METHOD AND DEVICE FOR ERECTION OF HORIZONTAL DRAIN HOLE IN WATERED SANDS Russian patent published in 2010 - IPC E21B7/00 E21F16/00 E02F5/18 

FIELD: construction.

SUBSTANCE: method and device for erection of horizontal and drain hole in watered sands is related to mining industry and construction, in particular - to methods and devices for erection of horizontal wells with the help of rotary drilling in watered unstable sands and may be used to dry mineral deposits, industrial sites, to clear heads of underground waters in process of tunneling, construction of buildings with preliminary water drawdown, in erection of horizontal wells of various technical purpose in loose watered soils, also under conditions of high urban saturation. Achievement of result became possible due to maintenance of technological process at permanently maintained pressure of structural flushing liquid higher than pressure of stratal ground waters by 0.3-0.5 atmospheres under protection of stable layer, which is formed by structured flushing liquid on well walls, as a result of which impact of mountain pressure at drilling string is eliminated. Realisation of method is carried out by complex device characterised with availability of mechanical part, including drilling plant, conductor, sealant or drill string, or filtering string and support of vertical excavation, and also hydraulic system of structured flushing liquid pressure provision and maintenance in erected well as higher than pressure of stratal ground waters in periods of horizontal drain hole erection and installation of filters in it, which is made of three functional hydraulic lines.

EFFECT: provision of horizontal drain hole walls stability in process of drilling and installation of filters, increased depth of drilling and diametre of erected well, provision of controlled carryover of sand from layer, preservation of natural soil properties in near-filer zone; increased safety of technological process, increased efficiency of drilling, reduced load at performing elements of drilling plant.

10 cl, 2 dwg, 1 ex