Relay transmission measurement-while-drilling system

Abstract

The invention discloses a relay transmission measurement-while-drilling (MWD) system, which relates to the technical field of manufacture of underground MWD apparatus and comprises a drilling tool combination, an underground data measuring apparatus, a signal receiving-sending assembly and a ground signal acquisition assembly, wherein the front end of the drilling tool combination is connected with a non-magnetic drilling tool, while the rear end is connected with an instrument compartment drilling rod, the underground data measuring apparatus assembly comprises a measuring apparatus and a measuring apparatus battery, the signal receiving-sending assembly comprises an electromagnetic wave transmitting device and an electromagnetic wave transmitting device battery, and the ground signal acquisition assembly comprises a signal receiving device. The invention adopts a method of wired and wireless relay transmission to design the relay transmission MWD system with two-stage relay transmission signals, thus the problem that electromagnetic wave signals are easy to be absorbed by low-resistivity stratum and interfered by the ground environment can be effectively solved.

Description

Technical field: [0001] A relay transmission measurement-while-drilling system is used for wellbore trajectory monitoring in the process of drilling directional wells or horizontal wells with gas medium in oil and gas drilling, and relates to the technical field of manufacturing downhole measurement-while-drilling instruments. Background technique: [0002] In the prior art, in order to protect the drilled formation from the pollution of the drilling process to the greatest extent during the drilling process, and to keep the oil-producing or gas-producing formations in the original storage state, especially in the construction of drilling horizontal wells, drilling engineers Many solutions have been conceived. Among these methods, drilling horizontal wells with gas can liberate production layers to the greatest extent and protect reservoirs from contamination by drilling fluids. However, using gas as a drilling medium has the problem of difficulty in monitoring wellbore traje...

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Problems solved by technology

[0002] In the prior art, in order to protect the drilled formation from the pollution of the drilling process to the greatest extent during the drilling process, and to keep the oil-producing or gas-producing formations in the original storage state, especially in the construction of drilling horizontal wells, drilling engineers Many solutions have been conceived. Among these methods, drilling horizontal wells with gas can liberate production layers to the greatest extent and protect reservoirs from contamination by drilling fluids. However, using gas as a drilling medium has the problem of difficulty in monitoring wellbore trajectories; At present, the electromagnetic wave measurement-while-drilling system is mainly used to monitor the wellbore trajectory when drilling horizontal wells at home and abroad. The main problem is that the electromagnetic wave signal is easily absorbed by the low-resistivity formation. Environmental interference, after many tests, the telemetry depth of electromagnetic waves to the downhole will not exceed 2000m; therefore, in foreign technologies, mainly adopt relay stations, extend antenna technology, increase the power of downhole signal reception and reduce the frequency of signal reception and transmission However, none of these four methods can greatly improve the telemetry depth; currently, there is no mature electromagnetic wave measurement-while-drilling application technology in China

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