Downhole Cement Plug CCL Location Accuracy

The patent replaces the conventional mechanical calculation method (based on casing ID and length assumptions) with an acoustic signal transmission method. The downhole tool transmits acoustic signals through the displacement fluid to the surface, where the two-way travel time is measured and converted to depth information. This substitution eliminates the need for manual calculations and assumptions about casing uniformity, providing direct empirical measurement of the tool's position and thus the accurate displacement fluid volume required.

The patent uses the displacement fluid itself as an intermediary medium to transmit acoustic signals between the downhole tool and the surface. Instead of requiring complex wireless communication systems or physical connections, the system leverages the existing displacement fluid in the wellbore as the transmission medium. This approach achieves accurate location measurement while minimizing additional device complexity, as the fluid is already present and serves a dual purpose: displacement function and signal transmission medium.

The patent implements periodic signal transmission rather than continuous transmission. The downhole tool transmits acoustic signals at specific intervals or at key operational moments (such as when the tool reaches certain depths or during critical cementing phases). This periodic approach provides sufficient real-time monitoring data to ensure cementing reliability while significantly reducing the energy consumption compared to continuous transmission, as the tool only activates its transducer when needed.