Drilling coring method enwrapping rock core by using mud coating in sandy soil

Abstract

The invention discloses a drilling coring method enwrapping a rock core by using a mud coating in sandy soil. The drilling coring method comprises the following steps of putting a drilling apparatus in position and assembling; preparing natural compound mud according to the distribution condition of a stratum; drilling coring: according to the category of the stratum, drilling, by the drilling apparatus, until a drilling depth of 1.50m according to a corresponding drilling parameter; stopping a pump, stopping circulating the natural compound mud in a hole of a drill pipe and a drilled hole, opening a mud return valve, and putting a water-stop marble into the drill pipe; burning a bit, carrying out dry drilling after stopping the pump, drilling by adopting a low rotational speed and low drilling pressure in the beginning, when a rock core barrel is filled with the rock core, drilling by adopting high drilling pressure and a high rotational speed, generating a higher temperature betweenthe bottom of an alloy bit and a rock core sample of the sandy soil within a short time, and slightly sintering the bottom of the alloy bit and the rock core together; lifting the bit; withdrawing thecore by the pressure of the mud. The drilling coring method has the advantages that the recovery rate of the rock core sample of the sandy soil is improved by a wide margin, and can reach 100 percent; the rock core sample of the sandy soil is enwrapped by the mud coating, and the rock core sample of the sandy soil is enabled to maintain the undisturbed grain composition and structure of the sandysoil.

Description

technical field [0001] The invention relates to the technical field of taking sandy soil core samples, specifically it is a drilling and core-taking method in which mud coats are used to wrap rock cores in sandy soil; more specifically, it is a combination of a new type of mud material and a proportioning scheme The determined drilling method can greatly increase the collection rate of sandy soil core samples, up to 100%. The sandy soil core samples are wrapped in mud coat, so that the sandy soil core samples can maintain the original particle gradation and structure of sandy soil. Background technique [0002] Sandy soil is a common loose soil in Quaternary strata, which is granular, has no cohesive force, is easily broken under the condition of no confining pressure, and is easy to form quicksand flowing with water under the action of hydraulic force. The low rate of drilling cores in sandy soil layers has always been one of the main problems affecting the quality of engin...

AI Technical Summary

Problems solved by technology

The low rate of drilling cores in sandy soil layers has always been one of the main problems affecting the quality of engineering drilling. For some projects that need to study the microstructure of sand layers, the existing techniques and methods are difficult to meet the engineering requirements

[0003] The existing sand core sample collection technology level is low, and the sand layer core sample collection rate has always been low, mostly below 50%, which affects the sand layer and geological identification accuracy

[0004] Sandy soil core samples are often mixed with mud, it is difficult to accurately determine the particle composition of sandy soil core samples, and repeatedly disturbed in the drilling tool, the sandy soil core samples taken out cannot reflect the original structure of sandy soil

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