深海井口吸力锚安装分析与实践

Analysis and practice of wellhead suction anchor installation in deep sea

摘要:

第二轮海域天然气水合物试采在神狐海域首次应用了深海井口吸力锚技术，为浅软地层水平井开采水合物提供了稳定的井口支撑。通过理论计算及有限元分析对吸力锚沉贯过程中的自重沉贯深度以及需求负压进行研究，同时现场采用“步渐间歇式自重贯入、拖拽连续负压沉贯”施工工艺，保障了国产首个深海井口吸力锚成功安装。现场实践结果表明，理论计算结果与实际施工情况较为接近，理论分析可指导井口吸力锚安装；沉贯施工工艺快速、高效、安全，井口吸力锚安装的各项指标满足使用需求，对吸力锚技术在深海油气领域应用具有借鉴意义。

Abstract:

During the second gas hydrate trial production test， the deep-sea wellhead suction anchor technology was firstly applied in the Shenhu sea area， which provids stable wellhead support for horizontal gas hydrate production wells in shallow soft formations. Through the theoretical calculation and finite element analysis， the self-weight penetration depth and negative pressure demand in the process of suction anchor penetration are studied. At the same time， the construction technology of “step-by-step intermittent self-weight penetration， dragging and continuous negative pressure sinking” was adopted in site， which ensured the successful installation of the first domestically produced deep-sea wellhead suction anchor. The field practice results show that the theoretical calculation results are close to the actual construction situation， and the theoretical analysis can guide the installation of suction anchors at the wellhead. In addition， the penetration construction technology is featured of fast， efficient and safe. The indicators of the wellhead suction anchor installation reached the usage demand. It has referential value for the application of suction anchor technology in the fields of deep-sea oil and gas.