Practice and application of drilling construction technology for littoral-shallow-sea sand layers

Abstract:

Drilling in littoral-shallow-sea sand layers faces complex construction environments and special stratigraphic conditions， significantly increasing construction difficulty. To address the construction challenges of drilling in littoral-shallow-sea sand layers， this paper analyzes the construction characteristics and environmental factors of drilling in sand layers， selects a rotary-table engineering drilling rig， and adopts bottom-hole impact drilling tools. It innovatively proposes a casing-while-coring technique featuring a "rotary-table-driven casing+in-hole wireline percussion+petal-type coring mechanism". At the same time， combined with a high-frequency vibrating hammer， the technique successfully solves problems such as difficulty in borehole formation and low core recovery rate in sand layers. Satisfactory application performance has been achieved in the sand-ore of littoral-shallow-sea areas，which provides a reference and guiding significance for future research and application of drilling and coring in littoral-shallow-sea sand layers.