Case Study: Wireless Control and Data Acquisition of Waterflooding Operation Using Pressure Waves

Abstract Waterflooding proved to be valuable and had been implemented in the oilfield worldwide. Bullheading water into well was out of date since permeability varied hugely downhole in the vertical way. Cable controlled water injection technology enabled us to have a real time understanding of injection rate and pressure, however it was not a good choice in the scenario of snubbing well, deviated or deep well. We attempted the approach of pressure wave to address this issue. In this paper, the characteristics of pressure wave transmission downhole was explored, the structure of wireless control and data acquisition system was presented, and finally the field trial was performed and summarized. The results indicated that the pressure transmission was influenced by pump source, reservoir pressure and tubing resistance, and the dynamic response of pressure wave under different conditions could be explained by the model established. The wireless control and data acquisition system comprised two parts, the control and monitoring device on the ground, the injector integrated with communication modular downhole. The device on the ground could produce and detect pressure fluctuation with the precision 0.1MPa. The downhole injector could detect the pressure signal from the surface and responded accordingly. There were two valves in the injector, one was for the injection, and the other was for the communication. Field trial demonstrated that it took 7mins to acquire one set of data, 11mins for the three sets of data, including pressure and flowrate. The communication was reliable and removed the requirement of physical cable line. As one of the most EOR technologies, Water injection had to keep updating to meet new challenges. Wireless control and data acquisition system was developed based on the mechanism of pressure wave transmission and proved to be simple in structure, efficient in communication. It helped operator resolve thorny issues such as snubbing well, deviated or deep well, it also helped expand the application of pressure wave in the oil and gas community.