南海文昌区块深部地层旋转切削齿PDC钻头提速技术

摘要

Drilling deep formations in the Wenchang Block offshore of Western South China Sea with conventional PDC bits often resulted in severe abrasion and low rates of penetration (ROP) issues.Studies have been conducted to enhance ROPs by using innovative PDC bits with rotary cutters.By analyzing challenges in drilling operations in deep formations in the Wenchang Block,with considerations of formation properties and drill bit abrasion,the decision was made to use rotary cutters instead of fixed cutters in the highly abrasive shoulders of conventional PDC bits.With optimized distribution of rotary cutters,innovative PDC bits with rotary cutters were developed in deep formations drilling in the Wenchang Block.The newly-developed PDC bits with rotary cutters were deployed in three exploration wells in the Wenchang Block.Field application results showed that these bits can effectively enhance ROP with higher bit footage and outstanding abrasion-proof performances.Research results showed that innovative PDC bits with rotary cutters have outstanding aggressiveness and anti-abrasion performances.Since these bits can effectively enhance ROPs in deep formations of the Wenchang Block in the Western South China Sea,they can be deployed on a large scale within the block as well as other formations with similar high abrasion properties.%针对南海西部海域文昌区块深部地层常规固定齿PDC钻头磨损严重、机械钻速较低的问题,研究了旋转切削齿PDC钻头提速技术.分析了文昌区块深部地层的钻井难点,基于地层和钻头磨损特征分析结果,用旋转切削齿代替常规PDC钻头肩部高磨蚀区的固定切削齿,并优化布齿,形成了适用于文昌区块深部地层的旋转切削齿PDC钻头,并在文昌区块3口探井进行了应用,结果表明,该钻头提速效果明显、单只钻头进尺长且出井钻头磨损评价良好.研究认为,旋转切削齿PDC钻头兼具攻击性和耐磨性,可有效提高南海西部海域文昌区块深部地层的机械钻速,建议在该区块和类似强研磨性地层推广应用.