings fall down to the bottom and block up the hole, resulting in severe sticking. Great friction of drilling string and barite deposit also hinder the drilling. All these problems are solved by timely checking and adjusting drilling fluid properties, using short trip, controlling the speed, enlarging water hole of drill bits, further increasing drilling fluid displacement, and using rotary borehole drilling tools. This lays solid basis for the development of similar wells in the future.