Research of Downhole Instructions Decoding with Variable Drilling Fluid Displacement

Abstract

Abstract This paper studied a downlink communication mode in which the effective downhole control instruction was generated by the use of drilling fluid pump displacement to format three descending and three ascending pulse instruction encoding. The principle of the downlink communication was introduced. The encoding idea of the downlink instruction code with 5-bit pulse was described. This downlink code was used to compose the corresponding control instruction which includes the information of the tool face angle and the guide force percentage. The downhole pulse widths were recognized by using STM32 as a micro control chip. The corresponding control commands were identified through the development of the software in the downhole drilling tool. Laboratory ground experiments demonstrated the feasibility of this downlink transmission mode by using variable drilling fluid displacement and the achievability of instruction decoding software.