海上顶部双驱动联动隔水管钻探取心技术

Ocean core drilling with the top double‑drive linkage riser system

我国南海海域分布着大量礁灰岩地层,这种地层具有原生孔隙大、压缩性强、容易变形、强度小等特点,因此易渗透、易破碎、易坍塌。在岛礁上钻探也常常出现断钻、垮孔、埋钻等事故。对于海洋礁灰岩地层钻探,不仅要克服陆地上面临的问题,还需要面对更为复杂的海洋环境。为解决海上特殊地层取心困难问题,基于船载无隔水管钻探系统,开发了海上顶部双驱动联动隔水管钻探取心技术。该钻探取心技术方案在西沙海域4个不同的站位进行了海洋钻探试验。试验结果表明,该技术可实现高效率、高岩心采取率的海上礁灰岩取心目的,取心深度可达130.75 m,具有广阔的推广前景。

There are abundant reef limestone strata in the South China Sea.Coral reef strata have large primary pores,high compressibility,easy deformation and insufficient strength;so they are prone to filtration,breaking and collapsing.Drilling incidents,such as broken drilling string,hole caving,and bit burial,often happen during drilling on islands and reefs.In drilling marine reef limestone formations,it is not only necessary to overcome the problems encountered on land,but also to tackle the more complex marine environment.In order to solve the coring difficulty in special marine stratum,core drilling with the marine top double‑drive linkage riser system was developed on the basis of the ship‑borne riserless drilling system.Marine drilling test was carried out at four different stations in the Xisha waters,and the field tests show that this technology can take cores from offshore reef limestone with high efficiency and high recovery;and the coring footage up to 130.75m,which has a broad prospect for promotion.