Simple Pressure-Controlled Technical Services

Building on precision managed‑pressure drilling technology, this approach simplifies procedures and equipment by eliminating the need for costly backpressure pumps, automated choke manifolds, downhole pressure‑while‑drilling measurement tools, and surface automated control systems. Instead, it relies primarily on a rotary control head and a simplified, dedicated managed‑pressure choke manifold, which directs annular return flow away from the wellbore. By coordinating this setup with a simple managed‑pressure choke manifold connected in parallel to the rig’s standard choke manifold, dynamic backpressure is adjusted at the wellhead, enabling drilling operations—such as run‑in of drill pipe and tripping—to maintain the bottomhole pressure in a state of “slight overbalance” throughout.

MPD Precision Pressure Control Drilling System

The MPD precision pressure‑controlled drilling system comprises five key components: a drilling‑parameter monitoring system, a decision‑analysis system, a PLC‑based electrical control system, an automatic choke control system, and a rotary control blowout preventer.

MPD Precision Pressure Control Drilling System Parameters

Flow rate: 0–60 L/s, accuracy 0.1%

Density range: 1.0–2.7 g/cm³

Choke pressure differential: 0–17.5 MPa

Pressure rating: 35 MPa

Pressure control accuracy: ±0.1 MPa

Gate valve opening/closing time: 12 s

Precision Pressure-Controlled Automatic Choke Manifold

The precision pressure‑controlled automatic choke manifold has been upgraded from its previous design, with an optimized layout that reduces its footprint, simplifies commissioning and installation, and minimizes the required floor space.

Main Equipment of the Precision Pressure-Controlled Automatic Choke Manifold

• Automatic Choke Manifold Skid
• Automatic Throttling Control System
• PLC electrical control system
• Decision Analysis System
• Monitoring system
• High-precision mass flow meter

Main Parameters of the Prying Body

• Length: 3.3 m
• Width: 2.3 m
• Height: 2.55 m
• Weight: 8T
• Bore: 103 mm
• Cylindrical throttle valve

Automatic Throttling Control System

The automatic choke control system consists of multiple electro‑hydraulic choke‑gate valve assemblies and serves as the core equipment for managed pressure drilling. The system receives commands from the higher‑level PLC control subsystem, translates these commands into actuation signals for the electro‑hydraulic chokes or gate valves, and thereby achieves closed-loop control of wellbore pressure while managing logical switching between control modes. In addition, the automatic choke manifold is equipped with pressure sensors, valve‑position sensors, and high‑accuracy mass flow meters, providing robust support for pressure and flow monitoring and feedback.

• Throttling accuracy: ±0.1 MPa
• Choke pressure: 0–17.5 MPa
• Flow range: 0–60 L/s
• Density range: 1.0–2.7 g/cm³

Pressure sensor: A intrinsically safe pressure sensor is installed upstream of the choke to monitor wellhead casing pressure, while a valve‑position sensor is mounted on the choke actuator to measure the valve’s on/off status.

Mass flow meter: At the outlet of the automatic throttling control system, a high-precision mass flow meter is installed to monitor the density and flow rate of the drilling fluid. Currently, the primary brand of mass flow meters used in MPD-type automatic control systems is Emerson Mass Flow Meters (USA).

Ground connection: Connect using a flexible hose or a rigid pipeline.

Drilling Parameter Monitoring System (Surface)

The drilling‑parameter monitoring system primarily functions to acquire and monitor, in real time, parameters such as standpipe pressure, mud‑pump strokes, well depth, and hook load. At the same time, the collected drilling parameters serve as common data for the entire system, being shared with other subsystems to enable inter‑system data exchange.

Decision Analysis System — (Brain)

The decision‑analysis system comprises a computer local area network and decision‑analysis software installed on the computing platform, serving as the “brain” of the entire MPD system. It primarily performs wellbore pressure‑state analysis, generates pressure‑control setpoints, and transmits pressure‑control adjustment commands to the PLC subsystem.

• Performance Metrics: Real-time Acquisition Frequency: 2 seconds
• Instruction reception and execution interval: ≤120s

PLC electrical control system

The PLC electrical control system comprises a PLC master station and PLC remote stations mounted on the automatic choke manifold. The master station receives “parameter signals” from the data acquisition subsystem and “commands” from the decision‑analysis subsystem, while performing primary program‑logic processing; upon completion, it transmits “execution commands” to the lower‑level automatic choke manifold subsystem.