Determination method of overlying rock isolation grouting filling layer based on borehole injection flow measurement

Abstract

The invention discloses a method for determining a rock-coated isolation grouting filling position based on drilling injection flow measurement. The method is suitable for coal mines. Grouting and drilling are carried out arbitrarily above a rock-coated isolation grouting filling coal mining working surface; in the water injection or grouting process of drilling, a flowmeter is injected into a grouting drill rod at a constant speed through a wellhead anti-spray pipe, and after the flowmeter is put into a bare hole, stop point measurement carried out on different positions in the bare hole is started; after measurement is finished, the flowmeter is taken out from the bore hole; the depth and the flow of a measurement point are drawn as a curve, and all the flow sudden drop positions on thecurve are searched, namely, the grouting filling layer positions are obtained; and when the coal mining working surface is advanced to be away from the grouting drilling hole by different distances, the grouting filling position of the grouting drilling hole can be determined for a plurality of times to monitor the dynamic changes. The method does not affect the normal grouting and sinking controleffects of drilling, and is low in cost and time consumption, high in reliability and accuracy, simple in determination method and strong in repeatability.

Description

technical field [0001] The invention relates to a method for determining an overlying rock isolation grouting filling layer, which is especially suitable for the overlying rock isolation grouting filling layer based on the measurement of the injection flow rate of a borehole for coal mine mining and overlying rock isolation grouting filling mining. Determine the method. Background technique [0002] In recent years, coal mine overlying rock isolation grouting filling technology has played a very active role in coal mining under buildings (structures), ensuring the normal mining succession and service life of coal mining enterprises (especially aging mines), and protecting buildings. Material safety has become an important technical means for coal mining under buildings. This technology involves constructing multiple groups of grouting boreholes perpendicular to the coal seam from the surface above the coal mining face. Deformation of overlying strata and effective control ...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem of determining the filling layer of overlying rock grouting, there is a method of special construction and inspection of the borehole after the grouting filling is completed in the existing technology. Through the whole coring process during drilling, the filling layer is determined according to the taken out filling body. Although this method is effective, the cost is very high due to the need to construct a special inspection borehole, and it is a kind of after-the-fact detection, which lacks guidance for the grouting filling process. , it is difficult to inspect the borehole in the process of construction

The existing technology also discloses a method for determining the grouting filling layer during the grouting process. Patent ZL201510032975.7 discloses a method for detecting the grouting filling layer for isolation of overburden rock. This method selects two adjacent drill holes They are respectively used as auxiliary measuring grouting boreholes and detection grouting boreholes. The combined structure composed of water pipes, rubber plugs, etc. can determine the flow rate of grout at different depths, so as to determine the grouting filling layer of the detection borehole. Although this method avoids the need for separate construction and inspection of the borehole, it can also achieve layer detection, but it can only be measured when the grouting layers of the two holes are connected, and cannot directly detect the grouting layer of the detection grouting hole, and the auxiliary measuring grouting hole is put into grouting Afterwards, this method cannot be used, and this method needs to be lowered into the drill pipe during the measurement process of auxiliary grouting drilling, which requires a large amount of engineering and is difficult to implement

Images