海洋精细控压钻井技术现状及应用

Current Status and Application of Offshore Managed Pressure Drilling Technology

随着勘探技术的进步,不断向深部地层钻进,溢漏同存、窄压力窗口、异常高压等问题突出,往往会发生喷漏卡塌等复杂情况,这些已成为安全高效钻探面临和急需解决的难题。针对上述突出问题,考虑国内海洋钻井相比陆上钻井在地质特征、井身结构、作业模式等方面的差异,以陆上精细控压装备结构及工艺原理为基础,攻关形成了适合海洋作业的小型化、模块化、高效化精细控压装备及配套工艺,尤其在RCD系统结构、精细控压节流管汇结构、自动节流管汇回压补偿工艺等方面作出较大的优化升级,目前海洋化的精细控压钻井技术在加大推广应用,成为解决裂缝性储层、浅部大井眼钻进中的喷漏难题的有效手段之一。现场应用表明,精细控压钻井技术不仅有利于保障钻完井井控安全、减少井下复杂,而且可以大幅度降低钻井作业成本,在高压、裂缝发育、易漏失的储层钻井中具有广泛的应用前景,有助于提高勘探开发效益。

With the advancement of exploration technology and continuous drilling into deep formations,the problems,such as coexistence of kick and lost circulation,narrow pressure windows and abnormal high pressure,are still grim,and frequently occur blowout,overflow,stuck,collapse and other complex conditions,which have become challenges and urgent solutions to achieve safe and efficient drilling.In view of the above-mentioned problems,considering the differences between domestic offshore drilling and onshore drilling in terms of geological characteristics,wellbore structure,operation mode,etc.,based on the structure and process principle of onshore managed pressure drilling equipment,a miniaturized,modular and efficient managed pressure drilling equipment and supporting processes suitable for offshore operations have been formed,and especially the RCD system structure,chock manifold structure,back-pressure compensation process of automatic chock manifold and other aspects greatly optimized and upgraded.At present,the offshore managed pressure drilling has been widely applied,and it has become one of the effective means to solve the problem of kick and lost circulation in drilling shallow large wellbore and fractured reservoirs.On site applications have shown that managed pressure drilling technology not only helps to reduce downhole complexity and drilling costs,but also provides reliable guarantees for well control safety during drilling and completion operations.It has broad application prospects in drilling high pressure,fractured and loss-prone reservoirs,which helps to improve exploration and development efficiency.