Single-tube drill for improving loose washable stratum recovery factor

Abstract

The invention discloses a single-tube drill for improving a loose washable stratum recovery factor. The single-tube drill is composed of a pressure stabilizing flow splitting device, a core barrel, a water distribution device and a step drill. The water distribution device is located in the core barrel. The pressure stabilizing flow splitting device is installed at the upper end of the core barrel. The step drill is installed at the lower end of the core barrel. The single-tube drill is applicable to core drilling and coring of a loose washable stratum such as kaolin with large viscosity, high plasticity and hydrophilic expansion, due to the combination of the devices, the phenomenon that washing fluid perpendicularly washes a core can be avoided on the condition of ensuring smooth powder discharge at the bottom of a hole, meanwhile, the flow speed of the washing fluid on the periphery of the core inside a core tube is decreased, and the washing effect of the washing fluid on the core is lowered, so that the drilled core integrity is improved, and the core recovery factor is improved.

Description

technical field [0001] The invention relates to a single-pipe drilling tool for improving the core extraction rate of loose and easy-to-scour strata, and is especially suitable for drilling and coring of easily-scourable strata such as kaolin with high viscosity, strong plasticity and water expansion. Background technique [0002] The coring method is closely related to the drilling method, and should be matched with the drilling method to adapt to the cores of different rock and ore layers. The selection of the coring method should be based on the physical and mechanical properties formed by the composition and structural characteristics of the rock and ore layers and the corresponding coring difficulty. Degree selection of drilling and coring methods. The single-pipe coring tool has a simple structure and is mostly used in the upper Quaternary, Neogene, and Paleogene rock and ore layers to drill and coring in the geological core drilling. When conducting geological core d...

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Problems solved by technology

When geological core drilling is carried out in kaolin with high viscosity, strong plasticity, water-swelling and loose and easy-to-scour formations, the bentonite flushing fluid used is high in viscosity, and double-tube drilling tools cannot be used, and only single-layer core tube drilling can be used. Coring method with advanced coring method, in the drilling construction, the flushing fluid in the core tube will continuously scour the core, resulting in a low core recovery rate, the current coring method for loose and easy-to-scour formations is mainly by improving the performance of the flushing fluid, selecting a suitable There is no complete set of single-tube drilling tools for improving the core-taking rate of loose and easy-to-wash formations.

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