The Development Of Advanced Lateral Jet Coring Tool

Complex formations, such as broken strata, soft and erodible strata, are frequently encountered in core drilling. The domestic drilling workers had done lots of research on the drilling technique of broken complex stratum, such as the manufacture of all kinds of samplers, the extension of the wire-line coring tools and the use of the single tube core barrel, single tube jet reverse circulation core tool, double tube core barrel and no-pump drilling tools. All tools improved the quality of coring, but the recovery of core was still very low. The basic reason was the method of snapping the core failed to improve, as well as the measures taken to the water insulation and truth-preserving of the tool were ineffective.The main work and conclusion were as follows:(1)Two kinds of core tools, the advanced lateral jet double-tube coring tool and the advanced lateral jet reverse circulation wire-line coring tool without pump, were designed based on the reviewing and analysis of the advanced drilling technology currently at home and abroad, regarding to practical problems.(2)Based on the swivel type double tube core barrel, the advanced lateral jet double-tube coring tool innovatively was designed with inner tube size and used the advanced lateral jet bit.(3)Based on the wire-line coring tool, combined the working principle of the reverse circulation without pump and made the no-pump drilling tool and the wire-line coring tool one, the advanced lateral jet reverse circulation wire-line coring tool without pump tool was designed with joint without pump, pawl spring and advanced lateral jet bit.(4)The three-dimensional model of advanced lateral jet bit was established by using the Solidworks software and the bottom hole flow field of the bit was analyzed by applying the solidworks flow simulation software. The results showed good uniformity with the reality.(5) The results of the field experiment show that, these two tools could realize the normal operation in the broken and soft strata. Besides, the core recovery of the advanced lateral jet double-tube coring tool could achieve93%and the advanced lateral jet reverse circulation wire-line coring tool without pump could achieve94%. Both of them greatly improved the core recovery.