Constant current transmitting system for measurement while drilling of electromagnetic wave geosteering tool

Abstract

The invention provides a constant current transmitting system for measurement while drilling of an electromagnetic wave geosteering tool and belongs to the field of oil exploitation or underground mine exploration or the like. A wireless electromagnetic wave transmitting device is connected with a current detecting unit, the current detecting unit is connected with a current signal feedback unit and a transmitting antenna, and the current signal feedback unit is connected with a current control unit. The current control unit is connected with a power supply device, and the power supply device is connected with the wireless electromagnetic wave transmitting device. The constant current transmitting system can be applied to measurement while drilling of the wireless electromagnetic wave geosteering tool or other working modes with wireless electromagnetic waves used for achieving data transmission between stratums or between ore beds, and working media comprise drilling fluid, clean water, air, nitrogen and the like. A power control method for wireless electromagnetic wave data transmission has the advantages that attenuation on transmission signals by the change of resistivity of stratum and drilling media is well lowered so that the wireless electromagnetic data can be better detected on the ground.

Description

technical field [0001] The invention relates to a constant current emission system for a geo-steering tool for measuring electromagnetic waves while drilling, and belongs to the fields of oil exploitation, geological and mineral exploration, and the like. Background technique [0002] In oil drilling engineering or geological exploration, in directional drilling or horizontal drilling, and underbalanced wells, it is often necessary to use wireless electromagnetic wave geosteering tools. At present, relatively mature wireless electromagnetic wave geosteering tools at home and abroad are widely used in the field. Its working principle is: a geosteering unit is placed in the drilling tool, and the tool uses the drill collar as an electrode to transmit wireless electromagnetic wave signals to the formation, which are used to send geological parameters and drill bit position and other parameters while drilling to the ground receiving equipment. Whether these products are powered...

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Problems solved by technology

There is also a U.S. invention patent with application number 7,477,162, the name of the invention: Wireless electromagnetic telemetry system and method for bottomhole assembly, which only proposes how to launch low-frequency wireless electromagnetic waves in the formation to establish an electromagnetic channel in terms of tool structure, and does not specifically describe how to use it from From the perspective of the circuit to achieve and overcome the impact of the attenuation of electromagnetic waves on the results of ground reception under different formations and different drilling media

[0004] The existing wireless electromagnetic wave measurement while drilling tools that are commonly used only rely on the maximum natural discharge current of the battery to supply power, without considering how to avoid the current overload that may be affected by different formation resistivities when using an underground power generation system to achieve high-power power supply or super light load phenomenon

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