Model Investigation on Intelligent Sliding Sleeve Downlink System Based on Pressure Waves

Abstract

Aiming at efficiently and reliably controlling the intelligent sliding sleeve to open and close from the surface, a bypass downlink system is proposed without influencing the current stimulation equipment and process. A mathematics model based on the fluid hammer model and the method of characteristics is established to analyze the characteristics of the downlink system and validated by the experimental and field results. According to simulation results, the pressure change of the wellbore due to valve opening increasing\xa0or decreasing is coincident with the exponential expression. The expression contains three coefficients, which are the high pressure, the low pressure, and the system constant. The system constant is relative to the volume of the wellbore and the steady-state pressure. According to the characteristics of the pressure wave in the cased wellbore, digital base-band transmission is adopted for sending the pressure signal. A float matching decode method is proposed based on these characteristics and validated by the simulation results. The simulation results also indicate that the float matching decode method has high transmission efficiency and a low bit error rate. It can adapt to complex conditions of stimulation treatment. The work of this article can improve the efficiency and reliability of controlling the intelligent down-hole sliding sleeves.