The application belongs to the technical field of
pressure control cementing, and discloses a high-precision, fast-response and
dynamic pressure control offshore cementing
system and method which can realize the whole process of offshore cementing without stopping the pump. The offshore cementing
system without stopping the pump comprises a stepless variable speed cementing pump sled, an automatic plug cementing head, a manual
throttle valve, a
mud pump, a parameter acquisition device and a real-time
analysis software for
pressure control cementing. The stepless variable speed cementing pump sled is used for adjusting the injection displacement according to real-
time control instructions to dynamically control the
bottom hole pressure. The automatic plug cementing head is connected with the stepless variable speed cementing pump sled and is used for automatically releasing the rubber plug during the cementing process without stopping the pump. The manual
throttle valve is arranged at the
wellhead annulus outlet and is used for adjusting the
wellhead back pressure. The
mud pump forms a small circulation loop with the manual
throttle valve and is used for compensating the
wellhead pressure when the pump is unexpectedly stopped. The parameter acquisition device is used for collecting the wellhead pressure, displacement and
fluid density data in real time. The real-time
analysis software for
pressure control cementing is used for calculating the equivalent circulating density at the bottom hole in real
time based on the data of the parameter acquisition device and dynamically controlling the displacement of the stepless variable speed cementing pump sled and the start and stop of the
mud pump.