Abstract As an advanced downhole instrument in drilling engineering, fluid continuous wave generator (DFCWG) has great application prospects. The large load torque is one of the key problems that hinder development DFCWG. In this paper, based on design theory rotary valve and finite element method, structure designed characteristics analyzed points out strong alternating characteristics. It poi...

one of the problems that sometimes occur in gas allocation optimization is instability phenomenon. this phenomenon reduces the oil production and damages downhole and surface facilities. different works have studied the stability and suggested some solutions to override it, but most of them (such as making the well intelligent) are very expensive and thus they are not applicable to many cases. ...

Downhole drilling motors or mud motors are frequently used during the oil and gas well construction, especially for construction of directional and horizontal segments. However, low operation life of the down hole drilling motors and high rate of wear in their working elements may constrain their application due to technical and economical disadvantageousness. In this work, a high-torque modula...

In the oil industry, the measurement-while-drilling (MWD) systems are usually used to provide the real-time position and orientation of the bottom hole assembly (BHA) during drilling. However, the present MWD systems based on magnetic surveying technology can barely ensure good performance because of magnetic interference phenomena. In this paper, a MWD surveying system based on a fiber optic g...

This paper considers downhole directional drilling systems in the presence of unexpected variations in steering force, input delays, measurement noise and measurement delays, and explores the application of L1 adaptive controller for the trajectory control problem. The Explicit Force, Finitely Sharp, Zero Mass (EFFSZM) model is used for the steering system, in which spatial delays, modeling ina...

The development of highly reliable downhole equipment is an essential element in enabling the widespread utilization of Enhanced Geothermal Systems (EGS). The equipment used in these systems is required to operate at high voltages and temperatures on the order of 200 to 250°C (and eventually to 300 ̊C). These conditions exceed the practical operating ranges of currently available thermoplastic w...